Author Topic: MkV centre stand  (Read 322 times)

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Offline Pallijen15

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MkV centre stand
« on: 12 Nov 2021 at 13:35 »
Hi, should the tube fitted through the centre stand not be a tight fit? On my 1951 MkV I took the centre stand spring off and noticed that there was lots of play. The stand has been wearing away the underside of the gearbox slightly. The tube fitted looks like it could be a home made part but not sure. The bolt threads are flattened where it passes through one of the frame lugs. I assume it is the correct one as it is 1/2" BSF. It has been modified by having an edge of the head taken off to facilitate fitting and removal. I started a thread previously regarding oil which was accumulating on the left leg of the stand and depositing on the floor when the stand was put down. Just wondering if the oil could seep through where the wear marks are. Thanks, Paul Jensen

Offline eddie

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Re: MkV centre stand
« Reply #1 on: 12 Nov 2021 at 14:41 »
Paul,
        The spacer tube through the stand should be 5/8" diameter - the hole in the stand should be 21/64" diameter - resulting in about 15 thou running clearance. The stand bolt having had one side of the head removed indicates that the frame cross tube with the stand mounting lugs has been overloaded and twisted, making it difficult to remove the pivot bolt. This is not unusual on Mark frames (in fact, club spares used to offer the option of a stud and 2 nuts - instead of a bolt and nut - to make fitting easier). This problem with the tube twisting is usually down to operator error - the kickstart should only be operated gently with the bike on the centre stand. In severe cases, the stand may make contact with the underside of the gearbox. If your spacer tube is a loose fit between the lugs, either replace it with one that is a neat fit, or add a spacer washer so that the pivot bolt can be fully tightened and trap the spacer tube, thus preventing any further wear/damage to the stand lugs. The wear marks you mention on the gearbox would have to be quite deep to cause an oil leak - the base of the gearbox is about 3/16" thick.

   Regards,
               Eddie.

Offline Pallijen15

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Re: MkV centre stand
« Reply #2 on: 12 Nov 2021 at 16:52 »
Thanks for quick reply Eddie, one side looks about up to a 1/8" gouge, the other slightly less so I suppose it's quite deep given the thickness of the casing. I'll measure the tube in the morning. Looks like it's made of mild steel. Paul J

Offline eddie

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Re: MkV centre stand
« Reply #3 on: 12 Nov 2021 at 17:55 »
Paul,
         From memory, I think the spacer tube is made from 5/8" x 18g mild steel tube, so that means that if the tube is not long enough to be clamped between the mounting lugs, the stand will have quite a bit of slack (15 thou on the outside and about 20 thou on the bore of the spacer tube plus any slack between the bolt and the lugs).

   Regards,
                  Eddie.

Offline Pallijen15

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Re: MkV centre stand
« Reply #4 on: 13 Nov 2021 at 06:48 »
Okay thanks Eddie, I'll check the sizes

Offline Pallijen15

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Re: MkV centre stand
« Reply #5 on: 19 Nov 2021 at 08:27 »
Hi Eddie, I have taken up the looseness with a thin washer between the tube and the lug. Fits nicely now, no slop. I think the repair must have already been done anyway because even when before I put the washer in between the top of the stand was nowhere near the bottom of the gearbox, there's about a cm clearance at least. The stand, measuring from centre of frame to bottom is way over 10". Thanks for your advice, greatly appreciated. Paul J