lazer line up for sprockets

[katman]

your alignment is now true but check the rear axle? it could be ascew which brings us back to my wonderful little tool....

and as always... you are most welcome..

[katman]

Maybe I'm just dense, but wouldn't a 15 tooth 530 front sprocket be the same diameter as a 17 tooth front sprocket, same as a 42 tooth 530 rear sprocket be the same diameter as a 47? How would adding more teeth to the sprockets keep the chain from hitting the swingarm?

Will probably be making small chain runners to be attached on both sides of the pivot area of the swingarm out small strips of UMHW tape to keep from transforming the bike into an overpowered chainsaw. A whole lot cheaper to replace the plastic as needed compared to the swingarm.

MOre teeth larger diameter=greater chain height. 17/48 keeps the chain about the same height above the pivot as the stock 15/42.

look at the two sprockets I posted. Left=15t Right=17T and still the 17 is a little smaller. 15 teeth 3/4" spacing is longer than 15t with 5/8 spacing. That makes a smaller cog. Which like going from a 19" front wheel to a 17" front you lose an inch of height..right! because the diameter is smaller. That drops your chain height too and brings it closer to the pivot. The smaller rear sprocket compounds things and more drop of chain height.

[80GS1000]

MOre teeth larger diameter=greater chain height. 17/48 keeps the chain about the same height above the pivot as the stock 15/42.

look at the two sprockets I posted. Left=15t Right=17T and still the 17 is a little smaller. 15 teeth 3/4" spacing is longer than 15t with 5/8 spacing. That makes a smaller cog. Which like going from a 19" front wheel to a 17" front you lose an inch of height..right! because the diameter is smaller. That drops your chain height too and brings it closer to the pivot. The smaller rear sprocket compounds things and more drop of chain height.

Thanks for the clarification. Looks like an exchange to 17/48 is in order for those 15/42 sprockets that are on order.

[katman]

Thanks for the clarification. Looks like an exchange to 17/48 is in order for those 15/42 sprockets that are on order.

what yr swing and rear wheel are you using?

did the swing fit or did you have to mod the frame?

Give me an email dude. stunts@telus.net

[KEITH KRAUSE]

katman, thanks a lot for taking the time to 100% prove what needs to be done. I sense a bunch of people have installed that spacer wrongly and they'll be wearing out chains and sprockets very quickly or even worse.
A few days ago chef started a related thread "Sunstar sprocket" that Tom replied to. My first reply was that the spacer shouldn't be used. But without wanting to take my bike apart to look at things, I soon got swayed into believing the spacer was needed too. Everyone was so sure of themselves. It still seemed wrong though but I figured I'd just wait and see for myself if I ever do the conversion. Some trusted sources that people here believe in turned out to be wrong.
I hope the word gets out so everyone who has done the conversion can make it right. This is a potentially serious mistake. The chain could break and cause damage, not to mention an accident. At the least, you'll wear out these expensive sprockets and chains very quickly.
You really have to be careful when changing things from stock. It's easy to believe in a source because they have a website or they've been in business for years or whatever. This is a great example.
katman, thanks again for taking the time to sort this out. You've saved a lot of people some trouble.
I think that those that have done the conversion should contact their supplier and inform them that they need to change the installation instructions for some models.