The general concensus is that broken belts are due to being too tight, unless they suffer foreign object damage. I suffered damage on one belt, from a small sharp stone, and after removing it the belt ran fine for around 4,000 miles, before it showed signs of the damage extending.

 

How can you possibly know that,unless you'd checked it?

 

Because over tight belts being the root cause of breakage is like an old wive's tale.

Want to even guess how tight that belt gets every time you accelerate, ( or downshift?) That's what it was designed to handle. Misalignment breakage, sure, but not just from being "too tight." Too loose? Absolutely. But not from being too tight.

A similar belt is used on Boss Hoss bikes with the big 355 HP Chevy motors, their belt tension is spec'd at 400 to 500 ft/lbs.!

Even with the swingarm variance, over tensioning didn't break the belt.

 

OK, what did? How do Sportys break belts?

 

Once again unless you checked it yourself,bla bla bla

remember you can't fix stupid.
twisting a belt to check the tension,is about as much use as pissing in the wind to check it.

 

Agreed! The reason Harley came up with the tension tool (or whoever invented it) was to enable everyone to check tension to the same uniform standard. A heavyweight boxer's twist will be very different to a flyweight's!

 

I believe that the uniformity the engineers were looking for was to prevent a "too loose" situation, which will snap a belt in a heartbeat if the shock from sudden acceleration or braking causes one pulley to 'catch up to the other,' so to speak.

Our 138 hp drag bike only broke one belt in 2 seasons, that one was set to factory specs. The second was banjo string tight.

The 12 year old belt on my Road Glide has 118,000 miles on it and it's "taut." I can barely rotate it 45* with good size hands. ( No seal issues either.)

Good debate, but Trev: " bla bla bla? Really?

 

What breaks the belt when it is not tight enough is that the belt teeth ride up on top of the pulley teeth creating too much tension and somethins gotta give. Same thing happens when a timing chain gets too worn, one day it will ride up on the teeth and bust the end off of the camshaft. That belt was obviously too tight.
When I replace my rear tire I marked the top of the adjusting nuts and backed each off 4 turns, the axle came right out and went right back in. I then put the nuts back in their original position and all is well.

 

Thanks for all of the insight fellas! I will be definitely buying one of the tensioning tools along with my new expensive *** belt. One more question. Is there any one belt that is better than the others to replace it with? I see that there is plenty of different makers out there.


On a side note I keep looking at the belt and it doesn't show any sign of foreign object damage, it simply looks as if its just pulled apart. After reading all of your reply's I'm leaning toward the belt being way to tight. Who knows it could have just been a bad belt. No need to speculate. Just hope it doesn't happen again! Thanks again guys.

 

the belt tension tool is pretty inexpensive from HD. Check the tension with the bike cold on it's sidestand. Also, after setting the tension make sure to check your rear axle alignment.