I have Race Face Diablous cranks on my Sunday (83mm) I would like to put them on a potential new frame, an Orange 224. Can i use my cranks on the 68mm (i think could be 73) bb? I would assume i need spacers but can it be done?
If you remove the internal spacer that is not really necessary (or get one out of a 68/73 BB) then the BB will go in. If you have a 68 shell set it up like a 73 with the spacer(s) between the shell and the BB. Then you can make two 5mm spacers and put one on each side of the spindle. Now the spindle thinks it's going into a 83mm BB. I found a piece of pvc that worked great.
I believe Santa Cruz actually recomends doing this on their VP Free since it's a 150mm hub and a 68 or 73 shell kind of bike.
You may even be able to get 10mm worth of those little spacers that are allready on the spindle from Race Face.
Now if the Orange or whatever bike you put these on uses a 135 hub the chainline will be horrible. Only do this with a 150 hub bike.
I still prefer a 73 BB on any bike for more clearance and better chainline in easy gears since the only time i backpedal much is in easy gears (like climbing some ladder bridge) and i can backpedal without the chain dropping down the cogs.
I haven't personally used one but I don't think they go over the bb threads, but sit on the outside of the bb cups on the spindle itself. I'd personally just sell the cranks and buy some different crank but it'll look like this i think.
in regards to the chainline issues, i know the older frames are 150 spaced, and I think the new ones are 135. So it will depend on what year the frame is. I'm sure Transcend will chime in (since his team is sponsored by Orange).
To add some exact info, The raceface Diabolous Xtype cranks will work on both 68, and 73 mm shells. Raceface uses spacers in two different locations, one set to shim for shell width, mounted on the threads of the BB, and one set to set your chainline when your installing the cranks themselves. Your standard setup for the BB spacers<The ones that go on the threads> for 73mm shell, you will have one spacer on the nondrive side, and one on the drive side. Removing the one on the drive side for use with Etype derailers/chainsystems. For 68mm you will have one on the nondrive, and two on the drive side, removing one driveside for use with etype derailers/chainsystems.
Like I said though, these are standard setups, not exact, always check with who makes the cranks how they want them set up on a particular bike.