Press Fit Bottom Bracket : No thanks

[bpsmith]

Bianchi

?

 

[bpsmith]

Praxis of course
http://www.praxiscycles.com/conversion-bb/

Have you used one of these? Any experience to add?

I am thinking of doing this conversion to run an Ultegra crankset on my Bianchi.

When it comes to replacing the bearings, is it a case of replacing the whole assembly, or can you just swap the bearings on this setup?

It's quite pricey if you have to pay £59.99 for a whole new BB each time?

 

[jowwy]

Or use one of these at half the cost

http://www.sjscycles.co.uk/kcnc-bb30-bottom-bracket-to-shimano-adaptor-road-68-mm-prod33009/

 

[User33236]

Have you used one of these? Any experience to add?

I am thinking of doing this conversion to run an Ultegra crankset on my Bianchi.

When it comes to replacing the bearings, is it a case of replacing the whole assembly, or can you just swap the bearings on this setup?

It's quite pricey if you have to pay £59.99 for a whole new BB each time?

The Praxis one would not fit my Cannondale CAAD X due to the BB shell not being flat all the way through. The KCNC one fitted no problem.

 

[wam68]

Praxis of course
http://www.praxiscycles.com/conversion-bb/

Cheers fossyant.

My choice is a lot better now. The Praxis BB converter will assist no end. Now to find a bike

 

[bpsmith]

Or use one of these at half the cost

http://www.sjscycles.co.uk/kcnc-bb30-bottom-bracket-to-shimano-adaptor-road-68-mm-prod33009/

Does this fit PF30 frames too?

I know the bearings are ultimately the same, but the shell I am unsure of.

 

[Profpointy]

presumably they'd all last longer if there was a grease nipple on the BB.

 

[Svendo]

Does this fit PF30 frames too?

I know the bearings are ultimately the same, but the shell I am unsure of.

Yes, in a PF30 frame the cups press in and then it's essentially a bb30 (although you don't need the circlips etc if using the normal bearings).
I've used a kcnc converter in my Cannondale. LBS pressed the cups in then screwed the kcnc converter in. it screws together using 2 hollowtech II spanners. It then accepts a shimano crank using two shims (don't pull these by the outer edges, they will snap!). It seemed a neater solution than having the cups, a converter an then a HII BB. I couldn't find PF30 converters when I bought mine.

 

[bpsmith]

Yes, in a PF30 frame the cups press in and then it's essentially a bb30 (although you don't need the circlips etc if using the normal bearings).
I've used a kcnc converter in my Cannondale. LBS pressed the cups in then screwed the kcnc converter in. it screws together using 2 hollowtech II spanners. It then accepts a shimano crank using two shims (don't pull these by the outer edges, they will snap!). It seemed a neater solution than having the cups, a converter an then a HII BB. I couldn't find PF30 converters when I bought mine.

Sounds good. Not quite ready to do mine, as loads of life in the current BB and Crankset, but definitely on my purchase list now.

I agree on the adapter comments. Having the cups, an adaptor, then the BB seems messy to me too.

 

[jowwy]

Does this fit PF30 frames too?

I know the bearings are ultimately the same, but the shell I am unsure of.

http://clee-cycles.co.uk/esite/P20004/product

 

[bpsmith]

http://clee-cycles.co.uk/esite/P20004/product

Cheers!

 

[ColinJ]

The Praxis one would not fit my Cannondale CAAD X due to the BB shell not being flat all the way through. The KCNC one fitted no problem.

Thanks for that. I have just bought a CAADX. The BB is currently ok, but if it ever starts creaking then I will give up on BB30. I have heard lots of creaky BB30-equipped bikes and the noise really bothers me!

 

[fossyant]

I've not used one as all mine are square taper. Even my latest bike(being a track derived frame came with square taper).

They (and others) are an excellent way of ensuring a correct fit. Some of the push fit adapters may not provide a correct alignment, increasing BB wear.

If Shimano and Campag are still making the HT2/ ultratorq there can't be much wrong.

 

[fossyant]

I personally think these adapters are far better for preserving the frame than having press fit. It's similar to the square taper cartridge. Guaranteed axel/bearing alignment.

 

[User482]

The older design carbon bikes did have a threaded BB but that was achieved by gluing in a threaded aluminium sleeve inside the carbon BB shell. This has huge problems with galvanic corrosion. Water enters the frame and a reaction between the carbon and aluminium causes the aluminium to corrode to the point where there's huge jagged gashes in it. Eventually the BB just breaks out. Other problems are that the alu insert comes loose and creaks like hell, just like a pressfit BB, so they may as well bypass the alu shell and go directly to the creaking PF BB.

Didn't happen to either of the CF frame, threaded BB bikes I've owned. One of which was made about 20 years ago.