Hi there

I’m considering a new frame that has a 68mm PF30 BB width, but want to run Shimano MTB hollowtech II cranks. What’s the best approach for the BB conversion? I’ve narrowed it down to three likely options, but don’t know if which is best, or if there is something better out there:

FSA PF30 Threaded Adapter

KCNC PF30 Adaptor

Praxis Bottom Bracket Converter

Any real world experience, or recommendations would be welcome.

I use a Wheels Mfrg one as find the ones that thread together in the middle are a better bet – slightly ironic that adding threads to a press-fit helps the situation 😉
http://www.madison.co.uk/products/cycling/transmission-braking-components/bottom-brackets/pressfit-30-to-outboard-bottom-bracket-shimano-compatible-black/

I put the FSA one in my spearfish and its a TIGHT fit! It’s good though, and stopped any creaks. I had a sram plastic adaptor in there first, as it was a cheap option, but it was cheap for a reason!

Hi, I have a 68mm Praxis converter for Shimano if you are interested. Fitted but un-used as it was incompatible with the internal cable routing on my frame.
Mail me if interested. £35 posted.

I’ve had the sram one – worked but tended to ‘walk’ out a bit.
Also had the KCNC one, but that had grumbly bearings fairly quickly. I’m sure it will fine if you upgrade to better bearings when they wear out.

Thanks for the replies …

Stedlocks

I put the FSA one in my spearfish and its a TIGHT fit!

I guess it has to be. I have a good headset press I could use, or is it a job for the LBS? Does the FSA one get fitted dry or with something like Loctite?

@Dekerf853 – I hadn’t thought about cable routing. I’ll need to look into that now as I think I’m going to have the same problem you described

My experience was that my Praxis version still needs taking out a greasing every few months or it creaks anyway. The Wheels one, without an expanding element, seems creak free so far (3months in)

We use the threaded Wheels MFG ones at work. No complaints so far.

hounslow – Member
We use the threaded Wheels MFG ones at work. No complaints so far.

I’ve just been looking at those. I can’t figure something out…

My BB shell is 68mm. If I was running a standard BB I’d need 2 spacers on the drive side, and one on the non-drive side to space the width out to run a MTB crankset.

I can’t see how this’ll work with the wheels mfg one.

Praxis one works well for me

Are these the answer to my own question?

Wheels MFG sell 24mm spacers to center the cranks rather than space out the bottom bracket. I thought the crank spindle was machined for the bearings to sit at specific points. Not sure I’m keen to just add spacers outside the BB cups. Must be OK though?

I’ve used a Chris King with a 24mm adapter running XTR cranks, ok so far 10 rides in just add shimes as you would normally for 68mm and 73mm BB

Just found the Wheels mfg 46mm BB spacer set. Sorted. Thanks