DRIVE BELT TENSION VS AMBIENT TEMPERATURE

[JUSTME1951]

If it's 60 degrees out does the belt expand?
Only explaination i can think of this morning.

 

[Papa Zook]

No, Harley drive belts do not expand.
Explanation for what?

 

[14TG]

If it's 60 degrees out does the belt expand?
Only explaination i can think of this morning.

Negative…. The belt will not expand.
What happened that you are asking?

 

[WindyOne]

I'll trade your 60 degrees for my 95.

 

[JUSTME1951]

Negative…. The belt will not expand.
What happened that you are asking?

Very cool morning; prob 55 to 60. During my preflight i noticed the belt had approx .5 to .75" of deflection which was more than when i installed it ~1k miles ago. Rode about .25 mi and rechecked; much tighter after. Jacked up and everything is turning and tracking good.
Wierd

 

[Gorilla]

Different angle of the suspension. as the suspension travels up and down the gap slightly changes as designed. so when you stopped and looked again the angle was probably different.

 

[JUSTME1951]

Different angle of the suspension. as the suspension travels up and down the gap slightly changes as designed. so when you stopped and looked again the angle was probably different.

Probably it.

 

[HDUSA1]

Everything is fine. You always check initial tension on a belt when the bike is cold after sitting overnight and with the full weight of the bike on the suspension. After you start the motor and run it even for a short distance, the pulleys and everything else heats up and the belt tension gets tighter.

I come from the world of Victory’s. They had all sorts of issues breaking belts on the new 2003 and 2004 TC’s. They came from the factory set correctly, but the dealer repair manual had you putting 1/4”-3/8” tension on them when cold and with the rear wheel off the ground unsuspended. Dealers were checking and adjusting belt tension on the first service interval, then a couple hundred miles later the belts were breaking. After that, they revised the manual for 3/4” tension cold and with the full weight on the suspension. People didn’t like having to leave their bikes overnight, but that was the only way to correctly adjust the belt.

 

[Papa Zook]

If it's 60 degrees out does the belt expand?
Only explaination i can think of this morning.

To clarify, both answers are correct. The drive belt will not expand nor contract based just on a cooller outside temperature (of 60 degrees) so those who answered no are correct. But Carl is also correct to point out that the friction and heat produced when your trike is driven, does cause the belt tension to increase.