Some gravel bikes support 180 / 160. You mentioned that gravel bikes are slower so don't benefit so much from bigger rotors, but you forgot the added weight from stuff like bikepacking.
I put a 180mm front disc on my Open UP, using it with the Hope RX4+ so no adapter needed. It gives a massive amount of braking power, tons of modulation as well. Super happy with it so far.
I think this is great one engineer to another. Recently experienced a crash on a steep descent in the Yorkshire dales which has left me with a broken collarbone. When looking at my bike after the incident, my 160mm front Sram rotor has significantly changed colour due to the overheating. Maybe a bigger disc would have reduced this and allowed me to scrub off enough speed to avoid the crash.
Thumbs up, purely for the selection of fasteners. Now work on the other side of the equation. I recommend Wera L wrenchs. By far the nicest set of hex and torx wrenches I have ever laid my hands on.
I have a Canyon Grail e-gravel bike and it needed a brake upgrade! I converted rotors from 160mm to 1800mm front and rear, thicker rotors, sintered brake pads, (1. organic, 2. semi metallic, 3. sintered or blocks of steel!!). It now stops vs. quickly coming to a stop.
I'm 80kgs, ran 140mm front and rear on a Cannondale. No issues, brakes were fantastic. Now run 160/160 and brakes are fantastic. No issues with warping braking down from 45mph to 15mph. Can't see the need, never felt there was a thermal problem. For me 160/140 is the perfect combo. 4 different bikes 2 were shimano 2 SRAM.
I just changed from 160 to 180 on my giant toughroad, and it feels much better, I've already ordered the rear kit. Hopefully the fork will handle it on the long run.
Great explanation. It ain't about the ability to lock the wheels. Heck I can lock the wheels with my shoe on the wheel. It's about how the braking feels and braking confidence. I have 203mm on 4 piston calipers on my mtb and the confidence I have vs my road bike is tremendous. Obviously overkill but having more rotor and larger pads is incredibly nice to have.
I agree that modulation is key. I also have 203mm rotors F/R with 4-piston Shimano brakes on my trail bike, and I find the modulation "addictive", and overheating hasn't been an issue so far. My BIL's trail HT that came with MT400 class 2-piston brakes and the typ. "resin only" rotors and pads, have zero issues locking either wheel but consistency suffers as the rotor gets hotter and hotter, and modulation @ the edge of locking up is worse throughout.
FWIW, I don't think that there is much concern about increased forces on the forks. The peak torque (heh!) about the spindle is still limited by the tyre grip, so assuming that the brake could be locked before, that remains unchanged. At this limit point the force at the brake pads it reduced, and the bending moment on the bottom of the fork leg is exactly the same. There is (maybe?) a different balance between the forces on the two mounting points. If you consider a very large adaptor then you could see the force at the bottom mount become a tension force, and the force at the top mount then becomes larger. I don't think that you have gone far enough for this to be a real issue.
I wouldn't take the risk on these weak road forks. When was the last time you locked up the front brake at high speeds? My forks broke on 32mm tires, 160mm rotors. I've switched to 140mm now and gravel forks. Be careful.
I use my brakes a lot more and for longer periods on my gravel bike than on the road, but I routinely do 800+m descents that are technical enough to require near constant braking. It has 180/160, which I've been happy with that.
Exactly. On gravel you are moving slowly enough that there is no aero drag, so you're putting 100% of the descent energy into the discs. My gravel bike has a lot more brake fade on gravel descents than road descents.
"You're not usually bombing down steep descents on a gravel bike" - you should come to Western North America, where the gravel roads can be >15%! Been having some issues with heat on 160mm rotors so I think an upgrade will happen with your adapters (or the Hope calipers).
You said longer pad life. I'm just really curious about the physics of that. The moment is greater, so you need less clamping force, but the rotor is travelling more quickly, which I would have thought would counteract that - ultimately you're still dealing with the same amount of energy. I can certainly see the rotors would last longer as they're bigger and there's just more material to grind. The only way I can think the pads would last longer is if they just work more efficiently because the temperature of the rotor (and the pads too) is reduced. But I'm not a trained physicist, so I expect I'm missing something?
From the study we did in FSAE (going back some years now) the longer life came from reduction in pad and disc surface temps. You are correct the energy conversion is completely analogous.
Don't pads also wear more quickly under high loads? To achieve the same power, you can do low speed+high force or high speed+low force. I would imagine that the high force option has a greater chance of taking chunks out of the pad. Basically, I'm talking about load sensitivity and shear resistance.
Pad life is significantly reduced above a certain temperature (varies for every pad type). So if you can decrease the pad temperature below that threshold value, pad life will increase a lot.
Very cool stuff. I wish bike industry went will large rotor options like you said. Unless you want aero gains, really no reason to not use 180mm rotor on all road bikes.
Cool product + discussion. You need a report on rotor life with this conversion. The 160mm was a fast-wearing consumable for you, if the 180 will last more, there might be a "pays for itself in X seasons / YMMV" argument. AFAIK, BMC URS is the "other" Gravel bike that also comes with a 180 Front Rotor, at least in the carbon frame versions. I definitely don't "need" it for my gravel bike, but I'd also definitely like one, cause...pimp. And 190lbs/87kg kitted =)
That’s a great idea. Just a few small issues might pop up: - width of tire limited - no use of hookless - temperature issues with latex tubes - worn brake tracks are a pain to swap - poor wet performance
it is not the diameter that is the issue, I ride on streets/gravel with a 203mm dual piston xt disc brakes but they still will overheat and glaze up the pads. the rotor needs simply be wider or rather thicker, it is basically razor thin at this point in time and that is the issue for me. My old xt v-brakes on ceramic coated rims is actually far better braking solution than current gen discbrakes.
I'm 6'3" and 220 lbs. I ride gravel and road. Gravel is way harder on brakes than road for a few reasons. I have never had any of the issues you and a few others complain about. I have had rotors on my gravel bike get pretty toasted to the point that they changed colors some. (They were a bit cheaper rotors I had to buy because of supply chain issues. Not sure if that has an effect.) But, they still worked fine, never had any issues during the ride, they always worked, didn't rub,... I've ridden my road bike in the mountains as well. But, it doesn't get near the abuse the gravel bike does. Both have SRAM if that matters. Regardless, people have overheated rim brakes and that is a problem. Especially if paired with carbon wheels. Edit: I am not arguing against the bigger brakes at all. Just some of the complaints people are making. I use 160 and wouldn't mind going to 180.
It is interesting to consider the extent that road design changes "how much brake" you need. You can still rip down a dirt road in the woods at 50-70km/h, but the corners aren't banked and the surface is loose, so you have to absolutely rail the brakes every time the road curves. On tarmac, at least on well-engineered roads, there are cambered turns and uphill runouts to reduce the amount that cars would have to rely on their brakes, and to be sure on these roads you barely need brakes at all (except in emergency situations). Still, there are edge cases for both gravel and road. From what I've ridden and seen in the UK, gravel tracks are really slow going, and there are not as many high-speed descents as there are in other parts of the world. Also, where I live in the United States, the roads I ride on are extremely steep, poorly paved, and poorly engineered, so there are many roads where bikes and cars alike burn their brakes. At any rate, there's riders who can benefit from a 180mm rotor in either camp, and since most bikes are flat mount these days, an adapter like this could be fitted in either case.
Shh... You're correct, of course, but he's crafting a narrative. My experience is the same... I never experience fade on road, but sometimes do on gravel descents.
I am 6’2 230lb, and have never had any issue with any disc rotor as far as thermal management goes. Been riding disc and rim for a long time…. But disc for about 15 years, even before disc was really a thing on road bikes. 180 is overkill for 99% of riders.
@@kidsafe "He's crafting a narrative", you mean he has an opinion, based on his lived experiences and understanding of physic and thermodynamics? lol I actually cannot believe how deep the victim complex runs in the cycling world, yeah, Peak Torque is independently engineering and manufacturing 180mm adapters because he's part of the BBC illuminati, out to craft a narrative and steal your hard-earned 20 quid.
@@ktakashismith He asserts that road needs bigger rotors than MTB when 1) MTB are heavier 2) traction is less predictable 3) descending speeds are slower resulting in 4) more energy lost as friction/heat and 5) less effective air cooling. My own lived experience is that my 1.85mm thick SRAM Centerline X rotors have worn down to 1.66mm and 1.69mm in 22500km and 250000m descended. By the time the rotors hit 1.5mm, they will have seen over 30000km. My SwissStop Disc E pads last 10000km or more. I ride in mostly dry conditions, but my bike is not a stranger to damp/foggy mornings. Meanwhile my dirt oriented bicycles chew through pads, not because of contamination, but because I am simply braking a hell of a lot more.
I totally agree that today's road disc brakes (front) especially are woefully inadequate for any kind of serious use (eg. Alps). I'm 65kgs riding a 6kg bike, with descent KOMs and I have all sorts of issues. How anyone heavy, descending on the brakes copes is beyond me. The temperatures generated on a hot day are insane. So yes to a 180mm disc on the front, perhaps even with water cooling?! (Fork leg is the reservoir - check out my recent vid!!)
That is a really nice invention and one that really makes a lot of sense, unlike some other inventions like hookless rims and hidden cables. Thanks for your contribution to the cycling community and I wish you some good success. Just have to ask, what centerlock rotor would be your choice for use on a road bike?
Here I am using XT. Merida use XT or XTR. In reality the holes are quite big so next time I would find something with smaller holes to be kinder on the smaller road pad.
@@PeakTorque I ordered one of your adapters because I like the idea also can never have enough adapters. And I ordered a Shimano SM-RT900 XTR/Dura-Ace 180mm rotor. Another question I have is pad material. Resin vs metallic. Metallic should also be better right, even if it is more noisy I understand it has more stopping power. Or do you think that those pads would be to harsh and aggressive on the Shimano rotors?
Yeah, you might be wrong with your suggestion on the gravel bike ridingstyle, some people ride hard and fast, whatever the bike…also dońt forget the additional weight when bike packing. I watch this vid for another reason. I run mech disc brakes. Had to save money, thought it was good for traveling and thought the newest gerenation would be fine. Setup is TRP Spire C with Rival Levers. The hard curve in the handlebar didńt help the friction.Very bad braking in the beginning until greasing the hoeses an using organic pads. Thats why I imidiatly searched for a 180mm conversion kit. Guess it makes a lot of sense for mech disc users. I think it might even help dosing the brakes as less force is needed. Actually i am still searching the point of engagement :)
Not sure if you've mentioned this, but not all forks will be wide enough to accommodate a 180mm rotor, and if it's a super tigjt fit then I'd personally be nervous about the rotor going slightly out of alignment and then eating into the fork
I think the greater breaking power is not a problem for the Fork/Frame Only the maximum breaking power is greater and the most roadbikes can't even get to that point because of the traction of the tire
Very tempting to do one of these conversions. Good to know that braking into a steep hairpin won't turn my fork into an origami crane with 180s too, which would have been my main concern
Haven't seen many forks break, not that it cannot be an issue. I would be more worried about super-light, low-spoke-count front rims tho, see those collapse in more than one occasion under really hard riding.
I got my fork made with the flat mount 180 spacing (which is printed on the side of the stock shimano adapter you have in the video) I think it's a better idea, marginal difference in weight or aerodynamics vs 160mm, probably see more road forks made that way
Just thought of this, but I recall Merida was using a heat sink that was mounted between the caliper and the rotor. I wonder if the heat sink takes up room and “forces” them to move to a 180 mm rotor. Obviously adding a heat sink and increasing the rotor size would be a win win toward the intended goal.
Wow very nice adapter! I do not ride road disc bikes,but I had the same brake mounted in various bikes/rotor size combos and 160mm rotors had more pad wear than bigger 180 or 203 mm,it is totally true. Yo need more time on the brakes with the small rotors to do the same job or pull harder the lever. My dirt jump bike wear very fast the pads,only 160mm rear brake to stop the bike,never had a problem with the small disc but I see why many riders would choose a bigger disc.
Couple of my bikes are flat mount to 160mm post, then a 160mm post to 180mm post adaptor to fit a 180mm rotor. (hack/bodge??) Never had any problems, although I could lock the front on 160mm or 180mm with enough lever force never really comes to that, find 180mm is a lot more in my sweet spot stopping, with a 4pot magura (115kg system weight) Your going over the bars before you overload your fork as far as I'm concerned
Okay so the proposed solution to brake fade is to increase the rotor size. Brake torque per pad pressure on the rotor is decreased for the equivalent torque on a smaller rotor, hence less heat on the pad so less brake fade. Peak heat has decreased as well. I feel like if we extended this train of thought you would eventually end up with rim brakes, no?
Not really. The rim has other jobs to do that compromise it's ability to act as a braking surface - more mass to act as a wear surface where it really isn't needed around the entire circumference, cannot engineer in aero, cannot clamp it as hard since it needs to be light, hollow to support the tyre. Let the rim be a rim, and concentrate braking on a device that can be engineered to optimise that function in isolation.
I put 180mm rotor on my bamboo disc bike. Problem Ive found with bigger rotors is they flex more when you power stomp the pedals and you get that 'ping, ting ding, sing, fing jing' rotor rub noise.
On my road bike, i never needed more breaking power than the ultegra 6800 160mm provided me. However on my gravelbike (force axs), i regularly need more power, than what is available to me. I weigh 75 kg + 10 kg for the bike and 4 kg in gear. The gnarly trails and massive traction (compared to skinny tires) of my WTB Raddlers demand immensly more power. For this reason, i will convert to RX4+ and 180/160.
I did it and one thing I can say is that if you have open dropouts it's easy to get the wheel out of the dropouts if you are too grabby on the brakes. A thru axle fork would be just fine imo. The flex when heavy braking could break aluminum from fatigue in the long run but other than that, meh.
thank you for doing this, I will look into it next time I change my rotors / pads ... I was actually already thinking about adapting some MTB mounts for this
Gotta love more options, it's one of the reasons why i stuck with my post mount brakes on my commuter, might not be the tidiest looking setup but easy rotor size conversion, running 180/203mm. Kinda sucks that all road groupsets usually don't offer post mount brakes.
Bigger is better. I dont get why my rental Giant Defy. In size XL, in the south of spain, with climbing gears, had 160F/140R discs 🤷 Previous renter had made those discs nice and blue
Love your channel bro.... As a long time mountain biker xc and long back trail rides.... Why do road riders not use MtB disks and hubs... Surely the light weight XC hubs and brakes would be a good choice
Mate, I’m just wondering , would it not be better to design an adapter that replace the existing adapter altogether ? I’m not an engineer but I seem to remember you said in a previous video that it’s a good practice to reduce the number of interfaces between components
Keeping the original plate and its slotted holes makes aligning the caliper as simple as before. It is nice to keep that interface to make adjusting the caliper simple. Also, it makes switching back to 160mm easy. In general though you are right!
PS the first prototype was like that, but there was so little room for adjustment if it was done like that. To keep the perfectly radial position and tangential sweep of the pad to disc interface, making it in 2 parts was much easier.
I have the option to buy another bike both have the rim and disc brake options. Leaning towards the rimbrake because my disc brake road bikes requires a lot of maintenance and cost is high. Is Rim brake still worth it? Its a Factor o2 VAM btw.
I didn't read every comment but why double up on the adapters? Just make a piece solid unit, it may give you a bit more hardware clearance. Love the concept!
I was literally just considering doing this for my gravel bike the other day to help manage heat on descents. Gravel races around me have a lot of descents that you'll be going 80kmh off and on the brakes hoping it doesn't fade by the end of the hill.
Gravel bikes get packed more than road bikes, I think that is why Merida chose to equip their gravel bikes with 180mm, there's typically more mass to brake. My Trek 920 has post mount, I swapped to 180 front right off the bat 2 years ago. I can recommend bigger rotors! (Touring bikes get loaded even more than bikepacking bikes). This looks like an elegant product to fix the somewhat limiting flatmount.
FWIW, just bought a new Merida gravel bike, and it's set up for 160/180mm rotors, noice... But, as a fatty, I'll certainly look at these for the roadie
My Defy is a 2015 disc bike which came with mtb type cup and cone caliper mounts which I think are better than flat mounts with more adjustment . I all have run a Hope 4 piston front caliper for 3 years with 160mm disc with all the braking I will ever need as I am not good down steep down hills due to speed wobble in the passed.
I was looking at 180mm options when I got my new road bike last year but couldn’t find anything suitable. Have ended up with spare 160mm discs now so it’s unlikely I’m going to change. 160 seems fine, have had some squealing on fast descents but hadn’t realised the bike came with resin pads rather than the sintered ones I’m used to
Have you considered thicker rotors a go for increased thermal dissipation and warping reduction (e.g. SRAM HS2 rotors at 2.00mm thick)? Not 100% if Shimano calipers can clear the +0.15mm in rotor thickness but SRAM HRD calipers certainly can even with new pads.
I have a Merida Scultura Endurance and I'll probably switch to 180 when the current 160 dies. I'm light (63kg) but I live in a mountainous area with long and steep descends. Oh, and it is hot climate too. Brake pad life hasn't been great and the rotor is going towards the 1.5mm limit quickly.
Moved to a new city with massive hills - as well as an 11-34 cassette, have bumped the rear rotor to 160 from 140 just for thermal management. Brake fade is scary…
JFYI. Pure road bikes, I don't know. But I can tell you the new gravel bike from Scott takes 180mm natively. And Hope is going, with their RX brakes, in that same direction, so there seems to be , tho slow, an industry shift in that direction. As a ranting digression. The whole decision of the bike industry to create a disk brake mounting standard purely for road bikes, and limit it to 160, is bewildering to me. What's wrong with PM? More so, on arguably the primary safety component on a bike.
@Peak Torque: back to Shimano discs? I'm pretty annoyed with my Ice Tech Rotors bending, especially with bags on the bike. Had zero problems with my cheap 105s and never had rubbing rotors. Thought about swapping to campi, what was your verdict on these?
with my MTB's i've aways prefere 203/180mm on everything (203/203 on dh bikes) when you're totally worn out and hands are tired bigger brakes means less lever pressure is needed. when i built my road/gravel bike from MTB type hybrid frame i also used 203/180 on that also. the brain gets used to the power, your hands will like the less effort needed.
Since more surface area dissipates heat faster, maybe two smaller disks would be better. Motorcycles have done this for years. The profit potential would be huge. Something obviously different and improved! Now that rotational weight no longer matters, aero advances could wait until the early adopters have bought in!
Unfortunately my adhx fork won’t accommodate bigger discs than 160mm. Anything bigger and it will start cutting in the carbon.. Had the 180mm discs before receiving the frameset… bummer.. On the flats the 160’s are absolutely fine, but as a taller/heavier rider i would have preferred the 180 rotor for in the mountains..
Cool project… thinking of getting this for my gravel bike. 2 questions: caliper/rotor adjustments will be made with factory 160mm bolt/plate and not from your adapter? And do you have a rear brake version?
I just put a 700c rotor on my road bike front and rear. Weirdly enough it is lighter than my road disc set up and is a lot quieter and more aero. My tires also dont break traction as easy which means I can brake into the corner with less worry about sliding out like happens with road disc on road race tires. Apparently all the fastest sprinters and climbers on earth uses 700c rotors for decades no problem until someone thought it would be good to downsize the rotors to 140/160mm and add more spokes to create a wind brake effect.
Why couldn't you run dual callipers on the front, just use a banjo fitting. Since you don't need to increase braking force it may increase pad life by 66%
I've got 180mm on the front of my XC bike and it does make a difference and the parts do last longer. Race cars have larger rotors over their road standard not because the road rotors are inadequate it's just that larger rotors reduce thermal issues. Materials are the other consideration but less of an issue on a bicycle. Torx is much better that hex.
Race cars tend to have the smallest rotor they can get away with to keep weight low. The primary reason they need larger rotors and more pad surface than road cars is because they travel much faster and the braking demands are very different. Agreed on the need to dissipate more heat, in a shorter period of time, as a result.(above references those race cars still using all metal rotors that bikes and most road cars use. carbon ceramic and other compounds are used in many race series these days.)
@@MrKipperfish Yes you're right that they do have the smallest they can get away with on a power to weight ratio. I should have said they are relatively large compared to a non sports car of similar weight. Probably over spec too.
0:51 As a moutain biker I can assure you that 140mm rotors are going to overheat fast. This causes the fluid to boil (in hydraulic systems) and the pads to cook and it will greatly reduce braking power in high brake usage situations. It can also lead to warped rotors. Going larger helps prevent the disc heating as fast in the first place and then also helps it to disipate the heat once it is hot. The adpators featured in this video are nothing new. MTB riders have been using something similar for years to adapt from 160mm up to a maximum 220mm (180 is common) and it turns out Shimano make these for road and they sell for ~£15 in the UK. They even make them up to 180mm.
This looks really interesting. I've still got a fairly new pair of Hope 160mm rotors on my bike, so I will try it in the future. Also, Hope rotors instead of Shimano worked absolute wonders for me. Edit: Hope doesn't make 180mm CL rotors D:
I very highly disagree with your comment on gravel bikes with regards to speed . My usual rides include big drops with big speed. This is why I purchased your kit even if it cost me $70.00+ to get it . I hope it's worth the price , given there's much, much cheaper options .
i have seen some significant variation between different wheels with the lateral position of centrelock discs. might be worth having people check that with the larger rotor. can cause some interference with the top of the rotor as the fork legs bow in. Easily solved by lapping the back of the centrelock disc or the adapter if people are prepared to do it!
Easy fix though! Just file out the fork leg more so the rotor fits and doesnt rub under power stomps. Less material on the fork means less weight and more aero. Dentists dont mind either.
Some gravel bikes support 180 / 160. You mentioned that gravel bikes are slower so don't benefit so much from bigger rotors, but you forgot the added weight from stuff like bikepacking.
not the mention gravel bikers' beer bellies
I put a 180mm front disc on my Open UP, using it with the Hope RX4+ so no adapter needed. It gives a massive amount of braking power, tons of modulation as well. Super happy with it so far.
Its a good option to have. Especially for heavier riders or for people who ride with lots of bikepacking gear.
Good luck to you and everyone that can benefit. I'm too light and too slow for such tech solutions.
Looking forward to future upgrades.
I think this is great one engineer to another. Recently experienced a crash on a steep descent in the Yorkshire dales which has left me with a broken collarbone. When looking at my bike after the incident, my 160mm front Sram rotor has significantly changed colour due to the overheating. Maybe a bigger disc would have reduced this and allowed me to scrub off enough speed to avoid the crash.
Or maybe just sticking to a well proven solution - clinchers would have prevented it?
Thumbs up, purely for the selection of fasteners.
Now work on the other side of the equation. I recommend Wera L wrenchs. By far the nicest set of hex and torx wrenches I have ever laid my hands on.
Mohorič used the Merida Scultura in MSR because it has a standard round seat tube for the dropper post.
But he took the fork from the Reacto! You can see if you research it. The scultura wont fork wont fit 180.
Damn, good spot then!
I have a Canyon Grail e-gravel bike and it needed a brake upgrade! I converted rotors from 160mm to 1800mm front and rear, thicker rotors, sintered brake pads, (1. organic, 2. semi metallic, 3. sintered or blocks of steel!!). It now stops vs. quickly coming to a stop.
I'm 80kgs, ran 140mm front and rear on a Cannondale. No issues, brakes were fantastic. Now run 160/160 and brakes are fantastic. No issues with warping braking down from 45mph to 15mph. Can't see the need, never felt there was a thermal problem. For me 160/140 is the perfect combo. 4 different bikes 2 were shimano 2 SRAM.
All depends on where you ride. If you 500m of descent at 15%+ on twisty corners the whole way, even 180mm on a mountain bike will struggle.
I just changed from 160 to 180 on my giant toughroad, and it feels much better, I've already ordered the rear kit. Hopefully the fork will handle it on the long run.
Very nice. When I need to replace my rotors I will be getting one of these.
Great explanation. It ain't about the ability to lock the wheels. Heck I can lock the wheels with my shoe on the wheel. It's about how the braking feels and braking confidence. I have 203mm on 4 piston calipers on my mtb and the confidence I have vs my road bike is tremendous. Obviously overkill but having more rotor and larger pads is incredibly nice to have.
I agree that modulation is key. I also have 203mm rotors F/R with 4-piston Shimano brakes on my trail bike, and I find the modulation "addictive", and overheating hasn't been an issue so far. My BIL's trail HT that came with MT400 class 2-piston brakes and the typ. "resin only" rotors and pads, have zero issues locking either wheel but consistency suffers as the rotor gets hotter and hotter, and modulation @ the edge of locking up is worse throughout.
FWIW, I don't think that there is much concern about increased forces on the forks.
The peak torque (heh!) about the spindle is still limited by the tyre grip, so assuming that the brake could be locked before, that remains unchanged.
At this limit point the force at the brake pads it reduced, and the bending moment on the bottom of the fork leg is exactly the same.
There is (maybe?) a different balance between the forces on the two mounting points. If you consider a very large adaptor then you could see the force at the bottom mount become a tension force, and the force at the top mount then becomes larger. I don't think that you have gone far enough for this to be a real issue.
I wouldn't take the risk on these weak road forks. When was the last time you locked up the front brake at high speeds? My forks broke on 32mm tires, 160mm rotors. I've switched to 140mm now and gravel forks. Be careful.
Bigus Discus
He has a wife youknow
I use my brakes a lot more and for longer periods on my gravel bike than on the road, but I routinely do 800+m descents that are technical enough to require near constant braking. It has 180/160, which I've been happy with that.
Exactly. On gravel you are moving slowly enough that there is no aero drag, so you're putting 100% of the descent energy into the discs. My gravel bike has a lot more brake fade on gravel descents than road descents.
"You're not usually bombing down steep descents on a gravel bike" - you should come to Western North America, where the gravel roads can be >15%!
Been having some issues with heat on 160mm rotors so I think an upgrade will happen with your adapters (or the Hope calipers).
You said longer pad life. I'm just really curious about the physics of that. The moment is greater, so you need less clamping force, but the rotor is travelling more quickly, which I would have thought would counteract that - ultimately you're still dealing with the same amount of energy. I can certainly see the rotors would last longer as they're bigger and there's just more material to grind. The only way I can think the pads would last longer is if they just work more efficiently because the temperature of the rotor (and the pads too) is reduced. But I'm not a trained physicist, so I expect I'm missing something?
From the study we did in FSAE (going back some years now) the longer life came from reduction in pad and disc surface temps. You are correct the energy conversion is completely analogous.
The difference in rotor speed is negligible compared to the leverage gained.
@@cup_and_cone no, it's proportional.
Don't pads also wear more quickly under high loads? To achieve the same power, you can do low speed+high force or high speed+low force. I would imagine that the high force option has a greater chance of taking chunks out of the pad.
Basically, I'm talking about load sensitivity and shear resistance.
Pad life is significantly reduced above a certain temperature (varies for every pad type). So if you can decrease the pad temperature below that threshold value, pad life will increase a lot.
That's a great idea!, living in the North Lake District with our 25% Road climbing and descending, I'd buy them.👍
thank you! I've had a 180mm disc sitting on my shelf for months waiting for a mounting solution
Happy to see some others people starting to run 180s - swapped about a year ago now and haven't looked back.
Very cool stuff. I wish bike industry went will large rotor options like you said. Unless you want aero gains, really no reason to not use 180mm rotor on all road bikes.
Cool product + discussion.
You need a report on rotor life with this conversion. The 160mm was a fast-wearing consumable for you, if the 180 will last more, there might be a "pays for itself in X seasons / YMMV" argument.
AFAIK, BMC URS is the "other" Gravel bike that also comes with a 180 Front Rotor, at least in the carbon frame versions.
I definitely don't "need" it for my gravel bike, but I'd also definitely like one, cause...pimp. And 190lbs/87kg kitted =)
I'm a 110 kg former rower and warped my front disc on a descent the other day. I think this would work really well for me. Great idea 👍
I'm a former rower, you'll soon lose that 10kg of muscle being a cyclist!
Imagine if you had 700c sized discs and you applied the brake to the outer surface of that larger disc.
I think you are really onto something. Let's hope the bike industry backs this idea. Sounds like less maintenance too
They tried that but they found that tyres were getting so hot the tubes were blowing the tyres of the rim in carbon versions.
Lol the circle of life
@@glennoc8585 mythological
That’s a great idea. Just a few small issues might pop up:
- width of tire limited
- no use of hookless
- temperature issues with latex tubes
- worn brake tracks are a pain to swap
- poor wet performance
it is not the diameter that is the issue, I ride on streets/gravel with a 203mm dual piston xt disc brakes but they still will overheat and glaze up the pads. the rotor needs simply be wider or rather thicker, it is basically razor thin at this point in time and that is the issue for me. My old xt v-brakes on ceramic coated rims is actually far better braking solution than current gen discbrakes.
I'm 6'3" and 220 lbs. I ride gravel and road. Gravel is way harder on brakes than road for a few reasons. I have never had any of the issues you and a few others complain about. I have had rotors on my gravel bike get pretty toasted to the point that they changed colors some. (They were a bit cheaper rotors I had to buy because of supply chain issues. Not sure if that has an effect.) But, they still worked fine, never had any issues during the ride, they always worked, didn't rub,... I've ridden my road bike in the mountains as well. But, it doesn't get near the abuse the gravel bike does. Both have SRAM if that matters. Regardless, people have overheated rim brakes and that is a problem. Especially if paired with carbon wheels.
Edit: I am not arguing against the bigger brakes at all. Just some of the complaints people are making. I use 160 and wouldn't mind going to 180.
It is interesting to consider the extent that road design changes "how much brake" you need. You can still rip down a dirt road in the woods at 50-70km/h, but the corners aren't banked and the surface is loose, so you have to absolutely rail the brakes every time the road curves. On tarmac, at least on well-engineered roads, there are cambered turns and uphill runouts to reduce the amount that cars would have to rely on their brakes, and to be sure on these roads you barely need brakes at all (except in emergency situations).
Still, there are edge cases for both gravel and road. From what I've ridden and seen in the UK, gravel tracks are really slow going, and there are not as many high-speed descents as there are in other parts of the world. Also, where I live in the United States, the roads I ride on are extremely steep, poorly paved, and poorly engineered, so there are many roads where bikes and cars alike burn their brakes.
At any rate, there's riders who can benefit from a 180mm rotor in either camp, and since most bikes are flat mount these days, an adapter like this could be fitted in either case.
Shh... You're correct, of course, but he's crafting a narrative. My experience is the same... I never experience fade on road, but sometimes do on gravel descents.
I am 6’2 230lb, and have never had any issue with any disc rotor as far as thermal management goes. Been riding disc and rim for a long time…. But disc for about 15 years, even before disc was really a thing on road bikes. 180 is overkill for 99% of riders.
@@kidsafe "He's crafting a narrative", you mean he has an opinion, based on his lived experiences and understanding of physic and thermodynamics? lol I actually cannot believe how deep the victim complex runs in the cycling world, yeah, Peak Torque is independently engineering and manufacturing 180mm adapters because he's part of the BBC illuminati, out to craft a narrative and steal your hard-earned 20 quid.
@@ktakashismith He asserts that road needs bigger rotors than MTB when 1) MTB are heavier 2) traction is less predictable 3) descending speeds are slower resulting in 4) more energy lost as friction/heat and 5) less effective air cooling.
My own lived experience is that my 1.85mm thick SRAM Centerline X rotors have worn down to 1.66mm and 1.69mm in 22500km and 250000m descended. By the time the rotors hit 1.5mm, they will have seen over 30000km. My SwissStop Disc E pads last 10000km or more. I ride in mostly dry conditions, but my bike is not a stranger to damp/foggy mornings.
Meanwhile my dirt oriented bicycles chew through pads, not because of contamination, but because I am simply braking a hell of a lot more.
I totally agree that today's road disc brakes (front) especially are woefully inadequate for any kind of serious use (eg. Alps). I'm 65kgs riding a 6kg bike, with descent KOMs and I have all sorts of issues. How anyone heavy, descending on the brakes copes is beyond me. The temperatures generated on a hot day are insane.
So yes to a 180mm disc on the front, perhaps even with water cooling?! (Fork leg is the reservoir - check out my recent vid!!)
I was in Mallorca last week! Unfortunately no time, nor legs, to get to Palma tho
Oh no!! Next time!
That is a really nice invention and one that really makes a lot of sense, unlike some other inventions like hookless rims and hidden cables. Thanks for your contribution to the cycling community and I wish you some good success. Just have to ask, what centerlock rotor would be your choice for use on a road bike?
Here I am using XT. Merida use XT or XTR. In reality the holes are quite big so next time I would find something with smaller holes to be kinder on the smaller road pad.
@@PeakTorque I ordered one of your adapters because I like the idea also can never have enough adapters. And I ordered a Shimano SM-RT900 XTR/Dura-Ace 180mm rotor. Another question I have is pad material. Resin vs metallic. Metallic should also be better right, even if it is more noisy I understand it has more stopping power. Or do you think that those pads would be to harsh and aggressive on the Shimano rotors?
Whats wrong with hookless?
@@smin4089 🤣 That was funny.
@@PeakTorque 160 are enough 140 trash 180 too much
My Ghost 7500 Cross from 2011 came with Shimano 445 Disc 180 mm Hydraulic Brakes, they work perfectly.
Yeah, you might be wrong with your suggestion on the gravel bike ridingstyle, some people ride hard and fast, whatever the bike…also dońt forget the additional weight when bike packing. I watch this vid for another reason. I run mech disc brakes. Had to save money, thought it was good for traveling and thought the newest gerenation would be fine. Setup is TRP Spire C with Rival Levers. The hard curve in the handlebar didńt help the friction.Very bad braking in the beginning until greasing the hoeses an using organic pads. Thats why I imidiatly searched for a 180mm conversion kit. Guess it makes a lot of sense for mech disc users. I think it might even help dosing the brakes as less force is needed. Actually i am still searching the point of engagement :)
Think you have a dead pixel on your camera sensor btw, awesome upgrade makes a lot of sense!
think you are correct there!
Not sure if you've mentioned this, but not all forks will be wide enough to accommodate a 180mm rotor, and if it's a super tigjt fit then I'd personally be nervous about the rotor going slightly out of alignment and then eating into the fork
Good point I'll add it
I think the greater breaking power is not a problem for the Fork/Frame
Only the maximum breaking power is greater and the most roadbikes can't even get to that point because of the traction of the tire
Very tempting to do one of these conversions. Good to know that braking into a steep hairpin won't turn my fork into an origami crane with 180s too, which would have been my main concern
Haven't seen many forks break, not that it cannot be an issue. I would be more worried about super-light, low-spoke-count front rims tho, see those collapse in more than one occasion under really hard riding.
I got my fork made with the flat mount 180 spacing (which is printed on the side of the stock shimano adapter you have in the video)
I think it's a better idea, marginal difference in weight or aerodynamics vs 160mm, probably see more road forks made that way
Just thought of this, but I recall Merida was using a heat sink that was mounted between the caliper and the rotor. I wonder if the heat sink takes up room and “forces” them to move to a 180 mm rotor. Obviously adding a heat sink and increasing the rotor size would be a win win toward the intended goal.
Just did some further research, their heatsink is designed into the fork. Scratch all that. 180 mm was an intended modification.
Check out the front brake design on the “Buell Lightning”
It’s basically a rim brake :)
Why do you think motorcycle manufacturers --- with much better engineers --- choose not to use the Zero Torsional Load (ZTL) brake design?
Wow very nice adapter! I do not ride road disc bikes,but I had the same brake mounted in various bikes/rotor size combos and 160mm rotors had more pad wear than bigger 180 or 203 mm,it is totally true. Yo need more time on the brakes with the small rotors to do the same job or pull harder the lever. My dirt jump bike wear very fast the pads,only 160mm rear brake to stop the bike,never had a problem with the small disc but I see why many riders would choose a bigger disc.
Couple of my bikes are flat mount to 160mm post, then a 160mm post to 180mm post adaptor to fit a 180mm rotor. (hack/bodge??)
Never had any problems, although I could lock the front on 160mm or 180mm with enough lever force never really comes to that, find 180mm is a lot more in my sweet spot stopping, with a 4pot magura (115kg system weight)
Your going over the bars before you overload your fork as far as I'm concerned
Okay so the proposed solution to brake fade is to increase the rotor size. Brake torque per pad pressure on the rotor is decreased for the equivalent torque on a smaller rotor, hence less heat on the pad so less brake fade. Peak heat has decreased as well.
I feel like if we extended this train of thought you would eventually end up with rim brakes, no?
Not really. The rim has other jobs to do that compromise it's ability to act as a braking surface - more mass to act as a wear surface where it really isn't needed around the entire circumference, cannot engineer in aero, cannot clamp it as hard since it needs to be light, hollow to support the tyre. Let the rim be a rim, and concentrate braking on a device that can be engineered to optimise that function in isolation.
torque is decreased, speed increased, total power stays the same. Dissipation of that power increases though through bigger heat mass
@@feedbackzaloop Oh, and they suck in the wet.
@@WeirdNeville who they? 180mm rotors? I was merely commenting on the premise, not conclusion
I put 180mm rotor on my bamboo disc bike. Problem Ive found with bigger rotors is they flex more when you power stomp the pedals and you get that 'ping, ting ding, sing, fing jing' rotor rub noise.
No one cares what you think
Thanks for the tips. I have been thinking about this set up for so long on my TT bike. Especially on a TT bike on a full aero disc rear wheel setup.
On my road bike, i never needed more breaking power than the ultegra 6800 160mm provided me. However on my gravelbike (force axs), i regularly need more power, than what is available to me. I weigh 75 kg + 10 kg for the bike and 4 kg in gear. The gnarly trails and massive traction (compared to skinny tires) of my WTB Raddlers demand immensly more power. For this reason, i will convert to RX4+ and 180/160.
I did it and one thing I can say is that if you have open dropouts it's easy to get the wheel out of the dropouts if you are too grabby on the brakes.
A thru axle fork would be just fine imo. The flex when heavy braking could break aluminum from fatigue in the long run but other than that, meh.
thank you for doing this, I will look into it next time I change my rotors / pads ... I was actually already thinking about adapting some MTB mounts for this
Gotta love more options, it's one of the reasons why i stuck with my post mount brakes on my commuter, might not be the tidiest looking setup but easy rotor size conversion, running 180/203mm. Kinda sucks that all road groupsets usually don't offer post mount brakes.
you could go shigura....
xt postmount brakes are pretty much compatible with shimano road levers.
Oh I'm broke and still on mechanical TRP spyres. If I end up on a frame with flat mount I'll probably just grab a PM on FM adapter
Bigger is better. I dont get why my rental Giant Defy. In size XL, in the south of spain, with climbing gears, had 160F/140R discs 🤷
Previous renter had made those discs nice and blue
160/140 is enough, just the braking management and technique
Love your channel bro.... As a long time mountain biker xc and long back trail rides.... Why do road riders not use MtB disks and hubs... Surely the light weight XC hubs and brakes would be a good choice
I do need extra power for my gravel since the very first day!. 87 kgs and sram force 1.
Mate, I’m just wondering , would it not be better to design an adapter that replace the existing adapter altogether ? I’m not an engineer but I seem to remember you said in a previous video that it’s a good practice to reduce the number of interfaces between components
Keeping the original plate and its slotted holes makes aligning the caliper as simple as before. It is nice to keep that interface to make adjusting the caliper simple. Also, it makes switching back to 160mm easy. In general though you are right!
PS the first prototype was like that, but there was so little room for adjustment if it was done like that. To keep the perfectly radial position and tangential sweep of the pad to disc interface, making it in 2 parts was much easier.
Hahaha I see, thanks for the explanation, really learning a lot from your vids
I have the option to buy another bike both have the rim and disc brake options. Leaning towards the rimbrake because my disc brake road bikes requires a lot of maintenance and cost is high. Is Rim brake still worth it? Its a Factor o2 VAM btw.
Absolutely, I have a rim brake Pinarello F8 it’s a-ma-zi-ng. No bullshit, no disc rubbing, lighter,…
I didn't read every comment but why double up on the adapters? Just make a piece solid unit, it may give you a bit more hardware clearance. Love the concept!
I was literally just considering doing this for my gravel bike the other day to help manage heat on descents. Gravel races around me have a lot of descents that you'll be going 80kmh off and on the brakes hoping it doesn't fade by the end of the hill.
Check if your fork will allow for it… before it snaps off
Good work, nice mod! 👍💯
Cheers mate. Seems to be working great, less noise, less noise and definitely less piston creep after a really long downhill
Surely this is why rim will always be better for heat dissipation the brake track is massive by comparison
Yes, as long as its not made of carbon
180 on a road bike? EPIC!!!
and I thought it was too much for a XC front bike lol 😜
Love it, great work again PT!
We need hambini to tell us the aero penalty when jumping from 160mm to 180mm
and the opinion from Durian Rider, because with 180mm the braking is closer to the rim
Gravel bikes get packed more than road bikes, I think that is why Merida chose to equip their gravel bikes with 180mm, there's typically more mass to brake.
My Trek 920 has post mount, I swapped to 180 front right off the bat 2 years ago. I can recommend bigger rotors! (Touring bikes get loaded even more than bikepacking bikes).
This looks like an elegant product to fix the somewhat limiting flatmount.
Mohoric was riding the scultura in MSR because he was also using a dropper which requires a round seat-tube
but he took the fork off the Reacto which fits 180mm discs...Look closely
FWIW, just bought a new Merida gravel bike, and it's set up for 160/180mm rotors, noice...
But, as a fatty, I'll certainly look at these for the roadie
My Defy is a 2015 disc bike which came with mtb type cup and cone caliper mounts which I think are better than flat mounts with more adjustment . I all have run a Hope 4 piston front caliper for 3 years with 160mm disc with all the braking I will ever need as I am not good down steep down hills due to speed wobble in the passed.
Cup and Cone is a type of bearing. I think you mean post mount brakes? 🤔
It Changed My Life :)
I was looking at 180mm options when I got my new road bike last year but couldn’t find anything suitable. Have ended up with spare 160mm discs now so it’s unlikely I’m going to change. 160 seems fine, have had some squealing on fast descents but hadn’t realised the bike came with resin pads rather than the sintered ones I’m used to
Next big tech in cycling is nickel covered copper heat pipes. Everyone needs those.
Have you considered thicker rotors a go for increased thermal dissipation and warping reduction (e.g. SRAM HS2 rotors at 2.00mm thick)? Not 100% if Shimano calipers can clear the +0.15mm in rotor thickness but SRAM HRD calipers certainly can even with new pads.
I have a Merida Scultura Endurance and I'll probably switch to 180 when the current 160 dies. I'm light (63kg) but I live in a mountainous area with long and steep descends. Oh, and it is hot climate too. Brake pad life hasn't been great and the rotor is going towards the 1.5mm limit quickly.
Moved to a new city with massive hills - as well as an 11-34 cassette, have bumped the rear rotor to 160 from 140 just for thermal management. Brake fade is scary…
Yeah first time I ever encountered my first mountain I smoked the disk brakes on a department store mtb on the descent. Was pretty scary.
Nice product. Though I'm not sure if you should clamp your frame on the top tube. Also, there is a dead pixel in the middle of your shot
Its not clamped of course
I have been waiting for this video! Thanks!!!!
Durianrider would definately approve of this. 😎
I put a 180mm on my ebike and I locked the front wheel a couple of times but managed to save it from skidding out. Went back to 160mm lol
JFYI. Pure road bikes, I don't know. But I can tell you the new gravel bike from Scott takes 180mm natively. And Hope is going, with their RX brakes, in that same direction, so there seems to be , tho slow, an industry shift in that direction.
As a ranting digression. The whole decision of the bike industry to create a disk brake mounting standard purely for road bikes, and limit it to 160, is bewildering to me. What's wrong with PM? More so, on arguably the primary safety component on a bike.
Really good video, really well thought out and made product. top work!
@Peak Torque: back to Shimano discs? I'm pretty annoyed with my Ice Tech Rotors bending, especially with bags on the bike. Had zero problems with my cheap 105s and never had rubbing rotors. Thought about swapping to campi, what was your verdict on these?
with my MTB's i've aways prefere 203/180mm on everything (203/203 on dh bikes) when you're totally worn out and hands are tired bigger brakes means less lever pressure is needed.
when i built my road/gravel bike from MTB type hybrid frame i also used 203/180 on that also.
the brain gets used to the power, your hands will like the less effort needed.
Since more surface area dissipates heat faster, maybe two smaller disks would be better. Motorcycles have done this for years. The profit potential would be huge. Something obviously different and improved! Now that rotational weight no longer matters, aero advances could wait until the early adopters have bought in!
Unfortunately my adhx fork won’t accommodate bigger discs than 160mm. Anything bigger and it will start cutting in the carbon.. Had the 180mm discs before receiving the frameset… bummer.. On the flats the 160’s are absolutely fine, but as a taller/heavier rider i would have preferred the 180 rotor for in the mountains..
@chrisfroome might want to see if these will help your brake issues
This is great. Gonna buy it soon for sure. Curious though why not just make it 1 piece and complete ditch the whole 140/160 adapter?
Canyon Grizl also accepts a 180mm disc natively
The Scott Addict Gravel too
Many gravel bikes do. This video is discussing road bikes.
@@markachternaam5207 he does specifically mention which gravel bikes have 180mm compatibility..
Cool project… thinking of getting this for my gravel bike. 2 questions: caliper/rotor adjustments will be made with factory 160mm bolt/plate and not from your adapter? And do you have a rear brake version?
I just put a 700c rotor on my road bike front and rear. Weirdly enough it is lighter than my road disc set up and is a lot quieter and more aero. My tires also dont break traction as easy which means I can brake into the corner with less worry about sliding out like happens with road disc on road race tires.
Apparently all the fastest sprinters and climbers on earth uses 700c rotors for decades no problem until someone thought it would be good to downsize the rotors to 140/160mm and add more spokes to create a wind brake effect.
Why couldn't you run dual callipers on the front, just use a banjo fitting. Since you don't need to increase braking force it may increase pad life by 66%
damn, i did not know that mohoric had a big disc on his bike for that. everyone was talking about the dropper!
got 160/160 at around 65kg ... no reason to go lower but thankfully bike usually can do 160/140-160 easy
Checked out your shop! If you design a neat logo and put that on some cycling merchandise (hats, socks, stickers, etc.), I'd buy them!
Hi! Are you thinking of doing a adapter for SRAM Groupsets? (SRAM Rival, Force, Red)
I've got 180mm on the front of my XC bike and it does make a difference and the parts do last longer. Race cars have larger rotors over their road standard not because the road rotors are inadequate it's just that larger rotors reduce thermal issues. Materials are the other consideration but less of an issue on a bicycle. Torx is much better that hex.
Race cars tend to have the smallest rotor they can get away with to keep weight low. The primary reason they need larger rotors and more pad surface than road cars is because they travel much faster and the braking demands are very different. Agreed on the need to dissipate more heat, in a shorter period of time, as a result.(above references those race cars still using all metal rotors that bikes and most road cars use. carbon ceramic and other compounds are used in many race series these days.)
@@MrKipperfish Yes you're right that they do have the smallest they can get away with on a power to weight ratio. I should have said they are relatively large compared to a non sports car of similar weight. Probably over spec too.
0:51 As a moutain biker I can assure you that 140mm rotors are going to overheat fast. This causes the fluid to boil (in hydraulic systems) and the pads to cook and it will greatly reduce braking power in high brake usage situations. It can also lead to warped rotors. Going larger helps prevent the disc heating as fast in the first place and then also helps it to disipate the heat once it is hot.
The adpators featured in this video are nothing new. MTB riders have been using something similar for years to adapt from 160mm up to a maximum 220mm (180 is common) and it turns out Shimano make these for road and they sell for ~£15 in the UK. They even make them up to 180mm.
Shimano do not make a 140/160 flat mount to 180mm adapter, no.
Nicely done!
This looks really interesting. I've still got a fairly new pair of Hope 160mm rotors on my bike, so I will try it in the future. Also, Hope rotors instead of Shimano worked absolute wonders for me.
Edit: Hope doesn't make 180mm CL rotors D:
I also use Hope rotors (floating type) on my Boardman road bik
A tandem fork has a 200 mm disc rotor as a standard. I realize that it is more expensive than your spacer.
If heat dissipation is an issue, I wonder why aftermarket suppliers do not offer disc braking upgraded with copper or the like
I very highly disagree with your comment on gravel bikes with regards to speed . My usual rides include big drops with big speed. This is why I purchased your kit even if it cost me $70.00+ to get it . I hope it's worth the price , given there's much, much cheaper options .
If anyone would go to 180mm rotors on road bike, the tyres should be at least 28 or 32 wide for better traction
Great idea for mechanical disc in cheaper road bikes!
i have seen some significant variation between different wheels with the lateral position of centrelock discs. might be worth having people check that with the larger rotor. can cause some interference with the top of the rotor as the fork legs bow in. Easily solved by lapping the back of the centrelock disc or the adapter if people are prepared to do it!
Good point. I cant believe how hubs can be so different, they clearly don't adhere to a standard!
Easy fix though! Just file out the fork leg more so the rotor fits and doesnt rub under power stomps. Less material on the fork means less weight and more aero.
Dentists dont mind either.
The Orbea Terra fork can take 180mm rotors, too.
got a Decathlon Van Rysel that came with a 160 rotor and the swap is 180 and to my annoyance, it came with m5 torx