Sprocket/Chain Alignment

[guest1406]

Hi all,

On my little GN250 project i had a gsx250 rear mag wheel but sprocket alignment was way off so i went back to the original hub set up it came with. However when putting the chain on it's slightly off to one side and there's an 8mm max gap between the spacer and swingarm. Anyone know why this is?

Im goinging to get one of these today:
www.machinemart.co.uk/shop/product/details/laser-5051-motorcycle-chain-alignment-tool?da=1&TC=RV-040815051
Hopefully it can tell me how far it is off?

Im not really sure on what to do as I want the chain in line of course. I can make spacer easily enough if i need o.

Thanks for any help,

Mackenzie

[guest564]

I would think that whoever fitted the wheel changed the spacers. When I was playing around with different wheels I found that it was reasonably easy to set up the spacing using spacers and large washers and watching the chain run to ensure that it came onto the rear sprocket properly centred. When you get the spacing right measure up the washers and whatever spacers you used and then find or machine some to fit.

[guest1406]

Yeh I think that's it, I bought the wheel, axle and sprocket hub separately so think they may have been chopped and changed or from different models.

Its all done now though, bought that tool and its great. Had to machine a spacer and use a big fat Harley washer as a spacer too. But its perfectly inline now.

Mackenzie

[guest564]

Cool, I find it quite a satisfying job.

[johnr]

i assume that youve checked that the wheel is in line with the front wheel first. not that its centred in the swingarm, but that its alligned with the front wheel. if it is, then check how much leeway you have with the splines on the front sprocket shaft, you might be able to space the front sprocket out to gain a few mm. when i last fitted a wider rear to a bike, i gained 9mm on the front by spacing the sprocket outwards. you can also buy rear sprockets that are hollow on one side, you can fit these back to front to space the rear sprocket another couple of mm inwards to gain clearance.