that's strange that magnesium should not be used on the street,,there seems to a lot of car wheels made of mag right from the factory and they seem to hold up fine,,,
That's a pretty generalized statement, and considering what "some folks" choose to use on the street ... well, cars to bikes is like comparing apples to oranges Mario.
= extreme light weight, short term use, consistent excessive speeds, frequent maintenance and hefty parts turnaround.
= dependable parts for long term use
Choosing what type of bike to use, and how it's to be used (e.g. - street, dirt, combination track/street, or direct racing) directly relates to the parts you choose.
Aluminum rims can bend when encountering a large pothole. Magnesium rims, however, can crack and fail - leading to failure of the entire wheel. Such a failure can cause a rider to lose control of their bike. Magnesium rims need to be replaced more often than aluminum, but durability will degrade less with regular maintenance. The probability of an average rider inspecting magnesium wheels on a regular basis, and the cost associated with it - would deter the choice of using this compound.
Choosing OLD mag wheels for street riding (or even track-use), as previously mentioned... is an even greater gamble. Please note we're discussing motorcycles here, so whatever those car-guys want to do - is fine, just remember they have 4-wheels - with doors to a framed capsule. You know what happens when a wheel goes out on a motorcycle yeah? ... well, it ain't pretty.
It's fairly safe to say we won't be seeing mag wheels on mass-produced cars from the factory, anytime soon. Cost to the consumer, longevity, and durability - are just three factors into why that won't happen.
So ... anyone have some specs/pics of their PM wheels, mounted or otherwise?