motogp: 800s vs 500s

alot of talk is about how the 800s favour the lilliputian guys.

so i stopped for a second to consider how different the 800s are to
the 500s.

they seem to put out about the same power. not sure about weights,
but i'll assume the 800s are slightly heavier.

physically & aerodynamically, they seem to put out about the same
size. there's no reason the 800s MUST be smaller than 500s.

so that leaves traction-control. is it simply that the trac-control
is now soooo good the 800s are so (relatively) benign to drive that
they require less physical strength than the 500s?

 

Yes

 

$5 says that in 5 years or less, motogp will limit TC in some
fashion...perhaps eliminating it altogether.

look at F1 this season. the "TC development in racing helps
production cars" argument still applies to cars, but TC has been
banned in F1 given how freaking boring it had become. with cars never
getting upset...it became largely a contest for engineers.

to get back to better racing, and give drivers a chance to make an
impact TC has been banned. heck, even in qualifying in OZ this
weekend, the cars were all over the place...allowing a skilled driver
to make a bigger difference in the success of the car.

once TC becomes more fully developed and widespread in the 2-wheeled
world, motogp will go the way of F1 in this area.

i hope it's sooner rather than later!

w

 

I disagree. TC in cars and TC in bikes are similar in theory, but
very different in practice. Motorcycles are notoriously difficult to
describe in theoretical models. Not impossible, of course, but much
more complicated than cars, in no small part because of the rider's
contribution to the handling. In car, you strap the driver down so
tight they can barely move their head, slam the center of mass down to
the ground and suddenly the whole thing lends itself very well to
physical models even a high school graduate can start to comprehend.

Now look at bikes. We still don't fully understand why and when big
bang engines provide advantage. That's something that's been
"discovered" over 10 years ago, and while we know how to implement it,
we don't really understand why it works when it does. Ever look at
the oscillation patterns for motorcycles? My goodness. A traction
control designer has to take these things into account. A bike is so
much shorter and taller than a car, with its CoM not completely
determined due to the rider being allowed a great freedom of
movement. And the results aren't the same as what we saw in F1. If
you look at Stoner's riding, the bike is not at all always composed.
It still slides the rear, gets controlled headshakes, and wheelies.
Watching his riding is absolutely fantastic. I don't like runaway
wins, but some people (Stoner, Rossi, some others) still make it
enjoyable to watch. Maybe it takes a bit closer watching to
appreciate it, but I don't mind.

 

Absolutely, IMO that's what Rossi was alluding to when he talked about
Stoner *really* using the TC. I think Rossi really was complimenting Stoner
on his ability to exploit TC to the maximum, not merely dissing him for
being reliant on it.

 

You don't? I thought it was pretty straightforward.

 

Champ says:

http://www.superbikeplanet.com/2007/Dec/071217b.htm

I think, Furusawa at Yamaha seems to agree, it's not
that straightforward at all.


Go fast. Take chances.
Mike S.

 

I pointed to:

I don't know this guy but an interesting summary:
http://blogger.xs4all.nl/daisy/archive/2008/02/24/355605.aspx


Go fast. Take chances.
Mike S.

 

I don't know. Do you?

The problem I have with this assertion is the notion of using "more"
TC. Knowing what we know about suspension, do we talk about using
"more" or "less" suspension and chassis technology? Of course not.
We talk about specifics: more or less high speed damping, ride height,
trail, etc. Similarly, fuel maps are multidimensional and allow us
many degrees of adjustability. I suspect the same is true with
advanced TC systems. I agree with Allen here. I think that Stoner
and his team have a very good understanding of the tools they're
using. Now, it may very well be that the factory and/or Magno Mirelli
helps them along by withholding certain pertinent intel from other
teams, but in theory anybody can engineer their own TC that at least
mimics what Stoner's does and then provide the same rider input while
on the bike. The fact that others have not been able to do it so far
is an indicator that TC is not simple and, at least for now, provides
an interesting challenge in the paddock and a good show on the
sidelines.

 

He's active on the PB forums and writes good stuff.

If Yamaha's Furusawa is right and it's all about crank configuration and
variations in crank inertia, then a V-Twin is already a big bang engine
because when one cylinder is stationary at TDC, the other is near max
velocity. Ducati's V-4s have always been 360 deg with pairs of pistons
rising and falling together. It appears that all the 2008 V-4s are the
same although the cylinder angles are different. V4s inevitably have an
uneven firing sequence. It's just a question of how uneven. This year
they're all firing the cylinders in each pair alternately if the exhaust
tuning is anything to go by.

On straight 4s there are lots of possibilities with a single plane crank
(as Kawasaki are thought to use) and lots more when you go to a two or
more plane crank as Yamaha do.

We did some calculations on mid gear corners at mid to high revs and
even the big bang engines move the rear wheel barely more than a contact
patch's length between firing strokes. So there's barely enough time for
a new patch of rubber to key itself into the tarmac.

I still don't think anyone knows why or even if big bang helps corner
exit traction. Maybe it's all in the rider's head.

PB built a big bang GSXR750 and sent Guy Martin out on it at Cadwell. It
was a single plane crank but with modified cams and firing order. After
testing the unmodified bike, they then blew up the 1st version. So there
was no opportunity for a before and after test. But Guy claimed it dug
in better than he expected. I'm not sure that proves anything.

 

Julian Bond notes:

Let's go flat tracking!



Go fast. Take chances.
Mike S.

 

Indeed! Flat track engines fire the cylinders on the same cycle of the
crank don't they for the big bang effect? And you could do something
similar on a 360 deg V-4. du-dum, pause, da-dum, etc And you'd still get
the exhaust tuning benefits of a pair of cylinders firing on equal
intervals for equal length primaries.

 

I think it must be because he is so young (with the talent and balls)
and TC is something he is comfortable with. I couldn't imagine riding
well into your 20s or more and then having TC dropped in your lap. I
think it would give you less feel for what is happening with the bike,
which is really what racing at this level has always been about, and
suddenly there is this other "invisible rider" helping you out, and
that could be very scary. It might be simply impossible for the old
crowd to trust it enough to effectively exploit it.


Byron

 

Thu, 10 Apr 2008 10:47:24

Like, say, Bayliss. Or Mladin for that matter.

 

Does WSBK use TC?? I''ve always loved watching Bayliss ride because
the bike is so frequently out-of-shape. Is this because the WSBK
Ducati team is using some sort of TC system that is similar to the
MotoGP Ducati system? Or would you simply attribute this to Bayliss'
riding style?

 

The game, and his riding style, is changing. TC has been common in WSBK
for a couple of years now. And it does seem that there's quite a bit of
cross over between the Ducati MotoGP and WSBK teams on electronics.
Ducati are very close to the Magnetti Marelli guys and their hardware
and software is used by both teams. And of course the new 1098R road
bike has another variation with an 8(?) level TC as stock.