Hello knowledgeable people! So I recently pulled the trigger on a 1993 Team Miyata frame:





The 1993 catalog states that the frame originally came with a BB-UN71 bottom bracket. I found a decent deal on an incomplete shimano 105 3x9 drivetrain on craigslist, but I was wondering if hollowtech will work on this frame. What do you guys think I should put on here? Your input would be greatly appreciated.

Aforementioned catalogue

5500 105 will likely be an octalink BB not HT II

Any standard English-thread 68mm BB or outboard BB cups will screw right in.

Top

The BB-UN 71 bottom bracket will not work with Hollowtech cranksets as it is square taper. Hollowtech cranksets require splined Octalink bottom brackets. However, Shimano offered Octalink bottom brackets for the 105 Hollowtech crankset that will fit this frame. The matching cartridge bottom bracket was part number BB-5500 but you can also use the Ultegra BB-6500. There was also a compatible Dura-Ace bottom bracket but it was not cartridge style and many members report difficultly obtaining proper adjustment.

Make sure you buy the correct version of BB-5500/6500. Your frame requires the English version (68mm width, 1.37 X 24 TPI threading) as opposed to Italian (70mm width, 36 x 24 TPI threading) . Also, depending on the number of chainrings, you'll have to choose between two lengths (109.5mm for double, 118.5mm for triple).

I think 8-speed Ultegra is a great choice for this bike. Just as shown in the catalog, except lose the Synchros stem for something with better aesthetics.

If going square taper, I usually take a try & see approach. It can be fickle. The crank has an offset of whatever amount, the bb is of what ever length, the q-factor is what ever length, the derailleur has it's range. It's not hard, it is just fickle.

When it comes to any project with external bottom bracket cups, I just buy a crankset that matches. It turns out golden every time. Anymore, my goto is the used bike shop before any place else.

Looking forward to seeing how the project proceeds.

Nice, thank you for the great info!

I'll definitely keep you guys updated

Fine frameset!
Choose your desired group and then go stealth with a Ti bottom bracket from Omni Racer. They have square tapers and proper Q factor for triples. Inquire.
https://www.omniracer.com/

Sweet frameset! The world is certainly your oyster with regard to component and groupset compatibility. Others have already said plenty. As for square taper bottom bracket spindle lengths, you may have to do some research, though by the late '80s Shimano (at least) had streamlined their BB spindle lengths. If talking about Dura-Ace around that time--previous cranksets would employ 109-111mm or so BB spindles. When Shimano went to 8-speed, they redesigned the crankset ("7410" is stamped on the back of the arms), making it more curved and also accepting of a much narrower ~102mm BB spindle. Hollowtech (aka Octalink) for road ("V1" designation, almost exclusively) went to two lengths as T-Mar said, depending on double/triple. Hollowtech II (external bearing cups) BBs for road (at least, all I know) were only one type. A double crankset had a standard spindle length, and a triple would come with 2mm or 3mm spacer(s) for the longer spindles. The spindles on Hollowtech II cranksets were attached to the drive side crank arm/spider.