Does Belt Tension Vary with the wheel on the ground or in the air?

[DaniBoy]

I’ve noticed that if I jack up the frame so that the rear wheel is off the ground, the belt tension is quite a bit less than with the full weight on the wheel. That being said, should the tension be adjusted while jacked up or not? Also does the tension increase when sitting on the bike, and even more so with a passenger?

[chipveres]

It varies considerably. Sitting on the ground mine has a tension of arguably 150 pounds. Jacked so the rear wheel is off the ground it has no tension at all, you can move the belt with your finger. I suppose that in an ideal world it would never vary. But that would require the swing arm pivot to be concentric with the front sprocket. That would set off a whole host of other problems.

[BajaRon]

You can do it either way. Tension value needs to be adjusted depending on which condition your belt is in when measured. As chipveres states. Tension varies with swingarm movement because the front pulley and the front swingarm pivot points are not the same. BRP values are given for wheel off the ground measurement. But this can be extrapolated to a wheel on the ground value. The wide spread in acceptable tension make an exact adjustment unnecessary.

[BLUEKNIGHT911]

You can do it either way. Tension value needs to be adjusted depending on which condition your belt is in when measured. As chipveres states. Tension varies with swingarm movement because the front pulley and the front swingarm pivot points are not the same. BRP values are given for wheel off the ground measurement. But this can be extrapolated to a wheel on the ground value. The wide spread in acceptable tension make an exact adjustment unnecessary.

... I use 160 +/- lbs. with wheel on-the-ground .... some here even use less with WOTG .... Mike

[DaniBoy]

IMG_5774.jpg This thing is the bomb for adjusting things! Wheel on the ground PLUS you can have it running in first gear. I still chock the fronts though.