Bolt on style knockoffs and radials

[Karl K.]

I just purchases a set of direct bolt knockoff wheels (these are
the latest retooled version)
and a set of BF Goodrich Silvertown radials 205/75/15.
Besides the tires just looking to large, when turning the
steering wheel the front of the tire contacts the fender
behind the turn signal. Has anyone had any experience
with this, they are the recommended size per the catalog.
I have not measured this but the wheels seem to stick
out further than the steel rims that I took off which isn't
helping. Would the different profile of a bias ply tire help
this situation.
Any help appreciated,
Thanks,
Karl

[John H.]

Re: Bolt on style knockoffs and radials

I just purchases a set of direct bolt knockoff wheels (these are
the latest retooled version)
and a set of BF Goodrich Silvertown radials 205/75/15.
Besides the tires just looking to large, when turning the
steering wheel the front of the tire contacts the fender
behind the turn signal. Has anyone had any experience
with this, they are the recommended size per the catalog.
I have not measured this but the wheels seem to stick
out further than the steel rims that I took off which isn't
helping. Would the different profile of a bias ply tire help
this situation.
Any help appreciated,
Thanks,
Karl

Karl -

Do the specs for the new wheels have a dimension for offset or backspacing?

I've used several brands of 205/75-15 radials over the years on stock 6" rims (both steel rally wheels and '67 aluminum bolt-ons) on several midyears, and have never had a clearance problem.

[Edward J.]

Re: Bolt on style knockoffs and radials

Karl, I don't know what it is with tire sizes these days, but if you put 6 of the same size tires from different manfacturers side by side they will all appear to be slightly different in width and height,to me for any C2 OR C3 car you really need the measurements on the tires you are buying, at least to compare with what your replacing. radials are really the only problems, the bias ply tires not as bad, but still do have occ. problems fitting in the tire tubs.

As John says 20575r15 tires should not have a problem, but if you have a tire you removed to compare I am sure your find the tires dimensions different.

[Karl K.]

Re: Bolt on style knockoffs and radials

The direct bolt knock offs have about 1/2 inch more offset than the the steel wheels that were on the car. I will get a better measurement when i take the wheel off of the car. I will probably have to go with bias ply tires
again, will the 7.75x15 tire work on a 6 inch rim, I think my steel ones are 5 inch? Looking in my Corvette black book only one tire size was available
that year.
Thanks,
Karl

[John H.]

Re: Bolt on style knockoffs and radials

The direct bolt knock offs have about 1/2 inch more offset than the the steel wheels that were on the car. I will get a better measurement when i take the wheel off of the car. I will probably have to go with bias ply tires
again, will the 7.75x15 tire work on a 6 inch rim, I think my steel ones are 5 inch? Looking in my Corvette black book only one tire size was available
that year.
Thanks,
Karl

Karl -

The original '65-'66 steel wheel had a 5-1/2" rim, and the optional knock-off wheels had a 6" rim; in '67, the standard steel rally wheel had a 6" rim, as did the optional '67 bolt-on aluminum wheel. In all cases, they wore 7.75-15 tires.