Let me know how it works out for you. I have found that the 43 tooth allows me to use 6th now on the freeway, only having to downshift when traffic slows to my estimated speed of about 65. or my rpms drop to 3500. Like I said this is estamated, I have not purchased a speedohealer yet so..... right now its all black magic.

 

Youre not gonna notice a 1 tooth rear sprocket change...

 

I don't think so either.

 

I just ordered a 43 thinking the same thing...just a smidge more grunt w/out too much tradeoff.