Speed Triple Gearing

[KiwiGeoff]

My apologies for another gearing post.
Over the summer holidays I will be replacing the chain and sprocket on my 95 speed triple. I have all the parts and intend going down 1 tooth on the rear sprocket from 43 to 42. Its currently running the standard 17/43 set. This is a small increase in gearing but I am looking for the engine to be less busy at highway speeds. This year I had the tacho rebuilt by an instrument specialist and it now works all of the time instead of occasionally or only at high revs. I am still suspicious of the reading though and want to know if anyone has a standard gearing chart for the standard 5-speed gearbox. Currently my tacho says 3500 rpm at 110Kms/hour (68 mph). I need to know if this is about right – seems a bit low to me.

Any help in pointing me in the right direction for a gearing chart or advice re your tacho reading at 110kmh (68 mph) would be greatfully received.

Cheers from Blenheim NZ - KiwiGeoff

[denny]

I sent you a Private Message.

[KiwiGeoff]

Thanks denny, I have sent a pm back.

Cheers KiwiGeoff

[sailfish]

Your tach reading seems to be about a thousand rpm low at that speed, relying on memory. There are formulas out there to help you with the math.

Are you sure that you want to put a 42 on the rear? You might have to slip the clutch a bit to get underway, especially if you ever travel with a load. I went the other way (45t) and love it but I travel with loaded luggage or a pillion about half the time. The other half I ride like a juvenile so it works either way.

[Lushy]

Gearing Commander is quite good. you can play with this for hours

http://www.gearingcommander.com/

[LongRoadHome]

at 70, I think mine hums at about 4800 rpm, 85 mph/6K if I remember correctly. I guess I should double check and see what # of teeth I have on the rear, or it won't be much help.

[KiwiGeoff]

Thanks for the responses,

Both Denny and Lushy have pointed me in the right direction for gearing calculators.

Sailfish - the table confirm that my tacho though "fixed" and working is reading about a grand short at 110 kph. Not sure if there is a calibration adjustment but will look into that. Going from 43 to 42 teeth on the rear sprocket is not that greater change (about 2.5%) or about 100 RPM at 110 kph. I figure I can change the rear back again if needed - less hassle than the countershaft sprocket.

Long Road Home - your numbers check out to standard gearing.

Appreciate the help and advice - KiwiGeoff

[tripletom]

Hey Geoff, my S3 had a 42 on the rear and i found would need changing down from 6th to 5th sometimes to get a move on when 2 up. I've gone to a 45 rear now and it's better. Still not quite the hoodlum machine I want, but it's getting there.

[KiwiGeoff]

Thanks Tripletom.

I've only got the 5 speed box so I'm hoping the result will be similar to the 6th gear on the highway. Time will tell.

Cheers Kiwigeoff

[Buckwheat]

please do tell us where to get the tach fixed if in fact its reading does get re-fixed and becomes accurate. Cost?

Thanks!