I was talked into keeping my front sprocket at 15T and going a few up in the rear. Better on the drivetrain they say. I went on gear commander and plugged the numbers in. I can comprehend about 2/3 of the info on the charts. I was told that +2 in the back is equivalent to -1 in the front. But according to the numbers on gearcommander, its more like +3 in the rear is closer to -1 in the front. Please correct me if I figured this out wrong.
My concern is, from what I read, that it is beneficial to stick with an odd or even number of teeth for both sprockets for proper mesh/wear. Keeping the 15T in front and going +3 in the rear would give me 15/44T. Is this OK? Also, by going up +2 or +3 in the rear, would I have to get a longer chain? The stock length on the M750 was 104.
Yes, 1 in the front is equal to somewhere between 2 - 3 in the back. In theory what you say about even and odd is correct, well, sot of. It has to do more with what divides into what. If you want more info, google hunting, partial hunting and non hunting differentials. Same theory, just two instead of three In practice maintenance and riding conditions will play a bigger role. This becomes more of an issue when not replacing all three due to established wear pattern.
The +2 or 3 is relative - it's based on the ratio of the size of the sprockets. The bigger the rear sprocket initially is, the more teeth you would have to add in the rear to effect the same math as reducing the front.
Regarding the chain length - better safe than sorry and get a longer one. You can always cut it down. Remember that the larger sprocket will have a bigger diameter and circumference which will eat up a good bit of chain length
Quote from: speedknot on September 20, 2010, 05:31:37 AM
I was talked into keeping my front sprocket at 15T and going a few up in the rear. Better on the drivetrain they say. I went on gear commander and plugged the numbers in. I can comprehend about 2/3 of the info on the charts. I was told that +2 in the back is equivalent to -1 in the front. But according to the numbers on gearcommander, its more like +3 in the rear is closer to -1 in the front. Please correct me if I figured this out wrong.
My concern is, from what I read, that it is beneficial to stick with an odd or even number of teeth for both sprockets for proper mesh/wear. Keeping the 15T in front and going +3 in the rear would give me 15/44T. Is this OK? Also, by going up +2 or +3 in the rear, would I have to get a longer chain? The stock length on the M750 was 104.
I've run this set-up for 8 years & 15k miles. Everything still looks brand-new (minus Maxima gunk everywhere). Continuing thanks to Chris at ca-cycleworks for providing the +2 sprocket & DID gold chain [thumbsup]