Old Carlton: Dropout/Wheel Size confusion.

CarltonWorksop

Retro Newbie
Hello everyone.

Just joined to get some specific advice but I'll hopefully stick around as I love my old bikes.

Bit of a long read so bear with me. So, I have an old Carlton Pro AM road bike. I've had it about four years. I was working on an old fella's house and I was admiring the bike in his garage. He ended up giving it to me for a small reduction on my bill. Happy days!

He told me that he bought it new, rode it for a few seasons then got bored and left it in the garage until I came along decades later. As far as I know, I can only assume it's as it was when it was sold. It has Suntour/Ralleigh parts, and 27" wheels.

I set about deep-cleaning the drivetrain, and replacing bearings/grease, bar-tape, cables, brake-blocks, and tyres (after buying the wrong size due to not knowing about the 27" standard...), and I then had a fantastic, fast and nimble fun bike, which I'm very fond of.

Anyway, to cut a long story short, after much fun and many enjoyable rides, at the end of last summer I managed to wreck it. I was just setting off from a stand-still. I put my weight on the pedal, and the rear derailleur went into the back wheel. It bent up the mech, the hanger, took out multiple spokes, and even cracked the frame where the (lug?) meets the end of the dropout. Annoyed and overwhelmed, I just threw it all in my shed and forgot about it until recently when I decided to sort it out.

So I ordered the replacement parts, got the wheel re-spoked and trued at my LBS, and on the advice of them, took the frame to a local frame-builder who braised (brazed?) a new lug onto the frame. All good. I was looking forward to getting it all back together and getting on the road.

Now this is where the confusion starts. When I went to collect the frame, I also had the wheels with me. And for reasons I can't remember, we ended up with the frame in the stand and offering up the rear wheel, whereupon, the frame-builder said that the wheel, or hub, or both, I can't remember - didn't match the frame.
I was utterly confused by this as I'd stripped it down and rebuilt it myself, and I knew it hadn't been modified as I knew it's provenance (provided the old chap I bought it from's memory could be relied upon). The frame-builder recommended either further fettling of the frame, essentially making the dropout gap narrower, or putting in 700c wheels/hub. A bit annoyed and bemused, I said I'd take it home and think about it. I love bikes, but I'm no mechanic/frame-builder so wasn't quite sure I was understanding what he was telling me.

So after getting it home, I put it in my stand, and sure enough, the hub/axle seems too short for the space between the dropouts. It needed considerable force to clamp them together to secure the wheel in the frame. I can't remember noticing this when I rebuilt it, but it must have been the same. And on thinking about it further, it occurred to me that, as it took so much pressure to clamp the wheel, that this could have caused the wheel to slip in the dropouts which caused the rear mech to foul the wheel (possibly, I'm not an expert). As such, I don't want all this to happen again. I was hoping I'd just be able to ride it regardless, as it was fine for a good while before it happened, but now I want to get to the bottom of the mystery before decided on the best course of action.

So, any ideas what the hell's going on here? I suppose in reality, lots of things could have happened to the bike in its 45 years lifespan. But if possible I'd like to keep it original. It wouldn't be too much trouble to have the frame-builder adapt the frame. Then I get to keep my wheels (such as they are). But 700c replacement wheels would mean a choice of better quality rims, but would then likely need new brake callipers... sigh...

I initially thought, why can't we just add a longer axle? but that idea was quickly dismissed by the frame-builder so I guess that's not possible.

Or should I just forget about the mystery, clamp it up, and ride it? I was perfectly happy before I destroyed it :) What're the potential consequences? Apart from difficulty changing tyres on the road.

Looking at the hub, on the rear-mech side, the axle is backed up into the end of the lug, but on the other side it sits about in the middle of the lug if that makes sense. Would it make sense, to put something somehow in this gap to keep the axle straight and perhaps stop the wheel/axle slipping again?

Thoughts? Thanks for reading. Apologies if I've got names/terms for things wrong, I'm completely self-taught with bikes.
 

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What probably happened (or one idea) is the dropouts had an old width standard (120 or 126mm). When the frame builder came to repair your frame, he used a frame jig with the modern 130mm and brazed it all up as such. If this is what happened, he should have discussed it with you.

Depending on what you intend to do, that can be both good and bad. Good in that you can now use modern wheels and go 8/9/10/11 etc speeds and so use modern transmission on your bike. It's bad in that if you want to keep it all period correct, then using older wheels and freewheels is a faff (although it can be done with a longer axle and spacing washers)
 
What's the width of the dropouts? Iirc it should be 126mm, so if it's wider than that then it's definitely been re-sized or has bent in some way, though that wheel/hub looks original. Here's a photo of how it looks on my corsair which is a similar bike
 

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Thanks for the replies guys.

I'm away from the bike now so can't measure. I did measure the width though when I got it back from the frame-builder and it was about 140mm - 150mm from memory.
 
Interesting. So perhaps the frame-builder made a mistake, but kind of a good mistake...

Yeah, I don't want to keep it original for any other reason than I like the way it looks presently. Can you even buy new steel/silver wheels? They all seem plastic/black on new bikes. And the fact that new size wheels would mean that the wheels are no longer compatible with XYZ... I just want to ride it before winter! ;)

If I just clamped it up hard and rode it for the summer, is there any chance of catastrophic frame fracture?
 
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"140 -150mm" is waaaaaaay wide

machine appears to hail from ~1976 so original spacing would have been 120mm (or 122mm)

what is the overlocknut width of rear hub?

no need of a caliper to measure you can simply put it between two flat surfaces such as blocks of wood and then measure the distance between them


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