Backspace/offset for wheels on my 1964 GT Hawk

Tom,
You can get some pretty meaty tires in the rear wheel wells, but you'll
need a fairly deep backspacing (5 1/2-6"?), or a narrowed rear, to make
it work. I recollect the standard backspacing available in the Torq
Thrust line makes it difficult to get much tire inside with a standard
axle. Your tire shop should be able to put the car on a rack and do
some measuring to determine ideal backspacing/tire size. The
speedometer will be effected if you change the overall diameter. Since
newer tires are lower profile, you might possibly end up with the same
diameter even with a 16" wheel but, again, you have to get out the
measuring tape.
S2DSteve
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

you need a front wheel drive offset in the rear and a rear wheel drive
offset in the front to run killer tires.
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Tom wrote:
> Hi guys!
> I'm new to this internet thing, so I need some help. Will a reply be
> sent to my e-mail address, or do I need to check the group listing
> occasionally?
> Anyway, my question deals with the backspacing/offset for wheels for
> my 1964 GT Hawk. My desire is to put American Racing Torq Thrust wheels
> on this beauty, but when I go to order them, this is the first
> question I'm asked. Can someone help me? What is the largest tire I can
> safely run, and what is the wheel size for that tire? Has anyone run 16
> inch wheels? Can this be done without effecting the speedometer?
> Any help from my Studebaker friends would be appreciated. Thanks in
> advance.
> Tom

do you want to run the same size wheels/tires front and rear? or do
you want as big as possible at both ends?

nate
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Someone posted this for the group a while back. It's helpfull.
http://www.1010tires.com/TireSizeCalculator.asp
What size were the origonal '64 Hawk GT wheel and tires. Were they
195/75/R15s on a 5" rim? I beleive that was the size for '62 Hawks.
And here's a question for the Stude faithful. What was the original
white wall size for a '62 Hawk? They don't look really huge in the old
photos. Maybe a inch and a quarter. The off white wheel paint that
shows around the hub caps kind of added to the white on the tire.

Tony in Austin
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Tony in Austin wrote:
> Someone posted this for the group a while back. It's helpfull.
> http://www.1010tires.com/TireSizeCalculator.asp
> What size were the origonal '64 Hawk GT wheel and tires. Were they
> 195/75/R15s on a 5" rim? I beleive that was the size for '62 Hawks.
> And here's a question for the Stude faithful. What was the original
> white wall size for a '62 Hawk? They don't look really huge in the old
> photos. Maybe a inch and a quarter. The off white wheel paint that
> shows around the hub caps kind of added to the white on the tire.
>
> Tony in Austin

original would have been 6.70-15 on a 4.5" rim, or 5" rim if equipped
with the optional "Avanti" wheels (standard on a "super" package car)

I am running 15x7" with 3/4" offset on my '55 coupe (same body) and it
works fine, but you could go bigger in the rear if you really wanted
to, all the space is on the inside though. That is why I asked above
if he wanted to keep the same size wheels front and rear because I
think 7" is probably about the max for the front, and certainly the max
you can get without playing with different offsets front and rear. I
am running 1/4" spacers on the front wheels to keep the tires away from
the tie rod ends but even though it is close I saw no signs of contact
without them with 215/60s

nate
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Yes, I want to run the same size all the way around, so they can easily
be rotated. I'm sorry I failed to mention this in the first posting.
One more question,. Will the rear axles be adversely affected by
larger tires? I've read the OEM axles are not all that strong, and now
that they're over forty years old, I don't need to put any more stress
on them. I don't want to go to the expense of up-grading, and yet I
want to drive te car as often as possible, mostly on extended road
trips. As usual, I appreciate all the help. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Thanks Mark. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Thanks for the reply. I appreciate it. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Thanks for your reply. I appreciate the help. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Yes, I do want to run the same size tires all the way around. Sorry I
didn't put this in my first posting. Eagerly awaiting your reply.
Thanks in advance. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Thanks for this helpful info. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Thanks for the info. I'll carefully consider all my options, and when I
get these wheels, I'll let everyone else know, too. Tom
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk 

Tom wrote:
> Yes, I want to run the same size all the way around, so they can easily
> be rotated. I'm sorry I failed to mention this in the first posting.
> One more question,. Will the rear axles be adversely affected by
> larger tires? I've read the OEM axles are not all that strong, and now
> that they're over forty years old, I don't need to put any more stress
> on them. I don't want to go to the expense of up-grading, and yet I
> want to drive te car as often as possible, mostly on extended road
> trips. As usual, I appreciate all the help. Tom

Personally, and this is just my opinion, I wouldn't go too nuts on the
tire size. With the wheels mentioned in my previous post, you can run
205 or 215/70 without any problem. You can even fit up to a 245/60 but
I don't know if you would really see any benefit from them unless you
had some other performance mods as well. For ease of steering I
wouldn't go past a 215 on a regular driver, remember that increased
effort at the wheel also means increased stress on tie rods, reach
rods, etc. etc. etc. I suggest a 70 series tire just because most
"sporty" tires aren't available in a 75 series.

It looks like the 15x7 torq-thrust original is only available in a 6mm
offset which ought to work on a C-K with 215s but if you think you
might want to go with wider tires you probably want to think about
going with a custom offset, maybe 13mm or so, or 18-20mm if you are not
opposed to using spacers on the front. I seriously doubt that the 6mm
offset would work at all on a Lark.

If you are concerned about the axles breaking, peace of mind can be
obtained from Fairborn Studebaker; the axles they sell are made by
Moser and should be strong enough for most any Studebaker. Not dumping
the clutch from a dead start and not speed shifting also help (but
where's the fun in that?)

nate
 >> Stay informed about: Backspace/offset for wheels on my 1964 GT Hawk