AJS & Matchless Owners Club

East Suffolk Section

Robert S’s 1961 Matchless G5 Lightweight Special “CSR”

I always wanted a lightweight. Exactly why, I’m not really sure, but since seeing the example on  the front cover of  the Jan 07 “Jampot”  I just had to have one. The plan was to obtain one for restoration and CSR-arise it, complete with alloy mudguards! Just as so many have been done before.

I had previously restored an old 1937 Matchless G2 which I love, mainly because of it’s  looks, simplicity and lightness. This being the case, you may ask yourself, why did I want an ugly fat-engined boring old heavy, slow lightweight that people love to hate? Fact is, I actually find them quite appealing in a funny sort of way, and have several mates who have them too, but they are pretty much good examples of stock machines.

The search began, with watching bikes come and go on a certain on-line auction website. In the end, possibly against my better judgement I “won” a 1961 G5 Lightweight in Barrow-In-Furness. This was fine for me, but she who must be obeyed was not best pleased as the bid was made from “sleepy” Suffolk!

Off I set at 6:10 am one Sunday in September 07, to go claim my “prize”, returning home, on a high from too much motorway service station caffeine at 21:20 pm.

The bike was a basket-case with the engine in one lump. It was notable during the journey, especially as I neared my Cumbrian destination that it is an extremely exposed part of the country, with plenty of “weather” that no doubt tests the durability of man and machine. Evident by the very deeply pitted and corroded nature of the parts that I had acquired!
The cycle parts had been blast cleaned, primed and sprayed black. Which was good, save for the fact that no attempt had been made to fill any of the pits first. The rear shocks had also been blasted and similarly painted. However this was carried out with the units still assembled, complete with rubber mounts, top and bottom covers and springs in place. The blasting grit was still inside!…Get the picture? The paintwork was de-greased, filled, rubbed down and painted with as many coats of black gloss enamel as was needed to achieve the desired finish.

The engine was a different story, having been removed whole and not dis-assembled. Whilst externally it was covered in a downy grey powdery patina, internally it was good. The distinct impression being that it had been re-built by somebody who knew what they were doing, and had not covered an excessive amount of miles since. Apart from freeing off the stuck up piston rings in a bean tin petrol soak, over a few nights, a good check over and freeing off of some tight valve gear, all seemed in order, and only a couple of small parts were needed along with gaskets.
The engine unit itself, is a 350cc single, similar to a heavyweight single in construction, but with additional features of; duplex primary chain, single camshaft with lever-type followers, cylinder positioned slightly forward of the crank axle with the aim of reducing piston slap to make for quieter running. The oil tank hides under the egg shaped offside engine case, and has a two and a half pint capacity. Power is claimed as  21bhp at 7,200rpm with the whole bike weighing in at 340lb, compared with say a 1964 G3 at 382lb and 18 bhp.
The Amal carb. is a massive 389 instrument. The inlet valve is correspondingly large, but the exhaust valve is tiny! The swept-back exhaust and cigar type silencer look the part though! The gearbox has 4 speeds in a cylindrical casing which fits into a concaved machined surface at the rear of the crankcases. The box is held in place by two steel straps. The primary chain is adjusted by rotating the box as the shaft is eccentrically located.  G5’s have 18” wheels compared with 17” for their smaller 250cc stable mates.

Getting back to “the plot” the bike came complete with the deep valenced steel mudguards. These of course did not feature in my plans for the finished article, and so were stowed away whilst the search commenced on parts to transform the ugly duckling into a thing of beauty! I didn’t learn my lesson about on-line purchasing and ended up spotting a new old CSR rear loop stay, quickly picking it up for the right price. Other parts were acquired at auto-jumbles and Jampot Spares. I tried to do as much of the work myself, not only to keep costs down, but to gain that sense of satisfaction that you can only experience when you have spent all weekend fashioning something from scratch yourself, having planned how you would do it all the previous week! This turned out to be the case for the stainless steel tank top strip that I made from an old door protection angle strip. The front mudguard stays and hand stitched seat cover too. Wide waxed flat dental floss is an ideal twine for attaching 4 layers of fabric using a needle and pair of pliers.

Some parts for the restoration were donated by my mates. The handlebars and front mudguard being two of the components (thanks Albert). The handlebars had to be modified by chopping out a 2” chunk to allow them to miss the tank on full lock, and the mudguard which was now being fitted to its 3rd bike? (Judging by the various arrangements of holes) was stripped of matt black paint and corrosion before the holes in it, were filled before re-drilling and fitting. This was offered as a temporary pattern!

The Wipac electrics remain largely as standard, but with the addition of one of Al Osborne’s solid state rectifiers in place of the old selenium job. The alternator electrics charge fine, and all is bright, as I ran extra earth wires through the original loom prior to re-soldering and re-binding the old cotton covered item.

The original Kendal registration number was reclaimed with the help of Les Ward, Dating Officer, and a local member, Andy, who did the verification honours after an inspection of the completed bike. DVLA issued  the documentation and I presented the machine at Davey Bros. my local MOT station, who are familiar with all things classic and modern.

On the open road, the bike is in my opinion, an absolute dream. It has the correct inch and an eighth teledraulic type forks found on the heavyweights, and it has what feels like a low centre of gravity and is well balanced. It is small and relatively short, so manoeuvring about is not too difficult. It goes onto the main stand easily. It starts with very little effort, despite not having an exhaust valve lifter. This is due to the previous owner removing it, and replacing same for a hollow spigot, for what I assume is a top-end breather. Either way a plastic tube now extends to the rear and discharges beyond the mudguard. The compression ratio is low and certainly for the time being does not present me with any effort in starting.

All in all, I am very pleased with my lightweight, achieving aesthetically, exactly what I set out to, all those years ago. It has been a labour of love, as have all my restorations, but best of all, the bike itself, the characteristics of which I did not consider, is great. It is really good fun to ride which actually came as very pleasant and unexpected surprise.
Even my 21-year-old daughter was impressed with her pillion ride.

To purists, this would no doubt be a fake CSR Special, but that is exactly what I wanted, and having created it, I think it is special! AMC did not make a G5 with alloy guards. They came later on the last G2  and Model 14 AJS 250cc models.
Finally,I know that the Wipac “Sabrina” rear light is definitely not correct, but I like it.  I saw it on e-bay and thought I need that to make the bike go faster when it’s standing still!1961 G5

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