Vented drum brakes?

[wbks]

I was looking at the scoop on the Norton Manx's front drum brake on trademe. Reading about this said that this (obviously under extreme racing conditions) helps prevent the drum warping, or the brake linings disintegrating in extreme heat. This was about car drum brakes but I'm assuming it's the same for bikes on a smaller scale. Did racing bikes ever need scoops on the back? And did the drum need vents drilled elsewhere away from the scoop to let the air flow through rather then build up in the drum?

I was thinking of doing it just for fun on my cb with the back drum, more for the experience than anything else but it would have to give at least a small effect on performance in a positive way to make it worth while. So do you experts think it would help (albeit possibly unnoticeable if you didn't look for it)? I'm hoping it wouldn't effect it badly, but I'm actually thinking it could take the brake below the optimum temperature between corners and then I would just be having to warm the brake up every corner.

Opinions welcome

[imdying]

Don't start drilling holes into things related to the braking system that you don't understand. I can reline your shoes with a high performance lining as used by classic racers if it's more fade resistance that you're after.

[wbks]

Not sure if it would be worth what you would probably need $$$ to do that to improve the back but I'm not too stressed about it. But like I said it's more of a fun thing for me, I did some cutting and welding, and some threading, and some other stuff so I'm just keen to do more workshop type stuff. I didn't think a small scoop on the outer side of the drum would wreck anything structurally?

[Ixion]

Plenty of people tried doing this back in the seventies, after the OEM ones came out. Never made bugger all difference. The OEM ones didn't make bugger all difference either. Maybe on a track where tiny differences count.

If you fit a scoop you need to drill a few small holes in the back plate . Few. Small.

[wbks]

Think it could be worth it purely for aesthetics? I've got to get the brake apart some time soon to see how much pad is left, anyway. I still don't know how much power is available from the brake at the back on this cb anyway so that'll come first. Pretty much just a small scoop anywhere on the drum wall with a few small holes in the backplate to get it flowing through? And what kind of diameter holes are you talking for "small"?

[imdying]

Don't reduce the rigidity of the backplate, or you'll be going backwards, not forwards.

One reason drums suck arse because they expand away from the friction surface when they get hot, unlike discs that expand towards.

[Motu]

You need the scoop on the backing plate,and holes in the centre of the drum - Manx,Goldstar and XS1 Yamaha.