4Rt : Which Sprocket Ratio ? 10 Front, 41, 42 Or 43 On The Rear ? Also 280 Conversion : Does It Give Beefy Power As A Bolt On Extra ?

[chrisedwards]

Would be very keen to know :

1: what do the 4RT community consider to be a good all round sprocket set up ?

2: It appears an S3 280 conversion kit is a straight "bolt on and ride" without having to do any extra machining work to cranks and cases etc. I am very tempted to buy one as I feel it may give extra talky power of the bottom , right or wrong ? I am an ageing expert that still likes to have a go but feel sometimes my 250 is a bit weak when pulling a higher gear from short approaches. Lowering the gearing , i.e.: 43 on the rear made it manageable in technical areas but I felt all gears were to short.

My bike currently has a mitani clutch and exhaust system and I am lead to believe is running a Sans setting. Rear sprocket is a 41.

Look forward to hearing experienced views on these subjects

Chris

[jimmyl]

I found the 280 kit a handfull and changed back to std 250 on the 09 I bought, Had sains map on at the time. Currently running a softer version of the sains map, Have rdden the clubman route with some success on a few of the S3 rounds including colmore and found the 250 was stilll getting me out of the big climbs as good as anything no problem .

I run std gearing (10 41?) and ride lots in bottom gear and use the rev band to get what I need top end. 4rt does not like to be revved and then dump the clutch like a 2 stroke. Have found ride off the throttle and then give it lots once the drive has hooked up, I find 250 does this where the 280 was spinning or just dragging me behind.

As you have a PTB would suggest probably best playing with alternative maps which costs nowt before spending money on a 280 kit. Youll probably want to play with maps if you do fit a 280 kit so may as well do first as last.

Best of luck

[chrisedwards]

Thanks Jimmy, a great reply and appreciated

[apj]

I run 9 on the front and 43 on the rear and find this ideal for myself. There are quite a few 4RT's in our area and most seem to run this combination, but a 9 and 42 might be worth trying.