I have a Titanium Bottom Bracket manufactured by Cook Bros. They no longer make these.
The retaining Collar, the ring with the set screw, is cracked at the set screw and no longer retains the shaft.

By chance does anyone know where this part can be found?
The ID is special at 15.875 mm but I can bore it if necessary
Otherwise I'll just put in a new BB

Thanks

I've no idea where to get that part But that thing is cool!! I like the idea of a sealed-bearing BB with replaceable cartridges.

I cant see how that works, can you explain what the grub screws lock on to. As far as replacing it goes, look at a replacement euro BMX bb, you may be able to use the cup from one of them.

edit - I get it now. I would look for a cone nut from an oversize 14mm bmx hub. some of these come with grub screws. You'll need to drill it out for sure, and it's almost certainly wider than that collar. but you may be ok.

Some BMX BBs used to be set up similarly (for the obvious reason) but your collars look pretty slim. Check out some long-term BMX shops for possibilities.

I'm also guessing that bike shops are your best bet, though not specifically BMX shops. I'm guessing there are some bike shops that deal and dealt in high-end parts that may have some Cook Bros. pieces sitting around. But maybe Cook Bros. only sold whole BB's and there might not be replacement parts sitting around anywhere, in which case your best bet might be BMX-migrated parts.

Thanks for the Advice.

I bought a BMX from a LBS Saturday for my sons 8th b-day. I'm sure they will help me out