Bottom Bracket advice needed!

techytuppers

Hello, long time reader here but first contribution...

I wondered if you wonderful people could help me out?

I'm nearing the end of a year long journey of building my own bike from all the individual bits and pieces. Super excited but I'm a bit stumped by my bottom bracket needs.

I have a BMC SLR01 2011 Frameset
http://www.evanscycles.com/products/bmc/teammachine-slr01-2011-frameset-ec024684

And the Shimano di2 Ultegra groupset
http://www.ribblecycles.co.uk/gsd/road-track-bike/shimano-di2-ultegra-6870-11-spd-double-groupset?part=GSSHIMULT6870DI211D

My frameset is listed as having a BB30, and my groupset comes with 24mm spindle. The bottom bracket that came with my groupset is actually completely wrong (combination of different sized parts).. So I'm open to the idea of buying a whole new bottom bracket rather than getting adapters.

After what felt like looking on every corner of internet(!) I found these:


Ceramic BB30 to 24mm spindle (in stock elsewhere): http://www.chainreactioncycles.com/rotor-bb30-to-24mm-ceramic-road-bottom-bracket/rp-prod130497


Steel BB30 to 24mm spindle: http://www.chainreactioncycles.com/rotor-bb30-to-24mm-steel-road-bottom-bracket/rp-prod130495

So I have a few questions

1) My frameset spec says BB30, but inside the bottom bracket hole on the frame it is completely smooth e.g. no threading. Does this actually make it a Press Fit one, and therefore a PF30(?) rather than a BB30? And as a result the Rotor BB's would be ineffective?

2) If that is the case, are there alternatives to the Rotor? I found some Chris King ones for Press Fit, but at either 30 or 24, not the two together.

2) Is there a real advantage of ceramic of steel in the case of £100 difference? Aware this could be more of an opinion question..

Many many thanks in advance!

Tuppers

keef66

BB30 is just one of several press-fit BB standards; your BB shell should be smooth rather than threaded. The adapters you've mentioned will do exactly what you need.

Save your money and get the steel version.

mfin

Praxis make something that will do it too. Well reviewed as well.

http://www.praxiscycles.com/conversion-bb/

techytuppers

keef66 wrote:

BB30 is just one of several press-fit BB standards; your BB shell should be smooth rather than threaded. The adapters you've mentioned will do exactly what you need.

Save your money and get the steel version.

Ah amazing - thanks so much!

86inch

I use the Rotor steel in the BB30 of my Planet X RT57 with Ultegra 6800 chainset, its far better than the plain bearings with adaptors which are a cheaper but inferior option.