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TR6 wheel offset/backspace TR6 ?

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crj7driver

Jedi Trainee
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In my search for different wheels for the TR6 I am looking at have some custom 3 piece wheels made but have a few questions. I have gleaned that the maximum allowable backspace is 4 inches.

The stock wheels are 6 inches wide and are 12 mm positive offset which equates to a 3.5 backspace. So by my calculation a 7 inch rim with a 0 offset also have a 3.5 inch backspace.

I know I can run 16 x 7 panasports which run a zero offset and that equates to a 3.9 inch backspace according to the hottr6 website (I am not sure why it is not 3.5 inches).
https://www.hottr6.com/triumph/tr6pana.html

Does anyone know if backspace (as far as the max allowable 4 inches) is with or without taking the added width of the tire extending past the rim? FWIW the rims I am considering are 17 x 7.

Thanks for any info.
 
Backspace does not include tire sidewall buldge but DOES include the edge of the rim. So by your calculation, the backspace of a 7" rim with 0 offset should = 3.5" + the trim lip (usually 1/2".) Measure from the back of the lug mounting to the rear of the edge of the rim.

I've found that 4" b.s. really needs spacers to clear the rear suspension by the tires, esp if you convert to tube shocks. Shoot for 3-3/4".

17's are good for modern cars with modern suspension. But on our cars, the sidewall flex is part of the suspension and with 17's the ride will numb your tailbone. 16x7 is about the limit.
 
Thanks, that is exactly what I was after. I did notice that the only place I was getting flex in the suspension was from the flex of the 75 series tires, I have the "racing" stiffness springs and poly bushings as well.

I am going for a raw race car type ride but don't want to make it too uncomfortable. So we will see.
 
crj7driver said:
I am going for a raw race car type ride but don't want to make it too uncomfortable.
Click to expand...

You can have either the race car ride, or comfort. Take your pick.
In a race car, you feel every pebble or chunk of rubber you run over, and every variation in the track surface. Not recommended for a street car.
Jeff
 
Bugeye58 said:
you feel every pebble or chunk of rubber you run over, and every variation in the track surface. Not recommended for a street car.
Click to expand...

Especially with the streets of the greater Denver area...
 
Bugeye58 said:
crj7driver said:
I am going for a raw race car type ride but don't want to make it too uncomfortable.
Click to expand...

You can have either the race car ride, or comfort. Take your pick.
In a race car, you feel every pebble or chunk of rubber you run over, and every variation in the track surface. Not recommended for a street car.
Jeff
Click to expand...

I really want the car, including the ride, to be raw violent and angry which is why I am looking at using a lower profile tire. I just don't want to regret doing it after the novelty of it wears off which is where the too uncomfortable qualifier came from.

One of my motorcycles is basically a race bike and while it is very constrained to ride on the steet it is still enjoyable. So I guess that is what I am going for with the TR.
 
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