Raleigh/Carlton Grand Prix: Setting Rear Derailleur [Huret Challenger '70s + other vintage mechs]

Setting up the rear derailleur is essential if you've fitted a new one or replaced your free-wheel. I fitted a freewheel with slightly smaller ratios and a new rear wheel which may have had slightly different spacing and found that I could no longer select the largest cog, while selecting the smallest cog would easily throw the chain off.

The Challenger, like all French-made Huret mechs and a lot of other vintage derailleurs, are simple in design and do not require a lot to set up. Online guides show modern and more complex mechs with functions that vintage ones lack.

1. Loosen the nut holding the gear cable at the rear derailleur and allow the cable to slacken. [It is likely a small bolt with a hole that the cable runs through and the nut holds the cable in position.]

2. Press the gear-lever fully forward, parallel to the cross-bar so the cable is in its full loose position.

3. Set the chain at the smallest / outermost cog on the freewheel.

4. Set the outer-limit of the derailleur's movement by adjusting the H-screw until the upper jockey-wheel is in line with the smallest cog of the freewheel. [This is the foremost of the two small screws located on the side of the derailleur itself.]

5. Pull the gear cable tight and tighten the nut holding it in place at the rear derailleur.

6. Pedal forward and draw the gear-lever up until the largest cog of the freewheel is comfortably selected. [The inner-limit screw on the mech may prevent this and will need adjusting first.]

7. Set the inner-limit screw [or B-screw] on the derailleur to prevent it going any further than the largest cog. [This is the left-hand screw located to the rear on the derailleur.]

Raleigh/Carlton Grand Prix: New Brake + Gear Cables - COMPLETE GUIDE

1. Front Brake Cable
2. Rear Brake Cable
3. Brake Straddle Cables

4. Gear Cables
5. Campagnolo Shifters

6. Setting Rear Derailleur / Mech

Raleigh/Carlton Grand Prix: Campagnolo Super Record Gear Shift Set [late '70s vintage]

Original chromed-steel Raleigh gear-levers, below, were perfectly functional, but showing a bit of rust and lacking the style of the alloy Campagnolo levers, above. These are Campagnolo Super Record of 1976 vintage, so are period correct for my bike and feature ring-type cable-guides as the Raleigh ones did, making them a straight swap with no hassle.

Raleigh/Carlton Grand Prix: Replacing Gear Cables [Jagwire Stainless / Braided Outers]

The gear cables were more or less a straight swap and did not require modification like the brake cables. I swapped in my vintage Campagnolo Super Record gear-shifters during this job, so if you are planning to change your shift-levers or front/rear derailleurs then wait until you are ready to fit them before replacing the cables.

My Jagwire kit came with 10 alloy ferrules. I guess this number caters for mountain bikers, as I struggled to find places were they would fit and ended up using just two of them, where the cable exits the outer at the derailleurs.

REAR:

The only bit of adapting required was to the metal ring that holds the cable-outer at the rear derailleur. The original aperture was 5.4mm and needed boring out a tiny bit to 5.8mm to allow the Jagwire ferrule to fit [2nd pic]. The old outer had no ferrule and fitted straight in to the metal ring, but was quite loose and sat at a bit of an angle anyway, causing the outer to split.

FRONT:

The front gear cable required no modification at all. The outer has nothing to hold it in place here, it just stops at a metal disc with a small hole where the cable exits the outer. I used an alloy ferrule here, but it just sits flush and is free to move, with only the tension of the cable holding it in place. It wanted to sit at an angle, so a cable-tie helps keep it straight. In future I will attempt to 3D-print a bracket that clips around the frame and holds the ferrule in position.

Raleigh/Carlton Grand Prix: New Weinmann Straddle Cables [New Old Stock '80s!]

My shiny new brake cables and outers looked great, but were let down by the rusty straddle cables that run from one side of the centre-pull brake to the other. Managed to find these, the exact replacement part, brand new old stock, found in an old bike shop that is now being cleared out. Nice one!

Raleigh/Carlton Grand Prix: Adapting rear brake for Jagwire stainless cables/outers.

I adapted the nylon ferrules in the top of the brake levers to fit the Jagwire ones in the same way as the front brakes, by boring out the centre-hole. This is better explained in this post: https://panabloga.blogspot.com/2018/04/raleighcarlton-grand-prix-adapting.html

The bracket on the rear forks that holds the outer and steel-ferrule has a tiny 4mm hole in it, which I carefully bored out to 4.5mm, 5mm and finally 5.8mm. This doesn't leave a lot of metal either side, maybe 1.5mm, but at least it is steel.

I caked the bracket in black paint, particularly in the freshly drilled hole. The 5.5mm diameter alloy Jagwire ferrule was slightly loose in the bracket, but tension from the outer cable holds it in place. I put a blob of black paint on the ferrule and slotted it into place before it had all dried, hopefully giving it an extra fix and minimising the alloy reacting with the steel.

The gold braided stainless-steel Jagwire outers look well retro on the '79 Grand Prix and won't bleed rust from the ends.

Raleigh/Carlton Grand Prix: Adapting front brake for Jagwire stainless cables/outers.

Old front cable was frayed around the nut and starting to unwind. Original nylon ferrule on the brake lever had seen better days and was allowing the outer to lean to one side.

The hole in the top of the alloy brake lever is too wide for the Jagwire ferrule to sit in, so it needed adapting into the original nylon one. 

First I took the nylon ferrule and bored the centre-hole out to 6mm. The diameter of the thinner part of the shank on the Jagwire ferrule is 5.5mm, so the hole was slightly too large in the nylon and only left about 1mm sidewall. 

I used strong epoxy resin to both fix the Jagwire ferrule in place and to reinforce the nylon ferrule. With a coat of black paint it looks quite smart and fits snugly back into the alloy brake lever, with the outer cable sticking straight up, as it should. Obviously, the ferrule is not fixed into the brake lever with anything, it is completely removable.

The original steel ferrule holding the outer on the head-stock bracket is held by an 8mm nut either side and snapped with hardly any force. This left a 5mm hole in bracket, not quite wide enough for the Jagwire ferrule. A benefit of the alloy ferrules in the upgraded stainless-braided Jagwire kit over the plastic ones, is that I was able to use an M6 die to thread the lower part of the shank.

This meant I could then bore out the hole in the head-stem bracket slightly and tap it to M6 thread as well, allowing the ferrule to screw directly into it. This not only solves the problem of fixing the ferrule in place, but I also think a larger hole in the tiny alloy bracket might weaken it too much.

It works fine in practice. Shame I couldn't thread the alloy ferrule all the way down the shank without damaging it, but it still just about has enough to come through the lower side of the bracket and seems pretty solid. The outer cable is straight again and looks a lot tidier.