AtNjineer

I have two shimano nexus 3 speed igh hubs. one coaster and one roller brake.
I’m trying to decided which to use.
what are y’all’s opinions on them both.

Serviceability and actual braking force

thanks.

veganbikes

Do you have the mounting points for either brake? A roller brake is probably going to be a bit better braking but it all depends if you can mount one or the other at this point.

The only time I would use a coaster brake as my main brake on a bike I was building was for a cheap beach cruiser that I was riding at the beach on flat ground where braking isn't really needed so much or if I was building a proper Klunker and was crazy enough to ride it and then I would probably have a proper brake on it because I am not a repack rider, those folks were insane and totally awesome.

Andrew R Stewart 

Most all the roller brakes I have serviced and test ridden after suffered from "mushy" feel. I don't like this. However I more don't like the lack of backpedaling ability so will never run a pedal operated brake of any type.

Since I don't know if the roller brake hub you have operates the brake with a cable/lever or by backpedaling I don't know if my reply applies.

Some of the Shimano IGHs have been modular in their design and the braking portion can be changed out. Don't know if yours are these.

Will you be running a ft brake? Andy

FBinNY 

Either should be more than capable of easily locking the rear wheel at will. That's the most stopping power you can get from a rear brake alone.

So go with whichever you prefer for reasons other than stopping power, then back it up with a front brake.

Gresp15C

+1 to having a front brake. In addition to the issue of total stopping power, coaster brakes have some weird failure modes that I've experienced over years of use.

If your feet leave the pedals for any reason... no brakes.

If they're in the wrong position when you need to stop... greatly reduced braking power.

If you're on a steep descent, greatly reduced braking power

Been there with all of those, and I'm an experienced urban cyclist. Some failures can be prevented by perfect attentiveness and anticipation... that's not good enough for me. It's tempting to omit the front brake because a stripped-down bike is simple and looks cool, but routing a front brake cable really doesn't add much in the way of complexity.

Andrew R Stewart 

To the OP's defense they didn't even mention a front brake. So my comment was not in response to any prompt from them. Andy

AtNjineer

the mounting points are the same both use the standard brake lever.

yes klunker build

I think the roller brake would not get the hub shell as hot

one benefit in the eyes of some.

AtNjineer

my roller brake is currently also mushy to be fair though I have yet to attempt to make an improvement since I’ve got it. Two months ago. It’s currently paired with a disc brake up front so I’m safe enough. I thought it was amusing how my bike if roller brake and disc brake from factory.

the roller brake is hand operated in my situation. So I have the ability to back pedal.


one more benefit to the roller brake?

yes I will be running a sturmey archer drum brake hub in the front.

AtNjineer

one more!

when you catch air. A simple example is going off a curb you have almost land perfect attempting to in a way avoid landing on the foot that is nearest the rear wheel.

cons of the coaster brake some may say.

AtNjineer

So far my experience with coaster brakes is perfect in terms of braking force. Not so much with my roller brake but I’m positive there is room for improvement.
I’m gonna go head and say that the roller brake is better. Base on a few pros like heat and wear and tear is isolated to a mechanism that is removable and replaceable. Without opening the hub.
Unlike the coaster brake that is destroying itself from the inside out.
also others that I didn’t even think of like what if your feet leave the pedals?
No brakes!

I think I’m going to go with the roller brake. I just thought it looked funky and I didn’t want to have to run the cable back to it. But oh well.

squirtdad

I have never seen a coaster brake with a lever, can you show a picture please

Andrew R Stewart 

Always nice to have more data Given the lever control for the roller brake and the pedal operated aspect of the coaster brake I vote for the roller to be used. Andy

veganbikes

Brake lever is not the issue, that is an easy swap if needed it is more the arms usually need a place to mount and not having mounted a roller brake arm (I have worked on a couple bikes with it but really didn't have to mess with brakes) I personally am not sure if they are the same or not and some frames can be particular.

The whole reason it was called Repack was because they repacked the hubs with grease after cooking it all out on a run. A roller brake possibly would be a little less heated but I don't know by how much if any. The shop I started wrenching at we rarely saw roller brakes and didn't sell anything with them and now I am at a higher volume shop but I am doing less wrenching except on special projects and oddball stuff but we are generally using discs or rim brakes so I just never get a chance to work on them and am so busy with other stuff I wouldn't have the chance if I wanted.

AtNjineer

lol yes you have. if it was a Schwinn the arm or lever that I’m referring to would say Bendix on it. You remember now lol

AtNjineer

I know I’ve repacked plenty lol

i think the roller brake would see the majority of the heat. More than just a little because it’s literally applying its braking force in a totally different part of the wheel.

both mounting points are the same for them both Just one has a cable and one does not.

AtNjineer

just two 15mm and a 10mm for the “arm” same same

squirtdad

LOL I meant brake lever on the handle bar which is how I read your post. didn't know drum brakes and the pedal back brake acutation option

certainly remember the lever you are referring to and the panic when the bolt holding the clamp works off and suddenly there is no braking

I was a kid so did not die....wouldn't want it happening now

Andrew R Stewart 

For the same rider/bike weight and same speed the energy needed to remove to slow down should be the same, regardless of the brake in use. However how that brake design handles the heat will be different (from a coaster to a roller). How much thermal mass (how much metal and what kind), how quick can the heat be removed from the brake (cooling) and how the heat affects the other parts of the rear hub are what I see as the aspects that count (independent of how well the roller brakes works as a brake if heat wasn't an issue).

I will suggest a roller brake has more mass than that of a typical coaster brake. That the roller brake housing is a separate and removeable part of the total hub has me speculating that the heat won't transfer from the brake (to the gearing/bearings) as quickly as with a coaster type. I also suspect that with its larger housing and sitting outside of the spokes the roller brake will cool at a faster rate than a coaster. And given all that I suspect the gearing and bearing lube in the rest of the hub will see less heat and thus work as a lube better. One could use grease with a high temperature capacity (as Shimano specs) in the roller housing and a different lube in the rest of the hub (again this is how the Shimano roller units I have dealt with were done from the factory).

But I'll add more opinion Roller brakes, as I know them and their history, were really intended for a more transportation oriented application. All weather, third world, urban commutes and the such. Where speeds tend to be lower that some MtB trails can see. Where the distance of applying the brakes is relatively short (parts of a block VS down a 2000' decent be that on or off road). So both the brake's horse power and its heat capacity don't need to be high. Additionally the design of having a roller (or 5) get wedged between a moving and a stationary set of ramps means there's little "bottoming out" of the ramp attached to the cable. Think about the angle the ramps are set at to each other and the flat contact other brake designs have. I could do the trig for the loss of contact pressure VS cable travel but will leave that for others. It is this aspect that I dislike. The initial lever/contact point will see little power compared to disk or rim systems (remember in my world the coaster brake isn't on the list anymore because of the lack of free back pedaling).

But I have learned well how to not call other preferences wrong, safety excluded (hence my ft brake question). Andy

sweeks

I think he means the "REACTION ARM"... ?

EDIT: I see problem solved.

GamblerGORD53

Neither. Get a SA drum brake. ZERO drag or service needed.

Schweinhund

Never had that problem ever. You hit the brakes and with nothing to stop the reaction arm, your coaster brake got so tight it was all brake all the time.

bwilli88 

I live in Cambodia and there are so many roller braked bikes here you can hardly swing a dead cat and not hit one. I only like them for flat ground riding/commuting. They will also cook the grease out of them but not as fast as a coaster brake. Keep the rollers well greased and they will last for a long time. They basically are a roller operated drum brake. Hard to rebuild them, just buy a new one and replace it, a fairly simple process. I have given away a dozen or more roller braked bikes. I have one coaster braked bike and it is fun to ride.

right now it only has the coaster brake, if I rode it in a more hilly are it would get a center pull front brake.

grumpus

Except no. The most rear braking you get is not quite locking the wheel, which is why we choose modulation in preference to digital braking.

FBinNY 

A semantic quibble.

The statement was about brake mechanism capabilities, not how best to stop a bike.

The ability to lock the wheel is a litmus test, confirming that the brake can meet or exceed the maximum possible torque requirements. Modulation for best and safer stopping power is the operators responsibility, not the brakes.

Schweinhund

Unless it's not?
I have beside me a still functioning TCW III. The TCW was a mistake. The 2, 3, and 4 were also mistakes.