Moto GP to go to 800cc in 2007

Yup, they are. Mind you, they're looking perceptibly more wiped out when
doing the post-race interviews these days than I remember them being 5-6
years ago.

The bikes might be easier to ride than the two-bangers, but that's just
making them take more chances, it looks like.
(is it just me, or do the bikes look like they're squirming and moving
around more this year than in quite a while; even Biaggi was sideways
last night)

 

Stupid question but how big are they now?
I thought they were 500cc 2 strokes, has this changed? Will they still be 2
strokes @ 800cc? Doesn't 2 stroke lose it's advantages over a certain size
(ie small good, big bad)?

So many questions...

 

Erm
They have a max capacity of approximately 950cc or something close to
that and they are 4 stroke.
500 2 strokes have been out of the picture for the last 3-4 years.

 

The rules specify 990cc if four stroke, 499cc if 2 stroke, there are
then minimum weights depending on how many cylinders you have (fewer
cylinders equals lower minimum weight), the weight brackets go in pairs
2&3 cylinders = ??? Kg (160 I think)
4&5 (something like 163kg)
6and greater (IIRC) say 165Kg

You can look up the exact weights on the motoGP website.

Basically the rules mean that a 4or 5 cylinder is the sweet spot,more
cylinders is generally better hence why all the Hondas are V5s, however
a 5 is engineering-wise slightly more tricky and hence the preponderance
of 4s (a V4 is inherently easy to balance and the weight is evenly
distributed, a V5 is uneven shape and needs balance shafts etc, odd
firing no. etc etc, nothing insurmountable but for the smaller factories
why make it harder than it has to be.

It's a shame they put a penalty on large no. of multi cylinders - I'd
have loved to have heard 1 litre V8s hammering around a track at 20,000
rpm

Same sort of rule changes* caused all the GP cars to go from V12s to
V10s, a V10 isn't a naturally balanced motor like a 12 but when there's
weight regs associated with cylinder numbers you get the outcome that is
the best under the rules, not necessarily what you would choose if there
were no restrictions

JL
*I'm going on hearsay on that one, I don't follow F1, Dale, care to
comment ?

 

Just 800cc 1 strokes they said. It'll be sad to see the 500cc bikes go.

Nev..
'03 ZX12R

 

Oh ok. How do they differ from Superbikes then?
I thought Superbikes were 1 litre four strokes?

 

He was doing some quite impressive frontwheel-offline-to-the-left
wheelies coming out of a few of the uphill corners too - the first time
I noticed it I thought I'd just seen him start his classic
fold-the-front-end crash...

big

 

I can't believe someone even bothered to explain the changes to someone who
obviously hasn't even paid enough attention to notice that they have been
racing 4 strokes for several years. I doubt he'll even read your reply.

I seem to recall Ferrari were already using V10 engines when all the others
had V12, V8 or whatever. The ferrari was never as economical as the others
and always required an pit stop for fuel while the others could run the entire
race without stopping.

Nev..
'03 ZX12R

 

Snipped my entire reply, leaving Smee's inaccurate one, good stuff Uncle !

4stroke 990cc must be a prototype, hence WCM Harris' problem (was it
last season or the year before ?) Because they were using some R1 bits.

SBK, must be based on a production bike, min of 500 produced to be
homologated IIRC, most of the Foggy Petronas' are still sitting in a
warehouse somewhere as I understand it. SBK can be 999cc, then there's
restrictions around min weights and intake diameters and what you can
modify and such. Run control tyres.

Basically SBKs are hotted up production bikes within what they're
allowed to change (hence the limited production run 999Rs to allow the
flash shocks and adjustable doodads, so they can race with them)

motoGP are bikes you can't buy off a showroom floor. Eventually some of
the technology trickles down (faster than it does on cars though)

JL
(why do i get the feeling I'm being trolled - oh well, stating the
bleeding obvious beats doing this blasted essay)

 

Superbikes run on super. MotoGP use Optimax.
That's why they're too powerful.

Nev..
'03 ZX12R

 

You obviously didn't notice the bit where I said :

There's nothing quite like desperately trawling for an excuse to not do
your essay :-/

JL
<sigh> I am *so* over this Masters thingy

 

How does one go about noticing this? I see two wheels, some plastic and a
man. The capacity and internal workings of the engine aren't apparent to the
casual observer.

 

I dont think the 500s will go, they will be easier to kickstart than
an 800cc single 4 stroke with no decompression lever..

 

What you mean they're going to get rid of the Le Mans push start as well ?

 

You got ears?
They sound totally different ffs.
Secondly the COMMENTATORS talk about the engines all the friggin time.
I really agree with Littler here you are trolling Bully boy.

 

Well... that depends... for racing large 2 strokes aren't common these
days, but Yamaha and Kawasaki used to make (and race) 750cc 2 strokes,
and many outboard motors are much larger than that and 2 stroke and
detroit and caterpillar makes 2 cycle diesels in capacities of up to
about 16 litres.

2 cycle engines maintain thier weight to power advantage over 4 strokes
even in the very large truck and marine diesels (and tend to retain
thier extra smoke output... which is the main reason they are becoming
less popular).


G-S

 

John Littler wrote:

I'm with you John!

 

Best beer fridge I ever had, had a big sticker on the front, "Don't blame me
I voted for Kevin Bloody Wilson!" I also had one of his stubbie coolers
with furry bits around one end.

 

Im afraid so.. there were rumours of pull start motors, but I think
ths wont happen.

 

I REALLY really want one of those 1200cc Polaris snowmobile 2 strokes to
stick in a sports bike frame. Trouble is emissions regs :-(

JL