FIA Frame survey for TTR

[ffindling]

Originally Posted by Three Peaks

FFR doesn't offer a pin drive hub. Their pin drive options are for addition of bolt on adaptors for pin drive wheels.

That's what I don't understand. The bolt on adapters would typically increase
the "flange to flange" measurement by no more than 1 inch. The Vintage adapters are .375" thick and I would assume Trigos are similar to that. So a
pair of them would increase the flange to flange measurement by .750". Normally, one compensates for that by adding the thickness of the adapter to
the rim backspace to maintain the same wheel position. So if I was using a
3.5" backspaced bolt-on rim and wanted to maintain the same position with
the adapters I would order the wheels with a 3.875" backspace. But FFR lops
off a full 5" on the flange to flange width when the "pin drive" option is specified.
So assuming a .375" inch thick adapter is being used, I would have to reduce
backspace on the wheels I ordered to 1.375" to maintain the same position.
It doesn't make any sense if they use the same hubs for their bolt-on setups and their pin-drive setups to narrow it by 5". I can see narrowing it by the
combined thickness of the adapters so the same backspace as bolt-ons
can be used, but this is far less than the 5" they narrow it.

....Fred