chain problems

Discussion in 'Transmission / Drivetrain' started by Tallen09161990, Sep 25, 2014.

  1. Tallen09161990

    Tallen09161990 New Member

    i had just bought a new chain for my bike after the last one got mangled and snapped and it fites fine on the rear wheel sprocket but it is not fitting on the ten toothed engine sprocket it just barely misses the hole in the chain i had bought a chain on ebay that say it was for up to 80 cc engines on on the side it says 415h did i get the wrong chain or something?

  2. Timbone

    Timbone Active Member

    I think you wanted a "415" chain. "415H" is different (heavy?) and I have read many reports that they won't work on HT engines. Details are important!

    I am a huge fan of the 415 chain. Mine has been a monster!

  3. crassius

    crassius Well-Known Member

    some of the drive sprockets these days are being machine stamped instead of cut - this leaves a very wide, flat top on the teeth so that with a heavy duty chain the edge of the tooth doesn't want to clear the wider roller between links

    this will clear up a bit if you want to keep the chain very tight and wait for it to stretch a bit, but I usually take off the sprocket and file or grind the teeth to make them pointy on top so the chain fits nicely
  4. Wolfshoes

    Wolfshoes Member

    In a recent motorbike fix, a 410 garage opener chain on the leftover shelf would not fit the drive sprocket at all. The only difference the dimensions of this chain was the outside link had 1/64 of an inch less in radius height. The drive sprocket has flanges on both sides of the teeth. Using stock chain; the drive sprocket flanges against the outer chain link determine depth into the teeth not the roller as when the chain reaches the rear sprocket. If this outside link height dimension of a replacement chain is not as expected; the fit in the drive sprocket teeth may be all wrong. Usually, I would expect the height of the outside link to not be important. In the China Girl build, the drive sprocket flanges appear to be factory tuned to a particular chain link height. I could suggest keeping a piece of the original roller chain as a reference in checking replacement chain. The chain link height of 410 and 415 Grubee chain appears to be the same. Replacement chain regardless of manufacturer, must match this original link height exactly or its not a China Girl chain. The garage opener chain is a lighter 410 version. Perhaps by brazing a filler on the flanges and regrinding to add the 1/64 of an inch, this lighter 410 1/8 inch by ½ inch chain could be used on the motorized bike. If the motor to wheel alignment is correct, the garage opener chain should be plenty strong enough. The 66 engine only develops about 27 lbs of pulling power.