I have a 21" Hogpro Big Daddy spoked wheel with a Dunlop GT502 tire. I have noticed some severe cupping on the tread and trying to figure out why. I replaced my neck bearings about 8,000 miles ago and have taken it into the local HD shop to have the fallaway checked and they stated the wheel is heavier than the stock wheel and it would not be an accurate fall away test. The bike rides fine with no shimmy at any speed. Just curious what your opinions are and if any of you with after market wire or billet rims have had any issues similar to this. Thanks in advance

 

Every time I see cupping it is due to running at low pressure.

 

Are you maintaining proper tire pressure?

 

As UT said...suspect low tire pressure...I know I have been guilty of that in the past, with the same results...so I bought a new tire meter (quality - found out my old one was 8 pounds off...).

But for the HD dealer to say they could not do a fall away test/adjustment because it has a heavier wheel on it?????? That sounds stupid...really stupid...

 

Air pressure, yes, but also balance.

 

I just had this problem with my Dunlop on the front. The pressure is a possability. The local custom shop told me that they have had quite a few like that this year already, and are trying to contact other shops in the area. They think Dunlop may have had a bad run of 21 inch tires, because all the bikes that came in with this problem had no front end issues. I'm sure it would be hard to prove though.

 

I maintain 30 psi. I am getting a new one installed on Thursday and will talk to them about it as well. Thanks for the input.

 

This is usually the case with low air pressure. What is your name you ordered under. Let me know (via PM if you prefer) and I can look your order up and see if there is something we can do for you. And that is what we call HogPro service.

 

In the 18 yrs since I built my chopper, I have always run my 21" at 35+ psi. 30 is quite low for best handling. Just my Opinion.

 

I'd have to agree on that. I'm not familiar with the GT502 but the new Metzeler 120/70/21 run at 50. Michelins take 42. If I ran any at 30 I am sure it would cup badly, not to mention handle poorly.