This is my THIRD broken drive belt. I have a 1998 Fatboy and changed my both wheels to 18s and 1 1/8 rear pulley. Rear tire is 160/60 -18. Then after some 1500 miles or less suddenly my first Genuine HD belt broke. Back to the shop, some $$$ and on the road again. After some 1,000 or so miles my second aftermarket belt went south. Changed the rear pulley and the belt, this time Gates. Poorer but there I went again to the road. Then, this weekend, after some 2000 or so miles...my third belt! I use the bike just for touring not racing nor even spirited driving.
Do I have to change belt to chain?

I'm so disappointed that I'm starting to look to Japan but resisting at the same time.

Suggestions?

Thanks

 

Is the motor stock? How is the belt alignment? I am sure these questions have been asked before but I am just curious. I know a stock belt on an EVO is 1.5" but if you have ran a newer HD 1 1/8 then you should be fine. A belt out of alignment, impropper tension or a belt hitting something can cause it to break. But just breaking for no reason makes no sense. Esspcially since you have been through 3.

 

Something else is wrong here.

What is the condition of the "teeth" on these broken belts?

What is the condition of the primary pulley?

Did you install a narrower belt and pulley set when you put on the oversize tire? (130/90 is stock)

 

Engine is almost stock.The three of them broke about the same way. No teeth missing, just broke apart.
I have been working on motorcycles and autos for long time. The first belt was installed by myself. I got the workshop manual and know about tension, alignment, etc. But then, the 2nd and 3rd belts were installed by a Certified HD mechanic.
The rear pulley was installed along with the wheels and wider tire. At the 2nd event I changed it again for another one because it seems to fit better than the first one.
The only component that was not changed is the front pulley. I checked it the last time and looked ok to us. What about aluminum front pulleys?
Yesterday I found also a chain conversion kit that cost about the same as the belt components($300). Is there someone that has used it?

 

The reason I asked about the narrower belt and pulley set was because I have heard about the problem, but I've not seen it in person, where the slightly wider tire pushed on the inner side of the belt making it run up against the outside of both pulleys. When this happens one or more of the cords can break cause the belt to snap. Again I haven't seen this only heard about it.

 

I agree that it must be something such as the belt alignment or tension.

 

Did you remove the belt guards when you installed the larger rear tire?

 

Cogged belts will not tolerate misalignment. Running a 160 without offsetting the primary would be difficult. Pretty much a given your pulleys are not lined up.

 

If your breaking that many belts there is no doubt an alignment or pulley issue! I have a 240 in the rear along with a med build 96" in my 1995 Fatboy and have never broken a belt.

You will need to get a long straight edge out or borrow a laser aligning tool and look at the pulley alignment. From there determine what is out of whack. Then you can either shim accordingly or realign the rear wheel.

 

A close friend of mine has a 160 on the rear of his 05 and has for at least 20K miles without issue. Granted that when the wheel was put on the shop ensured a correct offset with the hub on their wheel. So I guess it could be the offset on the hub that is causing it.

Drew