Where do I find lugged bottom brackets for a smaller frame size that have angles in the 56-58* range? Everything I see has 60 and 62. I'm doing a little research as my wife would like me to build a frame for her, but I can't find a bottom bracket to fit a 51-52cm frame.

If they're out there I'm looking in the wrong place.

Thanks in advance.

Brandon

You are going to have to bend one. Although you can get up to 2 degrees without bending.

Agreed with Eric. get some bending bars, thick walled tubing of the same OD works well. Balcksmithy has always been a part of frame building. Hammer, punch, grinder (for ID work), needle nose pliers are all common tools for this. I over bend the sockets and as I work the tube/socket fit back the angle looses some. This was the beginning of my using brass/bronze for lugs years ago, to fill the gaps left by the heavy lifting. Andy

Bulge formed BB will be more flexible than an investment cast one .. Plus you can fabricate your own BB adding the lugged look

over a Tig joined tubular BB shell .. If nothing else is satisfactory..

Brandon have you thought about using smaller wheels? I never understand the reluctance to use a wheel size representative of the rider. By using smaller wheels you will be decreasing the BB drop and opening up the down tube/seat tube angle.

Hi Doug, I have not. That's a very good point! I'll look into that for sure.

Thank you!

You're going to likely run into the same issue with the lower head lug. You can also cut the lugs and braze them back together. Some builders fabricated their lugs with brass fillets and then silver solder the tubes in.

And smaller front wheels allow for shorter top tubes as well as lower stand over. Andy

+1 this.

BITD, people were reluctant to use smaller wheels because of the dearth of high-quality rims and tires for the non-standard wheel sizes. This is no longer the case, and there are plenty of options in rims and tires for 650A, 650B, and 559mm (MTB) wheels.

I ride a 51cm road frame, and they handle 700c wheels just fine, and I'm pleased to use this common size. But BB lugs still require a lot of modification to work for that size frame.