Pressfit BB replacement?

[UnclePolli]

https://wheelsmfg.com/bottom-brackets/bb386evo/386evo-abec-3-bb-black.html

 

https://wheelsmfg.com/bottom-brackets/pf30/pf30-abec-3-bb-black.html i have this one in the scalpel and have been very happy the treaded ones where out of stock, the 79mm ones are too short. 386 will work

[UnclePolli]

the shell must be between 86 and shorter if i recall the scalpel is around 83ish width wise. the outboard ones are too wide. so if going threaded make sure it the flush ones like your pf cups on the outside. i also had to remove a spacer otherwise the sideload is too much. replaced bearings only now no more of that other creaky stuff.

[matthieup]

What's the ball park cost for these Wheel Manuf conversion BB?

[Prince Albert Cycles]

That's spot on! Its implemented poorly by many manufacturers. 

 

Problem with threads is the same *&^wits will tap threads off centre too!

 

Threaded BB's were designed when BB's had loose balls and a cup and cone arrangement for the cups and axle. You could then preload the bearings properly.

The Italian BB's had the threads cut through the BB from one side so the Threads were always aligned because the thread tapas still engaged while the other side was being cut. One single operation and both sides were always aligned. (unless the appi cut them then all bets were off.)

Thanks as a still learning self taught appie mechanic found that informative

 

BSA BB's had to have the threads cut from each side and often suffered misalignment issues. But because the axle was free floating between the bearings and the bearing surfaces had to "run in" this was generally not a problem. Easily sorted at the first service by a little adjustment. The bearings would wear the correct running path into the race.

Today with separate cups that have bearings pressed in on either side and then either threaded in or pressed in,  bearing misalignment is still an issue if the threads or pressfit surface are not aligned. Pressfit is easier to correct though.

To me, press fitting a bearing into a cup then threading the cup into the frame seems daft. Just as daft as pressing bearings into a cup then pressing the cup into the frame is equally daft. This is just a cheap way to crook misalignment till the bike has been ridden for many miles.

 

I think LOOK have the best system. They mould an alloy sleeve into the frame. That sleeve is made as one part and manufactured to correct bearing tolerances on their BB65 and now BB386. Their BSA bikes also had a moulded in sleeve where the threads are cut in a single operation.

Most of these frame manufacturers don't allow correctly for shrinkage of the carbon resin.

 

Trek has a recent history of really poor BB design. BB92 was an absolute joke I wouldn't buy any of their bikes with that system. Bearings too small and often misalignment press fit surfaces or not round. I hope for their sake that they have a threaded alloy sleeve moulded in and then Cut the T47 threads from both sides with the frame not moved around to get the other side cut. If cut in separate operations they'll have a high risk of a misaligned threads that will create a misaligned BB that will be a bigger nightmare to correct. Time will tell. 

 

I still like the idea of the BB30 system but Cannondale really stuffed up the execution with maintaining a 68/73mm BB shell when they could have made the shell much wider. That original alloy BB30 shell was clever.

[RocknRolla]

Photos as promised.

mainly the non drive side where the bearing is stuck. As you can see the previous bearing fitter/replacer may have messed up the cups.

 

Also the adapters are pictured, for information.

[warick_wrx]

Not a fan of those adapters, rather just get a proper bb for 24 mm cranks. As the others have mentioned the threaded press fit interface types seem less problematic. 

[matthieup]

ive gad 3 and none had the same price 

 

cheeapest was R990 most expensive was R1350 

 

this is two years ago , since i got hope Ive not changed bearings or cups 

 

so probably a bit more with the current forex, but it's still not that bad

[NotSoBigBen]

I have the WheelsMfg BB on my Epic, best money I ever spent!

 

Having said that I went with those cups on one of my road bikes since I wanted to use an Ultegra crank I already had when building it. Haven't had any problems but then again I don't ride it that often (once or twice a week) and it's a road bike so less dirt and stuff?

[RocknRolla]

Photos as promised.

mainly the non drive side where the bearing is stuck. As you can see the previous bearing fitter/replacer may have messed up the cups.

 

Also the adapters are pictured, for information.

 

Right, so after lots of information, and peoples lamenting of the pressfit bearing implementation within the cycling industry, I am no closer to any answers.

 

Wheels mnf at this stage is not an option. Wife has severely diminished income (if anyone is looking for a cycling coach (with a sport science hons) - lemme know)

Do I only replace the bearings? or the cups as well. I assume the cups are the bigger "flange" type metal piece that the bearings sits in. Is this pressed into the carbon frame?

 

Bearings should be easy to source from bearingman, Cups? "Any reputable" bikeshop? 

Do I try and find bearings that will work without the adapters? Is there such things? the bearings will then basically be exposed to the elements ?

 

Apologies for my loads of questions. Working on my wife's prized Yeti, is taking my life into my own hands, I really don't want to stuff anything up. 

[DieselnDust]

Photos as promised.

mainly the non drive side where the bearing is stuck. As you can see the previous bearing fitter/replacer may have messed up the cups.

 

Also the adapters are pictured, for information.

 

 

Whoever fitted those cups is a butcher!

 

I can see where your problems lie. The cups are likely slightly distorted. They can be hammered out with a bearing remover tool for 30mm axles.

Bearings can be removed without the cups having to come out but I'd get the cups out too to ensure that they are refitted parallel to each other

[Veebee]

Not a fan of those adapters, rather just get a proper bb for 24 mm cranks. As the others have mentioned the threaded press fit interface types seem less problematic. 

this is it, no stock though

 

https://switchbacksports.co.za/products/black-shimano-compatible-pf30-to-outboard-btm-bracket?variant=29498091077731

[RocknRolla]

Whoever fitted those cups is a butcher!

 

I can see where your problems lie. The cups are likely slightly distorted. They can be hammered out with a bearing remover tool for 30mm axles.

Bearings can be removed without the cups having to come out but I'd get the cups out too to ensure that they are refitted parallel to each other

 

Thanks D'nD

I'm not sure who worked on the bb last. I will have to go back on some invoices to check.

 

I will get the cups out and see if they are salvageable. Looks to me the distorted part of the cup is pressing against the bearing, and thus the bearing isn't turning. 

 

Now to break the news to the wifey.....

[RocknRolla]

Just checked. The BB was serviced in Sept 2019. 

Not sure if I want to take the bike back and risk more damage if this is how a BB Cup is installed.

 

In fact, I think I'm done with the service provider.

[DieselnDust]

Cups should be pressed in with the bearings by pressing against the cups not. The damage to the cups suggest a hammer was used to drive it home flush with the BB shell face. Thats not correct.

 

If going for the Wheelsmfg BB the deep groove ABEC-3 bearings options are more cost effective than the ABEC 5 angular contact bearings. These are not necessarily better since they require the crank to provide preload. If your crank does not have the range of adjustment in the preload mechanism then the ABEC 3 DG will probably be the better choice. An ABEC 5 AC that isn't preloaded properly won't last very long