Originally Posted by
samuelstemarie
I heard some people fitting a 68mm deeper like you mention but I was wondering if you have thread left they will rust and after it would be a nightmare to take it out.
Use a bottom bracket with a plastic non-drive side cup and cover any exposed bare metal with something like Testors model paint or nail polish that won't put up too much of a fight when you need to remove the cup.
(Not nearly as ideal as facing the bottom bracket, but you're looking for cheap.)
Originally Posted by
samuelstemarie
The space option provides by Barabaika is really good, if I make sure I have long thread enough like mention by Andrew. I will verify if it is symmetric, if yes I assume 1.5 on each side will be the best option.
Spacers would go entirely on the drive side. That side gets cinched down to the bottom bracket shell. The non-drive side cup gets cinched down against the cartridge body. If the NDS cup has a flange, it may or may not seat tightly against the spacer. If the NDS cup doesn't have a flange, the spacer would just fall off.
3 mm of spacers will offset your spindle a bit to the drive side, which could actually be a good thing if your crankset was designed for an asymmetric spindle. That was
very common before (mostly) symmetrical cartridges became the norm. You'll have to measure your existing spindle to check.
I don't know if 3 mm spacers are commonly available, but 2.5 mm spacers are. That should be enough for you to seat a 73 mm cartridge.
Originally Posted by
samuelstemarie
Also, I never heard of threadless BB, I will look into that.
The Velo Orange cartridge I linked above is a threadless bottom bracket. There are less expensive ones, but most of them have beveled flanges that are designed to seat in a chamfered bottom bracket shell. If you're going to cut a chamfered edge into your bottom bracket shell, you might as well cut it down to 68 mm.