brake arm function compression, tension or either?

[clive]

I have sometimes commented on the fitment of the front brake when I see a picture of one fitted with the brake plate and brake arm on the offside rather than the nearside on one of our 50s singles or twins. My understanding was, when the engineers did their explanations, that it was not a good idea to fit the brakeplate on the other side because the brake arm was then in compression (or is it tension?) when the brakes were applied and THIS IS NOT GOOD. Fully accepted this explanation and passed on the advice to others. Now I see that the 1964 Model 14 was issued with the brake plate and brake arm on the offside. http://archives.jampot.dk/promotional/S ... ochure.pdf
Was it all engineering mumbo jumbo? Explanation please

[bjork]

Well it is on the opposite side but it is still not in compression there as the arm points out forward. So nothing to see here...

[clive]

Ah! Just goes to show I am probably a better bodger than engineer.

[Rob Harknett]

Well it is on the opposite side but it is still not in compression there as the arm points out forward. So nothing to see here...

In the past both front and rear brakes have changed sides. The front brake changed sides , I think 3 time's late 30's. But always with the lever facing forwards. Never trailing backwards, like a prewar 1937 AJS 250 seen here recently. The forks also had to change, as they had brake adjuster etc. fittings, on the front fork down tube. Unlike that 250 AJS here recently. Which had fittings bodged on the rear leg. The rear let at a greater angle than the front, causing the cable to exit the adjuster, At a different angle it enter by. I guess a brake anchor was also bodged on the wrong side for this bike. Which had the drum lever arm pointing backwards, bringing Clive's comment into question. I would ask " safe or not ?? " based on what Clive's comments. To add more for your thoughts. I have a Suzuki front wheel in one of my lightweights. Of all my bikes this has the best front brake. It has twin expansion, e.g. both ends of the shoes open. There is the main adjuster for one end, plus an adjuster in the link rod to the other end. This is adjusted so that both shoes open evenly. This gives contact of all the linings on the drum. I do believe this makes both ends in compression. I believe it depends on where the lever is on the drum. So brakes are on compression. Top, bottom, front, back ? I have not considered this, so would need to check my 30's bikes. 36 brake drum is on the right, 38 on the left.

[bjork]

Well it is on the opposite side but it is still not in compression there as the arm points out forward. So nothing to see here...

In the past both front and rear brakes have changed sides. The front brake changed sides , I think 3 time's late 30's. But always with the lever facing forwards. Never trailing backwards, like a prewar 1937 AJS 250 seen here recently. The forks also had to change, as they had brake adjuster etc. fittings, on the front fork down tube. Unlike that 250 AJS here recently. Which had fittings bodged on the rear leg. The rear let at a greater angle than the front, causing the cable to exit the adjuster, At a different angle it enter by. I guess a brake anchor was also bodged on the wrong side for this bike. Which had the drum lever arm pointing backwards, bringing Clive's comment into question. I would ask " safe or not ?? " based on what Clive's comments. To add more for your thoughts. I have a Suzuki front wheel in one of my lightweights. Of all my bikes this has the best front brake. It has twin expansion, e.g. both ends of the shoes open. There is the main adjuster for one end, plus an adjuster in the link rod to the other end. This is adjusted so that both shoes open evenly. This gives contact of all the linings on the drum. I do believe this makes both ends in compression. I believe it depends on where the lever is on the drum. So brakes are on compression. Top, bottom, front, back ? I have not considered this, so would need to check my 30's bikes. 36 brake drum is on the right, 38 on the left.

Rob, I think Clive was asking whether the brake torque arm is in compression or tension. It sounds like you are referring to something else.

In this case the correct way is to have the torque arm in tension, that is to say being pulled and trying to stretch it. If it was being pushed it would be in compression.

[clive]

Yep that's what I wanted to know Bjork. Always find it difficult working things out round the other way.

[SPRIDDLER]

When section chum 'Frugal Peter' is gripping his wallet the contents are in compression. When he has to hand over a fiver at the bar it's in tension and has to be pulled from his grip.

[ajscomboman]

When section chum 'Frugal Peter' is gripping his wallet the contents are in compression. When he has to hand over a fiver at the bar it's in tension and has to be pulled from his grip.

[dodger]

Is he related to "Frugal Ken" in our section?