What is BB30?

[adscrim]

I thought BB30 did away with the need for cups?

 

[Globalti]

Ah, well, I started this thread in the belief that BB30 is the same as Mega-Exo, but two fellow forumeers have put me right on that. It's not the same at all.

 

[GrasB]

adscrim, Yes, in crude terms you press-fit cartridge beatings directly into the frame.

 

[Proto]

This is turning into a saga! Been on the phone and the web all morning and I've now discovered that Shimano Hollowtech 11 BBs are compatible with FSA aluminium cranksets but according to various sources including FSA not with the carbon cranksets, which I have. My carbon SLK Mega-Exo crankset needs an FSA BB8000 bottom bracket, which I have ordered for £34.99 from Cyclo Sports UK as no LBS seemed to have one in stock. When it arrives I will compare it carefully with a Shimano BB out of interest and report here.

Watch this space......

I'm running a Shimano 105 Hollowtech II bottom bracket bearing and cup assembly with a FSA SLK carbon chainset. Works perfectly well.

 

[Globalti]

I'm sure they are fine but tomorrow when the FSA BB8000 arrives I'm going down to my LBS to compare it with a Shimano Hollowtech 11, because we both want to satisfy ourselves that they're the same.

 

[Globalti]

For anybody who is interested I did the comparison this afternoon at my LBS. The Hollowtech 11 BB is about 5mm narrower than the FSA BB8000. The FSA BB has a rigid ali body between the cups and a second ali tube that braces between the two inner races. The Shimano item has only a light plastic body between the cups. So we reckoned the two are not interchangeable; you'd get away with it but I reckon the FSA item is designed that way for a reason.

One thing that did surprise me was the amount of effort it took to remove then replace the LH crank on the splines on the axle - it's a damned tight engineering fit.