Can anyone rethread a BB for me? 26 TPI to 24

I think I've got this right. I've got an old Hercules roadster frame and I think the BB is old raleigh threading - 26 TPI (?)

Is there anyone here who can rethread it for me to standard threading?

Not sure if you can do that.
might not be enough metal to cut into cos your be threading a thread.

people can, its just quite difficult, involving recasting the inside and rethreading it.

just get one of those threadless YST BB.

recasting is extreme !

threadless makes more sense.

Argos Cycles in Bristol will do it for 65 quid - it's not the most straightforward job you can do on a bike

Cheers chaps. I appreciate it's not simple. Thing is I want to do a vintage restoration and keep the original cottered cranks. Presume that a threadless bb won't take the cottered axle unless anyone knows different? This is what Sheldon says:

The major areas of concern are headsets and bottom brackets. Raleigh used its own unique 26 threads-per-inch parts, which are not interchangeable with anything else. Non-Raleigh British bikes use B.S.C. parts, which are readily available. This is particularly a problem if you need to replace a fork on a Raleigh-built bike, because you will also have to replace the headset if you cannot locate a 26 TPI fork. Fortunately, the press-fit dimensions on the head tube of the frame are the same for both.
If you are not satisfied with cottered cranks, and want to upgrade a Nottingham Raleigh frame to cotterless cranks, you will have to re-use the old cups unless you are prepared to spring for a Phil Wood or Mavic bottom bracket. The inner diameter of Raleigh cups is a bit smaller than standard. Bottom bracket axles that are drilled and tapped to use bolts to hold on the cranks will not usually fit. BB axles that use nuts will usually work. Because of the wider BB shells used on Raleighs, you will need a 5** series axle.

Alternatively, it is possible to re-thread Raleigh bottom brackets to standard British (24 TPI) threading.

@goodhead - I am having a similar problem with an old Sun frame. Having had cottered cranks before I'm not too bothered about having them again (they can be awful) but trying to find a BB that fits is proving difficult. Looking at all the alternatives. Let me know how you get on!

Hi Huge.

I've solved the issue by getting new cups that are 26 TPI threaded.

I got them from here - warning - the seller took a bit of cajoling to actually send them!

http://cgi.ebay.co.uk/Raleigh-Replica-Bottom-Bracket-Cups_W0QQitemZ220371807464QQihZ012QQcategoryZ56197QQtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262

They do fit however.

You can simply run a standard 24tpi tap through each side of the BB - it does not cut too much metal away, rather it it rejigs the threads to 24tpi, I have done it several times to Raleigh BBs. You will also need to reduce the width of the BB shell - best way is with a BB shell facing tool. You must remember to use the correct taps on each side as the threads are handed ...

Hilary

^ Cheers fella