[litnin]

PostWYrider - a 40 tooth should be fine for your bike. That's only 2 teeth smaller than stock - roughly equivalent to a 39 tooth on a 750.

Actually, stock, the VLX, has a 44 tooth rear... that would be 4 teeth difference.

And no, a 40 tooth on a VLX wouldn't even close to a 39 tooth on a 750.

750's come with either a 41 or 42 tooth rear and a 17 tooth front.
That gives you either a 2.41 or 2.47 ratio.

The VLX comes with a 44 rear and a 16 front for a 2.75 ratio.

Putting a 39 tooth on the 750 will give you a 2.29 ratio.
A 40 tooth on the VLX will give you a 2.50 ratio. That's a pretty good difference.
Putting a 40 tooth on the VLX would put you close to the ratio
of a stock 750 with a 42 tooth chain (2.47 vs 2.50).