(front) drive sprocket removal

cdoug50

New Member
Jun 25, 2008
24
0
0
Maine
Hey Guys,
I would like to remove the small drive sprocket and place a washer behind it. Is this possible and if so, what is holding the sprocket on other than the visible nut? My chain is barely rubbing the tire as it comes off the bottom of the front sprocket.

By the way, I have gained alot of info from this forum and really appreciate all the post. Latest idea I got from the postings was to use a skate board wheel as a chain tensioner. I tried it and it works great. I used the original tensioner mount and just replaced the original roller assembly with a 5/16 bolt some spacers and the skate board wheel. It did take a little time to make sure it tracked right both forward and back. Adjustment was all in the vertical position of the mount which determines level of the wheel.

Now if I can just get that spacer behind the sprocket I will be a happy biker. :ride2:
 

hellbilly

New Member
Jun 4, 2008
10
0
0
Davenport, Iowa
Some other options for you might be to slightly dish the rim so the tire is moved slightly more to the peddle side, or add additional spacers on the big sprocket to move it out a little. Just something to consider. Good luck!!
 

cdoug50

New Member
Jun 25, 2008
24
0
0
Maine
Thanks guys!
I did get the mystery tool and did not know what it was for but will certainly try it out!

Re shimming with the big sprocket, I have already turned the big sprocket around to provide extra clearance there and think problem now lies with front sprocket since top of chain as it comes off the big sprocket clears tire, but the bottom rubs as it comes off of the small sprocket. Wheel has been alighned and balanced and spins true. Thanks Again!
 

bigbutterbean

New Member
Jan 31, 2011
2,417
1
0
Lebanon, PA
since we are on the subject, I want to know if it is possible to shim the front and rear sprockets out far enough to allow the use of wider tires. currently, I am unable to use any tire wider than 1.95. I would like to use at least a 2.25 or maybe even 2.5 size tire.
 

GearNut

Active Member
Aug 19, 2009
5,104
7
38
San Diego, Kaliforgnia
You can shim the rear sprocket.
You cannot shim the front sprocket. The front sprocket is a press fit onto a tapered shaft which is also keyed in place. Theoretically you could wrap the tapered shaft with a thin, hard metal material, making provisions for the key to still function, to prevent the sprocket from going on as far as it normally would. But in doing so you loose the positive locking affect of the taper that is crucial to the assembly. Anything between the internal taper of the sprocket and the external taper of the shaft will give the opportunity for movement and lead to wobble and the assembly coming loose. A disaster waiting to happen.

That said, there used to be front sprockets available with the chain teeth machined further outboard, away from the transmission shaft. These were intended to accommodate wider tires or ease troublesome chain alignment issues. I do not know if they are still available or not.

Also, some folks have moved the transmission shaft over to place the sprocket further out. You must consider the clutch placement in relation to rubbing on the the right side case, proper clutch hub taper engagement, and gear tooth alignment when doing this.
 

biknut

Well-Known Member
Sep 28, 2010
6,525
229
63
Dallas
Most stock china girl motors will allow for a 2.125 tire and even bigger, if you buy a KMC 415 chain from Pirate cycle. It's stronger, and smaller than the stock chains.

I'm running a 2.3 tire on mine, and it doesn't rub.
 

anthonyv

New Member
Nov 20, 2013
1
0
0
New Jersey
I'm having the same issue with a wide rear tire. I will keep you posted and hope you do the same. I am trying to put this kit in a Dyno GT Deuce Beach Cruiser...it hasn't been easy. I also need to do something about the coaster break since I added spacers to the rear sprocket to clear the tire.

Thanks,
Anthony