Whilst attending a local VMCC meeting on my M20 last night, an ex Don R pointed to the difference if diameter of my from wheel mudguard bottom stay (off side) and asked if I knew why that was? He said that all M20's had a thicker support as they were trained to shoot through the wheel using that as a rest and previously the rifle recoil had bent these after a short period!
Has anyone else heard of this??

Ha Ha! Never heard that one Pete! Could shooting through the spokes of a wheel be more awkward?
Best theory so far is from the army training film (have you seen it?) Were the recruits are instructed on how to recover a fallen machine on a steep off road hill, by using the right lower mudguard stay as a recovery handle. You swivel the bike on the left foot rest to get the bike facing down hill. It's possible BSA strengthened theirs for this purposes. Strange that we don't really know for sure though. Ron

email (option): ronpier@talk21.com

Shooting through the front wheel would be about as sensible as shooting through the propeller before they geared the machine gun to the prop..Even without the wheel moving I could well imagine some over enthusiastic squaddie shooting a spoke away...
If the bike was laid down you'd be shooting at the sky or the floor and if it was stood up the bike would be getting shot to pieces above your head by the enemy..watch out for the contents of the petrol tank!...
I think I'll stick with my theory for now, which Ron has outlined...A quick survey of the mudguard stays on other WD machines revealed the 'unsleeved' BSA stay was smaller in diameter than most which explains the strengthening for that particular application...
I remain open to any further sensible theories or documentary evidence, but at the moment I'm happy that a question that I looked for a logical answer to for about 20 years is satisfactorily resolved....
On another subject...Why did BSA remove the rib from the back mudguard but not the front one on late war M20s?...and why did they lengthen the forks by 1/2" which would have made no practical difference to ground clearance? Ariel trials forks (as used on WD models) were 2" longer than standard ones I believe..Ian

email (option): ian@wright52.plus.com

Hi Ian
Norton used their trials frame on the wd 16h which gave a whole extra one inch of ground clearance! Ideas on ground clearance seem to have been different in those days!

You may be right Kieth..even though bumps were the same size in 1942.. ...They must have really appreciated the 1/2" clearance when sailing over a 4" bump on an M20..only to go ass over tit on the following 5" one.. ...Ian

email (option): ian@wright52.plus.com

Did all WM20's have the thickened rhs mudguard stay, if not, when did it begin?
Scorp.

email (option): wm20@scorpionvideo.net

It doesn't look to be there on the 1939 Deluxe model in O&M. Henk or Leon will know for sure. I guess it was a true WD upgrade.
Ian I don't think the W/NG forks are as much as 2" longer? No doubt Mick will tell us. Ron

email (option): ronpier@talk21.com

Glad its not just me that keeps staring at that bracket and wonders why.

I'm sure we can all think up some almost believable other reasons for making it this way.

How about it was made thicker as a counterbalance of the weight of the speedo which is offset on the other side of the wheel?

email (option): tmuir12@gmail.com

You have probably discussed this option before but I would say a reinforcement for using the stay as a stand with the brakepivot as stop is quite logic.

The stop is gone when the front wheel is taken out but there when the bike is pulled backward to put it on the stand and it would explain the 'one side only' thickening.



Michiel / NL

email (option): m.wijbenga@hotmail.com

Personally I wouldn't think so Michiel? As you already said. Pointless when the wheel is removed. And why would it be so long when just 2"-3" would do. I wish I could go back in time and ask someone! Ron

email (option): ronpier@talk21.com

Hi Michiel...That sounds quite plausible (though that would mean some more of Rons paint getting chipped off ).....
One thing to consider though was that this was not deemed necessary on similarly equipped pre war models, including military versions. Rons points are also very pertinent regarding length and what happens when the wheel is removed..So what would have prompted a change of thinking?...Ian

email (option): ian@wright52.plus.com

I can imagine that the early small diameter front stand was used in a rough way and got to much damaged/bent by pulling it against the brakepivot that they decide to strengten it and thereby decided to use the brakepivot as a stop while it was never designed that way in the first place.

This stop is mostly needed when the bike is pulled on the stand so when the front wheel is still fitted. and if the thicker part was only a few inches long it would of course by less strong and more easily bent just where the thicker part ends.

Michiel

email (option): m.wijbenga@hotmail.com

Don't know why the stand is thicker one side, have always been curios' but I was told by a DR To always tie a short rope or the strap supplied in the tool kit back to the frame because they sometimes move when getting the front wheel out, but when I have used the stand in the past without using a strap, I have never had a problem, Was it early elf an safety, ? Andrew.h.

email (option): warbikes@gmail.com

why waste money strengthening both sides when one side does the job saving material as well

email (option): roger.beck@node6.com

I think Michiel's theory is interesting. In the mid 1930's the bottom stay had special barrel shaped pieces attached on both sides to perform exactly the function Michiel is describing. Those pieces rested against the forks to act as a stop.
However pre war M series bikes didn't have those and didn't have the strenghtened stay either. My 1940 WD M20 still has the "civilian" bottom stay without the strenghtening piece en so does my 1939 WD M20.

Regards,
Leon

email (option): leonhop3@planet.nl