Weighing in on Gears
Posted: Thu May 07, 2009 2:17 pm
Greetings:
Variator changes may be necessary if the Factory gear ratio is decreased - made "taller". The variator "shift" curve needs to be delayed so that the bike can contend with accelerating through the taller gears using the variator's ratio until groundspeed is sufficient. Lighter weights than stock - which are often 10 grams - accomplishes this. So does substituting a stronger Contra spring.
Nobody seems to be able clearly to explain which to do when, and advantages/disadvantages of each approach. I believe they produce virtually the same effect. If you get down below 4grams and still not enough RPM to drive the gears, it's time for a Contra spring.
Until then it's a lot easier to swap rollers than to replace the spring in the clutch, even with the right tools. I'm currently using 5.6 gram rollers and a stronger-than-stock Contra spring.
Variator changes may be necessary if the Factory gear ratio is decreased - made "taller". The variator "shift" curve needs to be delayed so that the bike can contend with accelerating through the taller gears using the variator's ratio until groundspeed is sufficient. Lighter weights than stock - which are often 10 grams - accomplishes this. So does substituting a stronger Contra spring.
Nobody seems to be able clearly to explain which to do when, and advantages/disadvantages of each approach. I believe they produce virtually the same effect. If you get down below 4grams and still not enough RPM to drive the gears, it's time for a Contra spring.
Until then it's a lot easier to swap rollers than to replace the spring in the clutch, even with the right tools. I'm currently using 5.6 gram rollers and a stronger-than-stock Contra spring.