# Brakes for an ebike



## Francis Cebedo (Aug 1, 1996)

Given that emtbs weigh close to 50 lbs, and more importantly, they routinely descend 5000+ feet with many rider types, the brakes are stressed. Heck, I'm only 150 lbs and all my ebike rotors are discolored from heat.

Brakes are often exposed a weak link.

What's your experience with brakes? 4-piston and 220 rotors up front seem to be the ticket huh?

What's your experience and what's your favorite? Seem to be some new offerings out there:

1) Shimano 4-piston SLX, XT, XTR, Deore or Saint
2) Sram Guide, or Sram Code
3) Magura MT7
4) Hayes Dominion
5) TRP DH-R EVO

Power, modulation, reliability, ease of bleeding?

And what about the poor man's easy upgrade, brake pads? Which ones are good?


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## mtnbkrmike (Mar 26, 2015)

Guide Ts with 200 rotors front and rear are more than sufficient for my 56 pound e-fat bike sled. 

IME, 220 rotors can get warped super easily and drive you crazy with the rubbing. 200s are pushing it but so far so good.


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## DtEW (Jun 14, 2004)

I've been a long-time Hayes user on my vintage nonelectric MTBs. The best that I've experienced in that particular feel/performance class was a set of Stroker Ace calipers (monobloc 4-pistons) w/Prime master cylinders and metallic pads (I don't use organic, period).

Now on an FF eMTB ('21 Specialized Turbo Levo Comp) that came stock with SLX BR-M7120 (bolted 4-pistons, Servo-wave levers) and metallic pads. 203mm SM-RT64 rotors F/R. The feel was very different from what I was used to (see prior paragraph). I would say less modulation by force and more modulation by travel. But certainly enough power at normal riding. It was not a bad setup at all until I upped my aggression, which started warping the rotor, and really got my attention when I gas-faded the pads.

So I tried a 203mm XT rotor (RT-MT800) in the front in hopes that the "disperses heat like one size bigger" spiel was true.

(Finned N04C pads hopefully forthcoming. Hard to acquire these days.)

Hating the XT rotor so hard. It howled from Day 1. The resonant vibration makes threshhold braking impossible. Today I locked-up and washed-out the front on a rutty and moderately steep what-was-once-a-flow-switchback, only miraculous/excellent effort turned it into a still-erect recovery. Had to catch my breath and process, esp. given that I took out stitches only a couple of weeks ago.

Pretty pissed. Taking the XT rotor off and going to do some surface processing to see if it'll help.


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## Vin829 (Mar 29, 2019)

I put on a set of Shimano XTR 9120s I’m hearing the XT and SLX have the same power? If I had to do it again I’m really liking the TRP DH-R Evo brakes with a 2.3mm thick rotors


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## KRob (Jan 13, 2004)

DtEW said:


> Now on an FF eMTB ('21 Specialized Turbo Levo Comp) that came stock with SLX BR-M7120 (bolted 4-pistons, Servo-wave levers) and metallic pads. 203mm SM-RT64 rotors F/R. The feel was very different from what I was used to (see prior paragraph). I would say less modulation by force and more modulation by travel. But certainly enough power at normal riding. It was not a bad setup at all until I upped my aggression, which started warping the rotor, and really got my attention when I gas-faded the pads.
> 
> (Finned N04C pads hopefully forthcoming. Hard to acquire these days.)


I've had the same problems with my SLX brakes and stock rotors on my '21 Turbo Levo Comp. They work great (good power and modulation) but glaze and warp with longer aggressive descents then start squawking loudly.

Resurfacing the metallic pads with sand paper and cleaning the rotors with brake cleaner solves the issue for a few rides or until they heat up again.

I was thinking about switching to XT Icetech rotors and finned semi-metallic pads but sounds like that's not the solution and maybe hard to come by(?).

Sent from my iPhone using Tapatalk


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## DtEW (Jun 14, 2004)

KRob said:


> I've had the same problems with my SLX brakes and stock rotors on my '21 Turbo Levo Comp. They work great (good power and modulation) but glaze and warp with longer aggressive descents then start squawking loudly.
> 
> Resurfacing the metallic pads with sand paper and cleaning the rotors with brake cleaner solves the issue for a few rides or until they heat up again.
> 
> I was thinking about switching to XT Icetech rotors and finned semi-metallic pads but sounds like that's not the solution and maybe hard to come by(?).


Well, I can only really attest to my own problems with the RT-MT800; I dare not say that my problem is definitive. But odds are, they might be more applicable to you since we're basically using them on the same setup (unless you've already made significant mods), and for the same reasons through the same progression of usage. When the weather clears up (we're in a storm pattern for a few days), I'm going to try the old SM-RT64 rotor again just to eliminate the possibility of the problem being some change in the D02S (stock) pads. It'll still warp and the pads will outgas when pushed hard enough, but it should be a different problem and not howl, at least not howl in the say way the XT's are.

It seems like the RT-MT800 rotors in 203mm are now hard to come-by. When I ordered the pair last month, I had to get it from overseas. The N04C pads still seem to be somewhat available though (I have two pairs coming from The Lost Co.; last I checked they were also available from Universal Cycles)... but supplies seem to be diminishing. I am leaving in-place a backorder made last month at Nashbar for another two pairs to see if they will ever make good on it.

(I might have mentioned this elsewhere, but the only reason I might appear to be aggressively stocking-up on supplies is because I am doing so for two '21 Levo Comps in the family.)

Update: Found out this past weekend it's not (solely) the RT-M800's fault. Found out when I swapped back the original SM-RT64, which now howled (albeit not as vigorously) where it didn't before. Pads will be the next test.


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## Francis Cebedo (Aug 1, 1996)

My favorite brakes were the Shimano XT 4-piston and Shimano SLX 4-piston. They brake so hard and I can modulate very well since they are soooo consistent. 6 months later too, they feel the same without a bleed. Quiet too.

I've tried to convert all my bikes to these brakes but they haven't been available at Jenson, QBP, BTI in the last year.

I just got the Canyon CF9 with Shimano XTR 4-piston. New looking 203 rotors. Holy moly, they make my eyes bleed. Insanely good. Probably unobtainable too.

Most of the bikes/ebikes I have use Sram Guides or Codes with 200 or 220 rotors. They are ok but they are truly the weak link on these bikes with regular rides with big descents.


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## RickBullottaPA (Mar 4, 2015)

Much ado about nothing maybe? The "e" adds about 20 lbs to the bike. Rider weight(s) vary by 120 lbs. Current eMTBs are in the same range as DH bikes from a while back. I certainly don't see the need for any eBike specific brakes. I had no issues with my 48 pound eMTB and my 170 pound self with a 203 in front and a 180 in back, with 4 piston Shimanos.


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## Francis Cebedo (Aug 1, 1996)

RickBullottaPA said:


> Much ado about nothing maybe? The "e" adds about 20 lbs to the bike. Rider weight(s) vary by 120 lbs. Current eMTBs are in the same range as DH bikes from a while back. I certainly don't see the need for any eBike specific brakes. I had no issues with my 48 pound eMTB and my 170 pound self with a 203 in front and a 180 in back, with 4 piston Shimanos.


So here's what I'm experiencing:

1) 20+ lbs on a bike makes a bigger difference than 20 lbs on the body - The reason is the body is weight that you can move with you on the downhills. You can weight, unweight, load-unload on jumps, corners, steeps. Some folks say that 20 lbs extra on the bike are like 40 lbs extra on the body.

2) On the ebike, one tends to do longer and steeper descents. Big folks too. Hear me out here. On an analog bike, a 200 lb rider is not likely to go up a 15% grade, 3000-foot climb then descent. On an ebike however, it is done. Not just occasionally but ride after ride. If one has the terrain for it, even 4000-5000 foot descents are brake fodder. So it does stress out brakes.

For some, if they don't have the big, steep hills, brakes make no difference perhaps. But to many, they are exposed.

Your 4-piston Shimanos are some of the most powerful around. If you were on 2 piston Avids, or even 4-piston Guides, it's a different world of squishy, boiling, screaming, charred brakes.


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## RickBullottaPA (Mar 4, 2015)

Francis Cebedo said:


> So here's what I'm experiencing:
> 
> 1) 20+ lbs on a bike makes a bigger difference than 20 lbs on the body - The reason is the body is weight that you can move with you on the downhills. You can weight, unweight, load-unload on jumps, corners, steeps. Some folks say that 20 lbs extra on the bike are like 40 lbs extra on the body.
> 
> ...


I agree. But I guess what I'm saying is that we shouldn't fall into the "eMTB-specific parts" trap - we have plenty of strong brake options already (and forks, and wheels, etc.). The one area where there is definitely a need for sturdier spec parts is with the freehubs on eMTBs - many aluminum freehub bodies can't stand up to the extra load. I would like to see more hub manufacturers offer steel freehub body options.


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## DtEW (Jun 14, 2004)

RickBullottaPA said:


> The one area where there is definitely a need for sturdier spec parts is with the freehubs on eMTBs - many aluminum freehub bodies can't stand up to the extra load. I would like to see more hub manufacturers offer steel freehub body options.


I'll apologize for deviating away from the original thread topic temporarily, but you just happen to hit something that's been on my mind waiting to be let out.

I had for the longest time stared warily at the hubs that came on my '21 Levo Comps, wondering why they weren't the "blue steel" M71XX-series hubs that would have matched the otherwise complete grouppos. I decided they were a cost-cutting measure, as per many less-conspicuous components that comes on full bikes.

Until deep-diving revealed that the FH-MT510-B is actually a Shimano-kosher alternative to the M71XX freehub (there is a flowchart out there). That led to curiosity as to the exact difference between the FH-MT510-B and the FH-M7110-B. This took deeper-diving, but what that revealed was that the former has a steel freewheel body with traditional pawls, while the latter has an aluminum freehub body with the "Sylence"-derived drive.

Can't comment on which drive-engagement design is actually stronger... but at least in terms of the freewheel body, Specialized is obviously paying attention.


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## ziscwg (May 18, 2007)

I like the modulation of the Codes, but hate the upkeep on them. (Piston cleans, pressure balancing, uneven piston movement). The stock pads/rotors suck. Magura rotors with Disco Kevlar pads are just way better.

The Shimano 4 pots were nice, but I never felt they modulated very well. Maybe bad user technique, but the rotors did not stay true very long.

For my brake upgrade, I was thinking of the Magura MT7 or the TRP DH-r evo. 

My concern with the MT7 is how fragile the lever threads are. Also, bleeding is more complicated (than shimano)

My concern (minor) with TRP is the lack of a bite point adjustment. Also, pad availability. I have heard the pads are the same as shimano


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## KRob (Jan 13, 2004)

DtEW said:


> Update: Found out this past weekend it's not (solely) the RT-M800's fault. Found out when I swapped back the original SM-RT64, which now howled (albeit not as vigorously) where it didn't before. Pads will be the next test.


Yes, I'm still using stock configuration. What pads are you thinking of trying? Different material? Whole different brand?


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## KRob (Jan 13, 2004)

Francis Cebedo said:


> My favorite brakes were the Shimano XT 4-piston and Shimano SLX 4-piston. They brake so hard and I can modulate very well since they are soooo consistent. 6 months later too, they feel the same without a bleed. Quiet too.
> 
> I've tried to convert all my bikes to these brakes but they haven't been available at Jenson, QBP, BTI in the last year.
> 
> I just got the Canyon CF9 with Shimano XTR 4-piston. New looking 203 rotors. Holy moly, they make my eyes bleed. Insanely good. Probably unobtainable too.


Any trouble with the rotors glazing then howling ( and losing braking grip once the pads get coated) with either your SLX set ups or the newer XTR with IceTech rotors, Francis? 
As stated above, I also have the SLX four piston on my 2021 Turbo Levo Comp which I like except the glazing and howling. I've run XT brakes for years and have never had this problem.

Also, I agree with you on the added strain/stress on the brakes with eBikes. When I do an eBike ride I'll easily do twice as much climbing and twice as much descending on a given 1-2 hr ride and on really steep sections I can feel the brakes working harder and it takes more lever pressure to get the same stopping power. FWIW, I weigh 160, maybe 170 geared up.


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## DtEW (Jun 14, 2004)

KRob said:


> Yes, I'm still using stock configuration. What pads are you thinking of trying? Different material? Whole different brand?


Well, my Shimano N04C (finned metallic) pads are coming tomorrow, so I'm going to try those. So fresh pads + the other (pristine) RT-MT800 I have lying about. This is pretty much a test of bedding-in, and my problems maybe being due to "errors" in that. If that turns out to solve the problem, then I'll see if the first (howling) RT-MT800 rotor and/or the stock (howling) D02S pads can be rehabilitated somehow.

Aside: the significant other's front SLX BR-M7120 + D02S + SM-RT64 has also started howling as of the last ride. And she babies her brakes. So I'm doubly-motivated to get to the bottom of this issue.


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## Francis Cebedo (Aug 1, 1996)

One of the really cool things about ebikes is bedding in brakes. It can be done quickly, easily, consistently. Brand new brakes, just put it in turbo mode. Get up to 20 mph, Slam on the brakes. Repeat 10x. Can even slam on the brakes and keep pedaling just to mix it up. The difference after just a few minutes is oh, so good.


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## KRob (Jan 13, 2004)

Francis Cebedo said:


> One of the really cool things about ebikes is bedding in brakes. It can be done quickly, easily, consistently. Brand new brakes, just put it in turbo mode. Get up to 20 mph, Slam on the brakes. Repeat 10x. Can even slam on the brakes and keep pedaling just to mix it up. The difference after just a few minutes is oh, so good.


I wonder if not bedding these pads in correctly has something to do with issues I'm having. It's my wife's bike and the first several rides were gentle road/bike path rides with gentle braking.

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## scatterbrained (Mar 11, 2008)

RickBullottaPA said:


> Much ado about nothing maybe? The "e" adds about 20 lbs to the bike. Rider weight(s) vary by 120 lbs. Current eMTBs are in the same range as DH bikes from a while back. I certainly don't see the need for any eBike specific brakes. I had no issues with my 48 pound eMTB and my 170 pound self with a 203 in front and a 180 in back, with 4 piston Shimanos.


I kinda agree here. Granted I believe anything with 29" wheels should be coming with at least 200mm rotors front and rear anyway, but that's just me. The difference in weight between my trail bruiser and my e-bike is about the difference in my weight from holiday season to riding season.  
.
.
Funny thing, I'm looking to get a 220 rotor for my regular bike, but I haven't even considered it for my e-bike.


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## cb750stu (Oct 1, 2019)

Francis Cebedo said:


> My favorite brakes were the Shimano XT 4-piston and Shimano SLX 4-piston. They brake so hard and I can modulate very well since they are soooo consistent. 6 months later too, they feel the same without a bleed. Quiet too.
> 
> I've tried to convert all my bikes to these brakes but they haven't been available at Jenson, QBP, BTI in the last year.
> 
> ...


Nice canyon  can I be cheeky and ask what size you went for and how tall / inseam you are

Regards Stuart

Sent from my CPH2009 using Tapatalk


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## Francis Cebedo (Aug 1, 1996)

cb750stu said:


> Nice canyon  can I be cheeky and ask what size you went for and how tall / inseam you are
> 
> Regards Stuart
> 
> Sent from my CPH2009 using Tapatalk


Yes, I'm 5'7", 30" inseam and I like a 450mm reach these days on All Mountain bikes with a 35mm stem.

I went with a Medium and it is perfect. The bike is pretty long and it runs big. So much so that they advice Medium in their size calculator for folks six feet tall.

The reason their bikes feel big is two-fold. One, is they have a 74.5 degree seat angle. So it puts you back there compared to modern bikes with similar reach. The longer the inseam, the more you're back there.

Second reason is they have a funky stem. that looks like a 30mm stem but it's actually equivalent to about a 50mm stem since it shoots forward, then back. This stem is not easy to change since it has all the wires inside.


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## Francis Cebedo (Aug 1, 1996)

KRob said:


> I wonder if not bedding these pads in correctly has something to do with issues I'm having. It's my wife's bike and the first several rides were gentle road/bike path rides with gentle braking.
> 
> Sent from my iPhone using Tapatalk


Probably. Worth a try for sure. Sand them down and do a proper bedding in. process.


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## Jack7782 (Jan 1, 2009)

Francis Cebedo said:


> I went with a Medium and it is perfect. The bike is pretty long and it runs big.


I am 5-9 with 31 inseam and I bought a Medium Spectral 7.0 which pretty much fits me fine. What annoys me is the OEM dropper is 1 inch too high for me (in the up position) so I am always manually adjusting it to get it right. I need to do an upgrade here.


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## Francis Cebedo (Aug 1, 1996)

Jack7782 said:


> I am 5-9 with 31 inseam and I bought a Medium Spectral 7.0 which pretty much fits me fine. What annoys me is the OEM dropper is 1 inch too high for me (in the up position) so I am always manually adjusting it to get it right. I need to do an upgrade here.


Yeah, change that. Quality of life/ride will increase significantly. Get a OneUP components dropper. It has a low stack height so you can use a longer drop. And the up position is adjustable with spacers.


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## _CJ (May 1, 2014)

Brakes are over-rated, and you especially don't need "special" brakes for the extra 20 pounds of motor and battery on an e-bike. If you're bluing your rotors, or otherwise wearing your brakes in some abnormal way, it's your riding style that's the problem, not the brakes.

The 160mm single pot Tektro brakes on my analog bike work just fine. The 180/220 Hayes brakes on my eMTB are total overkill, and I'm 210 pounds. 


.


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## Francis Cebedo (Aug 1, 1996)

_CJ said:


> Brakes are over-rated, and you especially don't need "special" brakes for the extra 20 pounds of motor and battery on an e-bike. If you're bluing your rotors, or otherwise wearing your brakes in some abnormal way, it's your riding style that's the problem, not the brakes.
> 
> The 160mm single pot Tektro brakes on my analog bike work just fine. The 180/220 Hayes brakes on my eMTB are total overkill, and I'm 210 pounds.


Could not disagree more unfortunately. But it sounds like you don't need anything different and that's fine.

I'm 150 lbs and all my rotors now are blackened. The bikes are heavy and the fact that it's not body weight makes a difference. But more important, folks are doing bigger, steeper descents of 3000-5000 feet in one shot.

And i think it's ok to discuss strong brake options for those that need them or looking for better performance.


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## Varaxis (Mar 16, 2010)

I got along fine with M8000 2-piston Shimanos for 3 years with a 55 lb emtb (150 lb rider inc gear), riding mostly 4x4 and moto trails, which get more beat-up, eroded, and steeper than mtb trails. The erosion makes 'em both technically narrower and more technical than singletrack.










I'd consider the BR-MT520 the best bang for buck if I were in the US. I'd consider the Tektro DH brakes if I wanted to spend.


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## DtEW (Jun 14, 2004)

_CJ said:


> If you're bluing your rotors, or otherwise wearing your brakes in some abnormal way, _it's your riding style that's the problem_, not the brakes.


This obviously dips deep into the, "you're not having fun correctly," chamber pot of nonsense.


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