Coaster brake hub failure

Discussion in 'Whizzer Motorized Bicycles' started by RdKryton, Jun 7, 2008.

  1. RdKryton

    RdKryton Active Member

    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.

    Last edited by a moderator: Jun 9, 2008

  2. Zev0

    Zev0 Member

    Rd, Augi is the absolute guru on coaster hubs
  3. WZ507

    WZ507 Member

    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.
  4. 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.

  5. 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.

    (Thank you Blaze for this link)
  6. RdKryton

    RdKryton Active Member

    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.

  7. 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.

  8. KilroyCD

    KilroyCD Active Member

    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?

    Attached Files:

  9. 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.

  10. uncle_punk13

    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.
  11. I got brake

    I have a rear hub from a 99 that o9nly has 11 miles on it.. Want it Cheap??
  12. KilroyCD

    KilroyCD Active Member

    I might take you up on that offer. But first I'll wait to see what Whizzer will do. I e-mailed them and got this reply:
    "Thank you for your mail. This is a very unusual failure. Please send me the bike VIN # and where you are located. I will check with
    our warranty group to see if we can help. We normally have the rear coaster brake but we are currently out of stock. Let me know the answers to my questions and I will see what we can do."

    I'm sending them the info they need and I'll see what they'll do.
    Even if they do come through with a replacement, I just might be interested in picking yours up as a spare.
  13. KilroyCD

    KilroyCD Active Member

    Here's the reply I got from Dave at Whizzer:
    " After discussing the rear wheel issue, we are going to send you a new rear wheel, without tire and tube for you to replace. I will also send a UPS call tag with the new wheel so you can return the defective wheel to us for our inspection. If you need any technical assistance to remove and replace the wheel, please call our toll free number at 1-877-944-9937 and we can help.
    I will send the wheel today via UPS ground service. Any questions call me or email."

    Those guys at Whizzer are the best!
  14. RdKryton

    RdKryton Active Member

    Holy carp!! That's great. I just hope you told them it's a 24 inch. Between the Whizzer guys here (Quenton, Mike,and Bill) and Dave at Whizzer, we are covered. Woo Hoo.

  15. RdKryton

    RdKryton Active Member

    Hey Zomby.
    PM me please with a price.

  16. KilroyCD

    KilroyCD Active Member

    Yes I did. I gave him both the size and rim color.
  17. Weedylot

    Weedylot Member

    My Whizzer coaster brake also does not work reliably, probably dry from being stored for 10 years.( I'm going through inspecting the whole bike this week) I'll do the brake at the same time as I fix my flat. It looks like upgradingthe rear brake would be better than just repairing the original. I was mildly disappointed that Whizzer would use such a "lightweight" method to stop my 220 pound mass. Luckily I have a copy of the dealers' repair manual.
  18. lazybikeusa

    lazybikeusa New Member

    when you regrease you hub be sure to use high temp wheel bearing grease.
    NLGI no. 2 grease
  19. KilroyCD

    KilroyCD Active Member

    Dave at Whizzer came through as he said he would. My new rear wheel arrived this morning, and I swapped the wheels out this evening. However, I noticed that the chain sprocket is a wee bit larger in diameter, as the chain is quite tight yet the drive belt isn't quite tight enough. I'll just have to pop a half-link into the chain, readjust the wheel in the dropouts and all will be hunky-dory again.
  20. chain and belt

    Hey, whynot just switch the 2 sprockets?
    Only a wire clip holds it on.
    I changed wifey's rear ratio that way myself, to make hers easier to pedal.