Triumph Repair: tr6 wheels, factory rims, stock wheels

Question
QUESTION: i'd like other options besides panasports, wires, or stock wheels.  i'd like to go to 15x7's and i read the offset is 39.9mm stock, but is this pos or neg, and which is which, farther away from the car or closer to the car???
sorry, in all the cars i have built up, never had to worry about custom wheel offset!!!
thanks!!


ANSWER: merle or rusty,

One option for custom wheels for the TR6 is Diamond Racing wheels (http://www.diamondracingwheels.com/).  They'll make up pretty much whatever you want in terms of width and offset.

From what I've been seeing the offset on the TR6 factory rims is 0".  

A good explanation on wheel offset can be found at:

http://www.discounttire.com/dtcs/infoWheelOffsets.dos

The most common problem is that in order to keep the wheels within the wheel wells you'll need more positive offset.  Too much and the wheels tend to hit the suspension parts.


Cheers,

Jim

---------- FOLLOW-UP ----------

QUESTION: o.k., but now i need to know about "back spacing"??
the 0 off set is a good advice answer, but this just opened up a new can about back spacing.  thanks for your help so far.  and i think your right about triumph not planning on lasting this long, anything not under the hood is impossible to reach!!!!

Answer
merle or rusty,

Keep in mind that when you're talking about wheels and offsets, it's related to "backspace".

For a simple example.  If you have a 7" wide rim with a 3.5" backspace (amount of rim "behind" the hub mounting surface) then you're looking at a wheel with "zero" offset.

That is... 7" divided by 2 is 3.5".

If you have the same 7" rim and there is a 1" negative offset then you'd have the rim width (7") minus 1" offset divided by 2... or a 3" backspace.

if it's a 1" positive offset... figure a 7" rim + the 1" offset divided by 2... for a backspace of 4".

One advantage these days is that there are a lot of tire choices available in a low profile... so instead of sticking with a 15" rim you can go to a 16" or 17" and avoid some of the suspension clearance issues while keeping the tires within the wheelwells.


Cheers,

Jim