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Tech => Home Brew => Topic started by: Gregski on September 19, 2011, 04:15:51 AM

Title: 12 to 13 Tooth Front Sprocket - Nothing to Write Home About
Post by: Gregski on September 19, 2011, 04:15:51 AM

Replaced the 12 tooth front sprocket with a 13 tooth one on my 1989 Suzuki Katana GSX600F yesterday.  The rear is the original stock 47 tooth one.  I didn't have to add any links to the chain after adding 3 or 4 initially for the conversion as the motor sits further away than the engine/transmission had.

I think I may be getting 2 MPH more on the top speed maybe a little more somewhere around high 30's, ie 38 MPH.  The good news is the bike is not any slower off the line.  So I question all the people who told me electric bikes need to run a 5:1 gear ratio, that or I misunderstood their advice.

Bike Specs:

• Mars ME0709 motor (heavy)
• 48 Volt Alltrax 300 amp controller (soon to be upgraded to 72 volts)
  
• four 55 Ah sealed lead acid batteries (soon to be six)
  
• 48 volt Elcon 20 amp on board charger (awesome)
  
• Magura Twist Grip Throttle (kinda cheap and plasticky)
  

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(http://gregandsandy.com//wattana/pics/small/DSCI0007.jpg)

(http://gregandsandy.com//wattana/pics/small/DSCI0009.jpg)

Title: Re: 12 to 13 Tooth Front Sprocket - Nothing to Write Home About
Post by: Allen_OKC on October 10, 2011, 09:26:33 PM

i have a 48 volt 400 amp set up with the kelly controller and mars motor, pretty much what your using...

i started with a 12 tooth up front and a 48 tooth rear sprocket... awesome take off but pretty slow on the top end...

i finally went to a 15 tooth up front and took a loss in the low end but i did gain a lot on the top end...


12 tooth 400 feet 38.7 mph

15 tooth 400 foot 42.5 mph

top speed at 53 mph...