I was watching The Man Who Cycled The Americas on iPlayer last night, and the narrator mentioned as he was getting the BB replaced that the bearings have an expected life of around 1600 miles.

My BB has started clicking a bit, so out of curiosity I totalled up the (mostly commuting) miles and got to about 1500, which sounds about right! (or not when you compare it to how long stuff lasts on a car – can you imagine if something wore out in less than 2k on a car?)

So does anyone know the estimated lifespans of other components? I'm thinking tyres, pivot bearings, pedals, chain and cassette etc. I know these are all dependent on riding conditions but it would be interesting to hear some ballpark figures 🙂 Does anyone keep track of this sort of stuff? I think there was a mention on here recently of someone keeping a repair logbook…

ok – ill build you a BB that will last 100000 miles BUT i doubt youll be riding far 😉

weight and space constraints are a huge issue on bikes – not so on a car !

Consider the lack of maintenance/the conditions he was riding in non stop.
The forces because of the weight he was carrying.

And the fact that he probably did'nt choose the spec.

I bet there's no Race Face components on his bike… He'd not have made it out of Alaska otherwise.

If he avoids anything gritty and sticky off road then I daresay his components will last longer still 😉

I usually get 18 months out of a BB
7-800 miles out of a road chain if its in damp conditions, though I'll get at least three chain swaps out of a cassette. (sorry 'dont really take as much notice of offroad lifespan)
Bars, stems last ages if I dont crash.
I've got a few 10 year+ saddles.

Used to get a lot more out of a bottom bracket before they were 'improved'.

7-800 miles out of a road chain if its in damp conditions

Really? That's terrible!

I get at least 5000 miles out of a road chain/cassette, then tend to change because I feel I ought to replace my transmission, rather than because it's worn out!

Probably get about that long on the MTB, but nothing wears out on the road!

It's so much down to how they're maintained and used that it makes no sense to compare really.

The other thing is, you have to bear in mind how many of these parts are aimed at, basically, weekend warriors- how many miles will an average trailbike or XC bike do in a year? Less than the average STW rider will I'm sure. And then there's the multiple bikes thing. So what's the point in a BB that lasts 5000 miles if you only ride 20 miles at a trail centre twice a month (except in winter) or you ride every week but you've got 3 bikes?

The last square taper BB I fitted to my old bike lasted for 19 years, and some absolutely outrageous amount of miles. But it's amazing that it got to live out its lifespan, most bikes bought then and used as much as that bike would have been stolen, broken, or just binned or thrown up the back of the garage long before that. So when you look at it like that all that longevity starts to look less useful.

It's the exact same with motorbikes- people say "Why is the finish so much worse than cars". Well, the average mileage for a new sports motorbike is 4000 miles per year, and the average lifespan of same is about 5 years, according to industry stats- so why build a bike that'll cost £1000 more and last for 100000 miles when on average, most people will get more out of a cheaper or lighter one that lasts 20000 miles.

I should explain better njee,
When I said 7-800 miles I didn't mean that it did that mileage then snapped! (I've never snapped a Shimano chain)
I just mean that I replace it when it starts to get noisier and potentially worn.

duraace groupset was designed with 1200miles in question – it is a race groupset – light and smooth

was rocking a non slipping tiagra 9speed groupset from 2005 – at about 3000 miles a year averaged in those 4 years till i changed it last year – not because i had to but because i wanted to for safetys sake – and the barrel adjuster had siezed 😀 ….its a long walk home from some of the places i ride.

likewise i had a tiagra groupset that i did 3000miles on in 4 months on another bike and it was still under the .75% on the indicator