Gearing S2R 1000+

Bitza · 24-04-2018, 12:18 PM

Hi all,

I'm just trying to decide on what size rear sprocket to use on the latest stage of my 1994 bike now fitted with an overbored S2R lump, HC pistons, vee-two cams etc, but std valves. now I do tend to go for over-gearing rather than under so my thinking is to use a 39 tooth sprocket or maybe 38. I was also planning on fitting 120/70 front and 180/55 rear (in part for the electronic speedo accuracy issues). Top speed isn't really a priority, bur mid range "Go" is. Has anybody got experience to share? Cheers Bitza.

slob · 24-04-2018, 01:21 PM

My stock roadgoing 1000 (not S2R but damn similar) runs 15/42 (less strain on chain than 14t front)and tops out at about 135 (well known German toll road.
My 1078hc, big valves, pure-tech sports cams, gas flow, lightened everything: runs stock 15/39. It tries to hoist the front wheel changing into 4th at ~110 and gearing commander said it was doing 143 at 8k in top before getting on the brakes down the back straight at Aragon.
HTIOH

Bitza · 24-04-2018, 03:54 PM

Thanks for that insight "Slob", keeping the front wheel down near the road does seem to be the pay back for so much torque. I should have said that I'm using a 15 tooth gearbox sprocket too. Bitza.

24-04-2018, 12:18 PM	#1
Bitza Bronze Member Join Date: Jul 2006 Location: Poole Bike: M900ie Posts: 470	Gearing S2R 1000+ Hi all, I'm just trying to decide on what size rear sprocket to use on the latest stage of my 1994 bike now fitted with an overbored S2R lump, HC pistons, vee-two cams etc, but std valves. now I do tend to go for over-gearing rather than under so my thinking is to use a 39 tooth sprocket or maybe 38. I was also planning on fitting 120/70 front and 180/55 rear (in part for the electronic speedo accuracy issues). Top speed isn't really a priority, bur mid range "Go" is. Has anybody got experience to share? Cheers Bitza. __________________ Bitza

24-04-2018, 03:54 PM	#3
Bitza Bronze Member Join Date: Jul 2006 Location: Poole Bike: M900ie Posts: 470	Thanks for that insight "Slob", keeping the front wheel down near the road does seem to be the pay back for so much torque. I should have said that I'm using a 15 tooth gearbox sprocket too. Bitza. __________________ Bitza

24-04-2018, 01:21 PM	#2
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	My stock roadgoing 1000 (not S2R but damn similar) runs 15/42 (less strain on chain than 14t front)and tops out at about 135 (well known German toll road. My 1078hc, big valves, pure-tech sports cams, gas flow, lightened everything: runs stock 15/39. It tries to hoist the front wheel changing into 4th at ~110 and gearing commander said it was doing 143 at 8k in top before getting on the brakes down the back straight at Aragon. HTIOH