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the curse of .. warning (major) rant follows!


By spindog - Posted on 30 January 2017

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

press fit bottom brackets - aaaarrrgghhh!

I hate these changing standards, what was wrong with 26'ers anyway? My old one was light, ~10.5kg and very agile and the XTR bottom bracket in this bike was absolutely bullet proof, after almost three years of riding in frequently wet, muddy and shitty conditions it was immaculate, good as new, that was real engineering - simple, elegant & effective!

It all started very simply and like most N+1 disciples I was considering something new and started suffering serious gear envy when those fancy new bikes with the big wheels started appearing on our local trails, the sudden flurry of magazine articles with fabulous photos was too much to resist. Pretty soon I was riding my own big wheeled, XC charger, what was I thinking!

I should have taken a bit more time with the test rides. Going from 26" to 29" was like going from a go-cart to an old school bus, but I digress.

Little did I know what bastardry had been forced upon me with my new steed for hidden away from prying eyes was this plastic abomination called a Press Fit bottom bracket. A ticking plastic time bomb just waiting for your warranty to run out before it wreaks its nasty poison. It starts slowly - what’s that strange creaking noise, that wasn’t there last ride?

First it’s only when you put to power down or jump out of the saddle but before you know it it’s ever-present, a rising crescendo of unspeakable graunching that saps the enjoyment out of your ride!

One year on and again I’ve fallen for the hype a bought a new ride (N+1 fever strikes again - will I ever learn?) My new ride, is a 27.5 dually which is a sweet ride, the Fox 34 Float forks and Fox Nude DPS rear shock are big step forward really and have made a huge difference to my confidence riding some of the trickier stuff, but again I digress!

I replaced the bottom bracket in my 29er with the same piece of shit plastic it came with but this time it’s different, I'm going full nuclear to replace that insult to engineering.

So I’ve done some research, ’bin a bit shocked at the price of some of the aftermarket solutions so before I part with some serious bucks I wanted to know what you all have been doing to rid your ride of this shabby shit?

let me know what alternatives you’ve tested, the good and the bad.

wet with anticipation… Eye-wink

I've heard good things about this:

https://www.praxiscycles.com/conversion-bb/

Also see msg I've sent you

Go and see Dan at R&D speed shop.. and get one of these.
http://wheelsmfg.com/bottom-brackets/bb86-92/bb8...

He has them in stock, and they solved my completely flogged carbon fibre bottom bracket area. The bearings sealing isn't that fantastic, as they still remain semi exposed to the elements, but solve the stupid, piece of shite, plastic, carbon fibre destroying press fit bottom bracket.. the worst design change ever to a bike.

Pete

I too have suffered the wankery of creaky PF30 / other PF style bottom brackets.

I have a solution, it isnt cheap, but it is a dream of engineering and is guaranteed not to creak.
The company is called C-Bear and they make the best bottom-brackets in the world. Its a tiny company based over in Europe (Belgium) and they offer a chart for compatibility which allows you to pick a BB that will mix every / any frame standard with any / every crank.

It sounds like you dont need anything too exotic - just something that works really well. This is them.
Yes, its money. No - you wont ever regret it. I had my last C-Bear in my bike for 2 full years (2 race seasons and also winters training) without any problem. I have one in my roadie now too - as smooth as butter. Never creaks or knocks.

https://www.c-bear.com/

the more I dig into this the more I realise it's a steaming pile of poo! It seems the main motivation for the move to press fit came from the bike manufacturers who were having to throw away the odd frame in production due to a cross threaded BB...they cleverly dressed it up as a weight saving in their advertising however this saving amounts to about half the weight of the second gel/energy bar in your camelback!
any ways it appears the move back to threaded BB's may be underway with a few companies (Praxis, Chris King and one or two others) having recognised this issue and developing a (wait for it) new std for threaded BB's. I understand Ibis have been one of the first companies to reintroduce on their bikes so it seems theres more to come in this saga. one of the main issues is the tooling for carbon frames and the design cycle which stretches out 3-5yrs ahead. bottom line is there may be a threaded BB in your future - bring it on!
btw still keen to hear peoples experiences with aftermarket solutions..

I have gone through the bottom bracket woes and research led me to an awesome offering from big bearing manufacturer SKF. They designed it with better seals and larger balls with integrated cups but unfortunately by the time it came to market the industry standard had moved on and spindle/crank compatibility is now a problem.

SKF almost dropped the production but some encouragement from dedicated cyclists convinced them to stay in production. I am considering changing my cranks to be able to get one.

https://janheine.wordpress.com/2014/09/11/skf-bo...

If it's not carbon your BB may be out of round.

My stupid German made frame is 0.7mm out of round so I have to use alloy cups and bearing retainer to keep it quiet.

You do get more weld area with a PF BB, you could get a touch more again on a Boost frame. With loads of sensible brands going to single ring only frames you can get more stiffness from spacing the pivot bearings further apart so there is less need for stupid PF BBs.
Give me a threaded headtube, I'd be all over that!

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