OzVMX Forum
Marque Remarks => British (BSA, Greeves, Triumph etc) => Topic started by: Marc.com on September 13, 2011, 04:19:28 pm
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For the Rickman owner who has everything... lets see one for the Ricky and one for the Cheney, then all I have to do is convince the ole lady to live on corn flakes for a month ;D
http://cgi.ebay.com/ebaymotors/Rickman-Metisse-magnesium-rear-brake-backing-plates-NEW-/350461966082?pt=Motorcycles_Parts_Accessories&hash=item5199293702
(http://i245.photobucket.com/albums/gg71/marcFX_photo/KGrHqVisE2LCJV7d5BNyMfjBwUw0_12.jpg)
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Well that should help the the bike down to just under half a tonne. Money well spent!! :D
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I don't know I have magnesium hub on my TM250 and its a s light as a feather.
But magnesium anything always looks good in the pits and is one up in the trickmanship stakes. ;)
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I don't know I have magnesium hub on my TM250 and its a s light as a feather.
But magnesium anything always looks good in the pits and is one up in the trickmanship stakes. ;)
True, very light. But as you have to paint it who would know. You could always paint the stockers in magnesium colour. ;)
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You could always paint the stockers in magnesium colour.
The stockers are magnesium Jeff ;). The 7'' Rickman hubs, backing plate, the whole box'n'dice are magnesium....and notoriously fragile. I've got two pairs of Rickman mag hubs in the stash shed and there's no way I'd use them on a race bike as age and wear and tear break down the properties in magnesium, especially for some reason, in Rickman hubs. I saw the great Roy East crash his brains out at a Nepean vintage meet in the early 90's when he grabbed a hand full of front brake coming into turn one and the hub shattered like a broken dinner plate. I've seen a similar thing happen to a CZ hub a few years ago and I had my own encounter while I was lacing a CZ mag front hub I over tightened the spoke, and a loud 'bing! sound came from the hub and a crack between three spoke holes in the flange appeared. Not being a metalurgist I can't give a technical reason for magnesium becoming unstable with age....all I know is that it does.
That's why the 6" aluminium Rickman hubs are the racers choice over the mag 7'' version.
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Magnesium and Aluminum have the same kind of properties where they age harden due to heat cycles.... stress corrosion. With our turbochargers a big part of the design is the containment of a compressor wheel burst when it fails, the alloy compressor wheels are running at about 140 degrees and heating and cooling they don't last forever ( about 100000 hours) Turbine energy is about 4 MW and 10000 rpm so you are looking at serious forces, I have seen one spiit down the center line.
(http://i245.photobucket.com/albums/gg71/marcFX_photo/tpl91b01pn7.jpg)
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"stress corrosion" that's descriptive :).
But do brake hubs and backing plates go through this type of heat cycling.
I thought the VMX 'conventional wisdom' was that it was to do with painting or protective coating the hubs.
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"stress corrosion" that's descriptive :).
work hardening I guess is more familiar. Product of time and temperature, lower the temperature the longer the time. Drum brakes build up heat and the backing plate is part of the assembly. Then pick a material I am not sure is that suitable in the longer term.
But for looking prurty on the back of the Ricky, magnesium has no peers, thry this Menani mag 4LS front , just don't over tighten the spokes eh Firko
http://www.discovolantemoto.co.uk/brakes/menani-magnesium-brake-250mm/prod_192.html
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http://www.discovolantemoto.co.uk/brakes/rear-hub-brake-160mm/prod_988.html
I like these, they are beautiful and the pictures dont do them justice.
Interesting product code as well......