I'm having problems with the bottom bracket on my Thanet Silverlight. It has an unthreaded bb shell with a TDC bb insert which is prevented from turning in the shell by a brass bb oiler. The bb oiler screws into the shell and into a slot in the TDC insert.

From when I got the bike the bb lock ring would loosen after just a few miles so I Locktite'd it. That worked for a while but despite the lock ring being fixed the assembly started loosening again. I took it apart yesterday and found the end of the bb oiler had sheared off. The bike has a Sturmey Archer fixed-gear ASC hub and it's obvious the brass bb oiler is just not up to the stress of preventing the TDC insert from rotating in the bb shell with fixed gear.

I think the solution might be to replace the bb oiler with a blanking screw of some kind, made of a stronger material, perhaps stainless steel, but I can't find any info about the bb oiler's thread size. Does anyone know?

Also, I'd like to replace the present cottered crank with a cotterless Stronglight 49A/TA set that I have. Does anyone have experience of performing such a change on a machine with a BB shell? For example, will a TA or Stronglight axle work with TDC bearing cups?

The BB assembled


The BB Shell


The Insert


The Inadequate BB Oiler/Insert Lock