Hollow tech II old Raleigh
 

I have an old Raleigh Grand Prix maybe 1975. Cottered cranks junk. I have a spare fsa mega expo with External Bearings. Any possibility to make this work in the Raleigh, I mean even creative like loctite and plumbers tape? I don't think so but thought I would ask.

I have a mid-80s Super Gran Prix that now has a Hollowtech II on it.

I had to get my LBS to shave about 3mm off (1.5 each side) the BB to make it work.

By the mid-80's Raleigh had gone to English threading. In the 1970's they were still mostly Raleigh's proprietary threading. You can have it retapped from Raleigh's 26tpi to the standard English 24 tpi but it will be a weak connection.

If it a 26 TPI bottom bracket shell, then I'd punt. Trade it for a square-taper crank, find a new axle and use the original cups.

If you want to spend a couple of hours with no guarantee of success, then you could file down all but 3 good rows of threads on the BB cups- a 24 TPI cup will thread into a 26 TPI BB shell three turns. If you were to tap it to 24 TPI, those three threads would be all you get anyway- the others would be cut away by the tap. I'd leave the inner threads and file the outer (nearest the bearing).

The shell will be about 3 mm too wide, too- 71 mm rather than the desired 68 mm. You can file/grind this down as well, but it's mighty important to hollowtech bearings that the faces be parallel and tangential to the axis of threading. The crank may have 3 mm of tolerance there anyway, so I'd try it before grinding/ filing the shell. There is no such thing as a facing tool for 26 TPI BB's, which would be the right way to do it.

I like that idea. Years ago (many years ago) I put a Stronglight 93 on my '70 Super Course. The standard threads on the cups that came with the crank were wrong, so I used the originals. They worked fine.

Finding a square taper spindle for the crank you end up with could be difficult. If eBay and your local shop can't help, give these guys a try--http://www.renehersebicycles.com/. Finding old NOS is their specialty.

Buy a Phil BB for outboard-style cranks. http://www.philwood.com/products/obbhome.php Should fit anything road except SRAM. They make 2 different 26tpi versions; you'll want the 26tpi x 1.37 version