Chain Replacement and Sprocket Alignment

The job is done!

In my case, changing the output sprocket from a 12 T to a 10 T lead me into replacing everything in that drive line, chain and the rear wheel sprocket.

When fitting the chain I could not find the sweet spot to have the rear wheel centered in the fender and be safely in the rear horizontal drop outs.

It’s a good thing that the engine base had slots that the bolts go through and thus the engine could be moved forward or backward or I wouldn’t have another option.

I moved the engine forward about 3/4” and that got me the right tension on the drive side and got the peddle chain tension where I wanted it after removing the 1/2 link.

After moving the engine forward and bolting everything down I went back and pulled one bolt out at a time to clean them and put blue lock tight on them. Then check everything over again for being lined up, tighten up and then I cleaned, oiled the chains and changed the fuel lines and in line filter. And I wiped the bike down with a quick wax spray. :)

Thank you all for all the comments!
Nice job! & nice build! May I ask what brand your bike work stand is? Is it holding up the whole bike? Thanks.
Decided to take a closer look at the other side, at the peddle chain and it‘s sprockets to see if they should be changed out.

At first look, I felt the sprockets were fine and at most would be to replace the chain. But I went ahead and ordered new sprockets to have them on hand when it’s time.

Today I took my new sprockets and compared them to the ones on the bike and I took the chain off and actually measured it for stretch.

After comparing the old sprockets to new sprockets my opinion on the existing sprockets did not change, they were not needing to be replaced but after measuring the chain for stretching my opinion on needing to replace the chain did.

I do not have the fancy chain stretch measurement tool so I used a tape measure. What it looks like to me is the old chain has stretched approximately 1/16”. From what I have read here is anything 1/8” and over the chain should be changed.

So I’m thinking that the chain and sprockets on the peddle side can go another season or at least another 500 to 750 miles. But would I be better off to install a new chain now to extend the life of my sprockets?

The peddle crank operates very smoothly and quietly with zero movement So no reason to pull the crank and service the bearings other that it being 7 years and 2,200 miles put on the bike but it was only peddle assist on hills and start offs.

I’m interested in what you guys think?


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If ya really think the sprockets should be changed within the next 750 miles
Change em now along with a new chain and be done with it.
Thank you Wrench!

After thinking about it the chain needs to be changed. It pull off the back of the sprocket a half a tooth and I believe I was wrong in the 1/8” stretch limit? On Park Tool’s Site they are saying it’s 1/6” stretch limit.

I think the sprockets will be fine in 750 + miles if I put a new chain on it now?

I know the sprockets and chain wear into themselves and it might be best to replace them all at the same time but I was asking if the sprockets pictured look good enough to accept a new chain.

Might it be possible for me to go through 2 chains before before having to replace the sprockets?