Brakes: disc vs. roller vs. drum

[circuit]

I know that disc is strongest from all three, however I am planing a foldable bike build with 12" wheels. What this means is that the bike will be folded somewhere in the trunk time to time and it will be easy to bend the disk. So I want your opinions about roller and drum brakes. How are they? I have not ridden one and have no idea how it feels. Since 12" wheel is at least twice as small as we usually use, I think roller/drum brakes should be strong enough? Let's say I will be going 50 km/h with total mass of 110kg.

 

[-dg]

I know that disc is strongest from all three, however I am planing a foldable bike build with 12" wheels. What this means is that the bike will be folded somewhere in the trunk time to time and it will be easy to bend the disk. So I want your opinions about roller and drum brakes. How are they? I have not ridden one and have no idea how it feels. Since 12" wheel is at least twice as small as we usually use, I think roller/drum brakes should be strong enough? Let's say I will be going 50 km/h with total mass of 110kg.

I have that exact roller brake in your picture. It has some features you might want to think about:

- it is heavy
- it rattles
- it makes wheel removal a giant pain in the ass
- it has mushy lever feel
- and it is weak.

tl;dr way janky.

Discs are not stronger than rim brakes. They are nicer when your rim gets covered with mud etc. but bikes that get covered with mud don't usually go in the trunk.

The Sturmey-Archer drum brakes have a pretty good rep as far as effectiveness goes and the 8 speed S-A hub has great gearing for a small wheel bike as all ratios are increases over 1:1. I've not tried them though.

Finally, if you are really planning on going 50kph on 12" wheels, that's pretty brave, couldn't you just roll along on your huge balls?

 

[bowlofsalad]

Stopping power is a concern for all who have lots of momentum. Amberwolf suggested kool stop to myself for roller brakes. I haven't used them yet, but they have an interesting feature. They have a V groove in some of the models that is said to sort of push off anything that may be on the rim. http://sheldonbrown.com/harris/brakeshoes.html

 

[Drunkskunk]

Common misconception is that brake style affects brake power. Untrue. Braking power is function of the tire's traction. Any brake that can locking the wheel is capable of maximum braking force.

Drum brakes are great for many applications. they can't cool as easily as a disk or rim brakes, but they can absorb a lot more heat. They also don't get dirt all over your trunk, and won't bend when you drop a bag of groceries on them.
The down side with drums is you need good hand strength. The Sturmy-Archer set I have feels like I'm going to brake the handle when I try to lock the wheel. They just need a significantly higher amount of hand pressure than anything else.

I wouldn't use roller brakes unless suicide was in my plans.

 

[StudEbiker]

I love my 90mm SA drum in the 16" front wheel of the Bike E. I had a poorly designed rim brake on it before, and disc brakes are not an easy option on a Bike E. IMO the drum brake is very, very good. I love how it looks, I love how it performs, I love that I shouldn't need to worry about changing the pads for about another 9k miles, and I love not having to worry about how much braking power I'm going to lose when it rains. The modulation on it is very predictable too.

I never liked having to adjust my BB7s like every week, especially the adjuster on the back side of the caliper, what a PITA that was!

On the three bikes around here that still have front rim brakes, I have gone with the Koolstop dual compound pads and can vouch for them. Very smooth, quiet, and confident operation.

 

[circuit]

- it has mushy lever feel
- and it is weak.

Damn, that's a fun stopper right there...

Common misconception is that brake style affects brake power. Untrue. Braking power is function of the tire's traction. Any brake that can locking the wheel is capable of maximum braking force.

Yes, as you say, only it they are capable of locking the wheel. Front wheel is somewhat difficult to lock for some brakes...

The down side with drums is you need good hand strength. The Sturmy-Archer set I have feels like I'm going to brake the handle when I try to lock the wheel. They just need a significantly higher amount of hand pressure than anything else.

Oh buy. I'd like to use only one finger for braking, leaving the rest of fingers dealing with road.

I love my 90mm SA drum in the 16" front wheel of the Bike E. I had a poorly designed rim brake on it before, and disc brakes are not an easy option on a Bike E. IMO the drum brake is very, very good.

If I'm googling it right, this is in-hub brake? Problem is that I need an add-on brake to add to existing motor hub.


So probably the only brake that can lock up the front wheel (on dry asphalt) while operating with one finger, is hydraulic disc brake? I'd really like them to lock the wheel if I decided to. I'm not a novice cyclist and don't like to use all my strength with full palm to come into rapid stop...

 

[Lebowski]

Have you though about (hydraulic) rim brakes ?

 

[dogman dan]

Old school coaster brake perhaps? They sure locked up good when I rode them at age 10, and taught me the lifesaving (later on a motorcycle) skill of steering a skidding locked rear tire.

Then a good rim v brake up front. But for 50 kph, NOTHING wrong with two good v brakes IMO.

 

[MadRhino]

I'd still go for a disc in the front. The faster you ride the more important it is.
Fit a brake guard if you plan to fold and carry it often.

 

[Brentis]

I run a 90mm S.A. drum, up front of my "Ghetto" build and I love it.
Easy set up, almost zero maintenance, weather resistant, looks the cats ass.
Much stronger and longer lasting than box store discs or roller brakes.
Though not as effective as properly set up rim brakes or quality discs.
For a heavy ebike up to 50kph or so I think the 90mm Sturmey is a great choice.
Affordable as well.

 

[amberwolf]

Stopping power is a concern for all who have lots of momentum. Amberwolf suggested kool stop to myself for roller brakes.

For *rim* brakes, not roller brakes.

So probably the only brake that can lock up the front wheel (on dry asphalt) while operating with one finger, is hydraulic disc brake? I'd really like them to lock the wheel if I decided to. I'm not a novice cyclist and don't like to use all my strength with full palm to come into rapid stop...

I can lockup CrazyBike2's front wheel with two (weak and hurty) fingers (probably could use one on a really good day for me, and anybody normal could do it with one), using just rim brakes.

26" wheel, rim off I think it was a Mongoose Basher (junk bike), Avid single-digit 5 arms, I forget what pads (might still be the Avid pads? I forget if they already wore out). Junk cable off some other bike, with two housings in series so it's a bit squishy, and ATM I think it's a cheap ebike ebrake lever, either that or an older Shimano type--I swapped it out at some point for some reason I can't remember, and I forget which was last on there.


Regular pavement, 300lbs of bike and rider, no rear brake, can do it even with another couple hundred pounds of dog food on the trailer too. Max speed is 20MPH, from there I have to apply just enough brake so I slow gradually so I don't lockup and skid isntead of actually stopping....

So no, hydraulic or expensive is not needed. Might be better under some conditions, I guess.

Sorry I don't have any experience with roller or drum brakes.

Some experience with "coaster brakes" like the one in the Sachs 3speed IGH presently on my trike (brake is not used there, though); they're ok, but I don't think they'd stop CrazyBike2 very well--a normal bike, probably. But would have to be kludged to use on a front wheel.