This is NOT a hurley davison rubber belt (just wanted to get that clear since so much of what you read out on the net comes from hurley sources).

Do not use rubber belt thinking on our drive belts -- they are a super tough plastic material with cording that runs across the entire width that actually have different rules.

Those cracks are NORMAL for our belts, and mean almost nothing as far as how much life is still there.

From the looks of it you are spraying a lot of stuff on your belt.

Instead, bevel the edges of the teeth with an angle grinder as per tech section and stop having the squeaks.

HD musta had a shortage of rubber belts cause my buddies HD has the same belt as us... just narrower.

My experience with archery strings (some dacron and a whole lot of kevlar) says the only thing they don't like is to be bent.  avoid that and they'll live a lot longer.

Dacron is stretchy, so when bent all the fibers remain under load.
Kevlar is not as stretchy so when bent only some fibers are under load.  But boy do you get a lot of zing.  I'd get a 1000 shots outta a kevlar string which was about a months worth.  Dacron lasted all year and you replaced it just cause.

So can you tell the life by the cracks, maybe they are the only indication that the belt has been bent enough times to fatigue the plastic.  But you really can't tell if it cracked due to a manufacturing defect that wouldn't affect the life of the belt.

All I would spray on the belt would be a sealer of some sort like wax.

When the strings begin to break the belt pulls a hole in itself, which gives you time to get another one.

We have had people push rocks through the belt and make a sizable hole and keep on using the belt for years waiting for it to break.

..... your mileage may vary .....

                     

Oldfeller--FSO wrote on 07/22/15 at 09:03:00:


You have pictures of this?

I will post some pictures of the belt that did snap.  I saw no evidence of a hole.  
No, it wasn't under a lot of strain at the time it broke.  I was pulling away from a stop sign, shifted to second, and thought I had hit neutral instead.

Serowbot wrote on 07/22/15 at 08:58:06:


IDK either.  What are you seeing?  

That what it is Serow? I must be having one also, cause' I can't see some of the signature photo's.

I'll take a peek at our belts and see what I can... probably nothing though, cause both are still under 10k I think, but 70k... is that good or bad for belt?

I know parts wear, but what is the average life for a belt?

And let's all mark the spot where we jam that socket in between the belt and drive sprocket before hitting it with the impact wrench, just to see where the "sudden breaks" takes place relative to the mark ......