Does Braking Power Matter On Mountain Bikes? | GMBN Tech Does Science
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- Опубликовано: 28 июл 2024
- Braking is vital on a mountain bike! We all love going fast, but reliability, consistency and the power of our brakes is one thing that we do not take for granted. How much braking power do you need is one of the most frequently asked questions here on GMBN Tech, so Doddy strapped on a telemetry system (big thanks to Steve, @suspension_doctor ) and grabbed a few pairs of Magura brakes in the hills of Malaga to put the question to bed once and for all.
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⏰ Timestamps 👇
0:00 - Intro
1:54 - Telemetry System Explained
4:22 - The Trail
7:14 - 1 Pot Brakes - 180mm Rotors
9:03 - 2 Pot Brakes - 180mm Rotors
11:01 - 1 Pot Brakes - 220mm Rotors
13:18 - 2 Pot Brakes - 220mm Rotors
14:53 - Telemetry Analysis
22:35. - Conclusions
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85kg kitted up - running 4 pot Maguras on 220mm rotors F&R on my 180mm enduro bike. Its not just about power & modulation for me, the reduced hand effort required also helps reduce fatigue/arm pump, especially when combined with a near flat lever position.
Couldn’t agree more.
I have 220's and Hayes on mine, lots of really steep stuff here in the Rockies, reduced hand pressure is really nice, better modulation too. Another magazine did testing and every 20mm of rotor adds approx. 17% more power to the system, people on the internet who lived in flatter areas and are light weight riders will swear up and down all day that 180 is the most you'd ever need. Also 2vs4vs6 is not as important as master cylinder fluid movement and size\compound of brake pads, caliper size\more larger pistons helps reduce heat on long descents.
near flat lever position? what a madman. one of the best things I ever did was point the brakes almost to the ground. maybe 65-70 degrees off level
@@berengerchristy6256 Same thing for me, startet of with an almost flat position and now about 30-40°. Helped my hands more than anything, but everyone is different i guess.
I'm a flat lever person myself, on downhills the hand position straightens out your wrist for #1 control
I've used everything from old school bmx calipers to cantilevers, v-brakes, cheap mechanical discs, BB5's, BB7's, various Shimano Acera , Deore and Saint and discs from 160mm to 203mm. I don't recall ever once thinking, "man, these brakes are just too powerful," but there have been plenty of times that I've thought, "these things suck. I need something better." That was particularly true of certain caliper and cheap mechanical discs.
Try the Trickstuff Maxima if you ever get the chance. Grippy tires on hard ground mught get you to think "too much!"
Been on many braking systems over the years, especially coming from a motocross back ground. My biggest problem is my size I'm 6' 3" tall I'm nearly a 1 metre wide and single tracks can cause some skill control but it's my weight 120 kilo's or 295 pounds I not over weight it's all muscle be an athlete for 45 years. It is hard for anyone that weighs 70 kilo's compared to 120 kilo's your brakes are your life having great feed back no fade and braking under load for me takes a mechanic a while to dial in and really needs to be on the trails observing and applying there knowledge to how I'm going to feel composed and confident.
Apparently bike companies think they are the least important component. They always spec breaks 3-4 levels below everything else
I consider my brakes to be one of the most (if not the most) important components of my MTB. During my MTB "career" I have broken a couple of ribs at 2 occasions. I am pretty sure that without decent brakes I would have had many more injuries.
me too i broken ribs twice one of the times was directly due to very poor brakes to remedy i got some Hayes dominions a2 on the front with 203mm rotor a4 on rear with 180 best brakes in the world as far as im concerned
100 kg rider- Shimano 8120 4 pots. 203 fr 180 rr Icetech rotors. Metallic pads in the summer for enduro racing and park days. Resin pads in the winter for trail riding locally.
one remark: the way you measured the temperature of the rotor is completely flawed. non-contact infrared measurements (like we saw in the clip) are not to be done to shiny metal surfaces because these act as temperature mirrors and you end up measuring reflected temperature not the metal itself. normally the measured value needs to be compensated by a value of emissivity, but in the case of break rotors it would vary a lot based on dust or oxidation deposition or surface texture (grooves). it would be much safer if you measure rotors with a contact measurement method - for instance with a thermocouple. just make sure that the sensor is small and that you can keep it in contact with the rotor enough time so that the sensor's temperature reaches equilibrium with the rotor.
Cheers for pointing this out! Something I was not aware of, but definitely something to look into for future experiments! Since I was using the same method/equipment for every run I came away with pretty consistent results from each run. Something I'd like to do more experimenting on a longer, grippier track
Would be interesting to know if different brake pad types has an effect too on stopping performance and heat dissipation. Metal vs. resin, vs. other.
Buy MTXs Your Welcome
Great video! I think one of the variables left out of the experiment is the levers. You didn't like the carbon levers because of the feedback you perceived. Since the premise of the experiment was 2 vs 4 pot brakes keeping the same lever for both sets would have been a better comparison.
Underwhelming Brakes Are Dangerous .
Its just not only the power but feel. I have big rotor 4pot brakes on my daily full suspension ebike just for the extra feel. Having been used to braking hard and fast with really sensitive brakes. That setup allows me to be mm accurate on braking. The feel doesn't change from one stop to another and I have been saved by that more times than I can count. It's always better to have some extra power than minimum needed. Always start upgrading with tires and brakes.
@@R-Dub-Ya both ways are correct.
@@RealMTBAddict Brakes have cylinders aka pots where the pistons go... In hydraulic disc brakes the cylinders aka pots are pressurised by hydraulic fluid and push the piston towards the disc squeezing it bet ween brakepads creating friction aka stopping power. Pot is more of a street term but still correct.
@@RealMTBAddict you're really talking out your ass now aren't you... pistons move the brake pads, not the caliper. And 4 pot is as correct as 4 piston
Pure power ain’t my goal.
I’m enjoying a good modulation much more.
203mm 4 pot up front, 180mm 2 pot in the rear.
I was riding a Code R 200mm front and rear on my 11kg XC bike.
THAT was overkill! 🤣🤙🏼
I have tried for a start changing to big rotors (F 203 / R 180) and, using two pistons calipers. But, it became extreme strong and I felt difficulty to modulate in the trails as well as in the urban use (I keep two different sets of wheel-tyres to allow me one bike for both conditions). Then, I found the perfect setup for my hardtail: both 4 pistons calipers & F 180 / R 160 discs that I am running for years
As a dealer and mechanic, the first step I always recommend is to move to larger rotors, if compatible with the frame and fork. As this is the first and cheapest upgrade. If then actually still more brake power is needed: better, higher quality brake system, up to 4 cup.
This is the same way I have gone so far myself and now have on my Nomad V4 f+ r 4 cups with 203 mm rotors and it feels wonderful! Yes, devil me! I have XT levers with MT5 calipers because that is definitely positive and noticeable how the brake acts. Arm pump? What is that??? Of course, one must not forget, the higher the quality of the system and the more advanced in the technique, the more senseless becomes a Shigura, which it feels the XT definitely already very great.
To that power comes certainly only the Direstissima and even more so the Maxima.
In conclusion: Especially when it comes to long and hard rides, the "overly strong" brake system is your greatest friend!
210lbs in dry SoCal on a Chameleon hardtail. I like 180/180 Shimano 8100 2 pots front and rear with Shimano resin pads. My 20 mile rides have 2,800-3,100 feet of elevation with a lot of sketchy off camber steep (but short) descents and my system is perfect. I've tried 4 pot Shimanos front and rear and the only difference between them and the 2 pots is the constant fiddling with the 4 pistons needing maintenance due to rotor rub and all of them retracting differently. The 2 pistons need nothing between pad changes.
Best advice I was ever given when I was racing cars was "if you want to go faster, get better brakes". I'm not a small guy, 225lbs or so, and I run the setup you finished with, Doddy. MT7 4 piston and the 220/200 rotors. Not because I feel like I "need" that much, but because it takes a much less brutish grip on the brake lever and my hands don't fatigue really at all anymore. Much like auto racing, it allows me to brake later and for shorter periods and still control my speed.
We've heard that before too! Nice one though, sounds like you've taken the time to dial in your setup 🤘
Im 80kg, i ride a Transition Sentinel 2018, i got Deore XT 4 pistons, front 203mm and rear 180mm. Sometimes i feel like i"d rather have some more front power but most of the time im totally ok with it. Cool video... 🤘🏼
I would also like to add, good breaks are ride comfort. 😉
nice! I just got a v2 sentinel myself, and use to run a v1 with code r's. personally I grew to like sram brakes, I have 4 pot xt's on my other bike and it's kind of lacking compared to my code rscs on the new sentinel. I'd sell em on marketplace and upgrade if you can. MTX gold brake pads also help a lottt
I think a run down that hill with a set of cantilever brakes Vs V brakes Vs disc brakes would be a fun video.
Sounds like a job for Blake.
Sounds like fun, but there would be a lot of variables there such as bike type! Maybe something for the future though :)
Yes!! I have lots of bikes with lots of different brake technologies. Outside of wet / muddy conditions and extended downhills, I don't feel held back by 30 year old technology. I'm no Gee Atherton, but I'm not slow either.
Braking power is important but modulation is what separates average brakes with top end brakes. I had the rim hydro Maguras back in the day and now run the MT8SL. The power is insane as is the “feel”. Put on some older SRAM entry level brakes on my SS…after the 2nd ride had my LBS order me another set of Magura’s! Riding my HT at a bike park downhill at day…no fade.
Another thing I have noticed using both. Is on long descents, 4-pots reduce hand fatigue because I don’t have to pull as hard as long.
On a bike that sees long descents, I run 203/180 with 4-pot, for more XC use, 180/180 with 2 pots
On 180mm F/R with four pot XTR. The feel on the front is so much better. What I've been searching for is what happens when race braking, on the edge of traction. Bump breaking the tire loose vs grip when traction is on the edge. Feels to me like the dual pot breaks loose easier and is more reactive to the surface. Where the four is a little more a bull dog to the surface and does more what the rider is asking vs dual pot doing what the surface is asking.
Then we get into bike suspension with braking. Anti rise and how it reacts to braking. So interesting to go through this video and seem like you're on the brakes less which would allow the suspension to work better.
What I kinda of imagine here ... You are a football player crossing the line of the defense ... You have one arm holding the ball (dual pot). By instinct you may change your line, the ball may wiggle more as you bump players and others try to rip the ball out. You are closer to this edge or sorts. Now imaging crossing that line of defense with both arms holding the ball (four pot). The line instinct might feel different, less reaction to defence trying to rip the ball out.
Tech and data aside, the feedback we feel from brakes and suspension on the trail plays into the instincts when you're in "the flow".
So I know a lot of people only talk about power, there is way more going on.
Anyone else relate?
I would like to throw in one more variable which affects braking: wheel size. Presumably, as opposed to a 27.5, 29er would require larger rotors because it's exerting more leverage on the brakes. On the other hand, the speed of the rotor would be less than the smaller wheel, therefore, it could accumulate more heat (although more time to cool off...).
I'd like to see cargo/bike packing version of this, particularly with regards to sea/river-side urban cargo which tend to have steep paved descents with stops at intersections along the way, often including at and icy winter conditions where the ability to brake and speed control is extremely important. bike packing on mountain adventures is similar, especially for someone doing a lot off-trail (bush-wacking) riding
I ride a cargobike (long john style Bullitt). Yeah, it needs really significantly powerful braking that won't cook to death on downhills of any length. Not so different to tandems either.
love the geeky ways of this video. keep these coming!
That's what we do best on GMBN Tech! 👍
Hat off to all the work that went into the video! Looking forward to more deep dives into telemetry.
Switched from 180/203 Shimano MT520s to 200/200 SRAM Code RSCs, by far my favourite upgrade, combination of modulation and power is perfect, I have no troubles locking up either brake when need be. I am also running the new 2mm HS2 rotors, which make a big difference too and are super stiff! Definitely feel no need for 220s
The Codes will come alive with 220mm
@@th_js I really feel no need. They are bled super tight too, and sometimes I do lock up unintentionally. At my local trails there is an extremely high consequence rock roll into a wooden skinny, I ride this atleast 3 times a week and have witnessed many people fall after loosing traction, thanks to the lack of modulation from a 220 rotor 😂
@@reillys7981 I'm pretty sure that the size of the rotors have nothing to do with those people crashing.
@@reillys7981 If know anything about brakes then it should be harder to lock on bigger rotors.
@@reillys7981 a 220 rotor will have more modulation though....
This was AMAZING. Thanks Doddy. The telemetry provides incredible insight. The Magura engineer explained the choices for rotor size and piston selection in genius way.
Hi Will, Thanks for the support on the video! It was great to analyse the way we use brakes through the data gathered.
My Niner RKT9RDO came with the 160/180 disks and 4 pot Sram Guide R brakes, I do not race or very radical stuff and I really love the feel of the brakes, lots of modulation and braking power without the need to use much force on the lever.
When I just started out I had an MTB which handles took a lot of strength to squeeze in order for me to stop quickly. I figured 'eh, it's fine'. Boy was I wrong, riding that thing downhill was scary as shit. Tires and brakes are now the most important thing for me
We think everyone is guilty of that (including ourselves). Sometimes you don't realise how bad your brakes are because you're so used to the feeling of them.
116 kg on Turbo Levo - 220mm rotors, Magura MT7 brakes with HC3 levers. What I really enjoy with 220mm rotors on the rear is that I can just use the rear brake to control the speed on moderate trails, leaving the the fork to the job not being affected by brake dive. I never had that luxury on other brake setups I had previously. HC3 levers are another setup dimensions - love them and regularly adjust the brake feel depending on the conditions.
yeah and its awesome innit that you can also control the brake leverage ratio with hc3, something no other brake can do afaik...
@@jimi272 Yeah, I am considering upgrading my stock SRAM code RS to MT7 and HC3 levers and MDR-P rotors as the adjustability looks awesome.
Happy choosing this year my upgrade correctly. 4pot with 180mm front and rear. Seems that works perfect, I am getting all the needed modulation and being also able to lock up when is needed.
75kgs full gear and running 203 upfront and 180 outback with a 4 pot system for both. In Western Australia with pea gravel, I like to have control without locking up since pea gravel is slippery whatever conditions, wet, dry, etc. I found 180 upfront, I got brake fade towards the end of my runs so I went bigger rotors first but then found needed the extra so I wasn't working the brakes so hard on a 2 pot system. So then I went with a 4 pot.
Awesome video,it covers everything and almost all rotor sizes,nice video music to.I think it's one of your best ones yet.Safe riding.💯✌👌💪
Lots of good info to put to use. I'm currently using 180mm rear 203 front, 4 piston calipers front and rear.
90kg rider, running MT7 brakes with race pad and Loic Bruni levers ( the levers makes huge difference ) + 223 galfer rotors ( the Magura’s 220 floating started rattling after a while , so they are off the bike ). Now I am finally satisfied with the braking performance and feel much more confident.
Great to hear you've found what works for you Georgi :)
165 pound kitted up, Trek Remedy 150/140mm travel, advanced rider, Magura MT7, 203/180 rotor front/back. I was a motorcycle road racer in my younger days. I like powerful brakes with strong initial bite and good modulation with a solid lever feel. I run the 203 up front to keep the brake feel consistent throughout the run.
Just put Magura trail sport brakes on my Fuel EX 5 trail bike and what a difference!!! (From Shimano old Deore/m200)
Words can't describe the powerful feel of 4pot brakes vs 2.
It's not what I expected, it is much more controlled...like trying to grab a spinning wheel with 2 hands vs 1.
Haven't had a chance to test at the black trail head but can't wait for spring.
I'm going to be so fast this season.
I have TRP Trail EVO 203/front and 180/rear on my specialized enduro bike. Good enough power for me.
Great content, as usual! Thanks for trying out each particular set up, very informative.
Glad you enjoyed it!
140kg kitted up - running Magura MRD-P 220/200 F&R with set of MT5 with a combination of Race organic and Race metal brakepads. Running 4+4 brake pads makes all the difference in maximing stopping power without losing modulation.
On my enduro bike running 200/180 hope floating rotor up to hope tech 3 e4 breaks love them and works for me
Great setup, Stuart! 200/180 is a brilliant setup for enduro! 👍
You took the shuttle van from Rich! Poor guy! He had to pedal up that hill 8 times in three hours 😂😂
Priorities! 😂🤫
I REALLY appreciated this video… I enjoy seeing the data and especially the charts while riding along.
More of this please!
More to come Nikolis!
Interesting video Dody. I used to run 203/180 with old one pot avid elixir calipers and never had to little brake power but bad modulation though. Now on my new bike I’m running the MT7 with 203 front and rear and modulation feels great but I’m locking up my rear wheel much easier especially in loose terrain. Overall feel is way better though.
Running 4 pot Shimano SLX with 203/180mm rotors and metallic pads. Aggressive for a 130/120mm trail bike but is confidence inspiring.
Not really agressive at all.
This is great news for me. I just put on a set of G2s with 200/180 rotors front and rear on my trail bike. I wasn’t sure whether this was right for me (haven’t ridden 4 pot brakes before). And there’s a couple feet of snow outside right now so I have to wait until spring. But the way he’s describing the performance is exactly what I’m hoping for and that run looks like exactly what I ride.
Intresting because I have a similar setup here in the costa blanca in spain, a MT5 4 pot f/r and the big 220f and 203r. These brakes I bought for my ebike, and when I sold my ebike and build up my enduro I had these breaks. It's a massif amount of stopping power. To save weight I will reduce the rotors when they wear out to 203 front, I do like the foating magura disc. Takes heat super wel. And at the back I keep the 203, but will go to a normal lighter rotor type. The magura brakes are a bit of a pain to bleed and set up, but have good power and progressive feel. A very good product for steep loose rocky downhill.
I’m running 203’s with SLX 4 pot on my Levo and not only have serious brake fade on the front but also considerable rotor warping in which does dissipate with time once it cools. Due to the appreciation of modulation that the SLX have, but considering I’m weighing in at 210 lbs fully kited out on a 54 lbs e-mtb, I’ve ordered in a SRAM 220 centre lock for the front which is going to both increase the power but also being 2mm thickness should assist with heat dissipation. Yes, I would have chosen a Shimano Ice Tech rotor to match up better but don’t want to wait the 4+ months due to supply chain issues.
Great video, love the insight it provides! Personally I weigh about the same as Doddy and my benchmark even for trail riding always was my DH ride, so despite the weight penalty I always use big rotors and big brakes.
Helps with fatigue and arm pump, one finger braking is possible (most of the time)
One big factor not discussed here is brake feel/modulation of different brakes and lever ergonomics
I used to love Hopes but over the years my preferences shifted, now I prefer Trickstuff.
Regarding temperature management of the brakes, I've had my own issues and did some research. Definitely the type of oil used in the brakes determines their thermal response. Mineral oil has a lower boiling point than synthetic oil, and therefore it is key to how temperature must be managed. Synthetic oil, on the contrary can run at higher temperatures and therefore other parts of the braking system will have a more determining effect.
For mineral oil brakes everything is about avoiding heat to reach the oil in the pots. Heat is generated by the friction between the rotors and the brake pads. And it is transmitted by conduction as these two elements increase their temperature. The path for heat to reach the oil is: brake pads -> brake pad plates -> pistons -> oil
One easy way to avoid the heat to reach the oil is by using radiator fins built-in the brake pad plates.
This is a much cheaper and effective solution than changing the calipers. Increasing the size of the calipers increases de mass that is to be heated (and its temperature increased) in order to transmit the heat to the oil. Therefore it is like increasing the heat buffer that the brakes can absorb before failing. Therefore it is just a matter of increasing the descend altitude to make them fail.
On the other hand, using radiator fins lowers the working temperature of the brakes and diverts the heat away from the oil.
Temperature management at the brake rotors is a completely different thing. The rotors also draw heat away from the contact with the brake pads, so improving the sink of heat at the rotors can also benefit the oil. But temperature management at the rotors is more related to disc warping due to temperature differences between the braking track and the inner surfaces of the rotor. In order to effectively reduce temperature gradients and the stresses they cause, floating track brake rotors have been invented. These uncouple the temperature differences from the strain differences in the rotor avoiding the warping of the rotor.
But if we want the rotor to contribute as a heat sink, then there is the option of using an advanced sandwich brake track with steel used for the braking surfaces, and aluminium used in the center to draw the heat away more effectively towards the spokes of the rotor. There are models which in addition have built-in wavy-ish fins on the inner part of the brake tracks in order to improve further that function.
Again, increasing the size of the rotors -temperature-wise- will only increase the heat buffer of the rotor. It will also marginally increase its function as a heat sink thanks to the larger perimeter of the brake track radiating to the outside air. But the main benefit of increasing the size of the rotors is increasing the outright braking power.
Increasing the outright braking power has many benefits. When braking, we want to slow down as quickly as possible even if we carry a lot of momentum. No matter how we look at it, the brakes must dissipate that momentum in the form of heat.
The brakes must produce a torque much greater than that of the friction of the contact of the wheels with the ground, in order to slow down the wheel's rotation. That is, without locking the wheel before stopping the bike! If your brakes are capable of locking your wheels even at high speeds, you're in trouble. You don't want that. But if you feel that your braking distances are too long, then you need to increase your braking power. By increasing the rotor's diameter you are increasing the torque exerted by your calipers on the wheel. Going from 160mm to 220mm means a 37,5% increase in torque. Which means that you can reduce your braking distance by that percentage, applying the same force on the brakes. But the overall heat dissipated will be the same in less time, because the brake tracks are further from the wheel axles and therefore move a 37,5% faster, which increases the heat power production of the brakes. If the heat sink systems cannot cope with that much heat power, then you must tink on improving your heat sink systems, or add in heat buffers to your system hoping that they will be sufficient for all the situations.
And finally, by switching from 2-pot to 4-pot callipers, you are also increasing your braking power because at a given oil pressure you can produce with your brake levers, having the double of pistons (assuming they have the same diameters) you can produce the double of force on the brake pads; as force = pressure * area. But that will also increase the rate at which the brake pads wear down.
On the contrary, increasing the rotor diameter increases braking power by increasing the torque without increasing the force.
That is why it would be very interesting to explain how a 4-pot calliper improves modulation.
To me, modulation is all about the transmission of the oil pressure and how the brake levers produce that pressure, and little related to the amount of pots in the callipers.
@@RealMTBAddict as someone else said before: get over yourself dude! I said piston were I had to.
Holy shit dude. We don't need some essay.
@@ertai222 speak for yourself 😉
Fascinating video. On my FS, I'm running Shigura 4-pots with 203F/180R (I didn't much care for the flexy Magura levers). Braking power is phenomenal but, like you said, it's more on/off and trickier to modulate. I'm going to try 180 in the front and see if that will suit me better. I've also tweaked the brakes on my HT a bit: it came stock with 2-pot MT200s and ran 180F/160R. I swapped out the front caliper to an MT520 (kept the rear a 2-pot) and bumped the rotors to 203F/180R but have still yet to test them out on the trail (Canadian winters, eh?). I'm super curious now to see how the braking dynamics have changed. Again, great video!
Thanks for the information on the 4 parts an 2 parts
I have Magura MT5 ( 4 piston) with 180mm Magura Storm HC rotors on my '04 Cannondale Jekyll. Basically the same setup used during the test. I built this bike from a used frame (sadly minus the Lefty MAX 😭). I put it back together with Manitou Markhor front and the original Manitou rear. That give me 120mm /135 mm of travel. It is still does respectable on local trails considering it is 18 yrs old. I consider it proof that you don't have to have the latest and greatest tech to still ride a good performing bike. As for how well the brakes work, well the are amazing, little to no fade even under prolonged hard braking, very consistent feel under braking as well. They can be easy to lock up if you are "grabbing and stabbing" the brakes, but using good technique on modulating them prevents that. Overall, I am super happy with the combo.
Thanks Doddy for your interesting video! I'm 70kg. I ride a Scott Scale 950 hardtail, with 180mm rotors front and rear, 4 pistons Shimano SLX. I can therefore perform more powerful and precise braking tasks. I think I can also brake more modulated than with a 2 piston braking system.
I love my Magura brakes. The Hc3 is by far my favorite coupled with Mt7-4Pots. Custom disk kits and lever decals finish off my brake set. Mint!!👌
Yeah, I am considering upgrading my stock SRAM code RS to MT7 and HC3 levers and MDR-P rotors as the adjustability looks awesome.
So beautiful and informative video! Thank you! ❤
Hi very interesting, I’m running mt7 with four pot callipers and hc3 levers with 203 rotors front and rear on my allmtn e bike I’m 95 kilos after a few adjustments I’ve got them working just right for a bit of cross country and down hill stuff, the one thing I found is there is not one system fits all it’s finding out what suits you, another great presentation keep them coming.
Everyone puts a bigger rotor on front, my front pads were OK and my rears were gone. Both rotors were 200 mm. And yes I squeeze them at the same time all the time, unless it's really steep then I only use my front.
Certainly interesting info... Would be nice to calculate the area under the curves and figure out total braking input and compare that index across each run...
Be a blast to do the same test on the retro 26" rotors (i.e. rim brakes)
Super useful video! For me, it was a decision-maker when changing my brakes.
I’m about 190lbs all kitted up, riding a Epic Evo. I haven’t been quite happy with the 2-pot Level T brakes that came with it. I’m just about to install 4-pot G2 RSCs on it, keeping the same 180mm rotors. I’m hoping they are more confidence inspiring for “aggressive” XC
I upgraded my FELT Surplus 30 from Deore 2-pot 160 rear/180 front rotors - to XT 4-pot with 160 rear/180 front Ice Tech rotors. I LOVE the upgrade! I have compromised fingers and thumbs, so the easier pull, plus better modulation "feel" was huge, Plus they do not "fade" like the original Deore set up. It was well worth the investment. I am a "heavy" (OK, A FAT PIG) at 226lbs/102.5Kg, who use to race MX, so speed doesn't faze me - as long as I am incontrol, which I was not at first. Now I am in much more control, making me even faster (carrying higher speeds), as you found out in your testing.
I don't know if it makes sense, but I now have a 220mm disk out front sram code brakes, and to be honest I find that as it's bigger I don't lock the front as dont need to pull that hard as hard 😉
Yes, they are extremely important. We talk about being overbiked, or underbiked. We can also talk about is there such a thing as being over-braked? My answer is no! I will never go back to using two piston brakes again. Why would I do that? I will always opt for more power, not less!
another fantastic video doddy!
Interesting analysis. I'm running Hope E4's with 203 F and 180 R floating rotors. Recent upgrade from 180 front and rear. I find for trail / enduro riding in UK its a good set up. A nice balance between modulation and plenty of power in mud/loose terrain avoiding locking up and allowing wheels to keep turning. On harder packed surfaces speed can be scrubbed with quick dab's. Overall i've definitely noticed reduced arm pump, I don't have to pull as hard or for as long with the larger front rotor.
I used to have that setup but switched to v4 calipers with 203 front and rear, the power is insane!
Switched from SRAM Guides 203/180 to Magura MT7 203/203 - best upgrade I made so far :)
i'm doddy's size and I run 220-203 magura rotors (same combo you used in the video actually, MDR-P in 203 flavor are nowhere to be found!), 4pots SLX brakes and metallic pads (billett enduro now, but galfer purple are my favs). My local trails are similar to the one in this video. I tried 180 shimano rotors and they felt "not enough"; galfer 203 rotors, great on shorter descents but I kept cooking them on longer descents (1000m of vertical drop). now with magura rotors they're feeling perfect, no overheating issues, more than adequate braking power, my hands are less fatigued too.
Great video Doddy! Would love to see you do more telemetry tech videos in the future.. this time with suspension. Question; is it most preferable to have powerful enough brakes that will allow you to do your braking at the VERY last second before the section of trail that calls for a reduction in speed, allowing your top speed to maximize as much as possible?? Hopefully that makes sense. CHEERS
Stay tuned! Something coming your way shortly :)
Riding in coastal California, we have lots of variety, but most is similar to the riding conditions you had in the video.
95kg 6’4” rider with two bikes with 3 setups:
Mid-travel trail bike with 4 pot 203 f/180 r
Steel hardtail trail bike with 4 pot 180s f/r
Bikepacking the hardtail has 220 f/203 r due to added weight and harder braking.
68-70 kg kitted up, 180/180 4-pod/2-pod for me. Best of both worlds. And of course Magura :)
I love the power of my 4 pot XT's on 203mm rotors. I only use a single finger and it needs to be light pull.
I have MT8 Pros with 180s front and 160s rear on my trail bike and really like them - but I don't have a ton of steep hills around where I live, and certainly no long descents. Our longest are two or three minutes max.
I have 4pot and 180 rotor on my XC hardtail F&R. To most people this might be overkill but I’m 16 Stone and there is a lot of weight to slow down. Plus the 4pot appear to give better modulation (Shimano)
I use 2 pot calliper on a 180mm rotor for trail gravel and hard pack in Australia where it’s mostly dry dusty trails and all seems fine never had overheating issues 🚵♂️
Music in this episode is fire!
IMHO, get as much power as you can with your given budget. Usually most brands have roughly the same power across each type of brakes they have(i.e. 2 pot, 4 pot trail, 4 pot downhill). In almost all cases the more money you spend means the lighter the brake is, this means that if you aren’t a weight weeny you can get very powerful brakes for not too much money. A great example of this is the Magura MT Thirty. One set of them will cost you 90 usd a set, that isn’t on a sail or anything, thats full retail price. MT thirty’s are 4 pot brakes with the same calipers as the mt 7s, and actually weigh abou the same at 265 grams. Pair those up with a set of 200 mill MDR-C rotor you’ll have a brake stong enough to run only one set(which I do).
One of the best informative in layman's terms ever on mtb braking on youtube.
Just nodded all way through vid as my knowledge surpasses my saddle time currently lol damn flu fs
I'm running the Shimano SLX M7120 four pot on both my mountain bike. My Boardman FS team with 27.5" wheels and running 2.3 Maxxis Minion DHF an Aggressor rear. I run 203mm front and 180mm rear Shimano RT86 IceTech rotors. In my Orbea Laufey hardtail. I run 29x2.6 Maxxis Forkaster front and Maxxis Rekon rear. I run 180mm Shimano RT99 IceTech rotors front and rear. I also use sintered pads on both bikes all year round.
Should have tried 220m rear and 203 front. I've read this works well as the bigger rear can deal with more heat but the front is less aggressive and reduces front locking.
you get used to what ever you have eventually so id go 220 all round and just re learn the bike on a few quiet runs , im talking at least enduro style bike , super thin tyres would not cope with 220s well
Your front brake will generate far more heat than the rear, you can scrub more speed with the front brake before you lose grip compared to the rear. 220 rotors are unnecessary unless your racing purely dh or your a very heavy rider, a 220 rear rotor would lock up with minimal effort or modulation.
@@Adam-vm8kp not if you don't use it 🤣 I'm not wanting to scrub loads of speed off, generally I want to shave a small amount and I tend to use the rear for this, I also prefer the control it provides riding it slightly on steep stuff. In UK winters the front brake is the last thing you want 🤣 we all ride different ways, I just thought it'd have been a good test 👍
@@joebmtb109 I’m in the uk too buddy. 75 kilos kitted up with magura mt7 203f/180r. Eye watering stopping power but still enough modulation. Had 203 on both for a while but prefer the smaller rotor on the back.
It would be interesting to better understand how a 4-piston vs 2-piston caliper improves the modulation of the brake, taking away temperature issues.
On second thoughts, what makes a 4-pot calliper feel more modulable than a 2-pot calliper is the following:
The action of the pistons in a calliper can be broken down into 2 steps. First, the pistons have to bridge the gap between the resting position of the brake pads and the rotors. An second, the pistons increase the pressure onto the rotors as the different materials yield by the laws of elasticity.
By doubling the number of pistons in the calliper, the brakes have to pump double the amount of fluid into the callipers just to bridge the gap. In order to pump double the volume of fluid with the same lever stroke, either the piston in the lever has to travel double the distance, or have double the cross area, or a combination of both.
Once the gap is closed, the stroke remaining of the lever is diminished. Depending on the design of the lever the rider will feel more or less modulation. This depends on: how much stroke there's left, on the ratio of the motion of the lever vs the motion of the lever's piston and on the cross area of the lever's piston.
So the modularity of the brakes depends almost entirely on the design of the levers, and not so much on the amount of pots in the calliper.
Yes. More is always better. The faster you can stop the more speed you can carry before a corner or feature or poor splattered sod on the trail.
Hope 203 front and rear, Magura Trail Sport brakes running semi-sintered pads, 4 pot front, 2 pot rear.
Nice work Doddy. I'm having TRP Evo dh brakes installed at the moment and switching to tubeless.
I'm reading several comments here, and see tons of blokes giving their experiences, and so do I, well actually my weight is around 110kg, and I'm riding a hard tail with mechanical disc brakes and 160mm rotors, it seems having good braking power is key for better riding and also being safer on the road, I'm a little bit worried cause for my weight I don't know if my brakes are a little bit low
I don't ride super steep hills nor so much technical trails, but sometimes I feel like needing a bit extra bite
Thank you and cheers
A very helpful video
I've now realised it was a bit overkill to put Hope v4's with 203 vented rotors front and rear onto my orange p7, which is a hardtail.... stops me on a freaking dime though!!!
Hi doddy, personally I run 203 front and rear with 2 pots front and rear. I'm old school I like to be able to lock the rear up to let it slither for various purposes on wait for it, my old proflex 😃
Magura MT trail carbons with 180s front and rear on my Whyte 130 and upgraded the levers to the hc3 levers
I’ve got trp quadium 4 pots front and rear with 203 up front and 180 out back .
Plenty of braking for my nukeproof scout and I’m about 94kg loaded .
I use your beloved XT 8120 4 piston calipers front and rear. 203 in front, 180 in back SLX rotors. I am a 90kg rider on 15kg bike. I have confidence in my break system. I would consider upgrading the disc rotor tier when the SLXs are due for replacement.
I ungraded from 160 f/r to 180 on my Trek Farley witched helped a lot on keeping brakes consistent. Later upgraded front to 4 pot from 2 pot, gave me better modulation. Not sure if changing rear is worth it.
Thanks for another great video
Cool video! Also great new tunes
Very helpful video 👍👍
200mm/180mm Icetech Rotors + XT brakes with metal pads, only thing I'd like to try are 2mm thick galfer rotors. Otherwise perfect for even long descents for my 160mm enduro (im 67kg kitted up)
I'm a large man(heavier than Doddy) and am just getting back into riding. My original set up was 2 pot with 160mm rotors, I upgraded to 180mm rotors and still would like some more braking power. My next upgrade I think will be to go to 4 pot calipers.
I have Magura Trail Sport on my 29er hardtail. I use a 4 pot on 180 rotor in front, 2 pot 160 rotor on the rear. They are excellent brakes, great feel and enough power for a 100kg rider like myself. Value for money as well. Just be warned, Magura replacement parts aren't cheap. :)
I had a chance to upgrade to a four-pot setup with 180mm (f) and 160mm (r) rotors. Best thing I ever did considering where I live (NW Nevada), uses (mixed surface use, Long mountain road descents, urban commuting/errand runs, Bikepacking, and long day trail rides), and nice feel/modulation. I don't need to squeeze the brakes and call them George; real nice modulation and one-finger power. Have the stock alloy levers; Carbon just expensive bling with Zero benefit and more fragile to boot. [Upgrading to a 203mm on the front and 180 on the rear for Bikepacking might be valid even though, I'd worry more about the front rotor having contact with unpleasant rocks or bending in the wrong scenarios.]
I go down the car brake philosophy. These automotive companies spend millions on research. Typically a car is 70 40% between front and rear. Because of the centre of gravity shifting towards the front of the vehicle under breaking forces. This is seen when the front of the car dips when breaking. The same physics applies to cycling. Therefore it is more important to have a better braking force on the front of the bike than the back. In an extreme set up you could run discs on the front and vee on the rear to save wait. Because the wait goes to the front of the bicycle under breaking the back becomes light, why do you need to have a massive rota and four pots to just lock up the rear wheel that has no weight on it? I love breaking stuff 😂
Great experiment Doddy, but I wish you had tested 200 and 200 (or 203 and 203). My Spectral needs new rotors and I just made the decision today to upsize the rear from 180 to 200. I'm also going to SRAM HS2 rotors front and rear with Shimano XT 4-pistin calipers. Was debating hard about upsizing the front to 220, but I want to reset with 200 front and rear.
MT500 (2 pot) brakes front and rear with 203/180 RT-66 rotors. I weigh 100kg and these suit me just fine as I'm not constantly pointing down while riding!
Thanks for liking! While you're reading, how do I submit a photo of my bike for the show?
Excellent excellent study!
Glad you think so Tim! Thanks for watching :)
Ok. Part 2 of braking telemetry....Anna and Doddy (light vs heavy), in the traditional British wet and mud (Scottish mud preferably), slightly longer run to give a bit of insight into brake fade...though if temp are still around 2c, might not be too much to consider in that aspect! Part 3, throw in some different riding styles (and core discipline riders - so blake and rich maybe) and make similar comparisons including having them describe how it feels - particularly as you couldn't feel some of the difference in this test til the numbers were shown to you). Part 4 beginner, enthusiastic amateur and pro.
155lbs kitted up. I have MT7s w/203 rotors on my 160mm mullet but I still feel like the front doesn't have enough power. Gonna go up to 220 on the front. I like being able to stop on a dime.