KDXRIDER.NET

Hi guys

I know that this topic has been flogged to death but I have a specific question that maybe someone can help with.
The stock E model gearing is 13/47.
The stock F (SR) model in Australia is 14/45. (Noted that this is with a 28mm carb, restricted expansion chamber, restricted air box and possibly different ignition timing)
My 1990 SR has full DG exhaust, boeysen reeds (rad block), Lectron 36mm carb, E model airbox modified, BP8ES plug.
I will be doing 50:50 Road (including highway) and trail (some hilly stuff)
I am leaning towards 14/43 which is just a couple of rear teeth taller than stock. Do you reckon this seems a feasable option??
Has anyone in the US gone this tall before?

I purchased the bike with 12/50 and it pulled pretty hard down low but didn't really get it to 6th gear yet.
First thing I did was strip it down and a full restoration so didn't test much - Pic attached

cheers
Rick

The stock gearing at 14/45 will probably be sufficient for your 50/50 riding. 14/43 will give you a little more top end speed, but you will lose a bit of grunt on the bottom. 12/50?? I don't know of anyone running that low on a 200/220, unless you're going to chase mountain goats. I'm in the Pacific NW, lots of mountains and technical, and run 13/47 on my 220 which is good for about 60 MPH but will climb nearly anything. Check out Gearing Commander and you can play around with the numbers

Thanks for that. Great link. 43 sprocket does 100km/h at 5800 rpm and the 45 does it at 6000rpm. Might try the 43 just a touch taller but not a lot if difference. Hoping with the extra hp that i have over stock it should pull ok with the 43. Speed limit is mostly 100km/h here, not planning on going much quicker on the road. Will be riding against wr426 so extra legs wont hurt im thinking

Just a follow up. 14/43 is nice on the road and in the open flat tracks. Second is a big drifter with this ratio and it pulls off the line in first fine.
I have however now changed to 13/43 as I found out that the wr426 that i am riding with has a 14/50 so is pretty low itself ánd only cruises at 90kph so I dont need the legs to compete. Will update once I have riden 13/43

By the way, notice that the SR version has completely different gear ratios - first gear is shorter, and all other gears ratios are longer than the E version.