Roger,
Thanks for the reply.
RE:"I believe the hub to hub measurement of
the TR250 is the same as the TR6"
I concur, since all the parts between the hubs
seem to be identical or interchangable. (If they are not,
my IRS should be grenading any moment since it's full
of TR6 parts).
RE:"The offset on the TR6 is 0.25, i.e. the
center of the tread is 1/4" inboard of the mount point."
That's what I get when I measure a 5 1/2" TR6
wheel from my parts car: 6 1/2" overall width, 3 1/2 "
backspace = 1/4" positive offset. Someone on this list
quoted the offset as 3/4" about a year ago, and it threw
me off, I thought perhaps I was measuring incorrectly.
RE:"so I would use the TR6 offset, as I recall
the 4.5 wheels are goofy..."
For posterity, my 4 1/2" TR250 wheels are
5 1/2" overall width, 3 1/2" backspacing = 3/4" positive
offset. It looks like in '69 they added the entire 1" of wheel
width to the outside of the hub. Talk about goofy, the
Western mags on my car since '78 are 6 1/2" overall
with a whopping 4 1/4" backspacing. The front wheels
rub the a-arms at full lock even with scary-looking
3/8" spacers fitted. I guess Triumph stuck to a 3 1/2"
backspacing for a reason...
Thanks,
Tom Marincic
CD3574L
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