Help with mystery...bike won’t rev past 5000 rpms

#21
The spring can be installed by hand. Dover may have them, if not Dyno Cams or NR racing. That gear ratio is whats holding the overdrive back. What speed are you trying to attain? Street or Dirt?
 
#22
The spring can be installed by hand. Dover may have them, if not Dyno Cams or NR racing. That gear ratio is whats holding the overdrive back. What speed are you trying to attain? Street or Dirt?
I have other gears. Prior to the aluminum weights a few minutes ago gear range did nothing to gain rpm. I tried 72-10 and 50-8. Wouldn’t rev. The aluminum weight was what changed it all. The 50-9 is not optimal with the 6” driven...but it will be with the 7” driven I believe as there is no overdrive and the tav ratio is 1.12 with the 7”.
I’ll call Dover. I’m sure he has them. He is a nice dude.
 
#28
If I upgrade the springs with new cam it should do 7500 rpms. At 60mph I want between 6500-7000 rpms.

the aluminum weights definitely make it rev. But it also effectively takes away the ability to trail ride since it engages so much higher. But that’s ok for this build.
 
#29
If I upgrade the springs with new cam it should do 7500 rpms. At 60mph I want between 6500-7000 rpms.

the aluminum weights definitely make it rev. But it also effectively takes away the ability to trail ride since it engages so much higher. But that’s ok for this build.
How I handled that is using black springs with the aluminum weights. It engages low enough to be useful for low speeds, around 2100 rpm. But with the aluminum weights, it revs up so quick, it goes from 2100 to 3000 almost instantly.
I didn’t like the tav engaging at 3000-3300 rpm just to go really slow. Might be great for drag racing but not so great for low speed riding. Personally I think for this bike it works great, can just putt around at low speeds, accelerates quite rapidly, and top speed of 38mph is fast enough for me.
 
#33
Oh yah that’s a big difference in setups. I ordered pink springs a bit ago. The engagement with stock weight and white springs was perfect. The aluminum weight and stock springs is a little higher than advertised, so the pink will hopefully bring it down to where I want it. Waiting on my new belt for the 7” driven as well
 

SAS289

Well-Known Member
#35
Yeah pretty interesting thread.

I've never did a top speed run but have done short full throttle runs. I had 4500 RPM somewhere around 26 or 27 MPH with much less of an engine than he has. I'm using 9/60 tooth gearing and a Chinese TAV with a yellow spring in the driven on my Coleman 200. If I held full throttle it should make it to 5K or so then stop pulling. Happy with the bike as is.
 
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