Sportster Rear Drum Modifications

[Hrdly-Dangrs]

Have a couple of questions for you Sportster and Racing Freaks out there. #1. I would like to drill some 1/4 to 3/8 holes thru the back side of the brake drum to lighten the reciprocating weight of the drum itself. I've seen this done on other earlier period H-D racing bikes. My question is: Would the drum be likely to 'explode' when I apply the brakes at the end of the Race track?? I've already drilled out the rear aluminum brake plate and the sides of the brake shoes themselves. Have been racing Er..I mean...'running' this bike on the street to test all my mods and those I've done so far are holding up well. #2. I've seen and can recall guys using an 'aluminum' replacement rear brake drum sprocket. I believe they were available back to the late sixties at least and would be 'Period' correct for my Drag Bike. So my question on this is: Anyone ever use one of these type gears??...How do they hold up?? I know this may seem a little excessive to some but the name of the game in racing is weight to H.P Ratio. It's always cheaper to reduce weight and p.u. the useable H.P. thats already on hand, then dump a s**t load of money on expensive H.P. parts. And to make things a little harder I need to do only those mods and parts that were being used during the 'Period' year of my Sportster. Always welcome tips and comments!..... ....Racing Hrdly-Dangrs

[AdminGuy]

fast or make it last. Speed = dollars.

Finding a balance point at which the structural integrity of the metal will not collaps in relation to the drillings is tricky. I wouldn't do it on the drum. Sounds like you have enough ventalation. Run it hard a few times. Then reassess it.

#2 - I'm a big fan of titanium. ummm but I see you want period.

[Hrdly-Dangrs]

Yes, 'Period' correct to show at AMCA and still Qualified to run in a 'Vintage' Class or in a Class equivalent to its day while still being kept on a budget. A tall order and all the more important to choose the Mods and Parts carefully. That said, "SAFETY FIRST' is still the main rule. Thanks for your opinion AdminGuy.......All others are welcomed also...... ..Hrdly-Dangrs