Wider shoes in SLS front brakes

[woodypup59]

Someone has asked if fitting twin leading shoe brake shoes on a single leading shoe car would improve braking.

The drums are the same between SLS and TLS I belive.

Somehow I don't think it will improve the brakes, but can't quite put my finger on why. Its a question of pedal effort Vs line pressure Vs wheel cylinder force Vs shoe area.

[Peter Laidler]

TLShoes would make no difference when fitted to a SLshoe front hub. They would still be operating as SLshoes.

[minibitz]

Not sure on the differences between SLS & TLS backplates but my thinking is that the raised pressing that the shoe rests against may be a different height between the two.

I know this is the case between front & rear back plates on TLS cars. If you install front TLS shoes on the rear the deeper pressing causes the shoes to cock over towards the drum. Then the friction surface is not parallel to the drum.

May also be the case with front SLS back plates are they use the same width shoes as a TLS rear.

[1071 S]

I would agree with mini blitz.... BTDT. I thought wider rear shoes would be an excellent idea when looking for a more effective handbrake when Motorkhanaing. Took a little while to work out why the handbrake had basically ceased to operate.

However, woodypup is overthinking it... friction = force times area. So wider shoes would work IF the backplate allowed them full contact with the drum. Surely the easiest way to achieve this is by using a TLS back plate ... and you get a bonus extra wheel cylinder as well .

Someone will know whether a different (and which) master cylinder will work.... but it probably doesn’t matter. Second hand TLS backplates must be about a dime a dozen.... and new cylinder not much more....

Cheers, Ian

[woodypup59]

Thanks for the confirmation people.

[Ronnie]

Bigger area less pressure same as tracked vehicle ground loading