For You Mechanics- IDing a BB

[cd_davis]

My wife's son is getting married in October, postponed from 6/19. Wants to lose weight, so started riding his Specialized Hardrock Comp. BTW maintenance has been neglected for years.
I'm replacing chain, cassette, rotors, Hayes mech calipers and chain rings. Cables too. Had to pull drive side crank Truvativ Isoflow for chain ring removal; most components are Shimano Alivio.
The BB is shot, has square taper, but I have no clue that the BB is. The Park Tool BBT-2 and Shimano TL-UN74 tools fit to remove the 20 tooth BB cups.
I do not want to proceed further until I know whether a replacement BB is available. As I'm a road guy, can anyone recommend or specify what the BB is? ISIS type maybe. Thanks
Chris

[phoenix]

Can you post a pic so we can try and see what you’re working with?

[cd_davis]

Will take a few pics and post. Great idea.

[Gummee]

My wife's son is getting married in October, postponed from 6/19. Wants to lose weight, so started riding his Specialized Hardrock Comp. BTW maintenance has been neglected for years.
I'm replacing chain, cassette, rotors, Hayes mech calipers and chain rings. Cables too. Had to pull drive side crank Truvativ Isoflow for chain ring removal; most components are Shimano Alivio.
The BB is shot, has square taper, but I have no clue that the BB is. The Park Tool BBT-2 and Shimano TL-UN74 tools fit to remove the 20 tooth BB cups.
I do not want to proceed further until I know whether a replacement BB is available. As I'm a road guy, can anyone recommend or specify what the BB is? ISIS type maybe. Thanks
Chris

If it's square taper, pretty much all sizes are available from any of the wholesalers.

Personal opinion: update the crankset to the Hollowtech II type. It'll cost more than just a BB, but it's a better system.

HTH

M

[cmbicycles]

Just need to measure the BB shell width, its either 68 or 73mm, and then measure spindle length. As mentioned above, square taper is alive and well from most anywhere in a variety of sizes. I dont know that the bike you are working on is worth the upgrade to hollowtec2 cranks/bb, if you go that route you may be into more than the bike is worth with all the other work being done, but that's just my opinion.

[josephr]

I have a hardrock comp in my basement that my daughter used in college. Paid ~$100 10 years ago...would be lucky to get $50 for it now, I guess. Fixing the bike up is a good idea though because he has the bike in-hand, and good used bikes cheap are hard to find....especially when when its cyclists like us who have 'expectations.' ;)

[ultraman6970]

Looks like the friend has a mtb with disc brakes bicycle?? Is that crankset triple? So far i remember those fsa cranks came like in zillion of flavors and combinations depending of the bike.

Measure the BB shell, measure the length of the axle and get the BB u need (as CMB said). just remember to put grease in the cups, besides that doubt you will have any problem.

[charliedid]

Just a guess but likely something like a UN-55 square taper BB and a replacement from Shimano and or a Tange is no problem at all.

[Ralph]

Just a guess but likely something like a UN-55 square taper BB and a replacement from Shimano and or a Tange is no problem at all.

When you get the old one out, it may say on the BB what size it is.

[charliedid]

When you get the old one out, it may say on the BB what size it is.

Good point.

Sometimes needs a bit of cleaning depending on how much rust discoloration.

[cd_davis]

Here are a few pics. I did not want to remove the old BB if a replacement is not readily available. To the earlier comment, the bike does not warrant a new crankset as I bought new chainrings. Our son is saving for the wedding and he's just trashed the bike over the years.

[slambers3]

Standard square taper JIS. Measure shell width/ spindle length and voila. Oh yeah it’s BSA but you probably knew that

[BRad704]

Another vote for pulling the BB to check for a label. If it's loose ball, you could always clean and repack the existing BB.

[ultraman6970]

I have here a spech that has a similar set up, the BB is sealed like that one but inside has lose balls. Is like a weird hybrid BB cartridge which they put cones to it and then a shell around to sealed it.

Those can be fixed... because apparently the fall of that design is that the cones get tight over time. if you figure it out how to get lose the cones. In my case havent figure it out yet hehehe :D

Check it out, maybe you have one of those.