Fitting A New, Improved Centre Stand To The Matchless G80CS

 

        There comes a time in the life of every old or "born again" rider of old AMC heavyweight bikes when he, or she, has to make a number of decisions. First... "Do I still want to ride a motorcycle?" If the answer is "no", then go back to the Start, do not pass "Go" and do not collect £200. If the answer is "yes", then go on to the second question... "Do I still want to ride an old AMC machine?" If the answer is "no", then see previous negative answer. If the answer is "yes", then go on to the third, and final, question... "Can I still heave it onto the centre stand without risking a hernia, a heart attack or simply falling over?" If the answer is "yes", then goodbye, and enjoy your motorcycling. You need read no further. If the answer is "no", then there may just be a solution for you...

        Riders of elderly Meriden Triumphs will in some ways, appreciate the design of their centre stand. It incorporated a cranked extension on the left hand side which enabled you to use the weight of your own body to facilitate getting the bike onto the stand. It did have its drawbacks, however, as it severely limited your ability to push the bike hard into left hand bends. Lean it over a little too far and the centre stand extension would hit the road and in extreme cases, would lift the back wheel off the tarmac... definitely not good. I owned a new Triumph Bonneville for a few years in the middle 1970's. After a couple of close shaves, I removed the centre stand completely and relied of the side stand. I still own a '71 Bonneville but my riding is more sedate now and it's unlikely that this bike will be leaned over far enough for the stand to hit the road. "What's this all got to do with AMC bikes?" I can hear you all ask... Well, I'll tell you.

        A member of the AJS & Matchless Owners Club, one Rob Swift, or "ajscomboman" as he is known on the club forum, has designed, and had made a new and improved centre stand for the AMC heavyweight single and twin cylinder machines. This incorporates a cranked extension on the left, similar to the Meriden Triumphs. I had one of the early production models and successfully fitted it to my '55 AJS Model 18S. I can vouch for the ease with which I can now get that particular bike onto its centre stand. Rob claims that you can do it in stockinged feet. I don't wear stockings (and I'm just a bit worried about you, Rob!) so I'll let him be the judge of that.
        I bought a Matchless G80CS a year ago and thought it would be a good idea to fit one of Rob's stands to that machine. Because that bike is substantially taller than the AJS M18S by virtue of having a 21" front wheel and a larger section rear tyre, it was more difficult to get onto the factory fitted stand. The accepted wisdom is that you stand on the left, facing the bike. Left hand under the front of the dual seat, right hand on the rear mudguard side support rail. You use your left foot to push the centre stand down, and hold it down, while you simultaneously lift the back end of the bike and lean your whole body to the right to roll the bike back onto the stand. Sounds easy, but it takes some serious strength and if you should lose your balance for any reason, the chances of a recovery are slim. Another "problem" with this particular model is that it has, being a competition machine, an increased steering lock and the handlebars are free to move through a much bigger arc of travel. As soon as you attempt to lift the bike onto the centre stand, the handlebars swing to full left lock, causing the rear of the bike to come towards you as you roll it back onto the stand. All very off-putting.Centrestand01.jpg With the extra height of the G80CS and my little less than average 5'6", it was a bit of a struggle. Fortunately, Rob has had some longer stands made to suit the competition models, so I shelled out some of my hard earned pension and bought one. They come as a raw steel fabrication, so I cleaned up all the burrs and rough edges and took it down to Breckland Finishing, in Thetford, to be powder coated gloss black, the same as the rest of the bike.

        On the appointed day, the G80CS was brought into the workshop and rolled up onto the workbench. Normally, the bikes on the workbench would be on their centre stand but as I'm about to change the stand on this bike, I had to knock up a couple of wooden supports to fit under the footrests. They needed to be tall enough to allow the centre stand to swing freely under the bike without hitting the bench. They worked very well and were stable enough to allow me to work on the bike without fear of it toppling off the bench. I removed the exhaust pipe, just to allow a little easier access to the bits under the bike. Removing the old stand was relatively easy. Remove the nut and spigotted washer on one side and tap the long stud through the frame.Centrestand02.jpg The centre stand, along with the hardened steel pivot bushes, a long spacer that goes through the spring, the spring and the short spacer that fits on the right hand side all drop off. The old stand will, of course, be kept in case I or any future owner, want to return the bike to its original configuration.
        The powder coating needed to be cleaned out of the stand pivot holes using a fine sanding band on the Dremel and the other parts cleaned to remove all the accumulated grease, oil and road filth.
        Having already fitted a new stand to my AJS machine, I knew, first hand, that it can be a bit problematic. First, getting all the components lined up with the mounting holes in the bike frame and engine plates. Any misalignment and you could damage the fine thread on the end of the long stud as you tap it through. Secondly, once all the bits are in place, you have to persuade the "long end" of the spring through the stand to engage on the spacing bar. The first problem I could do something about. The second, we'll come to later. The main diameter of the stud is 5/8" but it is reduced at each end for the 7/16" x 26 t.p.i. thread. I had a length of 15mm diameter steel bar which is a gnat's cock smaller than the 5/8" stud. I turned a taper on one end and machined the other for the stud to fit into. I could use that to assemble the various bits into the frame, the tapered end facilitating the lining up of all the holes. Then I could fit the stud into the other end, and drive it thought. The thread would be protected and not be damaged. All in all, it worked very well; I was pleasantly surprised.
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        Having got the new stand located correctly and the nuts on the fixing stud fully tightened, it was time for the task that I wasn't looking forward to, namely getting the return spring correctly located. As far as I'm aware, you can't buy a tool to aid you in this task but a number of people on the forum have mentioned making one out of a length of pipe. The pipe is split lengthwise into two halves. These are fitted around the spring coils and secured with two Jubilee clips. The ends of the tube are notched to locate the ends of the spring. The notches are positioned in such a way as to keep the spring wound up under tension. The stand can then be assembled to the frame with the spring in the correct position. Once the stand has been fitted, the Jubilee clips are undone, and the two halves of the pipe removed. That all sounds remarkably simple and easy. Unfortunately, I didn't have one of these tools, nor did I have a length of suitable pipe. I struggled for a while, but I eventually got the free end of the spring located by using two hands and brute strength. I will be making a suitable tool in the not too distant future... Watch this space!!

        UPDATE... a week or two later.

        I was fast running out of jobs to keep me busy during the third Covid-19 lockdown, so I had the time and inclination to make the final tool I would need for any future centre stand replacement. As I mentioned earlier, I didn't have any suitable steel pipe but a quick search on eBay and I'd found what I needed. A 100mm length of cold drawn steel tube, 50.8mm O/D with a wall thickness of 3.25mm (or 2" O/D, 1/8" wall thickness in old money) for the princely sum of six quid. I also needed a spring as the only ones I had were already fitted to bikes... and I wasn't about to take one off again after all the trouble of fitting it. It's always good to have a spare so I ordered one from AMOC Spares.
        The spring fits between the rear engine plates and I knew from having just made a stand for the Burman/AMC gearboxes, that the plates were 3.1/2" apart. First job was to shorten the 100mm length down to 3.7/16". That would ensure that the tube fitted between the plates but would be close enough to keep the spring located and not allow it to come out of engagement with the tube notches when in position. The tube was then split lengthways into two halves using the angle grinder fitted with a 1.2mm thick cutting disc. With that done and all the burrs and sharp edges removed it was just a case of cutting a couple of notches to locate the ends of the spring. I could see by looking at the one fitted to the CS that the spring needed to be wound up until there was roughly 90° between them. That was it... Job done. With the two halves held together around the spring with a couple of Jubilee Clips and the short end located, the long end was wound round until it dropped into the locating notch on the other end. It's held securely, in roughly the right position, to be assembled to the frame with the stand. The Jubilee clips could then be undone and removed, along with the two pipe halves. It may be a while before I have to use it but I'm sure it will work and it's good to know that I have the right stuff to do the job in the future. Note... I will be using correctly sized Jubilee clips. Those shown are just a couple that I had in the workshop.
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Last updated 03/02/2021