Originally Posted by 5-7HEAVEN
Interesting combination...pb engine, midframed w/shift kit.
What gears are you running? 7/8-speed cassette? 3-speed internal hub?
FWIW, my gear ratio in 1st gear is 46.32:1. It's like a granny gear for climbing steep hills, and 8th gear is highway gear @ 15:1.
Your 1st gear is 20.53:1.
My 6th gear is 20.45:1, and I'm @ 30-something mph in that gear.
You might want lower gear ratios.
I'm running a 7 speed cassette. i'm gonna switch it to my 34t 1st gear one which will give me 24.93:1 in 1st.
running a 24" tire, that will put me at
1st=17.2 mph at 6000 rpm 34t 24.93:1
2nd= 24.3mph at 6000 rpm 24t 17.60:1
3rd= 26.6mph at 6000 rpm 22t 16.13:1
4th= 29.2mph at 6000rpm 20t 14.67:1
5th= 32.5mph at 6000rpm 18t 13.20:1
6th= 36.5mph at 6000rpm 16t 11.73:1
7th= 41.7mph at 6000rpm 14t 10.27:1
I've heard these motors can reach 10k rpm range, and from the design i've seen i'd say that's rather feasible. the cylinder has 4 transfer ports (two large ones on the sides, and 2 small auxiliary ones opposite of the exhaust port.) not to mention the crank case is amazingly tiny compared to the china girl's crank case.
i'm also thinking that since these little motors put out 3-ish horse power that it shouldn't have much of an issue with running it like this.