Does anyone know if the boss that is fitted to the BSA rear brake arm should be free to rotate with the brake rod?
Mine is solid, however on all my other BSA models that I have it does move.
I don't want to free mine off if it's meant to be fixed.
Thanks... Jon

email (option): jonsewell8@hotmail.com

Good question and one I asked myself when I saw one for the first time. No, the boss does not rotate. I think the idea is that the wide countersink/chamfer on the boss makes allowance for the change in rod/brake arm angle.

Thanks Dean, I did wonder about the large countersink on both sides.
Thanks... Jon

email (option): jonsewell8@hotmail.com

Do you mean brake arm bush 29-7328? It's a separate part that swivels and is often seized if never oiled. Which is what the extra little hole is for. Ron


https://www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/964-brake-rods



Ron

email (option): ronpier@talk21.com

Ron, I mean the actual brake arm, part number 15-7962. Regards Jon

email (option): jonsewell8@hotmail.com

In my copy of the RAF Manual the part number is 15-7961; is this different because of the sidecar?

Yes I can also only see that number 15-7961 in my parts lists (RAF or otherwise) and also here at Draganfly. Often any casting number can be close to the actual part number.

https://www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/920-8-qd-rear-3-bolt-fixing-1938-48-m

Ron

email (option): ronpier@talk21.com

This is the difference for a sidecar arm, it is quite a bit longer - this was one I sent Henk ages ago.
This view does show the stud is peened over and definitely solid.



The sleeve sits over that stud and is the bit that swivels - the spring and the wing nut bear up against that sleeve. The deep countersinks in the stud allow quite a bit of movement of the brake rod.
This sleeve is often missing and the stud flogged out within an inch of its life.

email (option): rays54@hotmail.com

Ray are you able to provide the dimensions of this sleeve please.
It looks pretty simple to make.
Thanks.

email (option): meck04@bigpond.com

Ray I didn't know there was a different arm for sidecar use. The RAF parts book gives the same number as the other contract books that I have??

Ron

email (option): ronpier@talk21.com

I now see my problem! Thanks to everyone for helping. I am missing the sleeve that fits over the boss.
Regards Jon

email (option): jonsewell8@hotmail.com

Ron, you are correct in that it isn't technically a WD part - if I recall it was in the 1938 or 1939 parts book as a sidecar part and then wasn't identified in the wartime lists.
My memory is a bit hazy on the specifics but I'll see if I can dig up the original info from a few years ago.
I don't know if the extra length was for clearance or leverage (I consider sidecars evil after an encounter with a fence while 'driving' one as a young man so didn't look into it deeply at the time).

I will post up the dimensions this evening.

email (option): rays54@hotmail.com

Mark - here is a 'rough as' drawing and as you say is a straight-forward job.
The only critical dimension would be the 9/16" bore so the sleeve is a nice fit on the stud. This is probably available from Russell Motors but give the brutal postage we pay here probably well worth knocking up on the lathe.
The oil hole is at 90 degrees to the brake rod hole and points upwards.
The brown sleeve is a NOS one I have and if you want to make a good replica don't de-burr the holes. :sunglasses:

email (option): rays54@hotmail.com

Thanks for that Ray.
I had one on order from the U. K. but somehow didn't make it into the package.
Oh well it will give me something simple to make on my new lathe!

email (option): meck04@bigpond.com

I'm glad I read this post. I checked my bike and the sleeve was missing, went out to shop and made one real quick. Too bad I didn't look

in my spare parts collection...there was the original.

I think the part number used is incorrect, and is the part number for the civilian bikes.
65-7037 I believe to be the correct part number.

https://pesltd.uk/?product=65-7037

Mark

email (option): pes.sales@btconnect.com

Hi Mark,
Apologies for hi-jacking the thread but I've been trying to purchase some M20 parts from you via the PES web-site. Is your email address or phone number actually working?
Thanks
Nigel

email (option): ndoe998@gmail.com

We have been away at the BSA awards weekend.
Got your email just before we left.
Anita is replying to you now.

Mark

email (option): pes.sales@btconnect.com