TRX250R.ORG

Workshop => Suspension and Chassis => Topic started by: Mickkey82984 on August 18, 2014, 04:34:42 PM

Title: Gearing help for my saber ?
Post by: Mickkey82984 on August 18, 2014, 04:34:42 PM

Hey guys,


I was just thinking I know I'm going to have change my gearing up with this saber motor, any advice? I ran 14/42 with my pos bdt sphynx I had, the coc told me to 15 but wouldn't even pull 3rd on the hill with a 15, had to run a 14. The cinders are pretty hard on a bike. I was thinking of trying a 16 but not running a case saver scares me. I've broke a couple of chains in the past.

Thanks,
mike

Title: Gearing help for my saber ?
Post by: JesseA420 on August 18, 2014, 05:13:57 PM

run a 530 street bike chain and you shouldnt have to worry about breakage. other than that, buy every front sprocket, try them all, then fine tune your gearing with the rear sprocket after that, if need be.

Title: Gearing help for my saber ?
Post by: rk88r on August 18, 2014, 06:35:07 PM

A 14-41 is close to the stock 13-38. Maybe try a smaller rear.

Title: Gearing help for my saber ?
Post by: GO OVRIT on August 18, 2014, 09:07:18 PM

I'd get rid of the big rear sprocket before gooing to a 16 tooth front.

Title: Gearing help for my saber ?
Post by: havinnoj on August 18, 2014, 09:46:08 PM

Mickkey - our Honda TRX250R Gearing Ratio RPM Speed MPH KM/H Calculator (http://trx250r.org/threads/3006-Honda-TRX250R-Gearing-Ratio-RPM-Speed-MPH-KM-H-Calculator) may be helpful in determining optimal gearing for your motor - especially the comparison function between different sprocket sizes & tire sizes.

Title: Gearing help for my saber ?
Post by: Morse250r on August 18, 2014, 10:05:12 PM

I'd start with a 15/ 36/37

Title: Gearing help for my saber ?
Post by: Rupp250 on August 19, 2014, 12:52:04 PM

I would toss the 15t you have back on there. Then start working your way down on the rear sprocket.  What is the elevation there at the Cinders, I thought it was fairly high. So you will be down on power somewhat.

Title: Gearing help for my saber ?
Post by: Mickkey82984 on August 19, 2014, 06:25:20 PM

Quote from: Rupp250;41235

I would toss the 15t you have back on there. Then start working your way down on the rear sprocket.  What is the elevation there at the Cinders, I thought it was fairly high. So you will be down on power somewhat.

The cinders are at 7000 feet up here in flagstaff. I been told you lose about a 1/4 of compression up here but don't know if that's true. I can say when I take my bike down to sea Level it feels like it has a extra gear. Way less oxygen up this high. I'm going to put the 15 on the front but the smallest I got for the back is a 38, I'm going to order a 36 and maybe 35 ,37 and see how she does. Trial and error I guess is the best way to go.

Title: Gearing help for my saber ?
Post by: rk88r on August 19, 2014, 06:35:24 PM

That sounds about right the sled guys say 3% loss in power every thousand feet.