rear brake arm-sq4 plunger 1939

[Henning G]

Hello, I do have a question regarding rear brake arm on a 1939 sq4.Does it point upwards or downwards. Its for my 1939 plunger sq4 4G. A bit confusing…Regards Henning

[Pete.Silson]

The lever points upwards to avoid the brake "self servoing" when the suspension deflects. The upward brake arm (4402-39) is longer than the downward pointing rigid part (4402-36) to give sufficient clearance for the brake rod.

Pete

[Henning G]

Hi Pete, thanks for answering. That makes sense, but I only have 5cm from the top of the up pointing brake arm to the lower rear fender stay, just afraid they will collide when the rear suspension is at work. But I don’t know how much action there is on the rear suspension. Regarding to my original parts catalogue, the brake arm return spring-441-29, is definitely for up pointing arm, but then the brake pedal rod.5426-39, is too short . The rod must then be around 50cm-20inch.

[Henning G]

I have another minor problem, that is about the distance between the frame and the rear mudguard stay, at the bolt that carry the spring for the rear stand and supports the stay.

[Pete.Silson]

I only have 5cm from the top of the up pointing brake arm to the lower rear fender stay, just afraid they will collide when the rear suspension is at work.

The '39 SQ4 does not have a rear stand (it has a very awkward centre stand instead) so your machine has been fitted with a later stud to accommodate a spring lug for a rear stand. The '39 stud should be a 5655-39 which has a 1" shoulder. Incidentally Drags seem to have mis-numbered 5655-39 as 5654-39 and vice-versa in their catalogue.

This give the correct clearance for the mudguard stays and the chainguard, the lower mudguard stay is outside the line of the brake arm and the chainguard inside the line (see below).

(picture courtesy Paul Wirdnam)

but then the brake pedal rod.5426-39, is too short . The rod must then be around 50cm-20inch.

The brake rod should be 18" long. Have you got the correct brake pedal (5399-39) as some other pedals have the arm in a slightly different position which effectively shortens the brake rod? However if a 20" brake rod works on your bike then use a 20" brake rod.

[Henning G]

Hi Pete, Thanks a lot. I have found the missing link in form of the distance bolt-5655-39.. I was confused because of Draganfly. I bought the bike in bit and pieces, so thanks to you, it all fell into place. The brake rod of 18inch fits perfect now. I now have around 2mm space for the mudguard stay and the chain guard. I know I have the rear stand, but the original is hopeless, but I have it. Thanks a lot for your help..
Regards
Henning

[Henning G]

Hi Pete, is it possible for you to take a picture of your LH footrest, I have the wrong one.Any idea where to bay the correct one-5384-37.