New BB needed, cartridge or cup and bearing type?

My Sbike's UN-10 BB is finally giving up the ghost (TBH I didn't expect it to last this long) and due to the switch to M730 and different BB length requirements, my Scott needs a new BB as well.

For the Sbike I was able to source a pair of NOS UN-72 BBs in the correct 68-113 fashion, so that's sorted and I should be good for another decade or so.
However the Scott is doing my head in. No UN-72s to be found in 68-122.5, but I did find a UN-55 and a NOS XT M730 BB in the correct size and thread type.

The bike would normally have a 1994 Alivio set instead of the M730-735 it's wearing now, so originality is not an issue. Reliability is, especially because I tend to break UN-45 and UN-50 BBs very quickly.
So which one would be most likely to be stronger and more reliable?

Also, I'm totally unfamiliar with those old BBs. Is it easy to set up, adjust and maintain? Not planning to put the bike in the workstand every week to re-grease the bearings and adjust the tension.

OR

I find the cartridge ones last well (5+ years / 5-10,000 miles).

Or you could go go for one of these...

http://www.ebay.co.uk/itm/New-neco-BB-C ... 3a7d0493ed

...never had any problems with them myself; the Acor BB's are also well worth a look.

Thanks Stevo. Thing is, I already decided to buy both the options in my first post. Never hurts to have a spare BB, especially if it's for something as common as M73x XT.

Think I'll have a go at the UN-55 first, just because I have the tools to install that. If it breaks, I'll need to tool up and install the XT BB.

For reliability I'd go with a cartridge type BB. fit it, forget about it. Replace when it dies (which is usually a good length of time).

Those real ones that were on the bay are nice in an old school way

My personal experience of the M730 BB is that it does require more maintainence and re-greasing regularily (especially if like me, your trails are still like swamps!) I replaced my knackered M730 for a UN55 last year as I'm one of those people that like to fit and forget when it comes to BB's, and so far so good!

Wook

Phil Wood

Shimano cartridge, I replaced an early worn UN50 with a M730 bitd & tbh it didn't seem much of an upgrade at the time.
I'd keep my eye open for a good UN70 used item.

Whatever you decide on, for gods sake, DONT GREASE IT... or wait... MAYBE DO GREASE IT

I DONT KNOW

AGGGGHHHHHHH