Coaster brake hub failure

RdKryton

Active Member
Joined
Nov 6, 2007
Messages
949
Well Kilroy had a major coaster brake and hub bearing melt down today. I guess I am asking from those know is actually how hard is it too rebuild one of these things. We have not had it apart yet but the wheel wobbles and even the chain sprocket slips. The thing sounds bad... I hope we don't have to replace the whole hub.

Jim
 
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WZ507

Member
Joined
Jan 11, 2008
Messages
88
Coaster Brake

Coaster brakes can be very dangerous when they lock-up as they can twist the axle so severely that it rotates in the brake arm and can break the axle in two, leaving you with a wheel wobbling between the two broken axle ends. When it happens at speed it can be terrifying. How do I know? You guessed it.

Ever since the time I broke a coaster brake axle, I tend to use the break with much more discretion and never apply it with full force since I now know the consequence of a lock-up. In my case the cause was me cleaning the bike with some gunk spray cleaner, which got into the rear hub, diluted the grease, caused more friction than should occur when the brake was applied, and caused the lock-up. My advice is to keep coaster brakes well lubricated with grease, use them gingerly, and if you really want good brakes, replace the coaster with an expander type brake.

If the hub ID is not galled, the brake can be rebuilt, assuming you can get the parts. If the hub ID has galled badly you have to replace it.
 
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MotorbikeMike

Guest
Whizzer Coaster

Hi there, well the coaster? I recently went thru Wifey's coaster, as it was making noise.

Removing the wheel is more trouble than to overhaul the coaster.

First the nuts come off, the coaster arm, the dust cover, and then unscrew the cone. Clean and study all parts. I use black Molylibdium grease, or Red High temp disk brake grease to liberally grease all internal parts after inspection.

What to look for? Balls out of cages on the bearings, pitted or flaking surfaces on the races, cracks on the ede of the hub shell, etc.

A little finesse is all that is needed to re-assemble the parts, set your lash, be CERTAIN that ALL nuts are really tight.

I have had much sucess rebuilding (clean and re-lubing, the occasioinal bearing).

The continuing problem that I see with the coaster, is that hard braking, under the speeds of a Whizzer, will sometimes melt the grease out of the hub, and require re-lubing.

I have wondered if drilling, tapping, and installing a zerk in the shell would be worthwhile?

If so equipped, after a hard run (evidence is grease blown on the wheel), the wheel could be cleaned, a couple shots of wheel bearing grease into the hub, and dis-assembly would be much less frequent?

The absolute worst coaster rebuilds are old units where the grease has dried up, Bloody h el l to clean for re-lubing.

Mike
 
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Large Filipino

Guest
When my coaster started making noise even after packing it full of grease I decided to convert it to free wheel. It's rather easy to do. I used to do this alot back in the day. The washers used is pretty identical to the washer used on the outside nuts. Get two of the same and your golden. Anyway,if you want to keep the coaster,this site has a good breakdown and an how to freewheel.
I like that I could do away with that coaster arm then I installed a caliper brake. It's also nice that I can pedal backwards again.
http://www.wtlw.net/ff/suntour/

(Thank you Blaze for this link)
 

RdKryton

Active Member
Joined
Nov 6, 2007
Messages
949
Thanks everyone for the replies. Upon closer inspection we have a much bigger problem. One of the rings that the spokes are lased too has broken loose and slipped to the center of the hub. I have never seen anything like this before. The Whizzer only has 148 miles on it but it's a 2005 so the warranty has expired. This hub is not like others I have seen because the ring the spokes are lased too is not part of the hub. What I mean by this is they are two pieces welded together not just one piece. Hopefully Kilroy will post a picture he took today.

Jim
 
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MotorbikeMike

Guest
Spoke flange

Hi I had a spoke flange strip on my 05, so I laced a Hi-Stop coaster into the hub and have used it like that ever since.

Mike
 

KilroyCD

Active Member
Joined
Dec 3, 2007
Messages
1,389
Here's a photo of the spoke flange that detached and slid to the center of the hub. Before this happened I heard clicking coming from the hub, then I lost my brake. The coaster brake is something I do know my way around, but I doubt I can do anything about the spoke flange. Has anyone tried to weld one of these back in place?
 

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MotorbikeMike

Guest
Yup, that's it!

HI well, that looks just like mine did, and I laced in a hi-stop, still riding it. I guess Whizzer has hubs also, tho I am 4-5 days away from those parts, and I have .105 coaster wheels availble here locally, reasonable, and the spokes worked just fine.

Mike
 
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uncle_punk13

Guest
I have one of the original, (near) bullet-proof, Bendix RB hub shells, that has done this same bit of trickery. I have yet to attempt repair, but I think it can be done without too much trouble; you just have to make certain it is pretty darn near to dead nuts on center, perpendicular, parallel, etc. before brazing... Probably easier to just lace a hi stop on to the wheel.
 
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