Disc or 'V', Which Is Best?

[Cyclezee]

I would like to know peoples opinion as to the best type of braking for electric for an electric bike, disc or 'V'?

 

[flecc]

I like V brakes, but much depends on the application. For a commuter doing very high mileages for whom rim wear can be an expensive problem, disc brakes could be preferable. If off-road in the sticky stuff is intended, once again disc is best.

However, low cost single actuator disc brakes can suffer rubbing problems, many mechanical ones are not very effective and discs can overheat and buckle during prolonged downhill braking. Disc brakes place considerable stresses on wheel spokes, all the braking force being transmitted through the spokes. The also need the correct pad make and type as replacements, not always easy to locate.

V brakes can easily be adjusted to avoid rubbing problems once one knows how, pads are readily available and not make specific and rim areas mean over heating is not a problem. They place no stress on spokes. Rim wear is the only real problem.

 

[Cyclezee]

Thanks again Tony for your concise comparison and explanation

 

[Geebee]

Disc´s require less actuating force and tend to be more powerful, and are further out of the mud if you go off road, plus your wheels look prettier for longer

 

[cwah]

However, don't forget that disc brakes add a significant weight to your bike.

That's why most folding bike don't have disc brake.

It's a trade off: Better brake power or lighter bike? Depending on the situation you may prefer the one or the other

 

[johnc461165]

My personal choice is for Disk brakes

 

[flecc]

I think that commercially it doesn't matter so much which is best, more which the market prefers. On that basis, the mainstream market preference is clearly for discs, not necessarily due to them being better but simply as them being seen as more up-to-date/with-it/aligned with car and m/c practice.

It's only on lightweight road sport bikes that V or caliper brakes need be retained as a good commercial decision, V for consumer sport-bike "wannabees" and calipers for the genuine road-race brigade.

 

[Tim]

There's another option of course, hydraulic rim brakes. Kalkhoff use these on most of their Agattu Impulse models, the Agattu C8 HS, Agattu C11 Premium and Agattu C8 XXL, as well as on the 20-inch wheeled Sahel Compact

I can't fault them - extremely reliable, good modulation of braking power, no cable-stretch to worry about and the pads seem to last ages. They are the way to go (and to stop efficiently).

They look good too - that view below indicates how the whole surface of the pad is applied to the rim, rather than being toed-in like V-brakes, which is why the pads last so long. Finally, if you have to remove the front wheel the brake on one-side can be removed by releasing the lever to the right below - much easier than fiddling about with noodles.

 

[Hugh]

As a Kalkhoff owner, I have to agree. My PCS has Magura rim brakes - they work well ion wet or dry, pads have lasted over 2.5 years so far, they're dead easy to modulate and don't grab. Only drawback is that of all rim brakes - mud and sandy crap isn't too great.

I've got Magura discs on my Cannondale, and they're also very good and without the mud problems, but cruder in modulation, I find.

Ordinary V brakes are light years better than the feeble cantilevers and stuff that came before them, and I reckon are the best budget bet unless you're an out and out roadie in which case you'll probably go caliper instead.

Cheap cable discs are awful.

My 2 penn'orth.

 

[wurly]

I like V brakes in the dry, but when it's wet and all the debris gets on the wheel you can hear the grinding that goes on with surface of the rim and the aluminium being shaved off.
For that reason i am in the process of adding discs to my bike now. Unfortunately, a costly thing to do. I had to buy a new wheel to get a hub with 6 mounting holes, so i bought two wheels to get the rear rim to match...now i have to relace my rear hub motor.
I was going for cable operated calipers to retain the brake cut out switches in my levers. Now i read they are awful....
Is it going to be worth the effort and cost?

 

[flecc]

I was going for cable operated calipers to retain the brake cut out switches in my levers. Now i read they are awful....
Is it going to be worth the effort and cost?

On the basis that not much braking force can be applied though the rear wheel, just changing to a front disc will be more economic and retain your present motor. While its true many cable operated disc brakes are poor, it not always so and the Avid BB7 moderate price cable disc brake has come in for lots of praise, many members switching to them.

 

[smudger1956]

I'm with flecc, application, my Cyclamatic front brake was awful, tbh I was not expecting much, but some set up fettling and new pads transformed the braking performance.
Cheap cable discs I agree, look good, and thats about it.....
My DH bike has Hayes hydraulic, superb feel and feedback.

 

[wurly]

Thanks for that flecc
Ok so, not all the cable operated disc sets are bad. I'll have a look for Avid BB7.
Any other recommdations? or one's i should avoid?
BTW flecc i typed relace not replace hub motor. The hub already has the disc mount holes, although i will have to fabricate a mounting bracket for the rear calipers.
I'm also wondering about fitting larger discs on the front. I have never had disc brakes on the bicycle before so i'm in the dark somewhat as to what to expect or pay.

 

[flecc]

The BB7 is the only cable one I've seen strongly recommended, though I suspect some of the other brands like Shimano are probably ok. It's the cheap generic Chinese ones on bikes and e-bikes which have been giving cable disc brakes such a bad name, quite a few changing theirs for BB7s and the like.

I'm no disc brake expert, but that Avid price is at the low end, you can pay much more than that as you'll see on this page. A larger disc gives greater braking force, so if you and your bike together are on the heavy side the extra braking could be worth it, especially in a hilly area. Otherwise the smaller BB7 option should be ok.

Thanks for the relace correction, teach me to read more carefully!

 

[Pedalo]

I like the low cost, low weight and simplicity of my V-brakes and I find they work very well even in wet conditions.

I was thinking of switching to disk brakes because I travel on muddy roads and do manage to wear out rims - but since learning how to change a rim myself (following much tinkering with motors), even that is not too much of a hassle now.

I'm sure I remember some horror stories from the early days of disk brakes that suggested that due to the way the forces work, it's possible for a wheel to force itself out of the dropouts when braking if the dropout is angled downwards. I guess this is probably more of a concern for those that might want to retro-fit disks to a bike not specifically designed for them.

 

[jasono]

I am very much in the V brake camp. Light weight, easy to maintain and above all very effective. Disc brakes maybe more aesthetically pleasing, but can't say I've ever found v brakes wanting?

 

[danfoto]

Another vote for the Magura hydraulic rim brakes, which I must admit I'd never heard of until we got our Agattus. Not quite as sensitive as the Deore V-brakes on our Thorn Sherpas, but more so than the discs on our Christiania.

IMO they're everything that brakes on a utility/commuting bike should be.

 

[piotrmacheta]

Sorry but hydraulic disc brakes every time for me. I have Hope, Avid, Magura and Tektro hydraulics and they all work well but the Magura are 1st with Hope a close 2nd. I agree that the Avid BB7 cable disc worked well but much less powerful than hydraulic and as for the Clark's cable discs, well, damn dangerous in my opinion. V brakes are good when new but soon go off and not powerful enough. The down side of hydraulics is that they can be costly to fix - I had to pay £60 to extend the line by 6 inches. But the pads last years. I read about a group of touring cyclists travelling in the Himalayas and the V brakes ones wore out their pads in 1 day on the long downhill whereas the hydraulic man's lasted the months.

 

[flecc]

V brakes are good when new but soon go off and not powerful enough.

This is often said but never true. Unless in a very sorry state, a front V brake can stop a bike quickly enough to pitch the rider over the bars. No brake can ever be more effective than that. Of course some strength of grip is needed and hydraulics are easier in that respect, but again the rim type are easily as effective as the disc type.

Almost any brake type is strong enough on the rear where braking force is always limited by wheel lift during rapid deceleration.
.

 

[Shannock]

Depending on the front forks, if they are too slender a disc can snap them, seen it happen.

Pete