Originally posted by Canope:
I suppose it could be a bad tire. I bought some pretty cheap rubber. They 'look' really good though. All 4 are round and I can't see any oddities.
If I switch the fronts around, should it pull to the left if there is indeed a bad one? Can the rears play into it?
They may look fine but you cannot see whether the deefect may be structural, which can cause the pull.
If you do switch the tires around and in fact it does pull the other way, then you're guaranteed that it's the tire. The rears will not have much effect on pulling, especially since you stated it was pulling rather hard.