Ok, lets say a Gossamer Pro ABS 46/36 crank could be had for cheap and is really appealing since its the tooth count i want (actualy want 46/34, but that only comes stock on a Sora crank at nicest).

Anyhoo, the FSA bb30 is pressfit. Ive read the megaexo bottom bracket would work as its threaded and the Gossamer crank can be used with that bottom bracket.

But FSA says otherwise. They say bb30 cranks cant go on thrwaded bottom brackets. FSA Crankset FAQs - FSA


So- anyone have actual experience with this? Is there no bottom bracket that would work? If there is a threaded bottom bracket thst would work, is there a Shimano one since the FSA bottom brackets get terrible reviews all over the internet?


I could get a Shimano CX50 crank or Sora crank, but both would be about $75 more than the Gossamer.

If it's a standard BB30 crankset, it cannot fit into an English-threaded bottom bracket.

BB30 and English bottom brackets are both 68 mm wide. You can't fit reasonably-sized bearings for a 30 mm spindle inside a 1.37" bottom bracket shell, which means you'd need to mount the bearings outboard. But if you do that, you increase the effective width of the bottom bracket and the BB30 spindle won't reach through to the other side.

What I've read leaves me thinking that there is no bearings with an ID big enough for the 30mm spindle of the BB30 cranks. Standard BB bearings work with a 24mm spindle.

When I was looking at cranks I found many BB30's at low prices but wasn't able to use them with the frame I had at the time. I think there is a seller on eBay (like crosslake or something) that always has FSA cranks for BB30 on the cheap, or they did at one time.

Ok, but arent bb30 bearings designed to be outside the shell?
Or are you referring to then being even further apart than they are supposed to be on a pressfit?

Gossamer (tm) has applied to Multiple Products from that Company.

No, BB30 bearings are pressed into the shell. They're not outboard.

Since BB30 bearings are inboard, a BB30 bottom bracket is 68 mm across whether or not bearings are installed. That's the distance a BB30 spindle is designed for.

Since you can't fit bearings that'll take a 30 mm spindle inside an English-threaded bottom bracket's 34.8 mm opening, you'd have to mount them outboard. A 68 mm shell plus an 11 mm bearing on each side means your spindle would have to traverse a 90 mm bottom bracket. A BB30 spindle designed for a 68 mm bottom bracket simply won't reach.

Have a few of these BB's. they have all lasted longer than the original chainrings, and I just can't seem to kill any of them.

I've killed a couple of FSA MegaExo bottom brackets. Neither lasted 3500 miles. That was years ago, so they may have fixed whatever problem was causing that.

I've had both Gossamer and CX50 cranksets. Neither is anything special, but I never saw anything wrong with either one.

You say you can get the Gossamer for $75 cheaper than the CX50, but I would think that must be a particular closeout deal and you won't be able to specify the bottom bracket that you need. You can get a CX50 crankset for under $100: https://www.universalcycles.com/shop...4&category=521

You can get it even cheaper if you're willing to order from a UK website. The Shimano bottom bracket you'd need sells for about $20 more.

BTW, you probably know this, but replacing the small ring with a 34T is cheap and easy.

FSA has a bunch of axle standards.

Square taper
ISIS spined
MegaExo(Omega)
MegaExo
BB30
BBRight
BB386

MegaExo that is not Omega uses a 24mm axle, and is sort of compatible with Shimano BBs which are cheaper, lighter, higher quality and last longer. You might need the blue o-rings, and it is a pretty tight fit. It's not an easy slip fit.

BB30 will not work with anything but a BB30 frame. This will not work with BSA because the axle is only long enough for internal bearings inside a 68mm BB shell.

BB386 has a 30mm axle, but will work with a BSA frame with the appropriate bottom bracket. This is because the axle is longer to allow for 86mm spacing, the width of external bearings outside of a 68mm BB shell.

[MENTION=232461]SkyDog75[/MENTION] - thanks for the further explanation. I had lumped bb30 and megaexo into the same group for how the bottom brackets work and after reading your info and more looking, i see they operate differently.
[MENTION=131875]andy k[/MENTION] - The Gossamer crank is a new take off that I could get for really cheap. I had planned on buying a CX50 from overseas since they are $75-90 plus BB cost, but liked the idea of a good crank I havent tried before for cheap. Trying something new and for cheap?...sounded great to me.
[MENTION=441228]2lo8[/MENTION] - Really appreciate the rundown, it helps clarify some things. Clearly, I havent used an FSA crank before, much less on a new build. Its all been square taper or Hallowtech II up to now.



So in the end, the Gossamer Pro ABS is a BB386 which means I can use a threaded BB with it...somehow. Now to read up on how the installation works.

Thanks all!

This probably doesn't help you, but the CX50 is a great crank, I have one on my gravel bike paired with a Ultegra BB, the total set-up cost less than $100. That's cheap for stuff like this!

I have a FSA Gossamer Pro 46/36 on my cross bike (BB30 version) and yes, as others have stated, there's no way it will work in a threaded bottom bracket as the spindle is too short. The BB386-EVO version will fit with a BSA30 BB, but I doubt you have that one if it has BB30 on it.