sall rear sprocket

Discussion in 'For Sale' started by Bikeuser, Jun 4, 2008.

  1. Bikeuser

    Bikeuser Member

    I am looking for rear sprockets with tooth count of 20-30 anybody have one of these?

  2. turbo/chaos

    turbo/chaos Guest

    um you will need a speical twin thread race rim from a bike shop and pick up a fixi cog to fit on its going to cost you some cash but its the best way to go
  3. you don't hav to go that far, look up tomi cogs they make cogs that bolt up to the disk break mounts on a mtb hub. I have been using that desighn for my fixed gear bike for a while w/ great sucsess, and I have stripped plenty of track cogs, good luck
  4. kjparker

    kjparker Member

  5. B.K. Hosken

    B.K. Hosken Member

    Aren't the tomicogs for BIKE chain, and the engine cogs we need are for MOTORCYCLE chain?
  6. not necasarily, as you may not in previous threads that hunk of junk chrome monster that comes w/ many of these kits is both extremely oversized and week.
    It is actually the same pitch as a bike chain (1/2) wich is the distance between the centre of a pin to the centre of the next. Now the difference is width, the monster is for 3/16 cog width all be it that many of the kits will work better with a 410 chain wich is for a 1/8 width. Either way the pitch is what matters the most. You can run a wider chain on a narrow cog, case and point the stanton kits, arguable the best kits out there. But frankly you would be beter off running a 410h ghain anyway, they are actually stronger than the monster as they are a bushingless desighn.
    Realize you are only dealing w/ a couple of horse power and very little torque. Don't assume that because it is a motor it is stronger, your motor can push you to 40 if your lucky, a pair of track sprinters on a tandem can hit 70mph in 6 crank revolutions that is TORQUE! The equipment they would use is wha the tomi was designed to replace as a stronger interface between cog and hub. The problem wasn't the aplication of torque in the driven direction but when anti torque was aplied jamming the cog into the reverse threaded lockring. Whened on your kit this ould be the direction that power would be aplied, the only time it would be aplied in the "proper"direction would be when you bump start it. Enter the disk brake interface. By bolting the cog directly to the hub you retain the concentric mounting but create a stronger interface using the 6 bolts.
    In short this design was a convienence for cyclist because many of them had a hub that fit a disk and there for could try fixed gear riding, further more it could also acomidate the high braking forces needed for riding fixed off road. For us it is a stronger interface that can handle the high torque aplied in bumpstarting.
    you don't have to spring for the tomi yet if you want to test the theory first. You can go to dirtrag forums and look up coaster cogs for how I drill these out of coaster brake cogs thatt yu can get from 15t to 25t total cost under $3. Try it and you will see just how strong it is.
  7. coaster cogs

    these are what I made out of coaster brake cogs, instructins are detailed at the dirtrag forum under coaster cogs in the fixed gear thread group

    Attached Files:

  8. B.K. Hosken

    B.K. Hosken Member

    I will probably go to one of these, now that I understand. I didn't like the spoke-cog interface, seems like a weak point. The bolt on cog would be much easier and always true, no flexing.