Press Fit Bottom Brackets – Why?

OK I know the manufacturers tell us they make a frame stiffer (probably true – larger diameter BB = stiffer frame in that area) but having had a press fit BB they are truly cr@p. They last for a few wet rides and to me at least are not fit for purpose on an MTB.

So, are there any ‘advantages’ I’m missing out on (apart from more time being ‘at one’ with your bike changing the BB)? Seems a pure marketing fad that’s pointless in the real world and I’m damned if I can tell if my non-PF BB bike is flexier than my last PF BB bike..

And are all the ‘mainstream’ manufacturers going press fit? Looking for a new FS at the end of the year and don’t want another press fit BB. I’ve looked at Specialized, Giant, Lapierre etc and seem only to be able to find frame-only options eg Santa Cruz or Yeti that have not gone press fit mad, but a custom build is too expensive. Any ideas?

Thanks.

Was yours a Lapierre?

My experience of them was shit on my old Zesty but had another on a Trek and it’s been OK, touch wood.

Was yours a Lapierre?

No, a Boardman hardtail that was actually a great bike (BB30 excepted) but I sold it as I couldn’t stand changing the BB every 4 rides. Now have 1 HT without a PF BB and want a new FS bike but nervous about getting PF again.

Hope your Trek stays ok!

Been done before, surely.
Cheaper tooling for mfr. And sticking 2 bits of BB and a frame in a hydraulic press is way quicker on the assembly line.

Sadly it’s not just the big mainstream mfrs that have gone to pressfit. Many/most of the smaller ones have too.

And 99% of bikes in the world will probably never see a replacement drivetrain component ever.

Andytherocketeer – most of what you say makes perfect sense but..

And 99% of bikes in the world will probably never see a replacement drivetrain component ever.

Why? Not sure what you mean. Bikes seen as disposable?

I had a Trek carbon road bike with BB90. Riding it last year in the wet resulted in the grease getting washed out on one side and rusting solid. Maybe if I’d checked it regularly I’d have noticed and re-greased keeping it OK. The BB90 also creaked from early on which seems to be because the bearing races get loose in the frame. Got a Giant road bike which is similar but looks better sealed, dunno really so will try to check regularly.

it also allows more versatility in frame design.
I’ve got one in a Stumpjumper and it’s been fine.

Cheap manufacturing costs – as owners dont realise they are crap till after they buy the bike.

My trek one has given up the ghost after 6 months…thinking of a hope press fit given their rep…just crapping myself at the £80

Hoping the solid BB shell on the meta will protect me against some of this… we shall see…

Why? Not sure what you mean. Bikes seen as disposable?

Look in your bike shed at work or at the local train station, how many of those bikes get maintained with new bits, and how many do you think just wear stuff out out and the bike gets scraped, then add to that 2nd category all the bikes that never get ridden the 5000 miles or so it takes to wear out a BB?

5000 miles or so it takes to wear out a BB?

I wish.

^^that, plus in places like Holland, they *will* ride the 5000km to wear out a BB, chain, rings, casette, etc. leave it outside in all weathers, never lube it, and then continue riding it for another 5000km with taco’d wheels, mudguard dangling and held on by 1 bolt, chain that is mostly rust, …

more bikes than people there. in fact probably more bikes there that have never had chain lube applied by the owner than there are MTB trail bikes, carbon road bling bikes, and c2w commuters in the UK (that’s my experience of living there for 4 years).

edit: pressfit should be fine if they last like that, or like ye olde worlde cup+cone BB. Unfortunately external BB basically became a consumable item. If pressfit is also consumable for what we do, then it’s c**p design.

and how many do you think just wear stuff out out and the bike gets scraped, then add to that 2nd category all the bikes that never get ridden the 5000 miles or so it takes to wear out a BB?

That’s my point. This rule of thumb can’t apply with PF BB. I’d be stunned if anyone got 5000 miles out of a PF BB on a mountain bike ridden off road. In my case this adage would have meant a new bike after less than 100 miles when the BB first died, or riding it less than 100 miles over the period when I’d normally have done 5000.

Just not fit for purpose IMHO.

pressfit should be fine if they last like that, or like ye olde worlde cup+cone BB. Unfortunately external BB basically became a consumable item. If pressfit is also consumable for what we do, then it’s c**p design.

What he said.

Surely not more BB angst?

Frame designers like it because that extra shell width that was taken up with external cups can now be incorporated into the BB shell to make the frame stiffer side to side.

Marketing guys like it because bullet points are their lifeblood and …
* 7.5% stiffer! means you can probably make it…
* 113g lighter too!

I think it makes some kind of sense on race bikes where gains in stiffness and weight loss might be worth the trade off. I think for the majority of bikes, however, a less esoteric system would probably be a better solution.

The thing that worries me is the interference fit between the BB bearings and the inner frame shell…if that gets damaged or worn at all, your whole frame is Kapput.

These kind of things are high up on my shopping list rules too. I’m sure for example that the latest specialized bikes are right at the top of their game but non standard shocks, press fit bottom brackets etc, no thank you.

I thought Lapierre had gone back to normal BBs?

The one on my 146 has been very good…admittedly my riding is patchy so is fair to say it’s had a very easy 2 years, but it’s been trouble free in all conditions that I ride in…not fair weather but work/family issues mean I don’t get out often!

Fancying the Hope solution but it seems very expensive initially…but if I get the same lifespan as I am getting now, then it could end up paying for itself (somehow).

MTBs are just doing it wrong.

If they just copied BMX, they’d be zero issues.

I have Press fit BB on my Stumpy Evo and the BB has shit it’s after two rides before!!!
I strip and clean it now every other ride,and replace after a few months.
IMO thery are not fit for use and I won’t be buying another bike with one on.
They can’t handle the Lakes anyway.

I strip and clean it now every other ride,and replace after a few months.

How exactly is the press fit BB advancing our sport? Having to strip and clean a BB after every other ride is evolution? Seriously?

I loved my old Stumpy FSR but it had to go. Specialized have been awesome to me over the years, sending me free stuff and all sorts just for being a fan of the brand, but I can’t spend my hard earned on another of their bikes when this is how the ownership experience will pan out. I rode my 07 Stumpy on its Truvativ external BB until this year and it was still on its original (and sound) BB. I rode my BB30 bike twice before I needed to replace the bearings. Not acceptable in my book.

The best thing about the press fit standard is that you can fit a threaded BB adapter.

I’ve read somewhere that the wear rate may be less of a maintenance issue and more to do with the cups not being truly parallel, either via installation or frame manufacturing. Not sure if that is more of an issue with this type of BB.

Lapierre went back to HT2 type BB’s in the very recent past (2013 MY?)

A bike shop I know who are Hope Tech dealers say that the Hope BB92 replacement *must* be installed with the correct Hope tool – which you only need once (they fit for free with purchase). Thereafter, it’s just like servicing an oversized ProII hub – the middle tube (bit that needs the tool) stays in the shell.

Apparently (again, the shop talking, but makes sense I think) the issue with pressfits usually is the plastic cups- metal cups (like your headset) when being pressed in will tend to correct themselves if being pressed in a little skew. Plastic cups just go in slightly sideways if not perfectly aligned and thus destroy themselves quite quickly… Plus any sloshy water issues (Lapierres tend not to have BB shell drain holes and not everyone remembers to remove saddle and invert bike after soaking it…)

Maybe it’s all guff, but I love my old Spicy and haven’t been bitten by a Hope product yet, so will probs take the plunge when the time comes next…

I’ve just fitted the new Hope press fit bottom bracket in to my new bike, so will report back how long it lasts

was just looking at…
http://singletrackworld.com/forum/topic/hope-pressfit-bb

doesn’t make it any clearer how easy they are to either fit or replace the bearings.

so for now, anything with PF BB of any variation gets crossed off my list, until such time as there’s a nice easy drop-in industry standard bearing. Maybe Hope is the answer?

andytherocketeer – Member
was just looking at…
http://singletrackworld.com/forum/topic/hope-pressfit-bb
doesn’t make it any clearer how easy they are to either fit or replace the bearings.
so for now, anything with PF BB of any variation gets crossed off my list, until such time as there’s a nice easy drop-in industry standard bearing. Maybe Hope is the answer?

Hope BB is very easy to fit if you have the tools, I’m sure swapping bearings isn’t difficult or expensive.

Not encouraging! Remember how long a UN52 bb used to last? 2years near daily use wasnt unheard of.

It maybe not be that hard or expensive, but a bit of a joke when you pay thousands for a bike and you have to replace them far to often.
People wouldn’t accept it in any other industry.

halfpint – Member
It maybe not be that hard or expensive, but a bit of a joke when you pay thousands for a bike and you have to replace them far to often.
People wouldn’t accept it in any other industry.

Good point, though I’m hoping that the Hope system will be long lasting

To be fair I also remember ISIS not lasting long and many people had mixed success with HTII when it first came out

Hope BB is very easy to fit if you have the tools, I’m sure swapping bearings isn’t difficult or expensive.

Correct. The job is straightforward (I should know I did it often enough) and you can change bearings ghetto style without much in the way of special tools. However the right tools make it way easier and lower the risk of damage to the bearings and your frame. I used:

– Park Tool PF BB30 ‘drift’ tool http://www.parktool.com/product/bottom-bracket-tool-set-for-bb30-bbt-30-3
– Circlip pliers (right angle ones to remove/fit the circlips that sit inside the BB shell stopping the bearings being pushed too far into the shell)
– Whatever size large allen key you need for your cranks and
– Potentially depending on model – crank extractor

So about £100 worth of tools over the other BB/crank tools I had 🙁

However a headset press is recommended for fitting the bearings to avoid damaging them and/or the frame. It would have made the job much easier in my experience (The Park tool is great for getting bearings out but getting them in isn’t as easy) but I bet not many people have them, and they are not cheap.

So, given the frequency with which PF bearings need replacing you either have to buy some quite specialised workshop tools or risk creating problems. Or book your bike into your LBS every couple of weeks. Helpful!

Or can we just go back to external BBs that last a lot longer and don’t need you to fit out your toolbox like a World Cup pits? Too revolutionary?

I’ve got one in a Stumpjumper and it’s been fine.

Ive just had my 2nd in my 2012 stumpjumper in just under year 🙁

Most Santa Cruz are still screw in….what better excuse to spend six grand on a Bronson! 😀

Not encouraging! Remember how long a UN52 bb used to last? 2years near daily use wasnt unheard of.

I think the current one on my all year round off road commuter is at least 3 years old.

I always thought press fit BB’s where shite and this just confirms it. I will never buy a bike with one now do unlucky manufacturers. Just bought a new frame and so glad it’s the trusted threaded bb shell type.

I used I have a chameleon with the eccentric BB shell and never had a problem with that. The bb shell on it was huge maybe the same as a BMX? Not user how big these PF30’s are, maybe it was the same as that.

The system Santa cruz used worked well and you just threaded a normall bb in to the bigger shell.

I also remember the spooky bandwagon frame had a BMX shell and with the use of some DMR wonder cups a normall BB was used. Worked perfectly.

The question is why are they so bad??

The bearings are the same size as HTII and they are inside the frame so you would assume they are more protected. Also you don’t have to worry about frame facing issues.

Bumps
I didn’t need any circling pliers for the Hope BB as it screws inside your frame, the tool cost me £40 which was similar price to the Park spanner that I purchased for my HTII bb years ago

Changing the bearings is the same as their normal bottom bracket….. I think

The question is why are they so bad??

The bearings are the same size as HTII and they are inside the frame so you would assume they are more protected. Also you don’t have to worry about frame facing issues.

Know what you mean but they must – de facto – be more poorly sealed than other bearings. My non-engineer’s brain thinks it’s something to do with the fact that when laid flat on a table and viewed from above they are wide in circumference but the actual bearing is narrow ie the outer and inner circumferences are quite similar. In my opinion that gives a small area in which to put an effective seal and it is therefore too difficult to engineer an effective one?

Could of course be that PF BBs were just brought across from road bikes without modification (ie expense), or is that being cynical?

Edit: the Hope system looks ok but still puzzles me why we have to buy aftermarket systems to get any longevity from a standard that is supposed to improve our lot.

The hope press-fit one is physically more or less the same as their HTII

Know what you mean but they must – de facto – be more poorly sealed than other bearings.

Ahhhh! So what you’re actually ranting about here is the quality of the bearing used within the press fit, not the actual design principal?

I just got my 1994 Kona Kilauea back after 16 years of it being used by someone else. The paint was shot on the frame, it needed a whole new repaint, drivetrain (mechs were ok), basically a full restoration.
However the original Shimano cartridge BB was still in there, smooth, tight and was refitted and is still in use now, 19 years after it was first installed.
Don’t tell me there has been ANY advances in BB technology!

There were people on here not long ago moaning about HT2 style bearings, PF technology is still relatively in its infancy. King are about to bring their solution out, Hope are bringing other style PF systems out. Eventually (Hopefully sooner rather than later) PF systems will be as reliable as a well fitted, well sealed *insert favourite BB bearing system*.

Maybe I’m just too optimistic, but hey, it’s sunny outside.