I bought the Harley belt tension gauge and the belt seems pretty damned tight adjusted by the book. I heard a kind of howling sound at speeds around 30-40 mph so I adjusted the belt looser. After some experimentation I don't think the sound is coming from the tranny but I left the belt a little on the loose side anyway. I can't tell any difference in how the bike sounds or runs with the looser belt.

What are the downsides of a slightly loose belt? Seems like it would be easier on the transmission bearing. The official method seems awfully tight. I think I read somewhere that Harley changed the belt tension service specs so that 1/8" more deflection was deemed acceptable. Maybe that was only certain models.

 

i have the same howling noise and its the fly wheels thats what my wrench told me. i run my belt to specs on my last bike i did run it a little looser and a few times when i jump on it the belt slipped. tightened it back never did it again.

 

Just as having a chain running loose is not a good thing, the same thing applies to the belt! There is a risk of damaging the belt if it is either too loose or too tight, which is where that gauge comes in. Having said that I always set mine (had belt drive Harleys over twenty years now) at the slack end of the scale, in other words, the gauge is telling me it is just right. Hope that helps!

 

I adjust mine on the loose end of the spec when cold. I've noticed that after riding a few miles the belt is a bit tighter. I assume this is due to a slight expansion of the pulleys when heated.

 

A loose belt will wear the belt and pulleys much quicker, and will give you more driveline lash. I run mine at the loose end of the factory spec.

 

I had to replace a rear pulley and the belt because my belt was too loose. The teeth on the belt broke off or were holding on by a small flap. This was found at 44,000 miles and was not covered by the warranty. My local HD dealer was the only one at that point to ever install new tires and keep a check on the belt tension. It never was explained to me whether the belt messed up the pulley, or the pulley messed up the belt...

 

I had same issue on my 08 ultra. Run it as recommended so often here. Loose aide of the specs. My belt and pulley wore almost smooth, ESP denied the coverage, but Harley motor company approved the repair and handled everything for me. I was at 40k then. I'm at 1K now... On my 11 RGU

 

When you do burnouts, it's way easier to shear the teeth off the belt...

 

On this 2010 bike it seems as if the belt tightens up or the pulleys expand when they get hot. Found the belt really tight after long hot rides. (Didn't notice this on my TC88 or my Evo) So now, I been checking it hot, and have it adjusted for the proper deflection when hot, and the next morning it will seem too slack. WTF! I ready to put a chain conversion on it. Is it just me again?

 

Yup! My other bike is a Buell Firebolt. It has a tensioning roller in the lower belt run that is not adjustable (nor is the wheelbase), so the belt is pre-tensioned by that, not by using a guage. It seems tight to me, but that is the way it is and it ain't proved a problem so far!