F: Frame Snapped Rear Mudguard Strut

[danno]

Hi
Just doing my clutch and noticed the LH mudguard support strut is broken at the top.
From what I can see, there’s four places the guard is held.

Might have been caused by the the bad roads around here or undue stresses on it somehow.
Maybe could try and weld it if I get a kit or take it to the guy from my local club who fixed the rear number plate bracket.
Is there a decent cheap welding kit that would do the job? Would be handy to have.
Any help appreciated.

 

[chankly bore]

There are a few things here worth checking. Firstly, do up your rear stand bolts F69 tight enough against their Thackeray washers so that the stand needs to be gently pushed down. The Thackeray washers are meant to reduce/ eliminate vibration. Secondly, have you got the stiffening pieces lengthwise on the underside of the guard? Thirdly, the stay is better if it conforms to the curve of the guard and also isn't held away from the guard surface by that odd bit of metal you have there. The set-up pictured may localise stress. Fourthly, you can run a strengthening support under the guard transversely between the two stays- no-one will see it. Fifthly, you may be able to weld it, but it is cheaper and better to make yourself two new ones. I think the original material was 1/2" o.d. x roughly .031" wall thickness. I make mine from 1/2" o.d. x .062" wall thickness, bending them to lie in position before final fitting and painting. I only ride a 665cc. Comet, so it barely copes with the extra weight! Sixthly, eliminate all other sources of vibration starting at the rear number plate (another Thackeray washer for the same reason), your carrier frame, and possibly all the way back to the crankshaft. As some forgotten cartoon character years ago said, "I told you the job was hard when you took it, Fred!" Let us know what you find. As always seek out a real engineer's opinion 'n' all. Cheers from Australia.

 

[danno]

There are a few things here worth checking. Firstly, do up your rear stand bolts F69 tight enough against their Thackeray washers so that the stand needs to be gently pushed down. The Thackeray washers are meant to reduce/ eliminate vibration. Secondly, have you got the stiffening pieces lengthwise on the underside of the guard? Thirdly, the stay is better if it conforms to the curve of the guard and also isn't held away from the guard surface by that odd bit of metal you have there. The set-up pictured may localise stress. Fourthly, you can run a strengthening support under the guard transversely between the two stays- no-one will see it. Fifthly, you may be able to weld it, but it is cheaper and better to make yourself two new ones. I think the original material was 1/2" o.d. x roughly .031" wall thickness. I make mine from 1/2" o.d. x .062" wall thickness, bending them to lie in position before final fitting and painting. I only ride a 665cc. Comet, so it barely copes with the extra weight! Sixthly, eliminate all other sources of vibration starting at the rear number plate (another Thackeray washer for the same reason), your carrier frame, and possibly all the way back to the crankshaft. As some forgotten cartoon character years ago said, "I told you the job was hard when you took it, Fred!" Let us know what you find. As always seek out a real engineer's opinion 'n' all. Cheers from Australia.

Thanks for the reply.
Not sure about the stiffening pieces in the 2nd point.
3rd point - just added that as there was damage to the alloy guard around the securing point.
I’ll need to look over all the points and check once I’ve reassembled the clutch.

 

[chankly bore]

You can repair the alloy guard with one of the low temperature alloy "welding" kits, or if it is original "Birmabrite" then use the alloy from a very early Land Rover as filler as I believe it is the same composition. Someone with more knowledge please confirm this as my memory is going in the same direction as most of my other functions.

 

[Speedtwin]

I hear the sound of padlocks snapping on vintage land rover garages all across Hertfordshire!

 

[Robert Watson]

You usually get breaks like that because the joint is a forced fit. They really need to fall into place before bolting up. The force fit puts a preload on the parts and then the natural stresses in use take the material up and down through the yield point of the material causing the fracture. Weld it up by all means but make sure it is an easy bolt up.

 

[danno]

I hear the sound of padlocks snapping on vintage land rover garages all across Hertfordshire!

Used to have a Series One.

 

[danno]

You usually get breaks like that because the joint is a forced fit.

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.

 

[Michael Vane-Hunt]

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

 

[timetraveller]

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.