[road]

I’m not convinced that the external bottom brackets are a step forward compared to the older internal type such as Isis splined, square taper or octalink. Thankfully I’ve never had the displeasure of press fit, but I’m probably not getting more than about 1500 miles from external ones. I’ve had pretty much all the shimano range from Tiagra to ultegra and Deore to xt and they’re all about the same. I’m currently on an Uberbike BB which has uprated skf bearings and I’m not sure if there’s a hint of clicking starting now I’m at about 1000mi.

It’s not the bike as I’ve had the same experience on three frames, (steel, alloy, carbon). BB shell is parallel, torqued correctly with correct number of spacers/washers, I don’t ride standing and I’m only 72kg.

What’s other peoples experience with BBs?

Topic

[Anonymous]

That said I’m not convinced
That said I’m not convinced it’s not the drive side pedal (I’ll have to borrow a spare to confirm) even though it’s only done about 2500mi and they’re good pedals too (shimano M540)
Ah joys

[Simon E]

OmuGuy wrote:

OmuGuy wrote:

After a couple of years of unfixable creaking, a mechanic spent three hours diagnosing the creak and found that the hole for the BB sleeve was not perfectly circular on the left.
The problem wasn’t the BB, it was the frame.
The manufacturer replaced the frame.

A recent Cycling Tips nerd alert podcast shone some light on this. Some manufacturers skip or skimp on finishing steps to save a few dollars and IIRC this tends to be the main issue with frames that have pressfit BBs.

[Liam Cahill]

I’ve got the WheelsMFG

I’ve got the WheelsMFG pressfit to external 24 bottom brackets on all of my bikes to avoid pressfit. The mileage I get from the bearings depends on the conditions. 

Summer bike is every other year (ish) at around 10,000 miles per year. Winter bike does around a year (it doubles as my commuter. My CX bike, meanwhile. That needed flusing with WD40, drying and regreasing four times this season. Though it was a very muddy winter.

When I get a click, my approach is to throw grease/fibre grip at every potential problem area and re-torque. I could do things one-by-one to see what’s the issue, but I see a full strip as a good safety check and a great self-isolation job.

[OmuGuy]

When, eight years ago, I had

When, eight years ago, I had the Tiagra crankset on my Kona Jake changed for Deore, the mechanic fitted a SM-BB51 (HollowTech ext). Recently, the LBS advised me that my chain rings are worn and should be replaced when the current chain has had it.
That sent me to Strava to see how far the rings have lasted:
13,500 km.
As far as I can tell, the BB is still working as well as it did at the start of that 13,500 km.
The Kona Jake has become my shopping trolley and overnight-trip bike when I stay at the in-laws’ (at least 50 km away). I mainly ride on pavement, but do quite a bit of riverside riding along loose gritty surfaces and gravelled trails. I avoid riding in the rain, but sometimes get caught in it. Riding after rain, when the front wheel more actively flings abrasives at the drivetrain, is unavoidable.
A few years ago, I my N+1 was a lighter bike with BB30a (pressfit).
After a couple of years of unfixable creaking, a mechanic spent three hours diagnosing the creak and found that the hole for the BB sleeve was not perfectly circular on the left.
The problem wasn’t the BB, it was the frame.
The manufacturer replaced the frame.
In an early YouTube video, before he got all sweary, Hambini said, while pressfit technology had theoretical merits, imperfect L-R hole alignment and mechanical distortion during and after working on carbon fibre were practical drawbacks. BB30 is not suited to rush production for the consumer market.

[Welsh boy]

I was getting through 2 or 3

I was getting through 2 or 3 bottom brackets a year (SRAM and Shimano, no real difference between them) so I bit the bullet and bought a Hope unit about 3 years ago.  Worth every penny, still running the original bearings so I recon it has paid for itself about 3 times over.  I was so impressed that I bought a second hand one for one of my other bikes, 2 years later and that one is still like new too.

[Podc]

I’ve not had one wear out but

I’ve not had one wear out but I was in the habit of replacing them every spring – so probably about 4,000kms including winter commuting. I too have moved to using Uberbike ones and I didn’t bother replacing them last spring so the current ones have about 8,000kms on them and they are still nice and smooth.

I have heard that introducing excessive sideloads on the bearings with the plastic screw in tensioner on the left hand crank can cause premature wear. I do them up quite tight with my fingers and then back them off ever so slightly before tightening up the left hand crank arm.

[ktache]

I have never had a problem

I have never had a problem with my XTR ones, the last on was only £30, so not particularly pricey.  Seems to be about £40 now.  Was just on the good bike (Ti MTB) so not huge mileage, but hard.  Now on the new Ultimate Commuter, almost a year old, no commute yet, but ridden every day, mostly off road through in some awful conditions since late August/September.

My shimano square tapers all lasted soo very long, many, many years.  And when they died you knew it, horrible noises, but it was so awful that I never got to seizing up.

[Author]

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