BMW's 450 Enduro

[AusSteve]

Just saw this story appear on MCN's site:

"Here's the world’s first pictures of BMW’s prototype 450cc enduro bike.

The next-generation beemer was spotted undergoing final tests as part of the Uelsen Enduro race in Germany at the weekend.

The bike was not badged in corporate colours but was entered in the event under the banner of the BMW AG Motorrad team.

What’s more, the bike was being ridden by former pro Enduro rider Sascha Eckert – a development rider and ex-racer. Eckert is being used by the factory to help develop its off-road project in the same way as GP rider Jeremy McWilliams was helping the superbike effort.

For all the information on the project and when we can see the bike in the flesh to buy, see Motor Cycle News on March 7."

Steve

 

[AusSteve]

BMW patents new chain drive

Also found this off a link on Adventure Riders - they're having quite a discussion on this new 450 BMW over there:

"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."

 

[AusSteve]

and some more pics...

Found these on Adventure Rider too...

 

[dazzer]

How would you change the front sprocket

 

[JohnnyBoxer]

How would you change the front sprocket

Expensively

 

[(RIP) philgunn]

remember the mz

250 with the engine mounted clutch and it was awful
no speed shifting there ?


but good to see some thinking been don

pg

 

[wedgie]

Also found this off a link on Adventure Riders - they're having quite a discussion on this new 450 BMW over there:

"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."

its been done before by the brits i cant remember the firm that did it will have to ask my old man he will know and knowing him have a picture or two

 

[Welshman]

its been done before by the brits i cant remember the firm that did it will have to ask my old man he will know and knowing him have a picture or two

Think it was Tony Foale, but without the revised clutch location it doesn,t count as it was too wide at that point.
Welsh

 

[cookie]

some bimotas had concentric sprocket & pivot too IIRC.

wasn't done like that though. that's on the same shaft by the look of it

 

[Mingh]

Expensively

not necessarily.
Well, that is, at BMW the rates will always be scary, but I can see an easy way to sort that out. It only requires a wide spacer between the cog and the frame
1 you loosen the bolt tru the pivot.
2 you take out the spacer - washer that sits between the cog and the frame.
3 with this space available, you pull the cog sideways towards the outside of the bike, so that it comes off a (conically shaped) axle with e.g. 16 teeth.
4 proud of your work, get a beer.

I do wonder what that bolt is doing on the swingarm pointing at the pivot

 

[VAL. H.]

its been done before by the brits i cant remember the firm that did it will have to ask my old man he will know and knowing him have a picture or two

Spondon, the frame company made several frame's in the late eighties/early ninties that had the swing arm pivot over the front sprocket.
Sure the frame was wider at that point. But I don't remember ever reading any thing negetive about it in the press.

some bimotas had concentric sprocket & pivot too IIRC.

wasn't done like that though. that's on the same shaft by the look of it

I think I read somwhere that the guys at Spondon made or designed the frame for one or more Bimotors.

If the sprocket shaft extends into the frame, then it would make the bearing point much stronger and more reliable. Though I'm not sure I'd be so confident about the cluch. Half the size, twice the speed, how long's that going to last

 

[mr moto]

how long before someone ruins it by fitting a huge tank, pannier,s and a big screen ?