Let's talk about brakes

[Ohbse]

Honestly I haven't had any experience with V brakes for years, however I have been through a progression of disk brakes on my pair of ebikes.

On my Specialized hardrock Initially I had Avid BB5's front and rear - these were pretty much terrible in hindsight. Somewhat scarily, I was told these were a HUGE improvement over the original specialized vbrakes by the bikes previous owner. Mechanical, prone to requiring constant adjustment, weirdly dusty and with tiny little pads. Definitely did the job, however I wouldn't recommend. I've heard much more complimentary things about their 'big brother' BB7's.

I upgraded that bike to Shimano XT hydraulic in the front with 203mm two piece rotors. Huge improvement, very confidence inspiring in comparison to the Avids. Still have those on the front of that bike and I won't be replacing them any time soon, at current rate of wear they will do 20,000km+.

My Giant DH comp originally came with a mismatched set of some random, fairly old Shimano hydraulic disks, 203mm front and rear. The rears in particular appear to have contaminated pads and just don't grip worth a damn and squeal you wouldn't believe. I replaced the fronts (that worked adequately, but not amazing) with Shimano Saint 4 pistons with the same 2 piece 203mm rotors. These things are awesome, between 140 phase amps of regen on the rear wheel and the front disk I can stop *very* quickly and probably collapse from exhaustion before I could overheat them. Accurate at all effort levels and can be modulated precisely without having to think about it.

My conclusion? Buy the best damn brakes you can afford. While there might be a price to pay if you're a 'weight weenie' on an ebike that just doesn't really matter anymore. Caliper kit, RT86 rotor and post adapter cost $172USD on special. Money well spent.

 

[flathill]

hydraulic rim brakes on carbon ceramic rims

 

[skyungjae]

You certainly opened up a can of worms. People will be arguing until the end of time which brake system is "better." :lol:

If there any doubts in your mind regarding V brakes, then perhaps you should stick with disc. Given your prospective options, I think you should try getting a handlebar riser like this:

... and a sprung seat.

It'll be cheaper, less of a hassle, less time consuming, etc...

 

[0utrider]

Hogwash. In my years as a bike mechanic, I have come across many disc brakes that worked about as well as dragging a brick on a string.

Amen!

And at the other extreme, rim brakes can dissipate more energy more quietly and sensitively than any disc brake--

And for me, rim brakes are easier to tune to my liking. Disc brakes are voodoo for me at the moment. I'm still trying to find the right adjustment to get rid of the stick/slip behavior on the front wheel which has me puzzled at the moment. I've checked and the rotor is not apparently warped. Different thickness of the rotor as it spins?

Rim brakes ARE disc brakes..

And I trust them much more than cheesy disc brakes on my Frankenstien EBike. I don't ride much in mud to say if that makes a difference but keeping the pads in shape and keeping the rims clean of gummy build up have always given me the smoothest strongest stopping power.

That being said...there is never a bad time to use Avid BB7's on the front of an E-bike.

Funny that you say so... that’s the very next upgrade for Frankie.

 

[MadRhino]

Disc brakes may not be for everyone, but when you are riding a fast ebike in all weather conditions they are a must.

Today, slushy salted streets here, another of numerous occasions that good disc brakes got me out of trouble. I am testing the Magura MT7 for the last 3 weeks, wonderful brakes for power and precision. They are on my winter commuter to see how they survive the corrosive melting agents, not so many brakes had lasted me a whole winter.

 

[crea2k]

my brakes are inadequate I have parallel push V brakes with brake boosters, because my old school carbon frame didn't have disc brake mounts. So, even with my top speed of 25mph, I find myself wishing for disc brakes of any kind.

You can get hydraulic v brakes you know

 

[skyungjae]

Their braking is easy to use in slippery conditions where most discs would lock the wheels inadvertently because of their lack of precision at low power.

I respectfully disagree with this assessment when you say "most." Unless you're talking specifically most improperly tuned disc brakes. I've seen plenty that feel very "digital," but that's usually due to improper bleed, cable adjustment, and/or types of pads/rotor combos.

Mountain bikers wouldn't use them if it meant instantly locking up wheels over loose technical terrain. Most disc brakes do offer precise modulation for better control in most situations including, but not limited to; slippery conditions.

I'm not saying one is better than the other. People should use what they're more comfortable with as well as what gives them the most confidence while on two wheels.

 

[k90211lee]

You certainly opened up a can of worms. People will be arguing until the end of time which brake system is "better." :lol:

If there any doubts in your mind regarding V brakes, then perhaps you should stick with disc. Given your prospective options, I think you should try getting a handlebar riser like this:

... and a sprung seat.

It'll be cheaper, less of a hassle, less time consuming, etc...

I was wondering where this thread go!

Decided to keep the Gaint Talon with disc brake. bought new rise handlebar and riser. thank for suggestion!



K.

 

[Alan B]

Rim brakes are not an option for these moped rims.

First the 160mm dual 4 pot Gatorbrakes, when they were first installed. I used these for a couple of years and many thousands of miles:

Now the new 203mm dual Tektro e-brakes:

Why upgrade the already good front brakes? I've asked this question myself, and others have asked it as well, so here's the list of differences:

from 4 pot Gatorbrakes to Tektro Auriga Ebrake
both are dual caliper mirrored caliper design (as required by DNM Volcano forks)
from 160mm to 203mm diameter discs (more thermal capacity)
from 1.6mm thin to 2.3mm thick discs for better thermal management and reduced stress
easier alignment process (pillar setup on new calipers)
hoses too long vs hoses cut to proper length (could have fixed this)
stainless steel mesh hoses vs plastic hoses (this was a step down)
additional feature: magnetic ebrake switch on the lever
additional feature: parking brake switch on the lever
additional feature: adjustable finger reach
The new pads appear to be more available (Gatorbrakes aren't as mainstream)

Out with the old and in with the new, the early test results are in. The new brakes are ... excellent. The stopping power feels better, with less lever pressure required and still having good modulation. Not that the Gatorbrakes were bad, they did a good job. But these feel a bit better. Maybe it is just because they are new. But those thicker larger discs are quite a bit more substantial and should help with heat dissipation. I've used them on a number of commutes and they modulate well, don't seem to heat up much at all on the big descents, and are silent when disengaged and make a nice quiet purring noise when engaged.

The brake locking lever is quite handy for stability when the bike is leaned for parking.

The switch built into the Tektro lever is connected to enable electric braking on the Sabvoton. This run of controllers from zombiess has variable regen/ebrake from a 0-5V input. I'm using a thumb throttle to supply a 1-4V signal for this, and it works nicely. There is a parameter in the Sabvoton configuration for the regen/ebraking level. It can produce up to full tire stopped skidding, which is well beyond regen and into reverse powered wheel braking. That is good for me since I don't have a disc on the rear wheel due to the tight space available on this particular early Greyborg frame. That can be fixed but it is a project I haven't done.

I adjusted the ebraking parameter to not quite skid the rear wheel on dry clean pavement, but it produces a very strong braking action, modulated by the thumb throttle and enabled by just pulling the Tektro front disc brake lever slightly but not enough to engage the disc pads on the discs. I haven't used this variable regen/ebrake much yet but in early testing it has been excellent. It quits braking at about 3mph.