Cottered to cotterless BB spindle

Hi all,
I use a Rudge frame as my fixed wheel bike and need to replace the crankset. The current setup is for a cottered crank but I am considering changing to a cotterless. The bottom bracket spindle on the bike at the moment is a 35-55-45 and the BB shell is a 26tpi 73mm affair. I have tried a threadless enclosed square ended BB with no joy, anyone know of a suitably sized cotterless spindle? (one with a fairly standard taper if possible, I'm thinking Stronglight cranks or similar).
Thanks for your help, Dallas

73mm is the OS MTB standard, so you shouldn't have a problem finding one to suit.

The Shimano UN55 is Tester Approved and available for less than a tenner.

It's very nice but English thread is usually 24tpi so almost certainly won't fit. The 26 tpi is very annoying, since all contempary Raleighs seem to be 24 tpi and the more conventional 68mm BB shell, but the Rudge has this weird BB despite having come out of the same factory as the Raleighs. At least it's not Chater Lea, I seem to remember nothing fits them!

what about filling the BB and re-cutting the threads in the english standard? LBS should be able to do it..

It does depend on your chain line requirement. But SJS do a 7R cotterless spindle for 73mm BB:
http://www.sjscycles.co.uk/mobile/cotterless-axle-7r-134mm-prod22175/

Edit: or maybe the 5R might work with the measurements given - just search 'cotterless' in the search box and it'll list all the sizes of spindle available.

c00ps, that looks quite promising and at that price is worth a try, I've got a bit of wiggle room on the back wheel and can dish it a bit to bring everything into line, so I think I'll give that a go, cheers.

I know you 26tpi pain. I have a couple of converted R20s! Another (overly expensive) option is Phil wood cups & shimano un72 bb.

Sorry, the 26 didn't register...

No problem, thanks for the help everyone. I think I'll give the SJS Cycles spindle a whirl (pun intended), unless a decent cottered Rudge chainset (one with teeth that don't look like shark fins!) turns up before I find a suitable cotterless alternative.

Just picked up a 1930s Raleigh frame with a 78mm shell which I assume is 26tpi. I got the frame bare, so have no cups to reuse.

Do you know of a good source for 26tpi cups, and information on what all the axle codes mean?