Square taper

[pumpkin]

Need a new square taper bb. 68x113 for a Sugino chain set. Is there a thread already for this? Or anyone have recommendations for a long lasting one without going Phil Wood?

[De Sisti]

Need a new square taper bb. 68x113 for a Sugino chain set. Is there a thread already for this? Or anyone have recommendations for a long lasting one without going Phil Wood?

https://www.spacycles.co.uk/m16b0s110p140/STRONGLIGHT-Bottom-Bracket-JP400-Aluminium

[Tim Hall]

Don't forget that square taper comes in two flavours, ISO and JIS.

Putting an ISO taper crank on a JIS bottom bracket means it will sit around 4mm further out. AFAIK Sugino make both ISO and JIS cranks.

<end of egg sucking lesson>

[Gattopardo]

Thought the UN55 shimano was the go to BB.

[rogerzilla]

Thought the UN55 shimano was the go to BB.

Discontinued and replaced with the (probably deliberately shite, because they want you to use HT2) UN-300.

[Paul H]

Tange-Seiki have a good reputation. I don't have one, though I do have a couple branded IRD with Tange bearings, which might be the same thing.   The top of the range IRD Defiant feels quality, it  was the only option for a 73mm BB with the axle length I needed when I bought it, the bearings are replaceable, though I've yet to discover at what cost and effort. Hub Jub stock Tange, SJS stock IRD. 

[LittleWheelsandBig]

Tange used to make some of Shimano’s BBs.

[pumpkin]

Thanks. The 55 is still available in some shops but collection only apparently. JIS is what I'm after and that Stronglight was my thought after the 55.

[Kim]

Thought the UN55 shimano was the go to BB.

Discontinued and replaced with the (probably deliberately shite, because they want you to use HT2) UN-300.

What's so bad about the UN-300?  I replaced the UN-55 on my Streetmachine with one a couple of thousand miles before the frame failed, so it got consigned to the bits box while barely run-in.

[LittleWheelsandBig]

There are several reports of UN-300s failing not too many months after installation but I am not sure why.

[morbihan]

rene herse make both types.

[zigzag]

most sq taper bb's can be refurbished by removing the old bearings and pressing on the new ones of choice. the question is whether it's worth doing.

https://www.youtube.com/watch?v=meErJdr_fUI

[drossall]

... the question is whether it's worth doing.

I think, having seen one or two of these videos, my question is why wouldn't you do it, especially with supplies of good new models getting scarcer, and (I assume) the opportunity to buy quality replacement bearings?

When push-fitting sealed bearings, I'd generally use the old one outside the new one, to protect it and take any lateral loads in the pushing. Should also negate the need for a deep socket in that video.

[zigzag]

while i have access to a cycle workshop and necessary tools, not many people do (or have the tools/skills themselves). therefore it's simpler to just buy a new one and swap it out (not that i agree with throw-away mentality).

[Kim]

while i have access to a cycle workshop and necessary tools, not many people do (or have the tools/skills themselves). therefore it's simpler to just buy a new one and swap it out (not that i agree with throw-away mentality).

To be fair, the obscure tools are the ones you need to get the BB off the bike in the first place, not the ones needed for the above procedure.  The real barrier is likely knowing that you can even do it (I didn't - it just looks like a sealed tube of mechanical magic with nothing obvious to unscrew!), and being confident that you can find the right replacement bearings.

[drossall]

Quite. If you can replace a BB in the first place, you can definitely replace those bearings in the sealed BB.