brakes

[Vancevr]

I read a while ago that if the brakes on a seven are 'tuned' right you can lock em' up on gravel. I needed to make a panic stop at a light and ended up a few feet past the cross walk. How do I go about tuning the brakes to stop better.

[Tiger]

There is lots of help and advice on the forum.
Just search under brakes.
People with more experience than me will probably ask what the set up is.

[Andy Bennett]

I will ask the obvious to help the more learned to assist you.
Are your brakes standard, coupled, uncoupled, or a 'later' retrofit etc and assume you have done the obvious condition checks, as brakes can suffer from oiling especially if you have been enthusiastic with hub greasing (as I was earlier in my ownership when I followed the hub greasing instructions to the letter and found myself with grease leaking out through the inner to outer hub seal onto the shoes).

After that, it can help to set your brakes up with all 4 wheels off the ground with car supported on axle stands, then someone watching to see/feel which wheels are locking first. Must be supported at the wheels of course not under the body as the wheels will hang and won't be set correctly when lowered to the ground (again one of my 'first year' silly errors).

There is lots written here about subtle nuances on set up. For example if you set up too tight then you can find yourself applying front brakes on tight corners.

Andy

[Charles Levien]

A couple of things to start with.
Make sure you fit the grey softer linings now available.
Jack the car up on all four — ask a friend to sit in the car and apply and hold pressure to brake pedal then go round the car 
and check each wheel individually. Ideally the fronts will be harder to turn than the rears as they are the important ones.
If none of this works go to your local ship chandler and buy a large anchor.
And Happy Christmas.

[Reckless Rat]

If your car still has the original brake set-up, it will be uncoupled. That means that the footbrake operates the rear wheels and the handbrake the front wheels. If all you did for your emergency stop was to jump on the footbrake then I'm not surprised that you overshot. The reason is that the front brakes are the most effective, and the lever gives more effort than the pedal. In essence you should use both at the same time.

I have found that this is the case even with a later car, with the coupled braking. A good heave on the handbrake will pull it up quicker than the pedal, unless you've got a right foot like Arnold Swarzenegger.

All this assumes of course, that everything is in good order and properly adjusted.

There are some basic points to observe:
Rear brake levers should point downwards
Angles between cables and levers should never exceed 90° when fully applied
Early brakes (prior to Semi-Girling) can only be adjusted at the shoes by shimming.
Brake cams can often be wrong (they are "handed")
Wear in bushes and associated parts doesn't help.
Locking the rear wheels at speed can cause the car to rotate.
Good forward observation, planning and awareness are necessary to avoid "panic stops".
Austin Sevens never have, nor ever will be able to stop like a "Modern" and allowances have to be made to your driving style.
Always allow for the actions of others, and expect the unexpected.

[stuartu]

It seems to me that there are some books that might help you.

As a starting point, the Pre War Austin Seven Club has recently reprinted the "Austin Seven Companion", although it doesn't yet appear on their website.
If you put A7 Companion / Beaulieu Rally into the search box on here it will send you in the right direction. Contact Graham and I'm sure he will sell you a copy.

Regards,

Stuart

[dickie65]

All Austin Sevens have no power assistance on the braking system.
Having strong leg muscles are essential to stop quickly.
A well set up system is also essential.
Please let the good folks on here know what Austin model you have for further help.
I can lock my front wheels on tarmac. I have the soft grey linings fitted.

[Vancevr]

The car is a 29' tourer. I think someone switched it to coupled brakes. Most of the time I just down shift to slow down and hardly use the brakes but i would like to prevent things like this from happening again.

[Robert Leigh]

On my 1928 car I have the later type coupled brake system, and also have the early '30s drums, shoes and linings. This increases the brake shoe area by 25% which means that for a given braking effect the pedal pressure will also be 25% lower, so if you are not good at pressing the pedal hard the car will stop better. On brake test in my car I can achieve 80% efficiency on dry tarmac. It is straightforward to change the earlier shoes and drums to the later type, with no other modifications.

[Tony Press]

On my 1928 car I have the later type coupled brake system, and also have the early '30s drums, shoes and linings. This increases the brake shoe area by 25% which means that for a given braking effect the pedal pressure will also be 25% lower, so if you are not good at pressing the pedal hard the car will stop better. On brake test in my car I can achieve 80% efficiency on dry tarmac. It is straightforward to change the earlier shoes and drums to the later type, with no other modifications.

Isn't friction independent of the area of contact?