[Closed] External BB Advice Please

I'm getting sick of the rate at which I'm going through Shimano XT BBs, and the fact that the bearings are non-standard sizes so I have to bin the whole thing instead of just replacing the bearings.

Just a standard 6805 2RS no?

I'm eyeing up Hope or possibly Pace replacements but IMO any external BB is going to suffer the same ingress problems regardless of bearing quality, so I want one that uses standard sized bearings if at all possible.

Yup, they all suffer the same way, kind of doesn't matter the bearing quality (to an extent, wouldn't put el super cheapo ones in myself) it's more to do with the sealing... And packing them full of grease, as just about all bearings come bone dry from the factory!

Hency why Chris King designed their BB to be purged with grease regularly (by their grease purge tool you can buy) which prolongs the life massively.

To be fair, buy ANY HT2 BB, lift the seals on the bearings, pack full of grease, and you will get a lot longer life out of it than you would if you don't. And an XT BB is much cheaper than most of the competition.

FWIW, I've had very good success with a Superstar SKF bearinged BB on one of my bikes by just putting a decent amount of grease in the bearings, a BB people have known to last a very short amount of time despite having perhaps the best quality bearings you can buy fitted...

Hi,

Shimano don't use a 6805-2RS, the bearing is something like a 6805-RD, which is 6mm thick instead of 7.

Cheers 🙂

How long are the BB's lasting before they die?
How often are they ridden?
I got a SS HT2 BB, and the bearings weren't very well sealed.
BUT
You can then takeout the old bearings and replace them with some cheapo ones (£2 ea) or put in some better quality ones (£6ea). They key seems to be to carefully prise the dust covers off the bearings and fill them with grease every now and then.
Also the preload screw on the crank only needs to be done up finger tight, otherwise there is too much load on the bearings.

search ebay for GUB BBs. Chris-King look-alike with sealed bearings, £30 for ceramic!
(but watch the spacers, you'll only need 1 or 2 for a 68mm shell)

Bigyin - I'm doing a couple a year. I have 2 bikes and ride 3-4 times a week.

The superstar idea isn't such a bad one 🙂

That's the sort of thing I'm after - just an external BB with a standard size bearing that I can replace when poked.

I have Hope ceramic, which has been faultless so far, over 6 months (XT lasted 3).

I saw a Superstar cup disintegrate completely - the shell that is, not the bearings. Proves nothing, but put me off.

Rose bikes were doing XTR BBs for £23 delivered. Mine arrived yesterday (with a bowl...)

Well, I bought a Hope one for my Nomad in the end as there seem to be lots of good reports on bearing life, and there are plenty of people selling bearings online for them.

I'm going to try fitting an extra seal to the Shimano BB on my singlespeed: the outer face of the bearings are open, I'll take the inner seals off a dead one and fit them to the outers on a good one after packing with decent grease 🙂

Neil.

Phil Wood makes replacement bearings that fit Shimano BBs

Tim@sideways should be able to advise

Hope ceramic, been in my 5 for 2 years gets taken out and given a quick clean when I can be bothered, works perfectly.

Curiouslt re the grease issue, I was told by a lbs that ceramic are self lubing and should be run dry.. any opinions... ?

Phil Wood makes replacement bearings that fit Shimano BBs

Phil Wood Bearings are no better (or worse) than many other bearings out there on the market. The key to them lasting so much longer than other bearings is that Phil Wood cunningly actually makes sure they are properly packed with a decent grease when they leave the factory!

I can guarantee the SKF bearings in one of my BB's (which left the factory dry as a pancake and I promptly sorted out) are of a higher quality than the Phil Wood ones, not that it matters, as anything even half decent will last a while as long as its properly packed with grease (and preferably regreased every so often).

I've just gone back to square taper! new cranks, chain rings and new squaretaper BB. not installed yet

Octalink was pants
ISIS is made of cheese
External BB's life spans can be measured in months not years.

I was tempted to go for a CK BB but the cost put me off and I needed new chain rings anyway so it wasn't much more to go the old school route.

shimano external BB's aren't that expensive but I don't want the faff of replacing them every few months.