my SKF was just starting to get a bit rough after 12 months, could only be felt when the axle was turned by hand and  hadnt developed any play yet.

would of been interesting to find out how long it would of lasted before it was unusable but  i snaped the axle on it about two months ago.

the hope one may be worth a look too..

It depends on the type of bearing they use. If it's a castellated bearing, then it'll almost certainly last longer than current offerings,(Shimano, Enduro, etc.) as they usually supply stainless balls & races.

But if they've gone down the "full compliment" Max bearing route, they may be prone to the same problems as Race Face BBs, but take longer to fail.

In Mavic wheelsets they supply 6805/61805(same size) bearings with C3 clearance, allowing them to roll more freely, and work for longer periods after dirt ingress to a small degree.

If they utilise these in HTII BB applications, minimising side loads from preload adusters will be paramount. But if it's managed correctly they could possibly last longer. Only time will tell.

They offer a 2 year warranty on other BB's, does it apply to the HTII version?

the body of the BB isnt made by SKF kevin just the bearings, in the same way that hope use INA bearings in theres.

Fwiw, I think the HT2 problem isn't with Shimano's bearings, but the basic mechanics of the system. There's a lot of force going through that area and it seems to be enough to distort the seals slightly and allow water / grit into the innards of the bearing. One of the reasons Hope's replacement does away with the plastic top hat, apparently, is to reduce the potential for play and flex.

The reason the SKF Isis BB works well - got two running, both fine - is that they've re-engineered the design with different, cylindrical bearings on the driveside, but the HT2 ones are - as I understand it - the same as everyone else's but with high quality SKF bearings. I've seen one of the hyped up Acros HT2 BBs die in a month of heavy use, so I wouldn't expect this to last significantly longer in the same conditions.

I wouldn't expect a massive improvement in durability as a result, I'd be more optimistic about the Hope design fwiw. I've also seen Neil, the guy who runs Superstar, posting elsewhere and saying that he thinks Isis, with his own or SKF BB, is a better system. Go figure. At least it's properly sealed.

Also, afaik, RF no longer use full complement bearings in their BBs after a string of failures - mine lasted about three weeks in the Peak. Anyway, I'd expect them - the Superstar ones that is, not RF - to last a bit longer than, say Shimano, but I wouldn't get your hopes up just yet.

Last time I built a bike I stuck an SKF Isis BB and RF Turbines on it because I don't believe outboard bearing designs are suitable for heavy use in aggressively abrasive UK conditions like the Peak. They may be great in California or for less gritty bits of the UK or occasional Dark Peak use, but round here, used lots, they are useless

Hello, the aerozine BBs should give longer and smoother life, as the bearings are much higher quality than no name generic low grade bearings. They chose SKF as the offer the most reliable and high quality bearings on the market.

 They use the top hat bush just like all crank manufacturers do, because if the bearings seize, the axle will rotate still with nylon on metal. I agree the hope BB should last longer because the balls are larger, but seal failiure is the usual cause of death. In that case the axle and the race spin against each other, and write your cranks off as lots of enduro bearing owners have found.

 Yes its swings and roundaouts.

 ( as a engineering geek, I want ISIS with better tooling so it doesnt come loose and an oversized BB so the bearings can be huge, and all made out of Ti so its light. But shimano went for cheap and simple.)

Can't comment on durability of the Hope BBs cos Bruv and I have only just had 'em fitted. However teveryone loves their super durable hubs, so that's a hopeful sign for their BBs I think. If you're from Southamtpon Mike, then GA Cycles in Shirley have Hope BBs in stock - or at least they did last week.

The reason they probably use a 'top hat' cover is to shim the bearing to fit over the 24mm crankshaft as SKF only make 25mm I.D. bearings. My RaceFace evolve BB bearings were all rusty behind the top-hat, I think the top-hat was holding all the crud next to the seal - it had no chance!

I've ordered an Aerozine BB with SKF ball bearings (eBay £20 from Oz), the SKF ISIS BBs have roller (cylindrical) bearings on the drive side and ball bearings on the non-drive side. With the different and internal ISIS design that's why they have a design life of 10yrs. Shame SKF haven't designed an x-type BB yet!

I've got the crappy own brand RaceFace ball bearing races out of the cups but i damaged the top hats so that precludes me simply ordering some SKF replacements (part number 61805-2RZ ). Bugger - it could have saved me some cash. Has anyone got any ideas how i can shim the shaft from 24mm O.D. to 25mm?

If you want to avoid what I did the plastic tophats should push out with your thumb if you degrease the unit and push really hard, don't use a tool they are really fragile. Try putting it in the freezer for a couple of hours first. Then twat the inner race of the bearing from the inside whilsh holding the cup in the removal tool. Even though the cups are Alu there's enough contact area with the tool to avoid damage. Remember to hit at evenly spaced intervals so the bearing comes out symmetrically.

 Good luck.

Just to spoil it for you, if you paid £20 for an aerozine BB it is most likely the standard bearing version not the SKF which is twice the price.

Neil (Aerozine UK Distrobutor)

Hmmm thanks for pointing that out, im am going to discuss this with aerozine.

 It must be grey market/OEM stock. It may come without packaging

The cranksets obviously comes with the basic bearings not the SKF ones like mine, the also come with the basic quality rings. So they are not much cheaper than mine.

 They will not be supported by Aerozine UK warranty.

Well it is the real article with the SKF bearing ID lazer etched onto the bearings. A lovely bit of kit unfortunately I will not be blinging it onto my bike though as I've discovered:

http://www.enduroforkseals.com/id182.html

And this is a far better solution, like Pace BBs they sit straight on the shaft enabling 0.5mm bigger diameter bearings. OK they're not SKF but as long as they're sealed OK they should be good.

I'll post within 6months if they let me down!

In the mean time buy my Aerozine on eBay!!

http://cgi.ebay.co.uk/Aerozine-Bottom-Bracket-for-Shimano-FSA-Race-Face_W0QQitemZ110256800158QQihZ001QQcategoryZ56193QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Matt

Far better if you accept that when the bearings seize the bearing race cuts into your expensive (and non replaceable) crank axle.....

 When i asked hope what they would do in this eventuallity they said "our bearings are such high quality they wont fail (smugly)", shame history has shown differently!

 There is a good reason why EVERY crank manufacturer uses nylon bushes, it lets the failed bearing spin on the bush, saving any damage.