I have a pal who restores old Indians & has greatly increased the power of the front drum brakes but has found that the added heat generated makes the alloy brake shoes grow to much. He wants to drill (6) 5/8" dia holes on the side of the brake drum and (24 to (36) 1/8" dia holes around the outside circumfrence of the drum between the two cooling fins. Has anyone had experiance drilling holes in a drum brake like this or know of bikes that have them & is it good or bad???

So have you met hobot?



holey-artifacts-t6942.html

Oh ya, forgot about those Swoosh but I need testamony from actual use as to weather it work well or just causes trouble from rain/dirt.

You can't hardly test in more dirt and grit than me and its an non issue and if I was to do it again I'd put a bunch of small holes in the friction surfaces too. Any dirt grit water that gets in there goes right out and carries away brake dust that interferes with friction. Don't expect much extra cooling in a thick steel drum even with holes, I did it more for the spun and unsprung weight lost which did help braking effect. The drum is not cast iron like the barrel so not very brittle. The damage done to my drum were from destroying the teeth on 1st one and then bad bearing with broken axle at 90 mph messed up insides on the other. On some Nortons they have opened vents on the backing cover plate and fancied up with screen.

He's not telling you the full story there , Theyre actually for squirting the Fire Extinguisher in , at pit stops .

Thanks Hobot, didn't think you were using those yet but since you are I'm glad it's working out well.

I don't use them anymore because I used them up but did run the life out of both of them. In my prior ignorance I actually put thin Al cover plate over the 1st drum holes, IOM like or radioactive symbol triad looking. Holes in front drum brake must allow for stiffness not to deflect with shoe pressure and heat. Grit and grime are not much an issue to any brake, just oil, soap and water are and they all can let that in even w/o extra portals.