New F800S and ST Anyone know?????????

[Sir Limpsalot]

How the crank is phased on the new twins?
Is it 360 degrees (like a Bonneville) or 270 degrees (like a TDM)? I asked the Salesman at a BMW Dealer yesterday and he didn't even understand the question. Just kept looking at the brochure and saying "it says here it's an inline twin".:eusa_wall:
Anyone know? Dean?
Cheers!
Si

[DJ Down Under]

Simon I'll ask my dealer and see if they know.

DJ

http://f800riders.org/IMG/F800ST/grey3.jpghttp://f800riders.org/IMG/F800ST/grey2.jpghttp://f800riders.org/IMG/F800ST/grey1.jpg

http://f800riders.org/img/news/chartf800.jpg

[Deans BMW]

Simon, I don't know the answer.

DJ, that is an intresting graph. My understanding is that the 800's will not be in the US until the '07 model year. More intresting is the US prices shown, what is the story behind the graph?

[arkline]

I may be losing my mind, but I think I read somewhere that it's a 180 degree crank. Or I may have that confused with the Ninja 650. Oh, never mind.:eusa_wall:

[DJ Down Under]

Dean-O...I'm not sure how accurate that graph is...I found it here.. http://f800riders.org/forum/forum.asp?FORUM_ID=11 and I hope an answer to Simon's Question also.

btw..have you guys seen this... http://www.seriousfun.com/ ...I found it very interesting...and a bit odd..:104:

DJ

[Deans BMW]

Thanks DJ.

[Dallara]

The new BMW 800cc parallel twins will have a 180 degree crank...

Just like Kawasaki's new Ninja 650-R and all of Honda's old air-cooled parallel twins (CA-150, CB-160, CA/CB-250, CA/CB-305, CB/CL/SL-175, CB/CL/SL-350, CB/CL-360, and CB/CL-450) up until the 1978 CB-400 Hawks and later 450 Hawks and Nighthawks (which used 360 degree cranks like the 1960's CL-250 and CL-305 Scramblers, and just about any British vertical parallel twin ever made).

Cheers!

Allan (Dallara - NACD)

p.s - Here's a trivia question - Why did the Brits initially pick 360 degree cranks, and what do they have in common with 500cc two-stroke GP road race bikes of the late 1990's and early 2000's?

[Sir Limpsalot]

Thanks Allan, see if you want to know anything about Motorcycles don't go to a Dealer, come to the Cafe!
I'm getting quite fond of the look of the ST version. I know it's not a "propper" BMW and only has "normal" forks but I find it's growing on me.....
Cheers for now,
Si.

[socalrob]

Little off topic, but DJ's price graph got me to thinking:

I predict the new R1200R will be priced at US $11,500 without ABS, US $13,000 with ABS. Will neatly fit right in between the F800's & the R1200ST. Not to much, not to little, just right.

[Sir Limpsalot]

While I was at the Dealer the other day I picked up an '06 catalogue and the 1150R is listed. In "new for 2006" colours too. This makes me think they've got at least one final batch (using up the parts?) planned. The Rockster is gone however.
All the other new stuff 1200S etc is there even if marked "due out later in 2006".
I can't see the R1200R hitting the Dealers untill the '07 model year. At least in the UK.
Si.

[Sir Limpsalot]

Your trivia question Allan.
I think the answer you're looking for is that Edward Turner when working for Ariel designed the "Square Four" model. This ran two crankshafts geared together. As an experiment Turner ran an engine with one crank removed and the result (a 360 twin) gave such good results that when he moved to Triumph he designed the "Speed Twin".
Fast forward to the "Two stroke" era of GP Racing and the Suzuki RG 500 was again a "Square" design, running two crankshafts geared together. The Yamaha's and Honda's (althoug Vee Fours) also ran geared, twin cranks.
Incidentally, Turner did experiment with 180 cranks but found it "very difficult to get the carburation right when fitted with a single instrument". Typical of Turner, everything had to be as light, simple and cheap to make as possible.
Twin carbs were unthinkable, untill market forces demanded them on the '59 T120.
Si.

[Deans BMW]

The collective M/C historical knowledge on this forum from the likes of Darth, Dallara and Simon among others is amazing.

[Dallara]

Right you are, Simon! :eusa_clap:

I really didn't think anyone here would get that one, and I was prepared to let a simpler answer take the prize... I should have known you would have known the whole story, though I was surprised you left out the part about Turner also using the 360 degree crank timing to try to better control the rocking couple vibration present in vertical, parallel twins.

Square-four two-stroke GP bikes actually go all the way back to the early '70's (and some were built even earlier than that, like by MZ)... (and BTW, Honda never built a two-stroke GP twin-crank engine that saw the light of day... The original NS-500 V-3 right through the last of the NSR-500 V-4's at the end of the two-stroke 500cc/MotoGP era were all single crank engines...) There was another reason Suzuki, Yamaha, and others used the square-four layout, too, though - and it leads right to where we are today with both Honda's RCV-211 and Yamaha's M-1.

Engines that rotate the crankshaft in the same direction as the wheels have a bad habit of unloading the front wheel on corner exit with application of power, and are alos more *wheelie prone*... Conversely, they also tend to overload the front wheel when the throttle has been closedm adding to front tire loading, also unloading the rear tire under braking, and worsening front end dive - all of which makes the motorcycle more unstable under braking along with making life much more difficult for the front suspension.

One of the initial reasons square-four layouts were tried is that the counter-rotating cranks tended to cancel this torque reaction out and leave the chassis more *neutral* both going into and out of the corner (not to mention this layouot lended itself to rotary-valve crankcase induction very well). At the time the extra complexity, increased flywheel effect, etc. It really wasn't until the reed-valve inducted Honda NS-500 V-3 came along and truly signalled the death knell of rotary-valves on two-stroke GP bikes that single-cranks started their reign in the premier class. Thought the NS-500 spun the crank in the same direction as the wheels (and was also the first bike to subscribe to the long-swingarm, *put-the-engine-as-far-forward-as-possible* layout), it didn't take Honda long to figure out that a single-crank spinning in the OPPOSITE direction as the wheels had huge handling gains... With the torque reaction of the spinning crank acting opposite of previous practice it was much easier to keep the front end down (and front tire loaded, lessening front-end *push*, or understeer, too) on corner exit, and it also tended to help load the rear wheel on braking and keep the bike more level and stable on corner entry - also making life easier all around on the front forks and tire all the way around. The handling benefits easily outweighed the minor additional complexity of added a *jackshaft* somewhere in the drive layout to allow for the opposite-spinning crank (more on this in a moment...).

What's odd is that Honda, with its single-crank two-stroke engines, was the first to use the "Big Bang" idea to help the rear tire have an easier time. Honda had learned the advantages of the "Big Bang" concept from their days in AMA flat-tracking... Something that Harley, of all people, had known for decades. (more on all this "Big Bang" theory stuff later if anyone whats to hear more about it...) Why is it odd that it was Honda and its single-cranks to use it first?

Because it is much simpler, and easier to implement, a "Big Bang" crank layout and firing order in a twin-crank, square-four engine configuration than it is on a single-crank engine.

Fast forward to 2003... Honda is dominating MotoGP, and one of the big reasons is they are the first to reason that they need broad, flat, easy to ride power curves in MotoGP rather than absolute peak power. They had learned this well already in the last years of the 500cc two-stroke class (though near the end of his career Mick Doohan went back to the peakier, non-"Big Bang" engines... But he was the only one who could ride 'em, with all of Honda's other riders staying with the "Big Bang" engines). The RCV-211 was designed from the ground up with a contra-rotating crank, and Yamaha's M-1 with its *normally* spinning crank was nothing but an also-ran... But then Valentino Rossi leaves Honda for Yamaha, and takes Jeremy Burgess with him, and after Rossi does his first test with Yamaha he literally demands that Yamaha change to a contra-rotating crank on the M-1. Since thye had hired Rossi for his developmental expertise as much as his brilliant talent on the track, Yamaha listened... And the rest is history. More than any other single reason (other than Rossi's aforementioned talent), the contra-rotating crank was what helped the Yamaha M-1 out of the doldrums and onto the podium to a championship.

As for the jackshaft I mentioned earlier... Both Honda and Yamaha found a perfect place to locate it and have it do double-duty. Both manufacturers don't just use it to reverse the direction of the drive rotation = they also each use it for a *balance shaft* to quell some engne vibration and smooth out power delivery from their constantly changing *split-crank* arrangements (ala' "Big Bang" engine theory...) and often bizarre firing orders.

Ain't engineneering grand? :026:

Cheers!

Allan (Dallara - NACD)

[Sir Limpsalot]

From that era. When Honda first used the "big bang" configuration on it's two stroke 500 it instantly gained a huge advantage in rideability (and therefore lap times). Understandably they kept the exact nature of the change a very closely guarded secret, all observers knew was that it had a curiously "flat" sound to the exhaust. Cagiva recorded the sound of the Honda out on the track and sent the tape off to a "Lab" somewhere. The "Boffins" used a clever device to determin from the sound waves exactly what Honda had done and within weeks Cagiva riders had a "big banger" of their very own!
The Honda guys were pissed!
Si

[Dallara]

Right-O, Simon...

Funny thing is EVERYBODY that had a decent engine designer all knew and understood a "Big Bang" layout... And it had always been right there in front of their face - like *hidden* out in plain sight. Problem was the entire GP community was so steeped in the old *maximum peak power* and *more power, more power* mindset that no one thought to use it anywhere but on the dirt... Except for Honda, that is. Funnier still is that Honda had been using both 180 and 360 degree cranks (nad even some 270 degree cranks) on their V-4 VF-750-F Interceptor, VFR-750-F Interceptor, RC-30, and RC-45 Superbikes all the ay back ot 1983, and often with "Big Bang" firing orders, but nobody even noticed that!

Also funny was that everyone caught on to the "Big Bang" crank-layouts and firing orders looooooooooooooooong before they caught on to the reverse-crank rotation idea... Despite Honda *hiding* that in plain site since the bearing bosses for the NSR-500's jackshaft were right out there in open on the cases. It literally wasn't until MotoGP that anyone else besides Honda used a reverse-rotation crankshaft in the premier class, despite the fact that everyone who had ever used a square-four knew of the concept.

Sometimes the best way to keep a secret is to put it right out in the open! :eusa_clap:

Cheers!

Allan (Dallara - NACD)

[Gord]

I hope DJ's graph is in the US Sawbuck and not Canadian! Last I checked, the Canadian price for a K12S was $22,500. With the surging Canadian Looney that works out to around $19,125 in Bush Bucks. So Canadian pricing is somewhere in between the US price and the German price in DJ's graph. That surprises me. The lower price for the US market makes sense - it is a huge market. The Canadian market would be smaller than the German market. And yet our prices are lower according to this graph. Is this the benefit that the beaver gets from living next door to the eagle?