70s Carlton frame identification

3wheeler7

rBotM Winner
Hi, been looking at one of the Carlton frames I was recently given, uncovered the serial number WD5003818 which I think dates it to March 1975. It's had a poor red overcoat but I managed to uncover the head badge and it's a nice small frame so could make nice beater. Didn't get the forks with it as the guy had sold them on Ebay - but did find a pic of them.
Don't know the model but I'm thinking it might be a "Ten" as that was the only Carlton model in the 1975 catalogue with Prugnat 62 lugs, what do you guys think? and who'll be first to spot the deliberate mistake in the BB picture? No prizes but it made me think!
 

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vcballbat

Senior Retro Guru
Hi, been looking at one of the Carlton frames I was recently given, uncovered the serial number WD5003818 which I think dates it to March 1975. It's had a poor red overcoat but I managed to uncover the head badge and it's a nice small frame so could make nice beater. Didn't get the forks with it as the guy had sold them on Ebay - but did find a pic of them.
Don't know the model but I'm thinking it might be a "Ten" as that was the only Carlton model in the 1975 catalogue with Prugnat 62 lugs, what do you guys think? and who'll be first to spot the deliberate mistake in the BB picture? No prizes but it made me think!
Cups are are the wrong way round, I have a Raleigh with the same issue?...was the bottom bracket shell threaded back to front?
 

vcballbat

Senior Retro Guru
Could it be another new bottom bracket standard, a practical joke or just a massive cock up..?.... this is my 80's Raleigh Medale..🤔

IMG_20220212_082111_HDR.jpgIMG_20220212_082104_HDR.jpgIMG_20220212_082056_HDR.jpg
 

3wheeler7

rBotM Winner
Well done that man! I thought it might be "unique".
The bottom bracket shell is threaded back to front, doesn't look like it's had a repair job but I can't really see it leaving Worksop that way and the cups are standard size Bramptons.
I'd never hear of a Carlton Ten before but the signs of copper paint on the BB shell appear to be the same colour as the catalogue picture and it came with the same double chainwheel fitted, so that'll be it - a very rare Carlton Ten.
 
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jim haseltine

Retro Guru
It's amazing what sort of thing can leave a factory. Workers make mistakes, they muck about and will do things for a joke to lighten the day - especially when working on production lines. Some get picked up by QC inspections while others go out the door. Take a production line worker fitting bottom brackets back in the 1970s when line stations were primitive compared to these days. If that worker actually has no interest in the product that they're helping to assemble (something which is not unusual) then as long as the BB fits in the frame then things are fine no matter what sides the cups have fitted - as far as they're concerned they've done their job and the line flows on.
In my younger years I spent some weeks working on a packing line. We filled a box with 48 items in 4 rows of 12 across the box. And then another. And another. For 8 hours. Mind numbing work so we played games like finding other ways to put 48 items in the box - dimensions were such that we managed to devise 3 other packing patterns over time - not that we had much of that because the was a bonus payable if we exceeded the shift packing targets.
 

Shuggy boy

Retro Newbie
Looking for some Info on this bike, trek oclv full carbon, looking for year of manafacture
 

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Midlife

Retro Wizard
There were som odd "back to front" bottom bracket cups BITD for left hand side drive trains on tandems and old BMX.
 

3wheeler7

rBotM Winner
Hi, it appears that there's nothing wrong with the BB, only that the cups had been screwed into the wrong sides! I wouldn't have thought it possible to fit a RH thread onto a LH thread and vice versa but that's how they were. 45+ years working in engineering and still learning!
The weight of the frame with just the top and bottom headset races fitted is 2300g, frame size is 21", seat post size is 26.4mm, I don't know what this indicates but if it is a Ten model it should be made from 531 plain gauge main tubes according to the 1975 catalogue. It doesn't feel heavy and it's got a nice "ring" to it.
 

vcballbat

Senior Retro Guru
Hi, it appears that there's nothing wrong with the BB, only that the cups had been screwed into the wrong sides! I wouldn't have thought it possible to fit a RH thread onto a LH thread and vice versa but that's how they were. 45+ years working in engineering and still learning!
The weight of the frame with just the top and bottom headset races fitted is 2300g, frame size is 21", seat post size is 26.4mm, I don't know what this indicates but if it is a Ten model it should be made from 531 plain gauge main tubes according to the 1975 catalogue. It doesn't feel heavy and it's got a nice "ring" to it.
Reading up on Sheldon's blog you can re-tap a Raleigh 26tpi bottom bracket to take a 24tpi cup, maybe this is what's happened back to front?

Re-tapping to B.S.C./ISO​

This option is the most versatile, but also the most drastic. Only the top bike shops will have the necessary guided tap set required for this. The threads will not be as strong as they would be if the shell was made for standard threading, but this approach generally works well. You will still need to deal with the overall shell width. A shop that has the correct taps will also have the correct tool to face the ends of the shell, and this tool can be used to bring the width down to a more standard size (though it takes a lot of elbow grease! Beware, though, the welds to the bottom bracket shell of a Raleigh Twenty can be very hard, maybe harder than the taps.
 
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