[Closed] Press fit bottom braket .Will i regret it ?

Press fit bearings = bloody stupid IMHO. How many people have a the sort of tooling to remove and replace the bearings when they wear out, and it's not likely that most bike shops will either.

And don't get me started on 'standards' - how many different styles of bottom bracket now? Ggggrr 👿

I'm convinced by BB30, those great big bearings look like they ought to last an age.

"Thats the great thing about standards....there's so many to choose from"

Never a truer word spoken.

I've had no problems so far, I've got a 2009 316. When it does eventually go I'll book it into my LBS and let them have the headache of changing it.

No reason to think it's a particular problem, it just doesn't provide any advantages whatsoever!

BB30 on the other hand, is good!

Shimano BB85 removal tool:

[img] [/img]

And you need a vise to refit them:

[url= http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_0053A_001/SI_0053A_001_En_v1_m56577569830625426.pdf ]fitting instructions[/url]

yes they are crap.
my zesty has needed 2 so far

mind you, looks like its cracked at the BB now as well....

and send me a link to that 2011 spicy pic would ya please?

If you do have the correct tools they are easy to replace, easier than most IMHO. It's the way forward!

More crap from the crap providers of.............crap

6 months life???????

I've been using BB30 for a year now, no problems at all (yet) 🙂

BB30 is not the same as the spicy\zesty bottom bracket

Gfs Zesty is a pain. It gets ridden about once a month, then washed and put away. The BB has a tendency to seize, probably due to the irregular use. When it first seized she didn't realise, it was just a little heavier to pedal but the BB cup was spinning in the frame, its since had a new (XTR as thats all the LBS could get apparently) BB, that was about a year ago. Bike has probably been used less than once per month since, with a weeks riding whilst on holiday. Got it out last week and its seized again, managed to free it by rocking the cranks back and forth, each time the rotation increased until the bearings freed up and they are now fine...but I know it'll just jam up again 🙁

(Gf isn't lazy, its just the bike doesn't complain when its not ridden, whereas the horse tends to get really grumpy and agitated if it doesn't get out regularly!)

so whats the difference compared with BB30 ?

The zesty BB is (I think) simply a normal BB but the the external cups are replaced with press fit bearings inside the oversized BB shell. So the sealing should be better, but the bearings are the same (undersized) size.

BB30 has bigger bearings, and was developed by a bike company but made freely available for anyone who wants to use it.

Actually from an engineering point of view a press fit BB makes far more sense than some stupid undersized bearings in with silly fine threads originally designed for road bikes....

BB30 seems a reasonable idea but I reckon "Mid" should have been adopted for MTBs, a pre-existing off the shelf bearing and shell designed for higher loads, Impacts and cost effective manufacture of shell and BB/crank assembly.... IMO...

I don't see how a bigger bearing will help.
the problem is and always has been the sealing IMO

he's right you know.

For me the same problem exists with press-fit and HTII and that is sealing, the main problem is the design of the cranks that seem to allow water/mud ingress and then force that mud/water into the bearings as you pedal.

Always had sq taper, flirted briefly with isis but abandonded it fairly rapidly.
Got press fit (but not BB30) on the Yeti, somehow the bearings from an XTR BB have been pressed into the frame [i]sans[/i] cups. Really wanted to use a Tune AC38 sq taper but no adapters available.
So far they have been reliable, although being a race-only bike it was used maybe 20 times last year. Can't feel any improvement though, no stiffer, although being 9st12 and not very strong I can hardly flex anything, cerainly not sq cranks.
All others bikes are square and staying that way.

BB30 is fantastic. The only prob is that your frame needs to be BB30 specific (eg many Cannondales and many road bikes). You can put a threaded sleve in the BB30 shell to convert back to a 'traditional' BB but becas the BB30 is a bigger diameter you cant convert the other way.

[url= http://www.sram.com/en/truvativ/bottombrackets/bb30/mtb.php ]http://www.sram.com/en/truvativ/bottombrackets/bb30/mtb.php[/url]

Chris

You'd think they'd have used bigger bearings on the bb30 - the balls will be no bigger than HT2.

Oh well I guess they can come out with a new better standard in a couple of years.

Agree, why don't we have the mid standard on mountainbikes?

Big shells, big bearings, standard axel/bearing inner race diameters (22mm, 19mm or 19mm axels with plastic spacers to make it 22mm like HT11 cranks).

They could even make isis style axels so tarts could buy one Ti axel and upgrade their cranks at will.

Then again, the Laperier sustem is pretty close to mid, and doesn't appear to work. Maybe somethign closer to the ammerican BB with its inserts that press in before the bearings are pressed into the frame.

Sadly HT2 (for MTBs) has a 24mm axle dia’, quite why is beyond me, as 19mm (3/4”) would be perfectly adequate for pretty much any application I can think of and 22mm is (7/8”) is much pretty overkill…

Road HT2 is 19mm as is surprisingly Shimano’s DXR crankset (XTR money BMX race crank) obviously the smaller dia’ axle on a road bike means thicker section bearings and hence better life, and on the DXR? I presume it’s for the similar reasons, plus it gives you Mid/US BB compatibility (not sure if that’s intentional though).
The question has to be asked then why do Deore, SLX, XT, XTR - MTB HT2 cranks all have 24mm axles when 19mm is plainly enough?

Mid would work beautifully for MTBs with a sensible axle diameter… Unfortunately that isn’t HT2

P.S. Mid is basically the standard bearing used in profiles BMX BBs, just without the adapter to fit a US BB Shell, thus smaller shell, same bearing, less parts but with the same durability... oh and it's meant to be "Push" rather than press fit, so you can remove/replace bearing from the shell with your bare hands, no mallets, screwdrivers or Vices...