Press Fit Bottom Bracket Bearing Woes. Advice Required

I pressed a Hope PF46 into my Niner steel frame before my recent cycle trip and even after installation I found that the bearings felt ‘graunchy’ when turned by hand.  I also had real difficulty in sliding the crank shaft through the bearings.  The fit was extremely tight and I had to tap the crank hard to get it to press through.

As already mentioned on a previous post the bearing collapsed into a big mess on my trip.

A local bike shop used a dremmel to remove the remainder of the bearing and installed new ones.  He shook his head that he was not happy at the refitted bearings, but they would enable me to complete my trip.

I have just unpacked my bike and the crank was very stiff to turn and after removing (bashing required) the new bearings that had been fitted were also graunchy.  I have subsequently removed the bearings and Hope cups and to my surprise I discover.

1) Bearings removed from cups spin nice and freely and are not graunchy.

2) Bearing can be easily slid on and off crank shaft.

So I want to understand the possible reasons as to why new bearings were graunchy and why the crank was such a tight fit on the bearings.  Could it be that not facing the steel frame before cup installation caused the cup to distort when pressed into the frame and then the bearing when pressed in also distorted which in turn caused the tight crank spindle to bearing fit?

All down to tolerances of frame, BB, bearings crank etc, lots of variables on each of those that could impact on a tight or loose fit.

Frame may well need facing after welding as the heat from welding can distort the BB shell. The tolerance of the BB shell is the next suspect, how close to industry standard dimensions are they & the crank / bearings too.

I’ve a PF that I’ve had enough of and am going to fit this to overcome the issues:

https://www.sjscycles.co.uk/bottom-brackets/fsa-bb30-bottom-bracket-to-68-mm-threaded-adapter/

What surprises me is that the Hope PF is a system with metal cups so the usual PF alignment issues shouldn’t apply.

It pretty much has to be an alignment problem though if all are fine in isolation and it’s only when assembled that the problem exists.

IIRC, Hope are very specific that their install tool should be used for this. I’ve only had one Hope PF in an old Lapierre and I asked 18bikes to fit it for me (with the tool) so can’t really be anymore help.  I’d expect the cups to be out of alignment though I think – and as they won’t yield the bearings will be trapped in the wrong plane.

I did fit the BB with the Hope press fit tool so I am at a loss as to what has caused the miss alignment and like you say put the bearing slightly out of plane.

If they use metal cups then I am surprised they could have distorted when pressed in.

I fitted one of the press fit sleeves mentioned above to my carbon diverge as the BB always ticked and it solved the problem, but I was reluctant to fit one to the steel frame and ideally would like to understand what is the culprit.

If as qwerty suggests it’s a facing issue (ie, the faces of the shell are not exactly perpendicular then the problem could exactly be that the cups went in straight – to a shell that isn’t, and plastic PFs have been masking the issue by deforming suitably.

I think I’d remove, ask a trusted LBS or frame builder to check the facing, refit and see what happens…

Good point.  I’ll take it to the LBS and get them to face it before deciding what to do next.

The £120 Hope BB is trashed.  Expensive lesson.

Ouch. Well, if it turns out facing was the problem, then possibly the cups are still ok and if the second set of bearings are still smooth, should still be usable.  I wouldn’t write it all off just yet.   Good luck!

Maybe hope can supply you some spares? I’ve used a rotor one recently on my niner. It’s a nice bit of kit. I’m not sure that one linked to above would fit in due to protruding bits in the centre of the shell.

Can you install it on another bike to rule out the BB? Hope stuff is usually 100% spot on.

Hope customer services is also very good. Give them a call. I wouldn’t be surprised if they didn’t send you a free set or discounted set of bearings. I know they’ve done stuff like this in the past when people have had issues.

I’m currently running a pf BB on my stumpy. Assembly was straight forward  no issues. I recently developed a creak. I removed the bearings and tightened the BB and that fixed it. It’s pretty simple, not a kit to go wrong,

The only other possible thing I can think of is you have the cups in the wrong way round but even then I’m not sure that would make the problems you are experiencing.

Clutching at straws, Are the threads crossed or i<span style=”font-size: 0.8rem;”>s it the correct BB for the frame?</span>

Good luck

If the bearing becomes tight/rough when pressed in it is a fit issue (ID/OD incorrect interference fit, not fitting the bearing). If you are able to accurately measure everything you can see where the issue is (BB shell, BB cup, Bearing)

It is not uncommon for the BB shell in the frame to be undersized, when the bb cup or bearings are pressed in they are crushed.

For example BB86/92 with a 41mm OD BB cup the frame is reamed to 40.98 giving a 0.2mm interference fit. I have had frames come it with a shell ID of 40.4 giving a 0.6mm interference fit which crushed the bearing (would feel rough on initial install) and results in a very short bearing life.

Park do a 45.94 reamer (use with a HTR-1) for PF30 that I would use before installing a Hope PF46.

If the bearing becomes tight/rough when pressed in it is a fit issue (ID/OD incorrect interference fit, not fitting the bearing). If you are able to accurately measure everything you can see where the issue is (BB shell, BB cup, Bearing)

It is not uncommon for the BB shell in the frame to be undersized, when the bb cup or bearings are pressed in they are crushed.

For example BB86/92 with a 41mm OD BB cup the frame is reamed to 40.98 giving a 0.2mm interference fit. I have had frames come it with a shell ID of 40.4 giving a 0.6mm interference fit which crushed the bearing (would feel rough on initial install) and results in a very short bearing life.

Park do a 45.94 reamer (use with a HTR-1) for PF30 that I would use before installing a Hope PF46.

Thanks for that.  Having researched this for a good few hours today I need to get the frame checked before doing anything else.  Wondering whether LBS or an engineering company would be best placed to do it?

Decent LBS would be the cheapest place to get it reamed (one that has the tools and the knowledge to use them). I would phone around and ask if they can ream and face a PF30 BB (I take it your frame is PF30 if you have a Hope PF46?) Not all shops will do it as the tooling is expensive, but they might know who does. Cheapest if you take in the bike with the bb removed and they can just ream it, more labour time if they have to remove cranks, bb and refit etc.

I measure the BB OD before installing but have not had an issue yet, just frame ID.

A machine shop could do it but I would imagine the cost would be prohibitive.

If you mean just measuring first then anybody that has the equipment and skill to measure accurately. I would imagine a lot of LBS will not have accurate ID measuring tools, but if they have the correct size Park reamer they can just ream to size, its not like using an adjustable reamer or boring to size.

Ok.  I just wanted to ask as I know getting it right is crucial and I didn’t want a LBS having a go and making things worse.  But as reamers are a fixed size then it sounds like unless you have the right diameter reamer you can’t do the job anyway.

Thanks for your informative and helpful posts.