Topic: I watched Brent Waller's and his son's bike on the dyno today...

[gschuld]

OK, so the action photo is two years old, but if that's what it takes to get your race report...

George

[bwaller]

Haha, just waiting for one of the track photogs to release some pics.

[simon#42]

odd how these beemer contraptions with a sort of sidestand sticking out on each side can get around so fast 500 dutch champion couple years a go was bmw mounted too...

After speaking with a friend of mine who rebuilt 2 old BMW boxers and riding a BMW R1200 GS the other day, I think I understand it.  That boxer engine, with the dual pistons facing away from each other and down so low on the engine...that gives the engine (and thus the bike) a somewhat lower center of gravity.

I found that the BMW is much, much easier to lean down in a curve and come out than my 750, even though it's about the same weight.

trouble is when you race them you have to jack the engine up in the frame to stop the cylinders touching down

[calj737]

trouble is when you race them you have to jack the engine up in the frame to stop the cylinders touching down

A small price to pay to win a race, eh, Simon? 

[simon#42]

it is cal but my point was you loose the low centre of gravity that restoration fan was mentioning

[turboguzzi]

let's not mention what happened to honda when they tried to lower the CG on spencer's bike by putting the fuel under the engine....

most fast racing beemers ive seen have indeed the engine sitting pretty high

but a chain drive beemer? that's cheating!

[Tintop]

let's not mention what happened to honda when they tried to lower the CG on spencer's bike by putting the fuel under the engine....

most fast racing beemers ive seen have indeed the engine sitting pretty high

but a chain drive beemer? that's cheating!

That's a standard mod, and legal when they are used in sidecars.

[simon#42]

never seen a chain drive bm over here , if anyone has a picture i would love to see it .

[gschuld]

Here to help....

George

[bwaller]

Sorry Simon, I just didn't take any pictures. I emailed Gunther for a couple, we'll see how often he checks. It's very light & nimble and although it doesn't have the legs of my 550 it comes off the corners well. This doesn't show the drive well. I'll get pictures next time. Cool bike.

[simon#42]

thanks George , thanks brent !

i am very curious how he has done the conversion , looks a nice bike

[Tintop]

Generally they use a geared (crown & pinion?) 90 degree take off that bolts to the engine.  There was a picture of it on a sidecar site, I'll see if I can find it.

[bwaller]

The thing is tiny.

[Tintop]

This is the sidecar photo I was thinking of.  Used the stock rear drive attached directly to the engine with a custom adapter, and a custom shaft for the sprocket.  To bulky for a bike but gives you the idea of how it's done. 

http://www.steveenglish.com/forum/download/file.php?mode=view&id=12856

[simon#42]

thanks tintop i can see how that works on an outfit but it would make for a very long engine on a solo

[Tintop]

thanks tintop i can see how that works on an outfit but it would make for a very long engine on a solo

That is a basically 'down & dirty' solution using the original parts.  The housing could be made much more compact if custom machined, and it used a small crown & pinion.