Carlton Frames from the 70s and 80s - 24 or 26 TPI Threads?

robbarker

I am about to renovate a Carlton bike for a friend. It's a 5 speed, so I guess from the 70s. Can anyone tell me if this will have standard 24 TPI threads, or the Raleigh proprietary 26 TPI?
I can get the vernier on it but I'm sure someone must have been here before..

meagain

Better asked in Special Interests- bagpuss and/or others might know (but I suspect that without a PRECISE date will come down to measuring).

another jacko

I assume you want to know about BB threads?

I didn't even know there were thread ptiches for standard diameter BBs, so I've no idea if it is 24 or 26 TPI. I have, however, in my ignorance, replaced the adjustable BB on both of my late 70's Carltons (a Pro-am 12 and a slightly later tourer which is now a fixie) with ordinary modern shimano UN52s. Iit must, therefore, be whichever of those sizes is industry standard (english, not italian - I do know that!).

robbarker

Many thanks - that's useful.

meagain

"I didn't even know there were thread ptiches for standard diameter BBs"

Making all their own parts in house, unlike most brands, Raleigh had their *own* thread specs for b/bs and fork steerers for many years.

CiderMartin

My Carlton frame (circa 1973) definately has a 26 tpi bottom bracket thread. Kind of limits bottom brackets to the type you use for knackered threads. I survived by regular servicing, in fact the forks fractured before the bottom bracket cups wore out. Not bad for a 35 year old frame.

robbarker

Ah - b*gg*r, although as I suspected it might be. This will certainly make the project more interesting. I'll call SJS in the morning but AFAIAA you can't get BBs or headsets in Raleigh fitting anymore

Monowai

may I suggest you try re-posting on the road section of www.retrobike.co.uk

CiderMartin

I found this website:


http://www.ison-distribution.com/ison/e ... 2dqk9vfpu2

but never had to use it

geoff_ss

I seem to remember from some years ago that someone manufactured sealed bottom brackets that didn't use the threads at all. You did need to have a slight taper cut to allow it to seat properly but some bike shops had the special cutter.

Someone who's been in the trade for some years will surely remember. A long established bike shop may be a good place to try.

Geoff

robbarker

Thanks all.

meagain

I think that sjs cycles still sell threadless b/bs. I've often wondered why not more common - make a lot of sense to me. One I had worked just fine. Don't seize either!

Dales1

I find that my thread pitch gauge comes in very useful at awkward times like this. It only cost a handful of quid, and it's got lots of blades with serrated teeth in all sizes from fine to coarse, in both imperial and metric threads. You simply find the set of teeth which engage and sit nicely in your threads.

Dales

geoff_ss

I asked the guy who built my 653 frame tonight and he says the bottom bracket I was thinking of was made by Mavic. He's been involved in cycles since the 1940s (at least - I think he used to build penny farthing wheels ) and he thought all Carltons used standard bottom bracket threads.

Geoff

acorn_user

One of the shops around here reckons it's easy to rethread the BB shell for a normal BSC BB. You could try asking about that.

The other option is to use some Phil Wood bottom bracket cups in 26tpi with a suitable bottom bracket like a Shimano UN72 (one where you can remove the cups).