Bottom Bracket Life

[bpsmith]

Without starting a storm of epic proportions, I am interested in what sort of mileage people usually get from their bottom brackets. The reason for asking is that I have got more than ever expected from my first bike so far and wondering if this is actually normal. I appreciate that this will be a very circumstancial. The sheer variance in where and how people ride, along with the conditions and other factors make this a difficult comparison, but what's the harm in comparing overall?

Anyway, my Bianchi has an FSA PF30 BB and I have just hit 4,500 miles. Just took the crank out to check on the condition of the bearings and they are buttery smooth. Yes, I keep the bike clean, but it is used in all weather in fairness. How does this compare to you?

 

[screenman]

I would say my turbo bike had 4,000 miles in the bracket before it went on the turbo about 6 years ago, it is now a tad slack, with the music up loud you cannot hear it.

 

[Moodyman]

Depends on the BB type. The square taper I had on one bike had done 6k before it started creaking. But that was an entry level FSA OEM. The replacement Shimano UN54 had done 9k miles and was fit and forget, then some scrote nicked the bike.

Current fleet is on Hollowtechs. Get about 4k miles on dry weather bike and 2k on the all season commuter. However, they are not fit and forget. After, each wet ride I have to take it apart and pack fresh grease. The seals on them are not very good.

 

[bpsmith]

What type of BB is it @screenman?

 

[Rickshaw Phil]

Just been totting it up and the answer has surprised me. 11,500 miles on the knockabout bike and 7,300 on the Raleigh. Both fitted with basic UN26 bottom brackets and both are still running nicely. I'll let you know when I need to replace them.

The Raleigh is mostly a fair-weather bike while the knockabout bike is used all year round in pretty much any conditions.

 

[si_c]

My most recent FSA BB lasted 4k miles more or less looking at the records, which I think is a bit on the low side. I've got a HT2 BB which has done a similar amount and yet doesn't require replacing.

I'd reckon about 4k miles would make me happy from what is, on modern bikes, a £15 consumable. I've got another bike which has a loose bearing BB, and which I reckon will outlast me as its totally rebuildable.

 

[screenman]

What type of BB is it @screenman?

Sorry, not a clue. By now certainly a rusty worn out one though.

 

[MichaelW2]

My Dahonhas a decent square taper cartdridge and has been doing 10 miles / day most days for coming up to 10 years. I make that 36,000 miles. Modern external BB designs have all been a step backwards for durability but at least they are stiffer.

 

[Richard A Thackeray]

Not sure of the mileage. but my Dyna-Tech is 23 years old, & still wonderfully smooth, it's Campagnolo Chorus

Comversely, the BB, in my 'blue' Ribble, was shot, at about 2 years old, but it was a '365' commuter/do it all bike (Tiagra 'Hollowtech')
The R/H bearing had seemingly ground to dust, as all the play was in that side (closest to my fingers)

 

[cosmicbike]

Swings and roundabouts. I replaced the PF30 on the CX after 7000 miles off all weather riding, zero maintenance aside from a repack of grease at about 6000 miles.
Trek with square taper managed 1000 miles before it was knackered, OEM one mind.

 

[Smokin Joe]

I had a Centaur square taper do well over 10k. It was still sweet and smooth when I sold the bike.

 

[Cycleops]

Current fleet is on Hollowtechs. Get about 4k miles on dry weather bike and 2k on the all season commuter. However, they are not fit and forget. After, each wet ride I have to take it apart and pack fresh grease. The seals on them are not very good.

At around twenty quid even for a Ultegra one I think I’d just leave until it needs replacing.

Square tapers can go on for inter galactic mileages if serviced.

@cyberknight had his hollowtech crank fail spectacularly recently. As well as being stiffer they are also lighter. What price progress? I’ve just fitted my first one.

 

[raleighnut]

The 2 of my bikes that have done huge distances (the Carlton that was my only bike for25yrs and the Ridgeback I've had for 17yrs) both have over 60,000 miles on the same square taper BB shafts although I do change the bearings every few years (last set were £2 a pair)

Tips,

• Plenty of grease
• Keep em adjusted right
• Move the pedal arms 1 flat back each side to even out wear on the shaft hardening
• Never ever ride the bike if the BB is a bit 'iffy', sort it out first.

 

[Deleted member 1258]

The hollowtech on my Eastway recently handed its notice in, it was just over 2 years old and had done 6000 miles, that's about the same as I had got from the square taper ones in the past. I was doing an annual strip and regrease on the Hollowtech, on the square tapers it was just fit and forget.

 

[KnackeredBike]

Mine is original to the bike and so has done near-intergalatic mileage with no servicing. However, I mainly commute a flat route and almost never stand on the pedals which probably helps. When I used to work as an engineer replacing much bigger bearings the best thing you could do to get very long life was to fit decent ones in the first place. The second thing was to know what their specced load was and not exceed it.