Front Sprocket

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Apr 29, 2005
I have a 1971 Norton Highrider. Naturally it feels as if its geared lower than newer models are. My question is will a 19 tooth front sprocket off a 72 Norton fit/work and will it increase speed while reducing rpm's. Thanks for any input. semper fi devildog
19T gearbox sprocket


The 19T sprocket on the '72 combat engined 750s was done to lower the gearing not raise it. Changing to this will do the opposite of what you want. Get a 21T gearbox sprocket to lower your engine rpm at a given speed. If you already have this you can go to a 22T.
21t Sprocket

Thanks Dave, I need to get some books out and research. I am not so concerned about the power of the Highrider but would rather have a bit more speed and lower RPM. So if I understand correctly I need to make the gear change vice the primary or rear sprocket? Tks again. semper fi devildog
The Workshop manual for Models 850 & 750 Interstate,Roadster,Hi Rider, Interpole, Fastback,"SS" 'S' Type, Fastback L.R. in the Tech Data Section gives theoretical road speeds for the various countershaft (gearbox) sprockets.
Check it out but don't go too tall with a standard bike or you will make it a dog.......woof woof :(
Gearing changes are done at the countershaft sprocket behind the primary.
The rear sprocket is part of the brake drum.
gear ratio change


Each tooth increase at the gearbox sprocket (aka countershaft) will drop the engine speed about 250rpms.
I've been running an o-ring chain for 3 years / 10,000+ miles. Have yet to adjust it. Lube it 3-4 times per season.

I machined my existing sprockets myself. Take .060" of either side of the tranny sprocket, .120 off of the outside of the wheel sprocket. Machining only one side of the wheel sprocket will better center the chain on the chain gaurd.


You probably have a 19 tooth countershaft sprocket on the '71. 19T is best in town from light to light, and on twisty roads. For fast open roads, the 20T is better on a 750 IMO.
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