Are Big Disc Brakes REALLY Better?
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- Опубликовано: 2 окт 2024
- We know that bigger brakes can stop you faster, but what about their efficiency? We went to Girona to find out whether a bigger disc brake rotor will not only have a lower peak temperature, but also dissipate heat faster than a smaller disc brake rotor. It's time for some GCN Science!
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What did you think of the results?
You came to the same conclusions as I gave when selecting rotor size for the weight.
.....not really a scientific test.....you have to measure it permanently and you also have to know the speed, weight, energy which got transfered into heat for one ride and so on.
should try it with an alloy rim brake wheel 😉
Being a mtber and roadie id say fairly predictable, good to see some peak torque recognition tho. Yeah come on let's test some stuff to destruction, get the lathe out. Big brakes are great if you're an aggressive decender theyre always good to go - fade is a thing of the past and in 24hr races having more than enough power is a bonus with tired cold hands. If you're a bit of a panic braker tho good luck, best thing you can do is work on your spacial awareness so things don't suprize you.
The 55ish degrees across the board shows that the experiment probably isn't hard enough to show any difference between the rotors. (Although the faster heat dissapation of the 180mm is a hint at potential superior performance)
Would love to see some more experimentation on the subject :)
All for fire and flames! I use a 160mm on the front at 100kg. Would think about going to a 180mm next time I change the rotor. Nice to see Peak Torque getting some love on GCN
How are you getting on with the longevity of the rotors themselves? I'm much lighter, but Peak Torque saying his pair only lasts ~6 months is scaring me.
@@teknonmy7210 That was specifically about Shimano icetech rotors because they have aluminium in the middle. Get some cheaper full steel rotors and they will last ages.
Funny thing is that he hates gcn😅
@@teknonmy7210xD yeah fuck the icetech. If you're going to race icetech is fine.
For daily driver normal rotors are better
Why hate? And who is he?
If in doubt, ALWAYS get the biggest.
I’ve got a 622mm disc. It’s called rim brakes 😂
@@mondoabz pmsl brilliant
@@mondoabz ... Eroding the structural strength of a rim to us as braking surface is one of the more moronic things the cycling industry has come up with. Thankfully it is going away.
Is the extra stress from a larger rotor on the fork a concern?
As long you don't use Titanium bolts you should be okay.
Would love to see a weight based experiment between a 60kg rider and a 100kg rider descending
I can verify that on steep, loose gravel paths with high consequences for sliding, small rotors fade for Clydesdale riders, and are fatiguing.
Yes please
Should do heavier and less confident at descending.
(if all else being equal) Gravity. Means fatties should be faster at descending. Bigger discs will be king as it has enough surface area to handle and dissipate the heat from braking. You could also toast your brake pads as well but even a lot of those come with heatsinks or made with better materials like aluminium on the back of the pad to help remove the heat these days so its not as much of an issue as it used to be unless youre on a super super long descent then brake discipline is key to not cooking your brakes.
Agree. Do it!
Love to see this explored more. I built an adapter back in the early 2000s to mount 8" rotors to my MTB as there wasn't anything available at the time and discs were so new. Ran 9" up front and 8" at the rear for literally 20 years now. Love it. Keen to see how a bigger disc works on road bikes as I find my 5" fronts lacking in stopping power to be honest.
I use 622mm brake rotors. They're made of carbon and everything.
Depending where you live, in Lincolnshire hardly touch the brakes apart from reaching the cafe, vive the rim
If the heat dissipation is so quick as your temperature readings suggested, does the similarity in final temperature not suggest it was related to the final braking effort? In other words the heat from the heavier braking effort earlier in the descent would already have been dissipated
A group of us road across Switzerland in rainy weather, 2016 specialized Diverge/Dolce. My 130lb + 25lb rear panniers rides aggressively and had pristine rotors. I"m 200lb + 10 on the back and 20 in lowriders on the front, I returned with a smoked front rotor. Other lady at just slightly more weight than my wife was one model downspec with a hybrid cable/hydraulic TRP brake, she over braked and boiled the fluid off on both brakes.
I upsized my front Rotor when we arrived home, Have not toured on anything like the scale of Switzerland since, but I was happy with the change.
You touched on the real benefit, but wasn't the focus of your test. The biggest benefit is heat recovery in a situation where you have to brake on a continuous basis (same on a car/truck). A long technical descent where you are breaking hard on and off for 10 to 20 mins would be a better test.Also at what temperature do you start to loose breaking power? You could use a lath to perform both test.
My experience from MTBs is that discs heat up most on steep descents where they are used for an extended period. The descent on the video looked like one where braking was only needed at each corner giving the rotors time to cool down between them
I agree. A very steep descent at low speed would be a better test. And I would like to know the pad or the caliper temperature as well, as the disc temperature doesn't matter that much in my opinion.
I'd love to see the test done again with someone who IS in that 90kg range & 50 - 65kmph speeds! (I'm currently about to make the switch to discs)
Follow Peak Torque and have been impressed by his analysis and ingenuity. Plus the pros have complained about distortion of rotors 0on descents. A 180 (or larger) seems to be the way to go, particularly as the weight difference is marginal. Yes, please investigate further.
Peak torque has gone mainstream
Please, please, make an experiment indoors monitoring how the temperature builds up in the disc rotor, in the brake pads and in the oil with different setups:
a) standard 160mm rotors, 2-pot calipers and a fan blowing on the setup
b) standard 160mm rotors, 2-pot calipers and finned brake pads with the fan blowing
c) and d): repeat a) and b) with 180mm rotors
e) and f): repeat a) and b) with 4-pot calipers
Maybe you can do the experiment in association with GMBN for the 4-pot calipers. And make sure that in all cases you are dissipating the same power turning the wheel at the same speed.
So, if we make the rotors large enough, they become rim brakes. 😄
Don't give canyon any ideas
thats a good one! :D
Love the comparison and breakdown of each of the rotor sizes. I currently have the Shimano SM-MT800 140/140 and as a weekend/casual groupride cyclist 140s are good enough for me. I did however, swapped out my stock SM-RT800 (Ultegra road) for their MTB equvailent.
In my cause change front disc from 160 to 180mm was perfect decision. It cost me around 20usd for disc and adapter. Also when i had in one season Giant Fastroad i changed front one from 140 to 160 and i had not regret it
I weight around 95 kilograms so it is very efficient
I'm not sure how accurate an IR thermometer will be on a reflective surface.
Thermal couple will be a greater choice + recording temperature all through descent and plot the graph. True science.
Shame you did not discuss the impact of the greater leverage from increasing disc size on the hubs and spokes.
You do not have greater leverage with increase in rotor size that is merely a false narrative. Roller size has nothing to do with leverage and ratio at the master cylinder. The cylinder the hose and the caliper are the same size no matter what rotor is installed. It is merely a perception or a feel that braking force is less. Larger rotors have more swept area and are able to convert and dissipate thermal energy much more efficiently. This results in little to no fade compared to smaller rotors.
Would love to see a weight based experiment. Would like to see some lathe action too!
After reading the comments I conclude that a lot of cyclists are Luddites.
I don't have the science, but I can tell you my weight plus the weight my propel is 115kg, and washing off speed say from 80km/hr just before I enter a corner can result in being able to smell the brakes pads cooking and once my rotors go blue from the heat it's pretty much game over for them. Unless you like your brakes sounding like the mating call of a Lamma. I'm running 160's front and back and it took a while to master how to wash off speed quickly without cooking them. I have also blown out a front tyre from heat build-up on rim brakes. Yep, I need to lose a few kgs.
Would love to see a comparison of rotor size and rider weight (light vs heavy rider) - Heat, stopping distance, feel
I’d love to see GCN/GTN get an electric motorcycle for the camera crew so we don’t hear the exhaust noises. 👌👍
Or the riders have to smell the fumes
my gravel thing has 203/185mm rotors. hope m4 calipers mated to srram apex levers.
the lever feel is very light weight and super powerful due to the calipers being bigger surface area then the levers are made for, the pad area being much bigger and obviously the leverage.
braking is a no thought thing,
Look like you were testing on Dels Angles near Girona, which is not that steep. Maybe redo the test on Rocacorba....?
Depends on the bike really. I've got a touring bike, 160mm is good, but later 200mm might be better. Better heat dissipation when speeding downhill with a heavy load.
Definitely keen to see glowing rotors! Perhaps you could talk to some motorsports people - they have different sized rotors for different tracks in some series.
I've noticed that 160 mm disc's work better than 140 mm. However a 700mm disc works better. All are aluminum. Carbon doesn't work anywhere near as good.
There's nothing on that run needs braking unless you are trying to keep below the speed limit.
Bombed a hill at 113kg / 52mph. My rotors smelled funny and now have a nice blue color to them 🥵
Probably because you don't have a good understanding of proper breaking technique with regards to lever pressure. Something worth practicing
@@rider65 maybe, but it was also the T junction at the bottom of the hill.
Like rim brakes because it’s a cheaper option but I’ve noticed over the last week due to an awful lot of rain I’ve been breaking much earlier and been a lot more careful than other riders I’ve been cycling with who have disk breaks
No big deal. Seriously, how often are you descending, in the rain, under race conditions? Almost never? Then just anticipate early braking like you just described. No need to add a squealing kilo to your bike for the maybe what if moments.
I think I’m going to steal that from you. “squealing kilo” 😂 and don’t forget the additional cost of buying a disc brake equipped bike
I run a gravel bike with mountain bike brakes, using a 180mm rotor upfront and 160 in the back. No stopping issues. Sometimes too much. I love it.
Heeyyyy Peak Torque noice 👍🏼
Makes sense that all the rotors reached the same peak temperature. regardless of the rotor size the brake is transferring your momentum into heat so if you are braking from the same speed and weight the same then the same amount of heat will be generated. the advantage as you discovered is the rate that the rotors cool, allowing you to brake again sooner with a larger rotor. this is why you don't drag brakes, but gently "pulse" them, brake hard for a few seconds then off for a few seconds repeated on steep descents.
Finally somebody who understands physics and thermodynamics! 😄👍
Close, but there's a problem with what you claim for 'pulsing' (Yes it improves things, but not for the reason you state). If the relationship between heat generated (express it in Watts...kW) is the same as energy lost from braking, then pulsed or not, for the same braking power, you must dissipate the same amount of energy (and Watts is a linear and used way to express this, as it is for electricity to heat in a resistive element).
The advantages of pulsing are manifest in a different way that I won't go into here, but pulsing certainly does work advantageously in many ways...
I am no road bike cyclist, because I am stuck in the past(xc biker) and I use my old school ht from 2003 or 2005 with xt br785 brakes with 203 up front as ac commuter. swtiched to 203mm rotor up front because I could not stand how bad discbrakes actually were. 160mm rotors glazed my brake-pads very often, even at 203 it was quite common. So I switched to sintered pads and it actually did make a difference but still not as good braking perf as old school v-brakes, especially in combination with ceramic coated rims.
My work college is still a proper xc biker and tested my bike and said it had the best brakes he ever tried, well I have to say that bikers know absolutely nothing about brakes in that case. I still consider my brakes to perform very poorly. Try a motorcycle and see how good they brake or simply a bike with v-brakes :P
to get proper disc brakes we need thicker rotors.
All rotor sizes are probably totally safe and functional when it comes to stopping performance, but as a 90ish kg rider myself I'd probably go with a 180 mm just to avoid disc warp/rub. Disc rub is the most disappointing sound and I hate it
I wish they had discussed about the warping being often more prevalent on the larger rotors by comparison (usually due to just larger distance from the center axis).
My front 160mm Shimano definitely causes me considerably more grief than my rear 140mm.
Wouldn't that be down to using the front brake more?
@@SMlFFY85 how much you use the rotor, at least theoretically, shouldn't affect how much the rotor warps. It mainly warps (in the real world) because of the tight spacing along with the regular heat increase and decrease as materials expand and contract (particularly when it comes to bonded materials of different varieties like steel and aluminum). They inevitably tend to not always go back to normal dimensions (when we're talking sub-millimeter) because of these things.
From what I've read, the 140mm rotor is technically thicker by a hair than the 160mm. And since the length of the radius on the 160mm rotor is more, there's more potential for that material to get "out of true" to borrow the phrase, especially given the reduced thickness of the rotor. I'm luckily a smaller rider, so which diameter I use seems to largely be inconsequential, but I've considered running dual 140's to specifically avoid this issue. I pretty much never have rotor rub on my rear 140mm rotor when I have constant squealing and rub on my front 160mm rotor.
It would have been nice to see some of this mentioned in the video!
@@tmswfrkdid you ever try 140/140? How did it go?
@@thedownunderverse yeah it’s what I run now. I’m a lightweight rider, so weight isn’t an issue and I haven’t really experienced any fading.
So far my choice of SRAM rotors has been working without too much squealing, as long as they aren’t contaminated and have been bed in properly. I’ve also started using resin pads again, which I think can quiet things down a bit in some cases.
@@tmswfrk cheers for that! I’m 72kg and considering trying 140/140. Expensive test though
Yes, let’s get some glowing rotors please! Great video. I hope you had a great time in Spain!
Glad you enjoyed it!
I really hope I can easily buy those adapters
Try a Tektro Auriga Twin (a disc brake with 2 calipers on one lever, made for 3 wheel recumbent bikes) with a hub made for a rotor on each side with 220 mm rotors each
The problem with a large rotor is the extra force going through the fork, which could potentially make it fail.
They'll just make the fork heavier to compensate. People think the brakes are where the weight gain is but there is also a beefier carbon layup in the disc forks to compensate for the flex at the end where the rotors are.
@@charliedillon1400 doesn't help for an existing fork though
Please do more disc brake rotor experiments! 👍
On racing tandems you need the large disc brakes to cope with the extra weight like Ollie saw on my tandem submitted to Nice/Super nice.
My rider/bike weight is 172kg and we have blued the disc’s on a mountain descent.
On our (non-racing) tandem we use either 203mm XT(R) rotors front/rear from spring to fall or 160mm (Ultegra) during winter.
What size rotors do you use?
Correct, weight and load will be affecting factors on the conversion of kinetic to thermal energy. Increased weight and higher load transfers will require the highest efficient transfer anticipation mediums.
@@gcntech 200mm front 180mm rear
Captain/Stoker combined weight 270 lbs 123 kg we used 203mm rotors and metal pads on my road racing tandem (200 milers- 500 milers) - but I would never ride disc brakes on my solo road bike.
Having crashed and breaking my collarbone descending a hill and using 140 mm discs and 115kg I have little confidence descending hills now so on the brakes a lot more. On my new bike I wanted bigger discs but could only get 140 at time of purchase so am on the brakes a lot more due to confidence. I will definitely put bigger discs on when showing signs of wear because I worry that being a heavier rider the heat builds up quicker as braking more and will get brake fade. But I’m also 101kg now but still worry.
There are so many different brake pad formulations with copper or alloys and fiber combinations all of which will give different breaking performance's what about all that tech please .
I thought smutty innuendo died out in the 70s. It wasn’t funny then and is bordering on offensive these days. In a sport that needs to increase its appeal to all riders this is poor. Their are many fit larger riders that are over 100kg riding (will hoy is one) but this decent technical argument is lost with the inclusion of out of date clichés.
Best upgrade by streets (daylight second) for SRAM/Shimano disc is to fit Campagnolo rotors…
Can't agree more! So much more feeling and stopping powers with the Campag rotors 👍
MTB is my first sport and mixed disk brake rotor size has been around for a couple of years, however I did own a road bike as my 2nd bike (sorry GCN I flipped to a gravel bike recently) so I was really intrigued by the content of the disk brake on road bikes, maybe the pro teams will consider mixed disk brake rotors on their heavier riders or the fast descender. I think this opens a valid question in the future of the sport
Bigger rotors are better. I have 622mm discs
No, you have rim brakes and they are crap and dangerous
If only there was a way to get a larger rotor than 140, 160 or 180 on your bike OH YEAH a 622mm rotor called rim brake bike technology!
220 mm with 4 pot calipers have sufficient stopping power to rip fragile Road bike forks apart ;-)
MTB is a whole different gig.... bigger IS better if you want stopping power :-)
Gives you better disc cooling for long descents, and less lever force needed to slow the bike down
In my opinion. Which is the most important opinion. The Only good rim brakes. Have been melted down and recycled into baked been tins. I have always had a passionate hatred of rim brakes. Even that substandard tat was the only brakes you could get. As for disc size. Both my 27.5" full sus and my 29er mountain bikes have 203mm front and 180mm rear. Both have 4 pot calipers. As my hybrid on had 32mm tyres. Not the 2.3" on the full sus and 2.6" on the hard tail. My hybrid only has 180mm front and 160 rear. With 2 pot calipers.
🤘🤘 cool bike nice channel watching from Philippines
Thanks for watching!
Certainly for mountain and other offroad bikes I will always stay with disc brakes. There is just not substitute in my experience. I rode with rim brakes for YEARS and the first time I rode with a disc it was a revelation. The bike actually stopped in the heavy rain/mud and the front end felt more controllable. Not to mention my hands wouldn't tire after a long technical and cold/wet decent. For road it isn't as important but in the rain coming downhill on a long ride I'm sure it makes a difference.
140 front & rear on my Ritchey Outback. Looks sweet, have Klamper brakes so no issues! Well proportioned with my 10-42 cassette. I learned how to brake on a Beetle with 4 drum brakes😜
A big takeaway for me is how quickly they cool down. Good to know that if you are on a long descent, and you feel the brakes are getting too hot, just not braking for a relatively short period of time, of just switching back and forth between applying front and rear braking, can quickly bring the temp down considerably.
we’ll see bigger disparity if we were operating at the end of the rotors limitations. Within regular operating temps would be marginal gains.
But if it’s a heavier rider or a steeper descent the benefit of the larger rotors would be more apparent.
I'm useing caliper brakes I'm happy to be install ing a roter brake system .
Equip the motor with an infrared and drive next to the bike. Real time temperature during the descents!
Yes. Don't need to watch the video. High school physics. :)
I really like my 180 on my gravel. Brakes better and i do not run out of brake when going down hill off road around chavenage. Having said that, I cannot notice a difference between slx and XT performance…10g and £20…. SLX will be my choice when XT is worn out.
I'm a big guy, I'd rather have disc brakes than rim brakes, especially when it's wet out
Riding in uncontrolled environments and competing for far less than ego, I'm more than satisfied with disc. Rain, hail or shine.
I grew up in Washington in the 90s riding both road and mtn. Could never figure out why road took so long to adapt. I run a 160 on my road bike and 180 on my mtn.
I use Shimano XTR, 180 front and 160 rear on my 29er XC front bike
put a heavy guy and a light guy on the same rotors and see the difference at the bottom of the hill. make it a big enough hill so you can push the limits of heating up.
If you want to get disks really hot go and visit Hope Technology. They have all the kit for testing their own brakes. BTW the hill you were using wasn't nearly steep enough to get the rotors hot. You need an extended section >10%, then use one brake to hold a constant speed.
I switched from the supplied 140mm front disc Ultegra R8000, to the same in 160mm. I need much less force to brake equally, hence your idea of less wear is justified. Where I ride there are often stop lights on hills so coming to a complete stop from 70km/h was taxing on a 140mm front rotor, now seems to be less stressful!
12.5%
Much less force is merely a perception, your initial input of Force to the brake lever will be the same no matter what size rotor. Larger rotors can transfer & dissipate thermal energy. There is less fade with larger rotors thereby creating the perception that you need less force on the lever. After initial pull of the lever you need less Force to maintain the same braking power.
@@rider65 of course you need less force with a bigger rotor for the same braking power. its simple physics - bigger lever, less force required.
I have a rotor that is about 700c--rim brakes are state of the art tech.
Rim brakes for the win.
Another silly remark by somebody who is completely uninformed. A 700c rim is not a brake rotor. You're breaking surface is limited to the breaking track not the entire wheel. There is no swept area on a spoked rim. The spokes and the Hub are unable to absorb and dissipate any energy and heat. Whereas a disc rotor it's absolutely designed to do that. And is much more efficient. Physics does not care about your opinion or your feelings the fact is that a disc rotor is far more efficient and has far more performance than any rim brake. If you understood the basics of physics then you wouldn't make such a silly statements. Again the mechanical laws of physics do not care about your opinion or your feelings Fozzie Bear. Now do us a favor and pull your thumb out
...in 1980
Agree. A rim brake is after all a disc brake that uses the rim as the rotor. A rim brake probably never gets to 54C.
@@andredegraaf1643 I love rim brake! But I am curious for this experiment!
Didn't you guys just do a test where you basically drug your brakes all the way down a huge decent, and Campy even gave you the go-ahead to do it, and it turned out, nothing happened other than the rotor got hot? No system failure, nothing exploded into bits, etc. I run 140 on the road, front and rear, but of note, I have rolling terrain, and never decend for the durations you guys are by a long shot. I really want you guys to do a stop test with discs vs rim, like the one you did when Alex was riding a stoppie over and over.
Intrigued by the science here. One of the factors you need to accurately determine when using an IR temperature sensor is the emissivity of the material that you're measuring. It's pretty complex to explain but one of the best work arounds is to paint the measurement surface black and then set the emissivity value on the temperature gun to about 0.98. While the temperature matched at the beginning, incorrect emissivity values can cause dramatic variences. The temperatures seem a little low - at ~50 oC, you should be able to touch them very comfortably
Yes, I know we're not all thermal scientists here and the physics behind all of this is a snooze-fest but it might explain why all the results appeared very similar.
700c rotor crew - Rim brakes for the win in 23.
Drum brakes rule 🤘
Less heat, more surface to stop, strong enought, durable, less problems, less noises and lighter. In 2020 tour the france the 1st and 2nd were Tadej and roglic whom used rim brake.
Lol at the opening scene
Alex and Ollie are like cycling Myth Busters! Great job and would absolutely love to see rotors on a lathe.
"better"? At what metric?
"Small" discs have enough leverage to lock the brakes. Bigger discs can carry more heat because it has more material and can dissipate it easier by having more surface area. The same is true for car brakes: big brake kits are used to stave off brake fade not for stopping power, stock brakes are sized to be able to lock the brakes (hence why ABS is needed).
Force required at the lever and modulation. Softer levers are way better to use and allow way more control, allowing to get closer to the locking up point without crossing it.
I weigh a 100kg and the stopping power is very noticable for a 180mm disc. For comparison i did the test on a roadbike(140,160,180) and my downhill bike(160,180,203), both in Belgium and the alps.
That was unexpected, maybe final temperature was similar because brake pads wear faster above a certain temperature maybe 70 which means rotors reach maximum temperature maybe 75 , maybe you should repeat the experiment but with longer distance and see how worn out are the bads in each size
Having seen the difference between a 160 and a 180 mm rotor under a big guy (~150 kg) who was new to riding park and dragging only his rear brake all the way down the hill I can safely say 160 mm = boiled fluid and lever to the bars, 180 mm = a weekend of riding with only a discoloured rotor to show for it.
heat building means contact area, so the result will be the same as long as your brake pad keep the same.
so the only matter is the sharp of hole on the rotor, rider weight and rider brake practices
If the manufacturer want to change my rim brakes bikes for disc brakes fine but I'm happy with rim brakes
Love your vids
Thanks, glad you're enjoying them!
If only there were a disc, with a lever arm the same as the radius of the wheel for maximum leverage.
You need to test some MTB 220mm rotors
Weird to me is my front disc is 180 my rear disc is 140 being its mountain bike seems in better shape than front disc i ride mix terrain notice front disc squeaks a lot down steep hills while rear stays silent . maybe 2000 baby miles knee injury took me out this year so i thought maybe squeaks were cause my warm weather bike sat un used myself i'm confused at vast size difference on my bike i'm guess that folk must use front bike more on the trails guess your video left me more confused almost wanting to down size front disc
With bigger rotors being better , I wonder if someone could maybe invent real big rotors …..like maybe 700c size …. and then place the pads ,say, at the junction of the fork crown and the frame instead of at the end of a big heavy flexy fork ? Maybe it would be lighter and more aero ? Just thinking …..has this ever been done before ?
Great job though guys in trying to keep a straight face all through this 😊
Is the helmet needed to take the temp of the rotor, or is it more a fashion thing?
The margin of error is too great: Alex can NOT brake EXACTLY consistently on each run! He is braking on FEEL!
I ride a very roadbike-esque city bike (700C, no suspension, Tiagra all around) and I regularly tow my twins in a trailer. About 45kg for the whole lot (trailer and kids) switching from 140 to 160 made a significant feelable differece. At least in terms of stopping power and distance.
If you have the clearance, go to a 180 disc. The difference in stopping power is ludicrous.
The weight of the rider and a more controlled scenario of constant breaking would give a better result. Also using a FLIR camera would give a good insight of the heat buildup and heat disapation
13:06 Glowing Rotors sounds like the name of a band. I wonder if they can get a No.1 single one day?
Do the same on a downhill MTB 😄
You found the Giorgione - Giorgio Brambilla - rotors! 200mm for shure
Measuring heat with infrared sensor on a metal is VERY inaccurate. Most of the reading will be the reflected infrared emission of the surrounding enviroment and since it is even a polished material it won't even be the average of it but dependant of the angle how you hold the tool and the angle of the brake disc too.
Statements & Questions... Statements: 1. Larger discs provide more leverage, more surface area for heat dissipation, AND, more mass for Heat Soak... 2. Added leverage requires less force on the brake lever for the same amount of brake braking power(as a smaller rotor), OR more brake power for the same amount of lever force(with a larger rotor)... Questions: 1. Is using brake discs with cooling fins only a fair test? How would non finned discs perform? >.> P.S. What's that bulge on 'Not Ollie's'(I don't know his name)down tube? (I have one on MY bike - but's it's custom\I put it there) O.O & rim brakes are dead to me as their performance fades when riding in the wet(not that I condone riding in the wet - lol)...
This was interesting since I currently have rim brakes and did not know about options for various-size rotors. My riding has lots of hills, so when I do upgrade to a carbon bike with disc brakes, I would want the largest diameter rotor that can fit on my bike. This was a valuable video!
The biggest rotor you can get are rim brakes. 622mm > 160mm
@@lincolnlu9869 220 mm Dh rotors combined with 4 pot brakes will stop every road bike
@@lincolnlu9869 luckily it's not 1986 anymore and we can use discs instead 👍
@@lincolnlu9869 true, but don't confuse that statement with having the most stopping power.
@@simonm1447 overkill really, a bikes brakes are only as good as the grip of the tyres, for MTB it makes sense but for a road bike you'd rarely be able to utilise the full power
Nope mine 140mm works fine