RD350 gearing

[JB Weld]

Bike is converted to 520 chain, 14/39 from Economy. I always felt stock gearing was pretty adequate for hauling my 250 lbs around. Since re-doing the top end, Dave F, filters, spacers, reeds, and DG chambers, along with 520 conversion I don't feel that 6th gear is all that useful anymore. Was considering going up a tooth or two on the rear, but this setup doesn't have many miles and don't want to buy another chain.

Would a 13 tooth wear ok and give enough of a noticeable difference in performance? I know reducing the front is probably a big compromise if I step too far down. From what I figure a 13/39 is equal to a 14/42.

[Jspooner]

Isn't stock 15/39? If you go down to a 13 that's a huge jump from stock. Are you sure your jetting is right? Too rich or too lean will make it seem that way.

[Jspooner]

With your set up you should be around a 200 main. Maybe even as low as 190.

[m in sc]

I'd go up on  rear . 13 is small and will be rough on chain

[Kawtriplefreak]

Stock is 15/40 if memory serves. John at Economy Cycle recommended 15/39 and I went with that and am happy with it. I can cruise at 70 and the motor is happy.

[Dvsrd]

If memory serves me right, the RD350 user manual recommends 6000 rpm as the limit for cruising over any extended time. 6000 rpm with 15/40 gives around 115 km/h (just over 70 mph)
A 13 tooth countershaft sprocket will drop the 6000. rpm speed down to around 100 km/h. Which is just too low IMHO.

[JB Weld]

Yep stock gearing was 15/40. John lists the 250/350 conversion as 14/39. He may have recommended the 15/39 combo, but I can't really remember what I bought anymore.

Joe, I am almost certain I running 190 mains, maybe 180. Honestly I plan on messing with jetting a little more this year and may have to adjust clip position. I think you may be onto something as it really pulled hard with 220's, but couldn't get it wide open without falling on it's face.

I won't mess with gearing for now. It may be that I was trying to cruise at too slow in top gear too.