I've decided to keep my old tri bike as a dedicated indoor bike, but want to match it to my new bike fit as much as possible. Thus, I'm looking to swap out the DuraAce FC-7900 cranks that are on it (175mm) for something that's 165mm and compatible. No need for anything fancy on my indoor bike, so Ultegra, 105, Tiagra would do the trick...

I guess it wouldn't necessarily need to be Shimano, either, but I'm assuming sticking with Shimano might assist in the compatibility arena.

Thanks!