Chassis Evolution

[evo550]

1990....perimeter frame in dirt.....although earlier on road.

[Tim754]

Another Alf Hagon monocoque machine,. Past half way down this set of gorgeous  photos ,you cannot miss it http://twinshock-chairs.tripod.com/id2.html Yes there is a least one Hagon S/car in Australia.
The Wasp universal sidecar frames I have are bronze welded Reynolds 531 Tube , Wasp still to this day uses 531 tube as required. http://wasp-motorcycles.tripod.com/

[Bamford#69]

Hi evo555,
Check out the  perimeter frame CZ/Jawa 1963/4 (Banana frame) MXer, "czechpoint" web site will show you the photos ,  very collectable,very cool,  I have never seen one in the flesh though,

[cappra]

Not an mxer, but interesting none the less.
1969 works Ossa monocoque . 

[mainline]

not mx, but did anyone else get the latest Classic Dirtbike with the 1970 alloy/aluminium Mclaren Trials bike in it?

[LWC82PE]

i would have a photo oiff jeff smith TI framed B44 somewhere. i have a feeling it was in 65 though. im afraid i wont get to looking for the photo for a while though as i gotta sift through a stack of BSA books to find it.

i think the yamaha you want to see is on here somewhere

http://mxtrax.co.uk/official-factoryworksbike-pic-thread/forum/viewtopic/60/286430?siteid=6

whats the one with pink seat here?

http://mxtrax.co.uk/official-factoryworksbike-pic-thread/forum/viewtopic/60/286430?siteid=6&start=30

[Ji Gantor]

Thanks LWC3077,
Here is the works Yamaha YZM500 which we think was built in 1985.

Ji

[Ji Gantor]

Here is the mystery Yamaha that LWC3077 found. Does anyone know when this bike was made? It is a YZM but seems to have a frame almost like a modern bike.

Ji

[Ji Gantor]

This is the Honda CR250 R 1997. The first production all aluminium framed MX bike.

Ji

[Nathan S]

The pink seat, perimeter framed YZM is around a 91 model. The colours and the Deltabox styled swing arm fit with the production YZs of that era.
Trusting my very rubbery memory, but I don't think that bike was used in the World Championships - all the photos I've seen, show it being used in Japan.

Pretty sure that the older YZM500 is more like 1987/88 than 85 - at least in that (watercooled) spec. There was a similar, earlier air-cooled, power-valved YZM500 which is more like 85/86.  It was definitely used in Europe, in the World Champs and stuff like the Le Torquet (sp?) beach race.

[Ji Gantor]

Thanks Nathan S,
So the YZM alloy frame no matter what type of cooling system they used was somewhere between 85 to 88.

Ji

[evo550]

Yep, the yzm 250 was only used in the Japan national championships(where all the factories bring out the juicy stuff) in the early 90's. Although not on that particular bike, Yamaha was also experimenting with a single leaf rear suspension setup. I think they own the patent on it.
See if I can google something.

The 500 pictured came out about '88/'89, me thinks the original alloy framed ones where aircooled/powervalved in '85/'86

[Oggy Doggy]

Here's an interesting piece by Frank Melling on the development of the Ti BSA. There were some pretty trick works bikes built in the 70s but this bike would have to be considered for the trickest of the trick.
http://www.motorcycle-usa.com/290/1686/Motorcycle-Article/Memorable-Motorcyles-BSA-Titanium.aspx

[Ji Gantor]

Oggy Doggy that is a great history piece, well found.

Ji

[Ji Gantor]

The BSA with a titanium chassis.

Ji