Cannondale BB30 bottom bracket

[Yellow Saddle]

Sounds good. I'll do that next time I need a new BB. Forgive my ignorance, but would buying the converter and new cranks also necessitate a new chainset?


That's my intention. I went like-for-like this time around for financial reasons (i.e prioritising new helmet & wheels!) but next time I am looking to change it. Again, would this require a new chainset too though?
Could you recommend a good square taper? I was looking at one of these but I think it has outboard bearings - best avoided?
http://www.hopetech.com/product/threaded/


That would explain the phenomenon of the improved BB life second time around, I guess.

Yes, a converter will require a new crankset. If you go for square taper, you will require a square taper crank and if you go for 24mm Hollowtech crank, you'll go for a BB such as the Hope one you have linked.

Best Square Taper is Shimano UN-54. They don't come any better than that. Square taper and outboard bearings are the exact opposite of each other. Square taper has inboard bearings, Hollowtech has outboard bearings. The latter is an OK option.

 

[EasyPeez]

Yes, a converter will require a new crankset. If you go for square taper, you will require a square taper crank and if you go for 24mm Hollowtech crank, you'll go for a BB such as the Hope one you have linked.

Best Square Taper is Shimano UN-54. They don't come any better than that. Square taper and outboard bearings are the exact opposite of each other. Square taper has inboard bearings, Hollowtech has outboard bearings. The latter is an OK option.

Thanks for the explanation, much obliged.
Definately a project for next year if a new crankset is required though.
One day I'll have my bike all set up and specced exactly as I want it.
And will then probably decide I fancy a new bike!

 

[Milkfloat]

Personally - I would stick with BB30 until you actually need to change your cranks. It seems very extreme to run a praxis or other converter and buy new cranks and a bottom bracket when most people have not had a problem at all and those that have been able to fix it relatively easily.

 

[3narf]

Personally - I would stick with BB30 until you actually need to change your cranks. It seems very extreme to run a praxis or other converter and buy new cranks and a bottom bracket when most people have not had a problem at all and those that have been able to fix it relatively easily.

Yeah, probably the same. Although like YS, it'll always annoy me that I'm riding around on something that's a sh!t design...

I'd buy a nice new Campagnolo chainset if money was no object!

 

[andsaw]

I had same problem, i just put a Praxis converter on and put shimano 105 crank on a few months after i got mine, not had any problems since late 2014, i have the FSA converter on standby if the praxis goes, the FSA crank was all roughed up on drive side as well looked like it was made of cheese.

 

[Yellow Saddle]

I had same problem, i just put a Praxis converter on and put shimano 105 crank on a few months after i got mine, not had any problems since late 2014, i have the FSA converter on standby if the praxis goes, the FSA crank was all roughed up on drive side as well looked like it was made of cheese.

Your experience mirrors that of many people. You won't still have that FSA crank at hand, would you? I would be interested to see the damage.

 

[Globalti]

BB30 creaks are almost always attributed to the bearings moving in the frame but long experience with two bikes fitted with FSA BB30 cranksets has proved to me that the problem is the following: in order for the BB axle to pass though the two inner races it has to be a snug but not tight fit. This leaves sufficient play for the actual axle to fret under pedalling forces inside the bearing inner races, setting up a creak as friction and heat build up. In evidence of this, here's a picture of my FSA axle after only 500 miles:

Notice how the band of the machined area that's within the bearing inner races has eroded and notice how much less eroded the drive side is, thanks to the stabilising effect of the chainrings. White or green grease smeared on this area quickly turns black as the metal wears and the creaking soon returns. The remedy is to smear bearing fit compound on the axle; smear it on the axle at the drive end and inside the bearing at the non-drive end so that it has the best chance of not being wiped off as you push the crankset axle through from the RH side. This cures the creaking, permanently, or at least until you next dismantle the BB.

Edit: by contrast the bearings are a tight fit inside those alloy shells and require an extractor to move them so they don't fret and move.

 

[Yellow Saddle]

BB30 creaks are almost always attributed to the bearings moving in the frame but long experience with two bikes fitted with FSA BB30 cranksets has proved to me that the problem is the following: in order for the BB axle to pass though the two inner races it has to be a snug but not tight fit. This leaves sufficient play for the actual axle to fret under pedalling forces inside the bearing inner races, setting up a creak as friction and heat build up. In evidence of this, here's a picture of my FSA axle after only 500 miles:

Notice how the band of the machined area that's within the bearing inner races has eroded and notice how much less eroded the drive side is, thanks to the stabilising effect of the chainrings. White or green grease smeared on this area quickly turns black as the metal wears and the creaking soon returns. The remedy is to smear bearing fit compound on the axle; smear it on the axle at the drive end and inside the bearing at the non-drive end so that it has the best chance of not being wiped off as you push the crankset axle through from the RH side. This cures the creaking, permanently, or at least until you next dismantle the BB.

Edit: by contrast the bearings are a tight fit inside those alloy shells and require an extractor to move them so they don't fret and move.

I think your assessment is spot on. I've also come across many BB30s where the bearing is not a tight fit in the shell, merely a slip fit. Rouge on the shell proves that it moves there as well. Your bike hasn't started to do that yet and hopefully never will. Spindle flex is apparently something they didn't calculate before releasing this design in the wild. I think a steel spindle will sort the problem out.

 

[Globalti]

Close examination of those worn bands within the machined bands reveals tiny pockets of erosion, from where metal appears to have disappeared. I can only assume that this is where there's been a local build up of intense heat under pedalling pressure, the metal becoming rouge as you call it and blackened grease as I see it. I understand that metals are crystalline in structure and assume that these forged alloy axles have quite a coarse crystalline structure, which might explain the pockets of softness. Either that or my FSA crankset is a fake and the metal is really crap quality although after about 5000 hilly miles the crankset is still giving good service and looking as good as new so I'm hopeful that it's a real one. My cycling buddy's FSA BB30 crankset came with the bike so would be genuine yet that is showing exactly the same wear and has been quietened with the same solution.

 

[andsaw]

Yep, that's how mine looked.

BB30 creaks are almost always attributed to the bearings moving in the frame but long experience with two bikes fitted with FSA BB30 cranksets has proved to me that the problem is the following: in order for the BB axle to pass though the two inner races it has to be a snug but not tight fit. This leaves sufficient play for the actual axle to fret under pedalling forces inside the bearing inner races, setting up a creak as friction and heat build up. In evidence of this, here's a picture of my FSA axle after only 500 miles:

Notice how the band of the machined area that's within the bearing inner races has eroded and notice how much less eroded the drive side is, thanks to the stabilising effect of the chainrings. White or green grease smeared on this area quickly turns black as the metal wears and the creaking soon returns. The remedy is to smear bearing fit compound on the axle; smear it on the axle at the drive end and inside the bearing at the non-drive end so that it has the best chance of not being wiped off as you push the crankset axle through from the RH side. This cures the creaking, permanently, or at least until you next dismantle the BB.

Edit: by contrast the bearings are a tight fit inside those alloy shells and require an extractor to move them so they don't fret and move.

 

[I am Spartacus]

My bottom bracket started making a horrible rattling / clanking noise today. The bike has done less than 1000 miles!

Looking at the L/H end of the BB it looks like a seal has migrated (pics attached). Or should it look like this?

Thx

Who pressed the bearing in, in the first place?

 

[3narf]

The fine craftsmen at Cannondale...

 

[Yellow Saddle]

The fine AMERICAN craftsmen at Cannondale...

You forgot to add American. You know, those Americans who don't like other nations to also have jobs.

 

[3narf]

You forgot to add American. You know, those Americans who don't like other nations to also have jobs.

Hahaha

I was leaving an element of ambiguity, in case the BBs were fitted at an export processing zone in Taiwan...

 

[I am Spartacus]

take the nds crank off, and just check if the circlips have been installed in the shell.
I think you have just very unlucky for something like that to happen.
How rough does the actual bearing feel?
Press fit bb are very simple... but they do not tolerate water ingress at all well. Water getting in from the downtube for example and simply left to do its worst over months.