Sprocket Question

dmdee99 said:

I do recall reading somewhere that if you add teeth to the stock set up you get more torq and if you do the opposite you get more top speed. Is this correct.

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Yep, that's the basic deal. If you go bigger on the rear = more torque/quicker acceleration, if you go smaller = more top speed in each gear.

And general rule of thumb, the front sprocket has the opposite effect, and is similar to going 4 teeth in the back. But in general, you can think of it like a ratio.

For example:

53/13 = 4.1
48/12 = 4.0
52/13 = 4.0
51/13 = 3.9
47/12 = 3.9
50/13 = 3.8
53/14 = 3.8
52/14 = 3.7
48/13 = 3.7
50/14 = 3.6

So like a 48/12 and 52/13 are both a 4.0, so will have a pretty similar impact on the gearing. Another thing to keep in mind is the chain length, a bigger rear sprocket might need another link, and a with a smaller sprocket, you might need to cut off a link. Since you are getting a new chain you will be fine, but sometimes if you're switching with your current chain you might have issues.

i have an RM 250 and i have a 13 tooth front and a 49 tooth rear and its pretty torquie but has a good top speed still