Hey Mike,
At what average speed are you getting 20 miles? I am thing of moving to an AGM battery next time around.
Are you using 520 or 530 size chain?
As you know, I have a very similar bike. I went a little different route. I used ANSI 40 chain. There shorter pitch works better for the tight turn radius of a small front sprocket at high RPMs. I bought serveral front sprockets to play with gearing, a 60 tooth unbored rear and had it machined to fit the rear wheel, then roller chain, non o-ring type. I am pretty happy with those choices since parts are available from Mcmaster-Carr or Grainger and less expensive in general because of the larger industrial market.
The small front sprocket made motor placement
critical to keep the chain line from hitting the swing arm. That is one reason I like Johh Bidwell's design of mounting the motor on the swingarm. It also seemed to have less chain noise as it is a much shorter path. It leaves a lot more room for battery placement too.
[EMAIL PROTECTED] wrote:
I found smaller 7/8 front sprockets at Grainger in standard motorcycle chain sizes. I went down from a 14t front to a 12t and like the results although I might have gone to a 10 or 11 tooth as the top speed is currently 72 MPH plus. Range by the way is 20 miles although I don't have a good steady state amp reading. My motor is an older ADC A89-4001 6.7" running 72 volts of YTs and my gear ratio is 12t/45t. I do have the
ability to increase the size of the rear sprocket up to about 51 teeth so still some room to tune.
Please note. The standard industrial sprocket from Graigner requires modification in order to work with a standard motorcycle chain. Some folks just grind an approximate angle into the teeth, but I chose to take it to a machine shop which charged me $10 to do it right (both sides angle cut). The teeth are hardened steel so it takes a bit of effort to do it in your garage.
I am considering moving to a non O-Ring type chain to see if that improves things at all, but need some better instrumentation first.
Mike Bachand
Denver Electric Vehicle Council (DEVC)
Board Member, Web Administration and Newsletter Editor
Kawasaki Ninja EV
http://www.devc.org
[EMAIL PROTECTED]
