Convert Press Fit BB to External Bearing BB

vrsmatt

Hi

I have a 2015 Giant Defy Advanced with a press fit BB, it creaks, I don't like press fit anyway and was wondering if anyone had done a press fit to external bearing BB on this frame or any other for that matter.

Cheers

timothyw

Assuming it's PF86 (which my Giant is) then that's an impossibility I'm afraid.

A british screw fitting bottom bracket is considerably narrower than the press fit bottom bracket in your bike - it's only an option with the old BB30 press fit.

milemuncher1

You can get a converter. It goes in place of the PF shell, and has proprietary external cups.

https://wheelsmfg.com/bb86-92-outboard- ... black.html

timothyw

That doesn't convert your bottom bracket to a screw fit - it's just a different kind of bottom bracket for press fit, one that apparently screws into itself.

Which is lovely, but Ribble will sell you a shimano pf86 bottom bracket for less than a tenner
https://www.ribblecycles.co.uk/shimano- ... #pid=35879

I'd opt for the latter, personally.

milemuncher1

TimothyW wrote:

That doesn't convert your bottom bracket to a screw fit - it's just a different kind of bottom bracket for press fit, one that apparently screws into itself.

Which is lovely, but Ribble will sell you a shimano pf86 bottom bracket for less than a tenner
https://www.ribblecycles.co.uk/shimano- ... #pid=35879

I'd opt for the latter, personally.

The one I linked to replaces the existing, inboard bearing cups, with outboard cups, which gives the stability of an external threaded cup B.B., without having threads. They make a PF30 to Shimano HT2 version, which does the same sort of thing ( and reduces the spindle from 30 to 24 mm) I have done the conversion on my old 2014 Boardman Pro Carbon, it’s a superb idea, you get ( what is to all intents and purposes) a threaded B.B. with external cups, without having to bond in a threaded shell.

https://wheelsmfg.com/bottom-brackets/p ... black.html

timothyw

PF86 bottom brackets are already as wide as Shimano cranks (and other brands, FSA etc) so there's no possibility of fitting 'outboard' bearings to them to increase stability or anything else.

As I mentioned in my first post, such a conversion is only possible with BB30 (as you have done) because the original BB30 standard is more narrow, similar width to a standard screw thread bottom bracket.

If you look closely at the first product you linked you'll notice that almost none of it sits outside the bottom bracket - that's why the notches where you screw it in are so narrow - any wider and they'd interfere with the crank arms.

As per what I said though, PF86 is basically a decent standard as it goes (and this is why I think Shimano embraced it) - if it gets noisy, try regreasing things, if that doesn't work, knock out your old bottom bracket and pop in a new one.

imposter2.0

As above, Milemuncher hasn't really understood the question, so his answer is not relevant. PF/BB86 is actually pretty good, one of the better press fit standards and worth persevering with if poss...

vrsmatt

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

imposter2.0

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

Those aren't outboard bearings though, which I think is the point that TimW is making. BB86 is already the same external width as HT2, so fitting outboard bearing cups to a BB86 BB will give you a BB which would be too wide for any conventional chainset standard.

keef66

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

But that's still a press-fit BB. no? OK, the 2 halves screw together, pulling them into the BB shell, but if a correctly installed press-fit BB creaks in your frame, then I'm guessing that this would too.

Or is it the pressing in / drifting out you're not happy with, and want something to screw / unscrew?

vrsmatt

Imposter wrote:

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

Those aren't outboard bearings though, which I think is the point that TimW is making. BB86 is already the same external width as HT2, so fitting outboard bearing cups to a BB86 BB will give you a BB which will be too wide for any conventional chainset standard.

Thats where I havent been clear...i'm not after outboard bearings i realise thats the wrong terms.....just the screw together solution

vrsmatt

VRSMatt wrote:

Imposter wrote:

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

Those aren't outboard bearings though, which I think is the point that TimW is making. BB86 is already the same external width as HT2, so fitting outboard bearing cups to a BB86 BB will give you a BB which will be too wide for any conventional chainset standard.

Thats where I havent been clear...i'm not after outboard bearings i realise thats the wrong terms.....just the screw together solution

Exactly, the bike shop have already fitted a new BB once and it creaks, i prefer to do my own maintenance where possible and I suspect a properly installed screw together one will give me less headache in the long run.

arlowood

This might provide a suitable halfway house

http://www.hopetech.com/product/press-fit/

Sealed cartridge bearings that screw onto a central sleeve to give you a more secure fitment in the pressfit BB shell

£100 plus a special fitting tool so not cheap

milemuncher1

TimothyW wrote:

PF86 bottom brackets are already as wide as Shimano cranks (and other brands, FSA etc) so there's no possibility of fitting 'outboard' bearings to them to increase stability or anything else.

As I mentioned in my first post, such a conversion is only possible with BB30 (as you have done) because the original BB30 standard is more narrow, similar width to a standard screw thread bottom bracket.

If you look closely at the first product you linked you'll notice that almost none of it sits outside the bottom bracket - that's why the notches where you screw it in are so narrow - any wider and they'd interfere with the crank arms.

As per what I said though, PF86 is basically a decent standard as it goes (and this is why I think Shimano embraced it) - if it gets noisy, try regreasing things, if that doesn't work, knock out your old bottom bracket and pop in a new one.

The product I linked to is designed to address the issues that the OP was complaining about it behaves like a threaded set up, in the way in that the cups are linked with a solid shaft ( effectively) and should reduce the issues which the OP didn’t like with the standard B.B.( it won’t creak or flex as much ). Your right, I didn’t notice it’s not quite the same as the B.B. 30 - HT 2, in that the cups don’t sit externally. But if you used the thing I linked to, you would increase the stability of the cups, and just be able to unscrew them, rather than having to drift and press the cups, as you would with a standard PF86, which would save you Watts, when smashing stuff ( probably) and faffing, if you need to get them in and out, which can’t be a bad thing. So in summary, the wheels manufacturing thing I linked to, would be a great solution to the OPs issues.

keef66

VRSMatt wrote:

VRSMatt wrote:

Imposter wrote:

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

Those aren't outboard bearings though, which I think is the point that TimW is making. BB86 is already the same external width as HT2, so fitting outboard bearing cups to a BB86 BB will give you a BB which will be too wide for any conventional chainset standard.

Thats where I havent been clear...i'm not after outboard bearings i realise thats the wrong terms.....just the screw together solution

Exactly, the bike shop have already fitted a new BB once and it creaks, i prefer to do my own maintenance where possible and I suspect a properly installed screw together one will give me less headache in the long run.

So do the press-fit BBs creak as the cups work themselves out of the BB shell, and the screw-together types prevent that from happening??

Somebody with the engineering skill / measuring equipment should investigate!

kingdav

Hambini will tell you more about this... his latest video is on a similar topic.
https://www.youtube.com/channel/UCH9263 ... 25dkyGAu3Q

I was mystified and amazed by this video, I probably could understand more of it, but would need to concentrate! The amazing part for me was that someone with a creaky bottom bracket recorded a video of the creak. Hambini did some analysis of the harmonics in the soundtrack and was able to deduce which interface in the bottom bracket system was out of spec and generating the squeak.

milemuncher1

I’ve actually managed to convince myself that the PF 86 on one of my bikes needs to be killed with fire, thanks to this thread, and I like the look of the Wheels Manufacturing thingy ( if it’s as good as the BB30 -HT2 one alive previously used). So we shall see.

milemuncher1

keef66 wrote:

VRSMatt wrote:

VRSMatt wrote:

Imposter wrote:

VRSMatt wrote:

Perhaps i've not been completely clear with my 'outboard bearing comment' as i think milemuncher has come up with a product that should work https://www.sigmasports.com/item/Wheels ... ranks/EM28

Those aren't outboard bearings though, which I think is the point that TimW is making. BB86 is already the same external width as HT2, so fitting outboard bearing cups to a BB86 BB will give you a BB which will be too wide for any conventional chainset standard.

Thats where I havent been clear...i'm not after outboard bearings i realise thats the wrong terms.....just the screw together solution

Exactly, the bike shop have already fitted a new BB once and it creaks, i prefer to do my own maintenance where possible and I suspect a properly installed screw together one will give me less headache in the long run.

So do the press-fit BBs creak as the cups work themselves out of the BB shell, and the screw-together types prevent that from happening??

Somebody with the engineering skill / measuring equipment should investigate!

Kind of, yes. It’s the unbraced cups being acted on, by the spindle that’s causing the creaks ( normally ) so having a ‘braced’ set up, should stop it, and so help with the truly massive power losses caused by the flex in the standard system.

vrsmatt

Milemuncher1 wrote:

I’ve actually managed to convince myself that the PF 86 on one of my bikes needs to be killed with fire, thanks to this thread, and I like the look of the Wheels Manufacturing thingy ( if it’s as good as the BB30 -HT2 one alive previously used). So we shall see.

I've already convinced myself the ceramic bearing version is the way to go lol

Vino'sGhost

PF is great for the mfrs since they can build bikes to lower tolerances. On the face of it the consumer gets a wider bearing which should increase stiffness which is good. In the case of BB86 those bearings are positioned as far apart as possible (typical Q factor maintained) also good.

Sadly unless the frame is manufactured to very high tolerances (not ususal )they can creak like my knees at the site of a hill. VERY BAD. this is caused by one of or a combination of lack of alignment from the drive side to the non drive side i.e the centre line through each side of the bearing wouldnt be along the same plane or the the bearings themselves not sitting parrallel to each other or a combination of the two. Since either condition causes uneven stress on teh axle and bearing interface there are losses which manifest themselves as creak

no amount of new bearings or grease will solve this problem, the issue is with the frame. The idea of these Wheels BB is that they create an entirely new BB that eliminates those alignment issues and as a happy by product presents the opportunity to change the bearing standard within an existing frame.

On the whole they're very good, I've never had a problem with them though of course they are screw together so there is always a loss of rigidity at the screw thread. This seems to be more of a theoretical problem than an actual one though. The Wheels bottom brackets are very easy to fit with drifts and bottom bracket tools you probably already have lying around and once fitted the process of replacing the bearing element is simple. bang em out and press in new ones.

I have heard tell of one piece bottom brackets for some of the standards. That would be a belt and braces approach.

If you're running Di2 or hydraulic or even cable brakes through the bottom bracket area make sure you can push everything out of the way of the new BB.

Nick Payne

The Wheels Mfg screw-together BBs with angular contact bearings cost a lot, but they last a lot longer, and in my experience they don't develop creaks either. I've fitted several of them to friend's bikes, and no-one has yet come back with any problems with them.

milemuncher1

Nick Payne wrote:

The Wheels Mfg screw-together BBs with angular contact bearings cost a lot, but they last a lot longer, and in my experience they don't develop creaks either. I've fitted several of them to friend's bikes, and no-one has yet come back with any problems with them.

My experience backs that up.

Monty Dog

Just fitted a Wheels Mfg Screw-together BB to one of my bikes, but one side really needs to be pressed in as the engagement notches on the cups are pretty thin and easy to distort if putting in a lot of torque. I like the fact they're well-sealed when installed, both internally and externally. They have decent seals over the cartridge bearings too - not some piece of shonky plastic.

Vino'sGhost

Monty Dog wrote:

Just fitted a Wheels Mfg Screw-together BB to one of my bikes, but one side really needs to be pressed in as the engagement notches on the cups are pretty thin and easy to distort if putting in a lot of torque. I like the fact they're well-sealed when installed, both internally and externally. They have decent seals over the cartridge bearings too - not some piece of shonky plastic.

Yes the drive side is pressed in, the non drive is screwed in

vrsmatt

Well i've ordered the ceramic version and it's being fitted friday so i'll report back.

The added bonus is that if I need to get at where the cables run through the frame ( round the bb area ) i can now get to it easily.

Thanks guys

vrsmatt

To update, its a nice bit of kit, it went in no problems and the creaking is banished. The other benefits are i can remove and replace it ( or bearings) myself and this allows access to internal cable routing should i have issues too.

All in all, happy so far

hpaul

Late to the party here i know, im looking to get rid of my bb86 on canyon aeroad 8.0 for the screw in wheels mfg one. Does a standard bb install this, i dont need a pressfit tool? Cheers

david37

hpaul said:

Late to the party here i know, im looking to get rid of my bb86 on canyon aeroad 8.0 for the screw in wheels mfg one. Does a standard bb install this, i dont need a pressfit tool? Cheers

.

you need a shimano bbtool and a press. the press doesnt have to be anything special at all, just a bit or rod, a couple of large washers or plates and a couple of nuts.

The Wheels BB tool is lovely though

ugo.santalucia

I would probably end up doing the same if I had Press Fit BB.
It's a bit ridiculous that they created this thing and people go to all lengths to revert to the previous standard.
What was the need for this thing, to make manufacturing frames easier without the need to install a metal threaded tube in the BB shell?

hpaul

Cheers guys, wheels bb aint cheap from what i seen.

Agree completely on pressfit, im on my third bb30 on my propel, in 18months from new. Curse. I did read going forward the manufacturers have returned to threaded.

elbowloh

hpaul said:

Cheers guys, wheels bb aint cheap from what i seen.

Agree completely on pressfit, im on my third bb30 on my propel, in 18months from new. Curse. I did read going forward the manufacturers have returned to threaded.

My Felt F1 frameset is also BB30. first thing i did was buy an adaptor. I think it's a wheels mfg one (it was 6 years ago now).