Offset Tranny Sprocket
- Thread starter 79mr79
- Start date
Bought a motorcycle I could afford, needs work, bank repo. Has been converted to chain drive with a 180 tire. Rear sprocket was shot, slapped a new one on to see what I had. Looking down the chain it appeared the tranny sprocket needed spaced out 1/4"? Had to ride it, broke 2 teeth off the rear sprocket. So here I am. Whats the best way to align the 2 spockets, hold a straight edge down them? Need to measure the offset on the front sprocket its stamped 281 pbi.
For whats it worth my bike was also converted to chain drive. He kept the standard tire.
What my brother inlaw did was buy an offset sprocket for the rear tire and used spacers to assign it up. A large straight edge was used to allign it all up.
In my case I used the stock HD tire so I am not sure whats involved with a 180 tire.
There are others on this board that can advise.
What my brother inlaw did was buy an offset sprocket for the rear tire and used spacers to assign it up. A large straight edge was used to allign it all up.
In my case I used the stock HD tire so I am not sure whats involved with a 180 tire.
There are others on this board that can advise.
Last edited:
Am a little out of my league but if the offset on the rear sprocket is .750 and your alignment is out .250 I would think you would need a .500 spacer on rear sprocket.
First, make sure the centre of the rear tire is properly centred in the frame and aligned with the front tire.
Once thats done, determine the offset required.
Place spacer equal to the offset between the rear wheel and sprocket until the tranny sprocket is inalignment.
If required, use multiple washers till the alignment is right , then measure the thickness of the washers and get a spacer that matches it.
As for chain type , I prefere O ring type
First, make sure the centre of the rear tire is properly centred in the frame and aligned with the front tire.
Once thats done, determine the offset required.
Place spacer equal to the offset between the rear wheel and sprocket until the tranny sprocket is inalignment.
If required, use multiple washers till the alignment is right , then measure the thickness of the washers and get a spacer that matches it.
As for chain type , I prefere O ring type
O-ring chain is the way to go for durability and quiet operation. Just currious, what size chain are you guys running, and how many teeth for the front and rear sprockets? Are you both happy with engine RPM vs MPH with stock tranny gearing and are you able to "pull" redline in top gear?
530 chain, 24T tranny sprocket, 51T dished 4-speed rear sprocket. As far as your other question I didn't get to ride it enough to tell. What I really want to know is, Will I have to worry about hitting/rubbing the inner primary by running more offset on the tranny sprocket+running a wider chain (oring)? How much offset can I run on the tranny sprocket with a stock primary??? Is this a legit question or am I just plain crazzy? Do I just need to go out to my 0 degree garage and figure it out myself??
Last edited by a moderator:
flh classic
Member
Dangerdan was right, First thing you should do is make sure the bike is traking straight (front tire inline with back tire) do this by putting a nice straight chalk line in your driveway and wheeling the bike over the line the chalk should be right in the center of the front and rear wheel. Then get some P.V.C. pipe and cut some spacers for the rear wheel to determine your offset. Had the same problem on a custom bike I have put together.
Hope this helps.
Hope this helps.
Thanks classic, Haven't been out in the garage for a while (cold, honey do list) I definitely need to check the tracking. After running a straight edge down the 2 sprockets they are a 1/2" off. Cant believe someone would put it together like that. Bought a new front sprocket with a 1/4" more offset. Feeling between the tire & fender there is quite a bit more room on the brake side. But no spacers I could take out to move it over that way. So have you ever heard of machining the brake caliper bracket down to make room? I know alot of things come into play here. I first need to check tracking, then put on new front sprocket, see how much room I have between chain & tire,frame. If the tracking checks out ok & clearence is good, I could then take the other 1/4" out of the spacer behind the rear sprocket. But the different gaps between the fender & tire bother me. O and that monkey Gary I know where you can shove that pipe!