Press fit BBs. The work of the devil or the best thing since sliced bread?

[Alex321]

the boardman BB wasnt an fsa powerdrive by any chance ?i find they do wear out very quickly

It was certainly FSA. Not sure exactly what model, all the spec said was

Bottom Bracket:

FSA, Cartridge, Square taper

 

[Sallar55]

Press fit BB, i would bet that it depends upon the frame and quality control. Have a few bike that are press fit and all are good.

 

[kingrollo]

I completely wrote off a Kuota frame which started with a creaking press fit BB. In the end I had the BB bonded into the frame - but then the frame cracked + cracked again.

It wasn't imo the press fit BB but a poorly manufactured frame. I didn't get a penny back from Kuota - no wonder they aren't around anymore.

 

[Peter Salt]

Of course press fit is the way to go. Not talking exclusively about bicycles here. That's just standard/good practice in all mechanical applications - there is no conversation to be had in that regard.

What can be the discussion point, as some have already pointed out, is the manufacturing quality of bike frames. When that's shoddy, you end up with a BB area that's misaligned, non-concentric, etc. which will be the root cause of any problems you'll end up having with the bracket itself.

 

[Cycleops]

You're right, it's all down to QC. But how are you supposed to know which manufactures practice it when you're looking for a bike to buy, they certainly won't tell you, or if they do boast it's good it could be a lie or there are bound to be the odd ones that get through.
It just throws another variable into the mix that can catch you out whereas other systems which don't depend on such fine tolerances won't have that problem.
So what can we take away from this? Everything being equal PF is a good system but if things do go wrong it can be a disaster. Don't forget this is something done for the makers convenience not yours.

 

[Peter Salt]

You're right, it's all down to QC. But how are you supposed to know which manufactures practice it when you're looking for a bike to buy, they certainly won't tell you, or if they do boast it's good it could be a lie or there are bound to be the odd ones that get through.
It just throws another variable into the mix that can catch you out whereas other systems which don't depend on such fine tolerances won't have that problem.
So what can we take away from this? Everything being equal PF is a good system but if things do go wrong it can be a disaster. Don't forget this is something done for the makers convenience not yours.

It's not even manufacturers. It's manufacturing facilities. You can have the same Spesh frame made in 5 different factories. One may be brilliant, another trash - a bit of a lottery, really.

I'd say, have a proper bike shop inspect your bike after purchase. Alternatively, there's a handful of brands that have just one factory and quality is basically known - but that's mostly the pricier end of the market.

 

[mjr]

I'd say, have a proper bike shop inspect your bike after purchase.

That's a drawback of a press-fit BB: any frame flaws are generally hard to spot before use, whereas it's usually damned obvious when fitting a threaded cartridge BB if the frame threads aren't true or have some other fault.

 

[Peter Salt]

That's a drawback of a press-fit BB: any frame flaws are generally hard to spot before use, whereas it's usually damned obvious when fitting a threaded cartridge BB if the frame threads aren't true or have some other fault.

I think you're missing the point - this wasn't specifically about the BB. It's generally good practice to have the bike shop inspect your bike. The manufacturing and assembly quality is so low nowadays that you get all sorts of problems. Have a friend who recently bought an SL7. On delivery, the brakes weren't properly bled, front calliper fixing was bodged, and rear drop out had a stripped thread. All faults that could have literally killed him. Unfortunately, these are the times we live in - very few manufacturers left that really value quality.

 

[kingrollo]

You're right, it's all down to QC. But how are you supposed to know which manufactures practice it when you're looking for a bike to buy, they certainly won't tell you, or if they do boast it's good it could be a lie or there are bound to be the odd ones that get through.
It just throws another variable into the mix that can catch you out whereas other systems which don't depend on such fine tolerances won't have that problem.
So what can we take away from this? Everything being equal PF is a good system but if things do go wrong it can be a disaster. Don't forget this is something done for the makers convenience not yours.

Before buying ask what the policy is re creaking frames. If they say ours don't creak or will sort any creaks - get that in writing.

I've known people be told - carbon frames creak that's just how they are .....gulp.

 

[Deleted member 121159]

With a traditional 68mm BSA frame, you have more choice: square taper, 68mm hollowtech, and 73mm hollowtech using spacers. With pressfit BB86, you can only use BB86 - no square taper and no MTB cranks. So your gear range will be limited to what Shimano offers.

Currently 46/30 is the smallest Shimano road cranks. These gears are too big for me. I found a 'hack' that allows me to use 36/26 direct mount chainrings, but would have preferred 40/24. With the release of Shimano Cues, hopefully this will change. But currently Cues cranks aren't compatible with BB86.

I haven't had any issues with my BB86 set up other than that. Installing BB86 is preferable to BSA. I used loctite so had to leave the bike alone for 3 days after installation.