chain alignment



i think some of us take for granted once we put the motor in place the chain will line up with the back sprocket ,,and then we start blaming the tension bracket because the chain is not running smooth ,,,i put a laser on mine and found it was out over 1 inch ,,now i have to make a off- set bracket on the back mount to line the chain up ,, in order for the chain to run smooth these sprockets must be line up and also very important they must be plume to each other ,,i am beginning to think setting up these motors properly is not a job for a mechanic but a job for a magician
if mine is out over a inch then i can not figure out if you have the same motor,, how yours could be true because they would have come from the same molds and i am sure your back sprocket is not mounted in the middle of your back wheel

i am only a half a mechanic and not a magician now i 'm in trouble
post some pics so people have a better understanding, and this way we can try to help you better, thanx
thanks for reply ,, if you take chain cover off and chain off place a straight edge between the small sprocket and the back one the straight edge ends up about 1 inch inside the back sprocket ,,, the only way i see to correct this i would have to give my motor a quarter in. turn clockwise and since the mounts and the bolts on the mounts are a snug fit it is impossible ,, so the only answer i see is to make a off-set bracket on the back mount ,,and what really puzzle me if mine is not true ,then if you have this 70cc motor from eBay then how could any of them be true ,because these are preset mounts ,,and if this is the case then it is no wonder there is so much talk about getting the tension bracket right ,,in other words its not the tension bracket thats the problem its the alignment of the chain ,, interesting to hear from other members that are running 70cc
on my frame, alignment was almost automatic...we need pics of your application to see what you're talking about.
My problem is after getting the chain aligned the bottom frame bar still rubs the chain and no matter how I raise the idler, it still rubs. I tried putting a spacer in between the drop out and axel but it still rubs. If I pull the chain out of alignment with the idler, it won't rub but the chain is then out of alignment.
Dear ABBEY, what next?
On my Specialized Rock Hopper I had to clamp the tensioner to the stay and use a large pipe wrench to modify the bracket so the idler wheel was centered with the chain.....I am not sure just how far out my alignment is but I do know the bracket did need a little tweaking....I haven't had a a thrown chain yet or any unusual wear.

whats strange i have had to work on 3 spelized frams now and each
one i have had to wrap cardboard arond the spot where i am placeing the tensinor

and then tapeing it tight with electric tape and you might have to
bend back the tensinor with a stupid wrench and on those frams
wont budge a inch at all beacasue the frame is box shaped in a way
but in a rectanguler way (still cant spell right AHHHHH!)

hope it helps you TURBO CHAOS
How did this work out? My chain is rubbing the tire just barely. I've twisted my tensioner with pliers but may have to tilt it back a hair to keep the bottom chain from rubbing.
I bent the tensioner and the tentioner is running straight with the chain but it still wants to pull the tensioner to one side so I know the chain alignment is out.
Will try to put more spacers in the back to see if the straight edge lines up.
Last edited by a moderator: