How to fix small jack shaft sprocket to pedal sprocket alignment issue?

[Anthony Barbosa]

I’ve got a jack shaft kit here and I’m at the final steps of finally getting the engine to run and to test the whole thing out. One big issue to this now is the smaller sprocket that goes to the freewheel is not aligned correctly to the big sprocket on the freewheel. The engine side sprocket and the bigger sprocket on that side of the shaft aligns perfectly and its tension is correct also. But now it’s the smaller sprocket that doesn’t want to align. I’m starting to feel that maybe I went wrong somewhere in the kit where it won’t allow room for alignment.

 

[MinimumVK]

If you have the same jackshaft kit as i do i believe you can move the shaft left/right. So loosen both of the jackshaft sprockets and slide the jackshaft to the right (driving direction). This should allow you to move the smaller sprocket a little more right.
Noticed you have a fat bike and i dont know if the bottom bracket is wider then normal. If so you might need a longer shaft. When i was rocking a shift kit i welded my own bracket that made everything easier.

 

[Sidewinder Jerry]

An issue I've often seen with shift kit builders is the bottom cups have to be all the way in. The cup's flanges must be touching the frame. Otherwise it can cause the freewheel to stick out too far. When installing the BB cups always clean and pre-grease the BB frame threads.

Notice on my shift kit how the BB cup is all the way in. As you can see I have 4 sprockets on my shift kit instead of just 2.

 

[meridianPeteJ]

An issue I've often seen with shift kit builders is the bottom cups have to be all the way in. The cup's flanges must be touching the frame. Otherwise it can cause the freewheel to stick out too far. When installing the BB cups always clean and pre-grease the BB frame threads.

Notice on my shift kit how the BB cup is all the way in. As you can see I have 4 sprockets on my shift kit instead of just 2.

View attachment 213917
View attachment 213919

All I see is dog hair

 

[Sidewinder Jerry]

All I see is dog hair

I haven't rode for over a year now. Back is getting better after getting surgery, should be back riding soon. However, shame on you can't tell the difference between dog hair and cat hair lol

 

[meridianPeteJ]

I did actually think cat hair but I remembered you and your dog pic,

 

[Anthony Barbosa]

If you have the same jackshaft kit as i do i believe you can move the shaft left/right. So loosen both of the jackshaft sprockets and slide the jackshaft to the right (driving direction). This should allow you to move the smaller sprocket a little more right.
Noticed you have a fat bike and i dont know if the bottom bracket is wider then normal. If so you might need a longer shaft. When i was rocking a shift kit i welded my own bracket that made everything easier.

I tried playing with different shaft and sprocket positions and eventually I found a spot where the pedal side is just a bit twisted but the engine side still remains mostly straight. Only until I actually try it will I see if this configuration is OK. On another note, is it ok to grind the freewheel's smaller sprocket's teeth because the stock chain doesn't fit?

 

[Anthony Barbosa]

An issue I've often seen with shift kit builders is the bottom cups have to be all the way in. The cup's flanges must be touching the frame. Otherwise it can cause the freewheel to stick out too far. When installing the BB cups always clean and pre-grease the BB frame threads.

Notice on my shift kit how the BB cup is all the way in. As you can see I have 4 sprockets on my shift kit instead of just 2.

View attachment 213917
View attachment 213919

Thanks for your suggestion, I'll try to adjust the cups and make sure they're completely in before trying anything else. However, is it ok if there's a bit of play in the spindle? Or does that mean that I didn't tighten the cups all the way in?

 

[Sidewinder Jerry]

I did actually think cat hair but I remembered you and your dog pic,

Got 5 cats

 

[Sidewinder Jerry]

Thanks for your suggestion, I'll try to adjust the cups and make sure they're completely in before trying anything else. However, is it ok if there's a bit of play in the spindle? Or does that mean that I didn't tighten the cups all the way in?

Did you clean and grease the bottom bracket threads on the frame?