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"BMW has filed a patent for a completely new motorcycle concept that would allow extreme suspension travel while minimising the amount of slack needed in a drive chain, belt or shaft. A conventional motorcycle needs free play in the drive chain to allow for movement in the rear suspension. On an off-road motorcycle this becomes even more important, and with suspension travel of 300mm the chain needs about 70mm free play at the tightest point. Such a slack chain results in power losses and high wear rates through friction, and would need a chain guide to stop the chain jumping off the sprockets. The clutch is usually mounted on the gearbox output shaft on a motorcycle, but inventor Markis Theobald, in Patent Number EP1743832 filed on behalf of Bayerische Motoren Werke AG (DE) on 17 January 2007 proposes mounting it on the engine crankshaft. The gearbox output shaft can then be co-axial with the swingarm pivot, so that chain tension is always maintained without unwanted slack. An added advantage of the BMW design is that because the clutch turns at engine speed instead of the usual half engine speed of a conventionally mounted clutch, a smaller, lighter unit can be used."
Post count: 2134Post count: 2134I want one
It could be a bike I would look at later when I can not lift the HP. 😕 I was able to ride all the hard options on the HP in South Island ride which I would not have been able to on the GS or Aventure. The 450 would only be a toy. If you really want a great bike get the last HP2 in NZ. This is the last, no more are being built at this stage. All the HP bikes are short build runs and my not be repeated.
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Post count: 2134Post count: 2134Last month our European correspondent, Ian Kerr, reported a rumor about a new 450cc enduro from BMW in his Euro Gossip column. Now comes along these spy photos taken at the Uelsen Enduro race in Germany. It's a logical place for Beemer to thrash-test a prototype machine, where Sascha Eckert, a BMW development rider, is shaking down reliability and performance in the E2 class of the German Enduro series. Those at the event say Eckert didn't race full-out and that he finished outside the top 10.But the fact that this bike is exposed to public competition indicates that it might be available, or at least released to the press, sometime late in 2007. Stamped engine cases and a complete-looking assembly also bode well for an early release date.The newly released G650X Challenge is quite different from the machine in these photos. BMW's 650 enduro has a right-side chain drive and left-exiting exhaust header. The 450 has a more traditional layout that seems in line with much of other equipment on the market. A right-side, titanium exhaust is tucked under normal-looking bodywork. Even the front fender looks more mainstream than most of BMW's beaks.From these photos and others that are popping up on the web (check the links in our Talk Back), it's clear that BMW has created something unique. The 450 machine uses a chain drive rather than the shaft or belt system that were presented on possible patent designs. One interesting feature of this chain-drive layout is the positioning of the countershaft sprocket on the swingarm pivot bolt. Another tech tidbit is how the clutch is positioned over the crankshaft area instead of the typical location behind it.The Ohlins rear suspension uses no linkage, kind of like KTM. Other notable goodies are the rear-mounted fuel injection, wave rotor brakes, single-piece radiator, cradle-less frame and lack of a kickstarter.BMW North America denies having any information about a 450, but we thought it might be worth stoking the fire a bit and seeing what else anyone has heard/seen of this mystery machine.
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