foot brake help

[banana seat Brian]

is there a way to adjust the play in a kick-back brake?

 

[Anonymous]

Brian,This might sound dumb,but...if your chain is loose it would require excessive back pedaling just to take up the slack in the chain before the brakes work.

Could be a worn hub or brake shoes too.

 

[mastershake916]

There's a lot of stuff that can be done to coaster brakes, it would be best to really learn how one works and then diagnose it.
http://www.sheldonbrown.com/coaster-brakes.html
That might be a good start, I'm sure that there are other sites with more information.

 

[SkidMark]

I think they pretty much have about a half-back pedal before they engage. I wouldn't get into one without a manual or at least an exploded view.

 

[JonnyMenudo]

What model coaster brake is it? If it is just a single speed coaster brake, like a New Departure Model D for example it is really pretty straight forward. Be careful taking off the end caps that hold the bearings in, in case they are loose bearings. Otherwise inside there is a spring/lock type mechanism that allows for the forward pedal motion and then many small washer like disks that fit into the inside wall of the hub in a keyhole type method. Make sure these are properly inserted, re-grease everything (there is no part that it is not OK to put grease on) and reassemble. Make sure the brake pad side (non freewheel side) is inserted properly and tightly and this should reduce any play in the braking process. Like mastershake said...sheldonbrown has an awesome explanation of these.

 

[bikepusher]

...(there is no part that it is not OK to put grease on) ...

are you sure about that? isn't there a risk that grease between the pads and the shell influences braking power?

 

[aka_locojoe]

...(there is no part that it is not OK to put grease on) ...

are you sure about that? isn't there a risk that grease between the pads and the shell influences braking power?

Somewhere I read to put a thin coat of oil on them but I just grease everything also. Don't know what effect if any it has on stopping.

 

[bikepusher]

coaster brakes have metal (bronze or copper?) brake pads so maybe lubricants don't affect them.

 

[SkidMark]

You need to grease EVERYTHING inside a coasterbrake. From sheldonbrown.com : "Coaster brakes are intended to be pretty much packed with grease. There is no part of a coaster brake that can be harmed by grease, so be generous in applying it. You should use a grease with tolerance for high temperatures, such as automotive (disc ) brake (bearng) grease, but even so, coaster brakes used in mountainous terrain can "cook" any common grease."

If there isn't grease on the brake pads and braking surface the coasterbrake will howl (and lock up abruptly) every time you apply the brakes. In old ones the brass shoes will wear away, and in newer ones the hardened steel shoes will eat the hub shell.

A coasterbrake is my favorite kind of hub, I even used one for Freestyle BMX back in the day.

 

[Unchained]

I'm no expert, and most members know a lot more than I do, but from my experience, hubs can be picky about what you grease them with, and I have found that different factors can affect breaking speed in coaster brake hubs. I had an off brand Durex? hub which I loaded with grease and That was a TERRIBLE idea. It gave me constant problems after I cleaned and relubed it... it skipped without warning (disengaged mometarily, always while in drive. Very dangerous, caused me to fall off or lose balance quite a few times, always while I was cruising at a good speed). The hub would also take several revolutions of the chainring to re-engage/drive after I relubed it- it never did this before lubrication. I relubed it with bicycle grease, not with automotive grade. I hear that automotive grade lubricant causes problems too... I've heard that heavy lubricants intended for automobiles can make a coster brake almost inoperable (painfully slow stopping). My hub was fixed after I removed all the grease and put SAE 30 motor oil in these instead Motor oil went on all the braking surfaces and driver threads; the bearings I greased). That seems to be the magic lubricant. The old service manuals for Model D New Departure's tell you to use SAE 20 oil on certain parts and bicycle grease on others... I follow these specific directions very carefully but use SAE30 instead of SAE20 and find that this gives you a quick (but not too quick) stop. As someone mentioned above, chain tension affects stop time, too. I find that when the hubs are loose they tend to stop a little slower... The best way to learn what affects your hub and stop time is by trial and error I guess. Best of luck. :mrgreen:

I do believe that different lubricants affect brake effectiveness, I also believe from my own personal experience that you have to be careful what you use grease on. However, I can't imagine grease could ever harm anything, so anything is worth a try. At worst you'll have to relubricate the hub and try again. If you need a good hub refernce book, I'd buy "The Big Book of Vintage Bicycle Hubs". I own a copy ot this book and find it very useful. It is full of exploded views, service directions, and step-by-step pictures. It covers quite a few different hub models and makes. I believe a copy of this book can be purchased from the bookstore on theCABE.

 

[SkidMark]

I regularly bomb a hill that is about 4 miles long, the beginning elevation is 750 feet and it drops almost to sea level. It's a weekly nighttime ride called Zoobomb. It's fairly twisty and speeds average 35mph. There is a stop about 2/3's of the way down and my 50's Bendix is usually hot enough where if you spit on it, it sizzles, and that is because it works, well. I use disc brake bearing grease, and I am pretty sure oil would evaporate by the time I went down that hill once.

A Durex is a Chinese copy of a Shimano D type, which is a marginal coasterbrake to start with anyways, never mind the inferior materials of a Chinese knockoff. I had a similar one, a Hi-Stop, go south on me while Zoobombing, basically I had all my weight on my back foot and the brake was just dragging a little and eventually backpedalling about a half a crank. I took it apart and found wear to the outside of the clutch cone, but nothing really catastrophic. It's because of problems like this that I prefer Bendix Red Bands, and Bendix 76, and if it must be a new one, a Shimano E-type. I don't know much about other brands, but I have heard good things about New Departure, and there was a group that rode Repack BITD that swore by Morrow coasterbrakes.


Also the symptoms you describe could be caused by the clutch cone spring being in backwards (I've done it) and by that "return spring" that the Shimano style coasterbrakes have being installed wrong or being worn out.