BB386 Press Fit bottom bracket

Maherees

Well-Known Member
Location
Northampton
I have a question not so much about a bike but a bike component:
A few times i have seen some quite negative reactions when a bike has a press-fit bottom bracket - what is the issue with this type of bracket and can they be upgraded if there is an issue?
Thanks
 

Ajax Bay

Guru
Location
East Devon
https://www.hambini.com/pressfit-vs-threaded-bottom-brackets/
NB Volume down to start with.
What do you mean by 'upgraded'?
 

si_c

Veteran
Location
Wirral
Thanks for the link, very useful
Not sure I understand the 'volume down' part of your reply though.
He meant turn the volume on your speakers down :laugh:

The problem with press fit bottom brackets is often down to poor manufacturing from the frame builders - they often have poor tolerances meaning that when the bottom bracket is pressed into the frame it doesn't fit quite as well as it should.

It's usually not a problem and manifests itself as a creak when pedalling. Some find this infuriating others don't seem to mind. You can mitigate the problems with a bad fit but it can be expensive to do so and involves a custom item for your particular frame. Most bottom brackets are press fit though so there's little chance of avoiding them with a modern bike.
 

Cycleops

Legendary Member
Location
Accra, Ghana
It was brought in by Cannondale as a cheaper/easier way to produce BBs, the only problem is that the BB shell needs to made to very exact tolerances which is not always the case and then the problems ooccur. There are various fixes for it with replacement units.
 

Ajax Bay

Guru
Location
East Devon
Most bottom brackets are press fit though so there's little chance of avoiding them with a modern bike.
Careless 'chat' costs lives time.
"Most bottom brackets are press fit" Is this true? Seems a wild assertion to me.
Every chance of avoiding them with a modern (sic) bike: don't buy one with a frame requiring a press-fit BB.
Elaborate on "modern" please. Do you mean 'liable to creak'? Plastic?
 

si_c

Veteran
Location
Wirral
Careless 'chat' costs lives time.
"Most bottom brackets are press fit" Is this true? Seems a wild assertion to me.
Every chance of avoiding them with a modern (sic) bike: don't buy one with a frame requiring a press-fit BB.
Elaborate on "modern" please. Do you mean 'liable to creak'? Plastic?
Not really - even Shimano's Hollowtech system when using a threaded BB uses a bearing pressed into the plastic cups. Just because the interface to the frame is better doesn't mean the bearings are held in differently. The exception being square taper type BBs such as BB-UN series from Shimano - but sadly they are not used on most bikes.

As to modern, my Trek Domane is an AL frame with press-fit so no I don't mean plastic bikes. I mean anything made recently by the major manufacturers.
 

SkipdiverJohn

Veteran
Location
London
If press fit BB's in bikes was done to normal industrial engineering standards, it would be fine - apart from the nuisance factor of DIY replacement.
The reason it's an utterly shite idea on bikes is entirely down to the cost-cutting bean-counting cowboys who control the mass market industry. Instead of building their frames to the correct tolerances, they produce the lowest grade crap they can get away with making, in whatever far east factory offers them the lowest unit price and the biggest profit margin. That includes a lot of supposedly high end stuff as well.
They only get away with it because the cyclists who come on forums moaning about press fit BB problems are still gullible enough to go out and buy yet another bike with a PF BB, even though they got burnt the last time. If you keep buying this shite, the manufacturers will keep making it. if you boycott all bikes with shite tolerance PF designs and refuse to buy them, then they'll either have to sort out their manufacturing QC or go back to threaded BBs. None of my bikes have PF and I won't be buying anything with PF either.
 
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DRM

Veteran
Location
West Yorks
If press fit BB's in bikes was done to normal industrial engineering standards, it would be fine - apart from the nuisance factor of DIY replacement.
The reason it's an utterly shite idea on bikes is entirely down to the cost-cutting bean-counting cowboys who control the mass market industry. Instead of building their frames to the correct tolerances, they produce the lowest grade crap they can get away with making, in whatever far east factory offers them the lowest unit price and the biggest profit margin. That includes a lot of supposedly high end stuff as well.
They only get away with it because the cyclists who come on forums moaning about press fit BB problems are still gullible enough to go out and buy yet another bike with a PF BB, even though they got burnt the last time. If you keep buying this shite, the manufacturers will keep making it. if you boycott all bikes with shite tolerance PF designs and refuse to buy them, then they'll either have to sort out their manufacturing QC or go back to threaded BBs. None of my bikes have PF and I won't be buying anything with PF either.
This in spades, as was pointed out go to you tube and watch some Hambini videos, and keep the volume down at first for the initial HELLO HAMBINI FANS!!!!!, and a warning that his language can be a bit, er, fruity to say the least, there are very few frames that get away from a Hambini roasting, the tolerances for BB's are, frankly shocking, and not just pressfit either, the build tolerances are terrible on some very expensive & well known frames, but he will praise good frames to the hilt when he comes across them, on one Open Upper (Gravel Frame) he actually said it was a death trap and wouldn't ride it due to voids in the carbon of the chain stay/BB area, now this isn't some you tuber bad mouthing things, he's a real engineer, that knows his stuff, and does sort out customers frames that really are bin material, he knows what he's talking about, I think the previous owner of Cervelo, Now current owner of OPEN, has threatened to sue him, funnily enough they never do, I think he would turn them inside out and back to front in court and, they know it.
He produces his own BB's they are expensive, and I'm sure some World Tour teams actually use his products.
 
OP
Maherees

Maherees

Well-Known Member
Location
Northampton
Thanks all, that’s help me decide on my next bike.
I was looking fondly at the new Boardman ADV 9.0 as I wanted a pliable and tolerant road bike as I had to sell my old road bike as it shook me to bits after a ride. But the Boardman has press fit.
 
OP
Maherees

Maherees

Well-Known Member
Location
Northampton
Boardmans are definitely prone to creaky BB
Agreed, I have a Boardman now and its all but perfect except for the creaking...
I like that planet x and have a good experience of them, especially the Uncle John I had but I was hoping to pay around 2k for an endurance road bike.
 

cyberknight

As long as I breathe, I attack.
Agreed, I have a Boardman now and its all but perfect except for the creaking...
I like that planet x and have a good experience of them, especially the Uncle John I had but I was hoping to pay around 2k for an endurance road bike.
odd innit my BB on mine is 3 and a half years old and has never creaked pf30
 
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