BB30 to FSA adapter on new frame

Hey guys, question to you, hope you may kindly advise.

I’ve recently built an Allez Sprint from bare frame and am really impressed by it, compared to my old carbon bike. Anyway, one thing I am dubious about is the BB30, that looks very narrow and in order to install Shimano (24) or FSA (30) crank I need to use plastic adapters, perhaps they are ok, but just don’t look serious (narrow shell, high load, plastic). Adapters are Wheels Mfg (for Shimano 24). To take full advantage of the width of the shimano/FSA crank, do you see any benefit in installing BB30 to FSA threaded adapter to take external BB cups? This would allow natively install FSA cranks and Shimano through small shims. Or am I overthinking it? I’m a bigger rider and want all the power transfer I can get.


I have the same bike and run a 105 crankset. I just used the wheels mfg BB30 to Shimano adapter and it has been working great for about a year. It isn’t plastic though, it’s metal of some kind (probably aluminum).


This is the one I have. The description does say they are aluminum. They also have other ones with lower friction bearing seals, ceramic, etc.

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By FSA do you mean BB386?

If so they having had a Focus Izalco with an BB386 crankset fitted and plastic spacers I can assure you the BB is more than stiff enough.

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Thanks guys, wheels mfg adapters do look plastic, some sort of hard plastic, here is the link:

I’ve got two cranksets in possesion, Ultegra R8000 and FSA Gossamer BB386 (100g heaver than Ultegra).
Currently as is, BB30 can take Ultegra R8000 via Wheels Mfg shims, but I like idea of 30mm crank spinde and wider bearing…
If I fit BB30 FSA adapter (+50g), I can then fit BB386 with nice NTN bearings, which would take either FSA crank or Ultegra via small shims. Too much choice!

Question perhaps, whether to keep it light as is, or make it “stiffer” with unknown gains, if any.


Have you tried a BB386 crankset? Personally I dislike the Q-factor, finding it a little too wide to be perfectly comfortable. I get on best with Cannondale Si, Shimano road is ok if move cleats slightly, but BB386 has never felt ‘right’ in width.

Another consideration is that Shimano is so simple to fit first time (side screw takes up slack and tighten two allen keys). BB386 takes a bit of faff fitting the right number of spacers (and working out which side if you are very fussy) to compress the wave-washer perfectly and centre the cranks.
Of course with Shimano you have the hassle of fitting the right BB rather than a simple adaptor.

I have these and they are mostly aluminium with plastic inserts…

Those wheels manufacturing ones have better reviews though.

Yes, the BB386 came off the “old” carbon bike. I actually retired it and frame goes onto the wall. It is a nice frame and I fear racing it. It’s a build on budget, all parts were transferred, except the BB. You are right, I like the Shimano preload screw better than the FSA system. I measured the Q factor earlier some time ago, it appears to be the same between cranks I have… Never tried narrower, but did try wider, via washers on pedal axles, did not like it much.

Just thinking now, perhaps I should leave it with plastic shims for now and if they develop any play, replace with what [mwglow15] suggested earlier, not sure…

Thanks, I considered those as well and, as you say, the Wheels Mfg get better reviews, mostly around manufacturing tolerances. I never had any issues with FSA stuff personally…

One more question. The frame BB doesn’t have the drain hole, hence no place for water to escape other than through bearing seals. Looking at the seatpost clamp, water will most likely get there no problem. Is this an issue, shall I drill one?

Apparently had a BB bearings I bought ages ago by mistake and found them today at the bottom of my parts box… Never thought I’ll use these!

These are crazy-fast, stiff, and last forever. Easily adapts different BB standards to different crank standards

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If you want to run Shimano, I’d recommend one of these:

I originally ran the 30mm --> 24 mm adapters and they’re plenty strong. My main complaint about them was it was just an extra layer of stuff to cause creaking and BB30 already sucks for that.

Much less creaking and easier to clean the BB with an outboard BB.

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