Bottom bracket, square taper upgrade?

[pat_h]

Doing an upgrade of my 91 British Eagle. Doing a quick search here, are they standard? I'm seeing 68 x 110 mm BB-UN73.
And how upgradable are they?
Any advice great-fully accepted, thanks

This is mine

 

[Remko]

Re:

The BB-UN 73 is the Shimano XT axle. If it's still working good I'd leave it in. There are new replacement axles available but they're heavier and no xt quality.

 

[hamster]

They are pretty light - 250g or so, there is not much lighter apart from a Royce, which will be £150+...

 

[pat_h]

Re:

Is it possible to upgrade to newer tech though? Or are you stuck with square taper only?

 

[Pipmeister]

Re: Re:

Is it possible to upgrade to newer tech though? Or are you stuck with square taper only?

You can fit the two versions of Octalink, as well as the ISIS type:



and also, the External Bottom Bracket technology, like Shimano's Hollowtech II:



Personally, I would use Square Taper.

Pip

 

[legrandefromage]

Newer doesnt always mean better.

Lots of issues with bottom brackets but all dependant on use. Well sealed square taper BB can last decades of churning away whereas cheap ones can last two rides or two years.

External BB start buggering up chainlines due to the thick bearing cups pushing the chainset out further than a square taper or splined version. Then you get the arguments around their longevity - if not properly seated they dont last long.

Then theres about 1 million million different version of the external BB depending on which brand chainset you go for.

So, if it were me and going along with the previous post, if the current BB is smooth feeling it will be fine and not worth replacing.

 

[pat_h]

Thanks all for the replies, the graphic is great!

 

[shedobits]

Re:

Nothing to add to the above other than I would take the chance to remove the BB and grease the threads especially if you don't know the frames history.

 

[pat_h]

Re: Re:

Nothing to add to the above other than I would take the chance to remove the BB and grease the threads especially if you don't know the frames history.

That's probably a good idea, it feels solid if a little rough from lack of use. A good dose of grease could do wonders.

 

[Rampage]

Re:

To answer your question: no, it isn’t possible to upgrade from square taper as it hasn’t been bettered yet.