[ST] Re: Sprockets

[Bare <barenekd@xxxxxxxxxxxxx>]

It's easy to calculate. Just divide the front sprocket teeth into the 
rear sprocket teeth.
Stock 19/43=2.26
17/44=2.59
18/46=2.55
The common change for gearing is to 18/43=2.39
The lower the number, higher the gearing, speedwise. I.E. You'll have a 
higher top speed and slower acceleration.
With higher numbers, your engine will be turning higher RPM at the same 
speeds, but have better acceleration.
As you can see, the numbers you mention are higher still, meaning lower 
top speed and quicker acceleration
As far as chain wear goes, it may be accelerated some with smaller front 
sprockets, but I'm nearing 30,000 miles with a Tsubaki chain and 18/43 
gearing and they are in great shape, so I don't think the chain has 
suffered too much with the smaller front sprocket. I got about 10,500 
out of the original chain with the 18 tooth sprocket, just a reminder 
what crap the OEM chains are. The 17 tooth gearing would probably 
increase the wear rate a bit, but I haven't tried it. When you replace 
chains, you should replace the sprockets. The wear pattern in the worn 
sprockets will affect the new chain's life.
Bare

> As I understand it, going down one tooth on the front OR going up two
> teeth on the back will have about the same effect. In this example it
> will shorten the gearing, by about the same ratio, giving slightly
> higher acceleration. 
> My local dealer recently told me that the front sprocket wears the
> fastest and the smaller the sprocket, the faster the wear and once it
> starts to wear it then wears the chain which in turn wears the rear
> sprocket.
>
> So my questions are:
>
> 1. An 18 tooth front & 46 tooth rear is about the same as 17/44, but
> the config with the bigger front will wear more slowly?
>
> 2. I normally get 20,000kms from my chains and sprockets. If I were to
> change the front sprocket more often, say every 3000kms, will this give
> extended life to the rear sprocket and chain?
> Does this make sense or is it all bunk???
>
> Cheers,
> Brett.

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