March 7, 20188 yr On 28/02/2018 at 8:21 AM, feetupfun said: Some alloy steels have a low coefficient of friction so be careful. Mild steel or cast iron are the go for brake drums I always found it interesting/amusing that other manufacturers used chrome on cylinder bores to reduce friction (as well as increase bore life) . Bultaco used it on brake drums...........
March 7, 20188 yr Author 18 minutes ago, 2stroke4stroke said: I always found it interesting/amusing that other manufacturers used chrome on cylinder bores to reduce friction (as well as increase bore life) . Bultaco used it on brake drums........... ?????
March 7, 20188 yr 1 hour ago, 2stroke4stroke said: I always found it interesting/amusing that other manufacturers used chrome on cylinder bores to reduce friction (as well as increase bore life) . Bultaco used it on brake drums........... The brakes on my M138 Alpina (with chrome plated drums) are amazing
March 7, 20188 yr 7 hours ago, feetupfun said: The brakes on my M138 Alpina (with chrome plated drums) are amazing I suppose I would have to concede that an almost frictionless chrome surface would not be any worse than the cast iron lined brakes on Bultacos I rode as a teenager☺
March 7, 20188 yr Interesting bit of machining Blueflag, how tight a fit are you going for on your liner, given the different coefficients of expansion of steel / alloy? And how are you going to stop the liner from turning, just by the interference fit alone? Or with the aid of a bit of Loctite or similar? Cheers, Craig
March 7, 20188 yr Author It's got an interference fit, chill the liner and warm the hub to get it in. I can't see it getting particularly warm the way I ride! I put a little bit of loctite on the face just as belt and braces. I'm pretty happy with the way it's gone. I need to sort out some shoes, a brake rod and a new lever. Keeps me out of mischief... I know the finish has chatter by the way...? Edited March 7, 20188 yr by blueflag Missing information
March 8, 20188 yr Author Thanks Craig, I know what you mean mate, feel like an active historian! So much I need to learn though!
March 8, 20188 yr 5 hours ago, blueflag said: It's got an interference fit, chill the liner and warm the hub to get it in. I can't see it getting particularly warm the way I ride! I put a little bit of loctite on the face just as belt and braces. I'm pretty happy with the way it's gone. I need to sort out some shoes, a brake rod and a new lever. Keeps me out of mischief... I know the finish has chatter by the way...? Nice work. I'm also impressed that you did it all with the wheel assembled
March 8, 20188 yr Author Kind words! I remember reading about a Japanese tuner in the 70s who would skim drums true, lace up the wheels then heat them up before a final skim. In my case, it's just laziness....??
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