G3 - rear mudguard droop

[doug m]

i am wondering, having tried brute force and ignorance on the central pinch bolt more than once, if there is an effective way of preventing the rear section of my mudguard from drooping under the effects of gravity and vibration - the mudguard is freshly painted so may be lacking a rusty contact patch for friction grip...... any ideas folks?

[Rob Harknett]

What year is the bike? Wild guess, if you have a central pinch bolt you should also have a nut and bolt each side, through guard and the open fork end of the grab handles. I'm sure the central bolt has a special chrome washer under the head. Make sure side fittings are tight holding rear rear bit on. Also make sure the end bit forked tag pushes in for the central bolt to pass through and grip. This may be broken and not reach???

[doug m]

Hi Rob, the bike is 1957 and i think all the right bits are present, the holes in the grab handles are a bit over-size for the bolts, possibly from previous movement - the centre attachment is a chromed nut and washer which does engage with the captive nut and tongue on the mudguard - again i think the fit is a bit oversize on the bolt.
when tightened up all seems well but after a few miles it is gapping - a bit like builders bum.
it strikes me that the back of the mudguard/number plate and light is a pretty heavy lump to rely on friction between two painted surfaces but presumably it works for others - i had wondered if it was missing a serrated washer or some - such to increase the grip.

[alanengineer]

Are you using the correct spigotted washers

[doug m]

Ahh maybe it is the washers - are there shouldered washers for the grab handles and for the centre or just the centre?
the centre bolt and washer i renewed with items supplied by amc classic spares as the one on the bike looked wrong and had lost its corners on the head - i seem to recall that there might be different options for the washer i recall i bought both and fitted the one that looked right i will look again .... thanks Alan

[alanengineer]

If you have a single bolt fixing, you need 3 spigoted washers and two flat washers (that look the same)(might even have a different size hole). Hard to get at the moment. Go Back to amc classic spares and see what they say.

[Rob Harknett]

Everything seems to be OK , perhaps apart from washers. There is tolerance where bolts pass through or it may prove difficult to line up. I have never had probs and may not have all correct washers. What you do not want, is cheap thin washers with larger inner hole dia. They may afford less grip also dish, so encourage the guard to slip back out of the grab handle and top fork tab slots. So at least make sure washers have the correct hold dia. also thick and strong, if you cannot get correct washers. This applies to many parts of the bike. Head & rocker bolt washers for example. Have you noticed how thick and sturdy these are. If a washer dishes its not good. I have got mixed size packs of cheap washers, so thin, I use two instead of one if I cannot find a decent washer.

[doug m]

thanks chaps - very helpful, im hoping to get to the jampot rally so will try to sort the washer problem there - i think i have spotted another relevant factor .. the slotted hole in the tongue is drilled somewhat like a key hole i guess the idea is that the spigoted washer engages with the larger radius to that the washer deals with the shear [slip]and the nut then holds the washer in place - my problem is that the keyhole shape has been lost [the hole has opened or spread] so that the the bolt is now trying to work as friction grip and the shiny black paint is preventing sufficient friction developing and allowing the droop.
Robs comment regarding washers made me smile - i obtained some nice beefy washers with a chamfered edges and used them widely in the re-build - including the gear box bottom pivot bolt ... i couldn't understand why the centre stand would neither go up or down - am reliably informed that matchless never fitted any washers to the pinch bolt because they stop the centre stand working doh!