F: Frame Snapped Rear Mudguard Strut

[danno]

You have a Craven rack on the bike? Is it mounted correctly?

I think so.
Seems to be a bit of a contraption. Only find it useful really for mounting the indicators on.

 

[danno]

danno there are more changes to the suspension on Vins than I care to write about here. The rear of the seat can be fully sprung, a coil over damper can be used to replace the two springs and the damper under the seat and the front end can be dramatically improved with very little change in the apearance. If you want to ride an 'as original' bike then that is your choice but if you would like more comfort and safety then you need to do some reading about the subject and be prepared to spend up to about a thousand pounds to do the whole lot.

Would certainly like to do something for more comfort. Cheapest, easiest and most effective option combined might not be possible but that’s what I’m after.
Minimal change in the appearance also.

 

[timetraveller]

In order of minimum appearance change with maximum increase in comfort fully support the rear of the seat so that it is not bouncing up and down on the rear frame. The son of Vibrac on here does a very nice modification for this. Replace the present rear springs with what are known as 'Pettiford' springs available from the SC and the comfort will be improved. Next is to replace the whole of the steering head with what is known as a JE stem. I supply these and I am not trying to sell you anything but the improvement to safety and comfort has to be experienced to be believed. The overall apearance is hardly changed. Cost about £500 - £600. Fit a hydrauic steering damper. Cost £125. Finally change the rear suspension to coil over damper. Cost about £240. Ask around, look at other bikes at rallies, read on here about these mods and then decide what you can live with. You can stay with what you have and many on here do that and enjoy their bikes. Just be aware that in seventy odd years several people have found ways to make the bikes safer and more comfortable

 

[Bill Thomas]

Could be although I don’t remember it being so when I refitted it.
Just wondering if jolts from the road would cause it. With the combination of awful rural roads and very hard suspension, I wouldn’t be surprised.
Just been out and the slightest irregularity in the road is felt.

You could loosen the seat damper knobs, And lube the friction stuff that's inside,
But you must loctite the Alloy knobs threads or they will unscrew and be lost !,
We don't really need the damping there because we have the hydraulic damper,
In the middle of the rear springs, That the "B" didn't have !.

I have never had a rack on the back,
But I am thinking the seat should still pivot on the front and rear pivots ?.
As Michael Vane - Hunt said ?.
Many don't because of rusted pivots or not enough end float on the bushes ?.
I have seen Vincents that look almost solid on the back, But they shouldn't be that bad ?,
I still ride my Comet with standard seat fitting.

 

[Michael Vane-Hunt]

The Craven rack should have little bronze bushes at most of the mounting points. There should be a little play at each point and not locked up tight.

 

[Chris Launders]

I found the problem with trying to improve comfort has lead down a never ending (so far) slope, I fitted the JE steering head alone initially to improve stability, then started on the front springing and damping, this then showed up how rough the back end was and I fitted a coil over, of course this then multiplied how much/quickly the rear end of the seat was moving, (a pillion likened it to being sat on a jack hammer) so I converted it to fully sprung, this then makes it really tall and the spring provided with the coil over needed changing for a stronger one, (all the rider and pillion weight is carried on the shocker now instead of being shared with the RFM) work is still progressing.

As for doing it cheaply, first you MUST have a hydraulic steering damper, then a pair of dampers, either rebuilt standard ones or AVO.

Any more than that read the "Modified Steering Stem" thread as this not only improves stability but allows the release of much more travel on the front fork.
Chris.

 

[danno]

The Craven rack should have little bronze bushes at most of the mounting points. There should be a little play at each point and not locked up tight.

Nyloc nuts needed then. The rack does seem over complicated with struts/linkages up near the seat and at the back.
Never seen one on another Vin so I'll remove it and find something else to mount the rear blinkers on.
These incidentally, have stopped working properly again. Thought I'd sorted them but have seen a worn cable/Lucas connector near the headstock. Not much room around there for free movement.
Seems to be never ending jobs.

 

[Bill Thomas]

Nyloc nuts needed then. The rack does seem over complicated with struts/linkages up near the seat and at the back.
Never seen one on another Vin so I'll remove it and find something else to mount the rear blinkers on.
These incidentally, have stopped working properly again. Thought I'd sorted them but have seen a worn cable/Lucas connector near the headstock. Not much room around there for free movement.
Seems to be never ending jobs.

If they are on pivots , Maybe need an extra earth wire ?.

 

[Peter Holmes]

In order of minimum appearance change with maximum increase in comfort fully support the rear of the seat so that it is not bouncing up and down on the rear frame. The son of Vibrac on here does a very nice modification for this. Replace the present rear springs with what are known as 'Pettiford' springs available from the SC and the comfort will be improved. Next is to replace the whole of the steering head with what is known as a JE stem. I supply these and I am not trying to sell you anything but the improvement to safety and comfort has to be experienced to be believed. The overall apearance is hardly changed. Cost about £500 - £600. Fit a hydrauic steering damper. Cost £125. Finally change the rear suspension to coil over damper. Cost about £240. Ask around, look at other bikes at rallies, read on here about these mods and then decide what you can live with. You can stay with what you have and many on here do that and enjoy their bikes. Just be aware that in seventy odd years several people have found ways to make the bikes safer and more comfortable

Norman, I cannot find anything on Ben Kingham's site, BKS Speedworks, relating to going fully sprung on a Vincent, could you expand on your comment a little, I have used a Cyril Maylem rear carrier for 30+ years, and it has served me very well, but always interested in different solutions.

Cheers Peter

 

[danno]

If they are on pivots , Maybe need an extra earth wire ?.

The earth wire’s connected to the mounting at the indicator. I think it’s just something that’s come adrift. Same problem as originally.