Upgrading a Claud Butler

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New Member
Just joined the network, which seems very informative and helpful.
Wondering if anyone could advise on upgrading my Claud Butler? Trying to get back into cycling, but live in a hilly area and gradients seem to be getting steeper ... So I'd like to streamline the bike without spoiling its character or breaking the bank. (If and when I invest in another, it'll be an e-bike.)
A few details: Bought second-hard early 80s, Reynolds 531 frame (men's), running gear replaced about 20 years ago, double-chain ring 12-speed (Shimano Biospace 52/40), 27-inch steel rim wheels, etc
Priorities: Extending gear range for climbing – with a triple chainring? Perhaps lighter wheels? Brakes & gear-change cables will also need replacing.
I'd appreciate any tips or advice you can offer. Thanks


Keeping the Carlton and Sun names alive...
Plymouth, Devon
Id concentrate on the gearing, lighter bits and bobs wont make a great deal of difference.
What set up do you have on the back in terms of a freewheel/cassette...? ie number of teeth? A bigger rear sprocket may mean you will need to have a long case rear mech. You could also look at the front chainset set up too, ie bigger range over two chainwheels ie 48/32.

Upgrading to a triple can work and give a much wider range of gears, but remember about the added complication with a difference BB spindle etc... Then we get into chainlines and clearances as well.


Accra, Ghana
Hello and welcome to the forum.
The first thing I'd do is replace the steel rim wheels for some alloy ones. You could then fit a wider range cassette and go for a 8/9 speed if you want lower gears. You'll need a new RD. You could fit a compact double if you don't want the bother of a triple if you find that suitable.
Buying secondhand should save a fair bit of cash.
You could also upgrade the brakes, change to STI levers but where do you stop?
Could you post some pics?


52/40 is definitely not hill friendly. What are you running on the back?
A square taper compact FROM spa or similar won't cost you a fortune, prob combined with a wider range cassette if possible. Although 12 spd suggests possibly a screw on freewheel, which may be harder to source with a biggish big cog. If it's friction shifters then you have the option of sticking an 8spd cassette on the back if you find a suitable wheel with a free hub.


Smile a mile bike provider
Reducing weight of the bike will make little difference , I presume you have alloy wheels not steel rimmed ?

Try and find a 50/36 crankset that will fit no problems , then as others have said go as big as you can on the rear end as the rear mechanism will take .

Hopefully that should give you a better range without costing a fortune

We need pictures though please


New Member
Many thanks for your thoughts. The rear set-up is a freewheel with 6 gears ranging from 28 to 14 teeth. The cheaper option would seem to be replacing this with a similar gearwheel incorporating a 'granny gear' (even typing that hurts!) and new rear mech. But it'd be a big step down from the other gears. I understand that changing the front chainwheel will require a wider bottom bracket and complete new drive train, and more than double the cost? But the versatility may be worth it. Just need to identify the best compatible options. As I'm not techie, I struggle with some of the terms and acronyms. Have uploaded some images as suggested. (Frame serial number seems to be 01 0(or8)65 161674, if that's relevant.) Thanks again.


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Bionic Subsonic
I have a feeling that your crankset is a 130mm BCD one (distance between the bolts holding the rings on), so will be limited to about 38t as the smallest you can go, but there are other doubles out there at 110mm BCD which can go down to 34t. 34x28 is a reasonably standard climbing gear on modern bikes, and 34x34 (from a megarange freewheel) would give you a very low bottom gear for a normal road bike.

I've used 7sp megarange freewheels before, and you get used to the big gap between the first two cogs. It does leave you rather committed to the big ring once yo change into it, as the jump out is big, however it works ok, and it looks like your rear deraileur has a rather long cage, so might be able to handle the 34t sprocket.
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