AJS & Matchless Owners Club

Do you thinks this would be the one I need to look for.

NO

plate looks like it is chrome plated so later than 55. You can tell 55 from pulling the wheel off, for 55 only metal pins go in metal holes no rubbers.

Hi All,

I used the online dating services and have now established that it is a 1955 Frame. Model 55/G3LS. So that's good, and in that sense papers are in order.

Now I would slowly work towards making sure all components and fittings conform to that of the model year 1955. I am not aiming for any concourse levels but inclined more towards reliability in using it.

1st step is to get the front brake switched to the left side. I saw the picture of anothr G20 in Photos section, where the Front brake was on the right side exactly like mine (the bike of member Kelvin). There was some comment on that as to why people switched to do that - something about some niggle with the brake activation arm - torque arm ??(pardon me as I cant remember the correct name of the lever on the hub drum).

The Comments were as follows

Quote:
"By ajscomboman
06 Feb 2015
Oh dear another bike with the brake assembly on the wrong side. The brake toque arm needs to be in tension not compression when the brake is applied. Dangerous, very dangerous!
By altette
07 Feb 2015
Nice old tool - I bet it sounds 'Rorty' with the single megga...The transposed brake assembly seems to be a popular 'Mod' - I guess owners have heard that the torque arm fails occasionally (with nasty results) and try this alternative arrangement to avoid the problem...
Unquote:

Any thoughts on that ?


Best Regards & Ride Safe

Ram

Thats correct, if the brake torque arm is in compression it can bend, if it is in tension then everything is down to the shear strength of the metal involved, and the force required will be much greater than that required to bend the metal.

Thanks for your explanation

leswaller wrote:Thats correct, if the brake torque arm is in compression it can bend, if it is in tension then everything is down to the shear strength of the metal involved, and the force required will be much greater than that required to bend the metal.

I am not person with much of "engineering" background, hence couple of questions for you to answer if you like

In the picture below; the one on the left is on tension (as in my bike) and one on the right is compression, am I right ?? If its otherway round my next question would stand answered



I am sure that jury may be still out on this as to which is better, but question is - other than the point of conformity with the original, why is this - brake arm set up on the right side - being described as dangerous ? Because of the shear strength of the metal involved being suspect ?

Would like the seniours views on this, please.

Best Regards & Ride Safe

Ram

R_Nairtvm wrote:In the picture below; the one on the left is on tension (as in my bike) and one on the right is compression, am I right ??

No, it is the opposite.
When the brake is applied the brake shoes/linings and the backplate try to rotate in the same direction as the wheel. With the brake fitted on the right as on your bike there is a risk that the torque arm will buckle (bend). This will not happen if the brake is on the left as the torque arm will be under tension.

Hi Ram,

In your setup, the torque arm isn't strong enough to resist the braking forces. During heavy braking, the compression force on that little bar will be equivalent to several hundred kg and it will bend, possibly resulting in a nasty accident.

Now look at the correct setup. You can pull on that arm with a tonne of force and it won't go anywhere...

To add (unnecessarily perhaps) a bit more information:
When you change the brake to the left side you may find for a while that it is less effective than it was previously. This is because if it had been used for some time on the right the linings (particularly the one which was previously the 'leading' shoe will now be the 'trailing' shoe) and will have 'bedded in' accordingly. It should improve after some miles when refitted on the left.

Here is some detail about front brake performance and improvement which I posted 5 years ago and which may help to identify and explain the importance of which are the leading and trailing shoes.

http://www.jampot.com/forum/viewtopic.p ... 66#p115566

Hello All !

Have another question (as usual )

Did the bike come with an Air Cleaner as an OE fitting? Or was this an optional one ??

My bike doesnt have one at the moment and am thinking of fitting one, as there's a fair bit of dust around where I would be operating the bike. If I can source an original one I may have to fashion one from one of the modern paper filters available.

Your thoughts on this please

Best Regards & Ride Safe

Ram

So many questions could be answered without any doubt as being right or wrong, by looking in the literature for your bike. In sales cat. & manual you will clearly see the brake torque arm in its correct place. In the sales cat. you will see air cleaner is an optional extra. In the parts list you will see a picture of the air cleaner. ( I think they are being reproduced in India )
You will need to change carb settings if a cleaner is fitted. The change can be found in Amal literature.