[Closed] Bottom bracket life span

When you say you've tightened it up, do you mean you've torqued up the preloaded cap and/or the pinch bolts? Because neither like being over torqued much...

That's better than usual!

19 months, fag packet maths says 4200ish miles? Not bad if you've not touched it once since fitting really...

[url= http://www.wiggle.co.uk/shimano-105-5700-bottom-bracket-cup-set/ ]straight replacement is £9 on special from wiggle at the moment. [/url]

Edit: Whoops, bugger out of stock. [url= http://www.wiggle.co.uk/shimano-tiagra-4600-bottom-bracket-cup-set/ ]But tiagra is even cheaper[/url], and [url= http://www.wiggle.co.uk/shimano-bb-r60-ultegra-6800105-5800-hollowtech-ii/ ]so far as I am aware a 6800/5800 should fit too. [/url] Right?

Yup tightened the cap and the pinch bolts (probably overtightened).

Just seems such a short life after the old square taper bottom brackets.

That wiggle link may be just the thing.

I wish there was a better alternative to Hollowtech.

TBH bearing life from square taper was better, smaller axle meant deeper section bearings without quite as stiff an axle. You can still buy good square taper cranks and BBs [url= http://www.spacycles.co.uk/products.php?plid=m2b0s109p45 ](for example)[/url] but you'd be diverging from the ubiquitous 'groupset' we've all become so used to and probably adding a pound or so...

I got 6 weeks out of a PF30 of dry dh. Poo poo

[quote=ktaylor ]Yup tightened the cap and the pinch bolts (probably overtightened).
Tighten the cap too much and you kill the bearings. It's only supposed to be "finger-tight" (well - hand-tight I suppose 🙂 )

Hope ceramic. Life span counted in years now, not weeks 😉

Just seen the price of the ceramic ones. Would have to last ages for that money. However even an extra years use is appealing. Have always hated messing with bbs. If you mess them up its either expensive or you get stranded with no easy fix!

My hope stainless is much better than the half dozen or so shimano ones that came before it.

Got a S/H Tiagra BB on my Peregrine - now, some 3k miles later, it's due for replacement, been out in all manner of rides and conditions, I'd say that wasn't bad.

Thanks for all the replies. I thought the mileage was a bit rubbish but perhaps not.

Just got a 105 5700 bottom bracket from Evans Cycles. They price matched Chain Reaction Cycles and I got it for £8.99. After the reassuring noises on here I'm quite pleased about that actually.

I use a chris king BB on my commuter. Had it just over a year and done about 4,300 miles. It's running smooth with no issues and gets greased every 4 months.

At the price of Shimano, it just makes sense for road use tbh. A Hope ceramic or King will last longer but not the 11 times longer it has to, to pay for itself (in all likelihood your bike won't last that long). The 105/Deore BBs are just a bit too poorly sealed to be a great choice for mountain biking but they're grand on the road.

(if you don't like disposability, and fair enough, then Gusset's EXT24 is a good one- fully servicable and takes standard bearings, unlike Hope which ties you to their own brand- costs about £25, lasts well, and you're not paying a massive upfront premium for it. Ace for mtb. But for road use I'd stick with Shimano)

Press fit shimano xtr on a spicy was about 14 minutes until i drilled a whole in the frame and fitted a rubber seal to the seatpost clamp.
Great design by Lappy.

1-2nm on the preload cap

12-13nm on the twin pinch bolts

Use a torque wrench to get the pinch bolts to correct torque, and balanced.

Overtightening the preload cap dramatically reduces bearing life.

If the cranks keep coming loose check the condition of the axle splines and the spline socket on the non driveside arm.