Still progressing with my 906 mini restoration, have fitted new chain with earlier rear 40/15 sprockets 108 link chain, but have no adjustment left at wheel axle end...slack about 30mm on centre stand, not sure what it will be when I sit on it...any ideas with lack of adjustment???

The standard chain has 106 links which also fits with a 40 tooth rear sprocket. That may be the problem.

Thats interesting, all ebay sellers I have seen sell 108 link chain to go with a 40/15 ratio....hence my purchase....will try the old chain for size tomorrow...

I believe the 907 swing arm is longer ( the wheel base is ) ..... maybe the seller didn't bother to differentiate between the 906 and the 907 and just put one chain out there ..... he may not even know there is a difference

Still not there, the 108 link chain is too long...so looks like 106 link chain was used for a 38 or 40 rear sprocket...??? however looks I will struggle to join the chain if I shorten it to 106 links....will leave it for now...too tired to work out what is wrong...

The mistake I made was that I was turning the concentric clockwise, so axle was at one o'clock position max rather than anti clockwise to 4 o'clock position where you get maximum chain slack before the caliper hits the axle bracket (it hits sooner turning clockwise)...took out two links (106) today everything is good...thanks everybody...

This confirms same chain can be used for 38 or 40 tooth rear sprocket..

if you would go over two teeth more on the rear sprocket you`d need a longer chain