835 20 30 vs 842 20 30 Belts

[Shadowfire]

When you put in a longer belt:

At idle, the belt is (compared to the correct belt) still in the same spot in the front, but it is higher up in back. The front:back drive ratio is shorter. The engine will need to rev up faster to get the clutch engaged (since it still engages at the same rotational speed in the rear). You may have a little bit better acceleration, too, since the gear ratio favors it.

As the variator completely opens up when at full throttle, the belt is still in the same position as a normal belt in the front, but now it will be higher up in back. The front:back ratio drive ratio is still shorter than it would be on a normal belt. This means, that at 8,000 rpm (or where ever your rev limiter is set at), the bike will actually be travelling slower than with the correct belt.

To make a long story short, you've basically traded some of your top end speed for acceleration.

[Mäwby]

Originally Posted by Shadowfire

When you put in a longer belt:

At idle, the belt is (compared to the correct belt) still in the same spot in the front, but it is higher up in back. The front:back drive ratio is shorter. The engine will need to rev up faster to get the clutch engaged (since it still engages at the same rotational speed in the rear). You may have a little bit better acceleration, too, since the gear ratio favors it.

As the variator completely opens up when at full throttle, the belt is still in the same position as a normal belt in the front, but now it will be higher up in back. The front:back ratio drive ratio is still shorter than it would be on a normal belt. This means, that at 8,000 rpm (or where ever your rev limiter is set at), the bike will actually be travelling slower than with the correct belt.

To make a long story short, you've basically traded some of your top end speed for acceleration.

Thanks for this info!

[Gene563]

For what it's worth ... I had replaced my belt with the longer, 842, but as of today, switched back.
It seemed to affect the RPMs and acceleration in a negative way. It was slow up to speed; once there, it ran well ... even hitting one of my fastest runs (in a tuck with a tailwind - 63MPH).
I was going to try the 11g weights I have, but think they are too light for my set-up. I ended up staying with the 13.5s and the original belt (835).
Out of curiosity, I video'd the CVT with the cover off. there didn't seem to be too much difference in the ride height on the variator, but there was a significant amount of slop with the longer belt that also showed up on the cover as rubbage.