Bottom bracket to fit a BB386 crank/spindle into a BB86 frame/BB shell
 

Hi All,

I'm seeking recommendations for a bottom bracket to fit a BB386 crank/spindle into a frame with a BB86 bottom bracket shell. I've attached a couple of screenshots of a suitable FSA bottom bracket from their website to avoid any confusion. I like the look of this design, with the two halves of the bottom bracket fitting together with a 'sleeve' through the bottom bracket shell, rather than totally separate press fit cups on each side of the shell. Can anyone in this forum recommend this FSA bottom bracket, or a similarly designed one from another manufacturer? I'm not a big guy and I'm no longer a competitive cyclist, so I'm really just looking for a bottom bracket that will fit this crank/frame combo properly and be fairly reliable for recreational cycling, i.e. it doesn't need to stand up to a pro tour sprinter.

Thanks for any tips!

https://cimg9.ibsrv.net/gimg/bikefor...cd60d384f8.jpg
https://cimg2.ibsrv.net/gimg/bikefor...d372322a19.jpg

Try wheels manufacturing. They make thread together BBs for many combinations. I have BB86 and 386 frames and use Shimano GRX cranks. They don't seem to make a 386 with angular contact bearings, which is what I prefer.

https://wheelsmfg.com/386evo-abec-3-bb-black.html

That linked product is for the wrong frame and wrong spindle (sorry that was your spindle I was thinking of) from what the OP is after though?

I haven’t used that FSA BB but their stuff is generally good and I can’t see it being a problem for the usage described.

Though - Don’t the 30mm spindles end up with pretty thin bearings in a shell designed for 24mm? I remember someone made one with dual bearings on both sides to extend the bearing life. Looking at that diagram again, looks like they have double races on this one in fact. For recreational use maybe ok but I’d be tempted to change crank.

Thank you. As an engineer, that's the same concern I have, i.e. the minimal clearance for the bearings with a 30mm spindle in a shell designed to accept a 24mm spindle. As you say, this BB looks like it has a double race each side, so it looks OK. I already have the crank but I'm looking at a BB86 frameset at a steal of a price, hence considering this option. My general impression of FSA BBs is they seem OK, so I'm looking to hear if anyone has had good or bad experiences with this specific BB (or similar) before I commit.

Have you looked at BBInfiinite? I've had a couple of their BB's and they have been really good.

https://www.bbinfinite.com/products/bb386evo-30mm

That’s also too big for a bb86 shell. Has to be 41mm outer diameter.

Ooops, yep, completely missed that. :o