sprocket/chain question

the 19 tooth sprocket on my gearbox is worn, and i was going to order a new one. Was considering changing to a 20 or 21 tooth, i thought i read somewhere that one of those options causes a pain in the ass when it comes to the chain length, but i searched and searched and couldn't find any mention. is it a painless ordeal? i'm replacing my chain as well. I plan on mostly back road cruising, no 1/4 mile sprints, long hauls, or highways, was going to change just because i don't mind compromise if it gives me "best of both worlds" and less wear and tear on the motor/gearbox. smart to change to a 20 or 21 while i'm replacing it?

Move up a notch to 20 T. My notes say 98 link for 21 T, so perhaps 99 for the 20 T. Others?

If you are changing the chain too, then simply get about 106 links to be safe. No matter what sprocket you get this will trim to fit. No big whoop. Grind off the rivet head and pop it through.

I find a 20 tooth to be ideal

Torontonian said:

Move up a notch to 20 T. My notes say 98 link for 21 T, so perhaps 99 for the 20 T. Others?

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i'll have to research the links. using a mix of norton and chilton manuals. i'm seeing 98 for the 19T, and 99 for the 21

1up3down said:

I find a 20 tooth to be ideal

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I agree totally, especially for the type riding you indicate. I changed from a 22 and the difference was amazing since my riding is also basically back road cruising. However:

kevbo82 said:

i'll have to research the links. using a mix of norton and chilton manuals. i'm seeing 98 for the 19T, and 99 for the 21

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Why not just listen to pvisseriii? Get the 106, set your adjustments where you want them, pull the new chain tight and mark where you need to cut it. No chance of buying one that is "supposed" to just fit a new 20 tooth and find out it's not right. Just my $0.02.

A standard master link will only work with an even number of links, i.e. 98 or 100. The original 850 chain had something called a cranked link.


This allows an odd number of links in a chain. 530 cranked links are available - you just need to find them. I know Regina makes crank links for individual sale for about $5. You could also start at 100 links, with the axle adjusters out pretty far, then pop out a link pair when you've got a little wear and run 98 links.

I vote for keeping what ya got. Best blast and easiest on the gearbox.

Unless a real torquer hot rod or long distant high speed traveler I liked 20T best for all around creeping to zooming in lower gears through chicanes to freeway cruising below 5000 rpm, which is happy nil wear and heat stress on Nortons. 20T need 100 link chain.