https://www.bikeradar.com/...ttom-brackets-36660/

FSA makes a bottom bracket that adapts BB386 to BB30. https://shop.fullspeedahead.com/...es/pf30bb386-bb-road

Wheels Manufacturing makes bottom brackets that adapt to BB30 and SRAM GXP. https://wheelsmfg.com/...tml?bb_standard=6853

I was going to write basically what has been said above. I think you should be able to get bottom brackets to work with either crank set. The Red, for instance, will come with a combination of spacers for it to work with different widths. See page 13 here

The first one is not an adapter. It's not even specific to BB30. PF30 and BB386 bearings and cups are the exact same thing. The only difference is the frame where the bearings end up 68mm wide (PF30) or 86.6mm wide (386). The actual bearings don't change, they are still a 30mm ID 46mm OD bearings.

I think your second link was meant to direct to https://wheelsmfg.com/...am-cranks-black.html.

To the OP, lets take this one step at a time.

Just bought a new frame that is BB386. Came with an FSA Megaexo bottom bracket that accepts a 24mm spindle.
My old frame was BB86 with an 24mm spindle. I'm running a Sram GXP Force 22 crank which worked on the BB86. MegaExo and GXP are not the same thing. GXP uses a 24mm ID bearing on one side and 22mm ID on the non-drive side. They are similar length spindles though.



The BB386 seems to be wider than the BB86. It shouldn't be. If anything, the GXP spindle is slightly long for a 386 and requires a couple mm of spacers.


Can I get a longer 24mm spindle for the Force crank? Not that I know of.


I also have a Red BB30 crankset I could use. A true BB30 crankset is too narrow. If it's a RED with the integrated (non removable spider) it is surely too narrow. SRAM makes things confusing by calling all of their 30mm spindle cranksets "BB30."


I noticed Stages has longer BB30 spindles I could get for the Red. It won't work assuming you have the integrated spider.


If I swapped out the bottom bracket, can I install a bottom bracket in the BB386 frame that would accept BB30. No. A BB386 frame is about 22mm wider than a BB30 frame.


What bearings are currently in your BB386 frame? Any chances there's 30mm bearings in there with a reducer/spacer installed? What frame is it?

No, and no. That first link is FSA's bottom bracket product that will let you use a BB30 (or PF30) in a BB386 frame. It solves one of the OP's specific asks... can he put a SRAM BB30 crank in a 386 Frame. This product would accomplish that. I used the term "adapts," because that it what that particular BB does, since the two BB standards are different. You are thinking of a a different product... a separate thing that must be used in conjunction with a separate BB. Think of these conversion BBs as two-in-one.

The second link is my intended link. That lists a bunch of Wheels Mfg. products that allow you to install either a BB30 crank or a GXP crank in a BB386 frame. That answer's the OP's other question about can he install a Force GPX crank in his 386 frame. with one of these WM products, he can do that.

That product will allow you to use a BB30 crank in a PF30 frame, or a BB386 crank in a BB386 frame. It will also allow you to use a BB386 crank in a PF30 frame, as long as you also use the appropriate adapter (https://shop.fullspeedahead.com/...-for-pf30-bb30-frame).

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"I'm thinking of a number between 1 and 10, and I don't know why!"

No adapter in the world is magically going to make a BB30 spindle long enough to fit a BB386 frame. The nearest thing to an exception would be a SRAM crank with a 30mm spindle on a removable spider crank...which is technically a BB386 crank, but labeled BB30.

The BB386 seems to be wider than the BB86. It shouldn't be. If anything, the GXP spindle is slightly long for a 386 and requires a couple mm of spacers.
When I installed the GXP crank. It was butted up against the frame on the drive side. The spindle came out the other side of the BB. But only the grooved part that the crank arm attaches too. The smooth main body of the spindle didn't reach the other side of the BB and the crank would wiggle in place and you could see the spindle wasn't fitting tightly around the BB where it exited. Which made me look at my old frame and realize it was BB86 not BB386 The confusing part is that BB86 and BB386 have the same bearing position (width).

I also have a Red BB30 crankset I could use. A true BB30 crankset is too narrow. If it's a RED with the integrated (non removable spider) it is surely too narrow. SRAM makes things confusing by calling all of their 30mm spindle cranksets "BB30."
It's a Red 22. It's 5-6 years old. The spider is removable. When I held it up alongside the GXP crank, the spindles appeared to be the same length. I might be wrong, didn't have a chance to measure them before I ran out for work. On the BB30 spindle is says PF30 BB30 if that makes any difference. Cool. Consider that crankset a BB386 crankset instead.

I noticed Stages has longer BB30 spindles I could get for the Red. It won't work assuming you have the integrated spider.
Spider is removable so I'm assuming I can order a new spindle? I think the current RED crank will fit.


If I swapped out the bottom bracket, can I install a bottom bracket in the BB386 frame that would accept BB30. No. A BB386 frame is about 22mm wider than a BB30 frame.
I'm assuming this point is moot if I can change the spindle.

What bearings are currently in your BB386 frame? Any chances there's 30mm bearings in there with a reducer/spacer installed? What frame is it?
I'll have to look again but from what I remember is said FSA Megaexo 24mm. They kind of look like this but not exactly sure.
https://shop.fullspeedahead.com/...indle-to-bb386-frame
If it is these, I'm assuming they can be removed? Would I then be left with a 30mm opening?

The frame is a Blue Triad Elite. Bought it without a groupset. Was putting my Di2 on it. I thought my old frame/crank was BB386 so didn't ask about the bottom bracket on the new bike.

Hot dang Mattr, I think we're getting close.

Is your RED crank a power meter crank like a Quarq spider based PM? (It doesn't matter for sizing, I'm just curious as it may explain a couple things.)

You jumped ahead of me with that FSA link. Nice work. The only BB386 frame I have owned came with 30mm ID bearings installed and the reducer spacer things you linked (which also widened things by about 5 mm). Those suckers pop right out. I'm pretty sure if you are installing GXP, you want these ones instead.

If those reducer things pop out, your RED crank should slip right in with no modifications or spacer needed. Make sure the dust caps didn't fall off the bearing when pulling those reducers out then put your RED crank on as normal. I think I removed the reducers with a long hex bolt since none of my BB specific tools fit right. Basically I placed the big hex head against the inside of the reducer (from the other side of the BB) and lightly tapped it starting at 12 o'clock, 1 o'clock and so on until it popped out, then repeated the process from the other side.

Think of it like this picture, but tapping around the edge of the reducer. It's been a year, so I don't remember why I didn't actually use the tool in the picture. There must have been some sort of fit issue.


I'm pretty curious now, so let us know how it goes.

Cutting back to your original question...

If your current crank (gxp/ PF86 sram parlance) fitted your BB86(shimano parlance) frame, then it will be long enough to fit your new BB386evo frame.

If it does have a 386evo 30mm BB fitted, then all you need is these: https://shop.fullspeedahead.com/...crank-to-bb386-frame to reduce the inner dia down.

If its got a "proper" 386-24 BB fitted then, it might be easier to bin it off and get this:
https://www.ribblecycles.co.uk/...road-bb86/#pid=34055 and dump the centre tube.

Or get a better crank..

Original BB30 red etc will not fit as stated earlier, its just that to keep p.no's down, most manufacturers make 1 crank that will do multiple fitments with adaptors etc.

Phil, you're absolutely right about this and your entire post. One thing SRAM did was re-paint the Force carbon crank arms as "RED" cranks and use them with Quarqs. Thus there are some "RED" branded cranks with BB386 spec spindles. I think Mattr may actually have one of those.

Thanks for all the help so far. Just got off the phone with FSA. I can pop the 24mm cups out and should be left with a 30mm opening which should fit the Red crank, hopefully. The spindle will still be short I think but then I can look at the Stages spindles and see what will work.
If I remember I'll take some pictures with the GXP crank installed and you can see the loose fit issue.

Cool. Decide which crank you want to use and then get back to us. In theory, a BB386 spec crank should fit perfectly. A GXP spindle would be slightly longer and need these popped into the bearings to fit correctly.

This the the BB with the 24mm spindle cups attached.



This the the Force GXP installed. You can kind of see the gap between the spindle and the BB cup. I could wiggle the crank, not a tight fit. The spindle needs to be a bit longer.



The 24mm reducer cup removed.





BB without the 24mm cups. Used a long screwdriver and hammer to pop them out. Came out pretty easy. The dimension is now 30mm. I think the BB30 Red crank is going to fit. It's tight getting the crank through the bearing but works. Was looking at the Sram manual. Need some small spacers to use the crank on the BB386. Going to order some then see if the spindle on the Red crank is long enough.

Mattr,

Thanks for the great pictures. One thing to note is that "MegaExo" is basically Shimano spec (24mm spindle on both sides) and GXP is 24mm on the drive side and 22mm on the non-driveside. That's why there's a gap on that side. Your reducer's hole is 2mm too big. The reducer set I linked a couple posts up would be the GXP specific one if you decide you are going with the GXP cranks on your build.

If you use your 30mm SRAM crank, being a tight fit in the 30mm bearing is right. Any shop should have a handful of spacers if you need them. I needed a couple mm on the drive side to center BB386 cranks on a BB386 frame.

I'm going to go with the BB30 Red, the arms are a little shorter than the GXP crank and worked well in the past.

#30mm4life

Red BB30 crankset went on perfectly. Had to get a couple of 2.5mm shims Sram details it the manual. Fits perfectly.
Thanks everyone for the help.

That's great! All you need now is some whistle tips and you'll be set. Woowooo!