Interesting development in OZ for 125GP class

[steveyb]

Honda Australia’s Moriwaki designed 250cc GP race bike - the "GP Mono" (MD250H) will be eligible to race in the GP125cc class this year, according to rule changes approved by Motorcycling Australia (MA).

Powered by a 4-stroke, liquid-cooled, electric start, single cylinder engine, the GP-Mono is designed for those who are looking for a way to make the step from junior to senior level racing.

In addition, MA have altered the General Competition Rules (GCR’s) in order to allow 15 year olds to compete on Honda’s 250cc 4-stroke race bike, as was allowed for the 125cc 2-stroke.

In addition to local club level competition, national series such as the Australian Superbike Championships (ASC) and MRRDA (Motorcycle Road Race Development Association) are open to competitors who are 15 years or older on the Honda machine.

The GP Mono is available now for $14,990 and is available from selected Dealers including Brisbane Motorcycles, Sydney City Motorcycles (Lane Cove), Redwing (VIC), Motologic (VIC), Honda World (SA) and Honda Shop (WA).

The MD250H is powered by a modified CRF250X engine.
The four-stroke, single-cylinder motocross based powerplant is housed in a Moriwaki built high specification
twin tube chassis derived from Honda's 125cc Grand Prix machines. USD forks, radial caliper, dry weight around 85kg.


This is the bike we all saw at Philip Is last year. Looks nice, but is still a tractor when it boils down to it.

[DEATH_INC.]

Sweet, this is a good thing, as any racebike development will find it's way to the street eventually. If moto gp follows suit it'll be great. Maybe some new sport 250's on the horizon, about damn time...

[Tim 39]

125 two strokes are better in my view, 15kgs less weight makes a big difference to a wee bike like that

[k14]

Yeah same here tim. Easier to change a piston on a 2 stroke than check the valve clearances on one of those diesels!!

[The Pastor]

what sort of hp does it put out?

[k14]

I've seen 42hp or something like that documented. If that is in fact correct then it may indeed be a potant weapon on most NZ tracks (tight and twisty) but be a while before it can be anything on the 125's on the likes of puke or philip island.

[xr-rider]

what sort of hp does it put out?

The standard CRF250X motor puts out 24.3HP and the CRF250R puts out 33.3HP so it will be around that.

[Dodgy]

Yeah, I reckon that 35hp at the rear wheel would be nicely optimistic.

As a comparism, what did Jaston Easton's 450 single put out? That must have been in the high 40s - low 50s?

[DEATH_INC.]

125 two strokes are better in my view, 15kgs less weight makes a big difference to a wee bike like that

That may be the case, but like it or not the days are numbered for the mighty two stroke. The reality is there's no longer road versions, so the racing tech from them doesn't go far = wasted r&d money...

[steveyb]

That may be the case, but like it or not the days are numbered for the mighty two stroke. The reality is there's no longer road versions, so the racing tech from them doesn't go far = wasted r&d money...

Not so.
Only the Japanese brands are quitting 2 stroke technology.
So while they do have the majority of the motorcycle market share, the european brands do well enough to keep going and are indeed growing internationally.
Aprilia, KTM, Derbi, Gilera (ie Aprilia), GasGas, Vespa etc are all committed to 2-stroke technology and are making steady inroads into new developments.
As an example, the new KTM 250GP bike is rumoured to produce around 120hp.
This can only be achieved with some flash new technologies.

The day of the 2-stroke is far from over.

Wasted R&D? Check out scooter sales numbers in Europe and their growth rates in other countries, even phillistinic NZ! This is where the R&D ends up. The mayor of Rome was once quoted as saying that if it was not for the scooter, Rome would die [through gridlock]. And don't underestimate race bike sales either. KTM especially are moving aggressively into the market once the domain of only Yamaha and Honda (TZ, RS). KTM GP125 bikes are now available on the market to privateer teams. Not cheap, E35,000 + E40,000 for the race kit, but that is just the start. Indeed the NZ KTM distributors are thinking about getting one or two for NZ!!

Also, check the latest development from FIM regarding MX1 and MX2. 2-strokes are now to be a legislated major part of the championship for the two main reasons: 4-strokes too big and heavy for younger and newer riders and 4-strokes far too expensive for privateer teams to run.

The NZ road bike market and one-eyed racing scene is not the end of the world you know.

Enjoy

Steve

[steveyb]

Further info out of Japan. See at end for HP figures.
Note price: Y1.5 million (about NZD$18,000) for the GP-Mono which is not competitive against 125GP bike.

Hi All,

I like to add a little more info from Japanese virsion of the 4st-250, GP Mono class.

In Japan, too, the regulation changes and 4st-250 bike will be eligible to race in 125GP class from '08. There will be actually 3 different specs of 4st-250 machines available: Prototype, Prototype 2 and GP-Mono.

Prototype will be complete factory built GP machine. This is a rumor, but HRC has started on track testing and may debut it as early as mid '08 season, and the machine goes to public in '10. There are basically only two things mentioned in rule book(interesting that they already added this in '08 rule book) , cc:175cc~250cc & min weight:75kg.

Prototype 2 is modified production base engine machine. This is the machine goes to race with 125GP. Harc-Pro sells the complete bike, HP250RF for 1,522,500Yen.(about $5,000US more than GP-Mono bike) The engine is CRF250R base with special EX, Carb, Ram Air System and more. Inside engine can also be modified, so more compression, porting, different piston, and so on. Min weight is 75kg.

GP-Mono is the same current spec machine of like using Honda's CRF250X engine, Moriwaki's MD250H, Harc-Pro's GPMR250X, 1047,900Yen.(about $10.000US) Basically no modification allowed to inside engine and using original carb and min weight is 85kg.

Because this GP-Mono spec machines are not competitive against 125GP bike so never raced together in Japan. To do so, the power/weight ratio need to be closer to its 125GP machine and now they are set to go with Prototype 2. Top ranked riders are switching to this 4st bike so it's going to be interesting to watch. I hear that Prototype 2 machine produce 46-47hp and HRC Prototype... 53hp.


_________________
Nobi Iso
veloce racing

[DEATH_INC.]

The NZ road bike market and one-eyed racing scene is not the end of the world you know.

Don't get me wrong, I love two strokes, and I still think four stroke MX bikes are just plain wrong....
I just think the greenies will see them in the grave before too long....especially if the japs get behind four strokes in racing, like the moto gp

[cowpoos]

Looks nice, but is still a tractor when it boils down to it.

I bet ya if beats the shit out of a 125 around the race track!!
Modern 250 fourstrokes are so fast and so quick reving!! I'd be impressed if they are out gunned with similar riders on board as the twostrokes!! the 15kg weight difference matters very little for top speed...and in acceleration terms...the HP accross the rev range a fourstroke 250 will make will more than make up for the 15kg in weight advantage.


what happened when the two strokes died in GP racing...similar HP...but it was how it was made!

[koba]

The standard CRF250X motor puts out 24.3HP and the CRF250R puts out 33.3HP so it will be around that.

Yeah, I reckon that 35hp at the rear wheel would be nicely optimistic.

As a comparism, what did Jaston Easton's 450 single put out? That must have been in the high 40s - low 50s?

Not below should not be taken as fact, just my reasoning.

Different beasts tho, a track bike doesn't need the low/midrange power that a motorcrosser still needs to retain some of, therefore It could be tuned to put out higher top-end power. I think?
I Doubt that tigcraft bike put out that little power, although superlight and aerodynamic it still walked the other F3 bikes when I saw it at manfield.
I think those 450 engines are in the 50's og HP from the factory?
I heard a rumor that the tigcraft one was closer to 80.

[diesel pig]

.what happened when the two strokes died in GP racing...similar HP...but it was how it was made!

That is plain wrong the fastest 500's (Always the NSRs) made 195hp in the last season for the 500's. The 990's that won races made 240-245hp from the start(Hondas and Ducatis, the Yamahas made 240hp by the time Rossi was on one.) So the 990s had more power from the start. Thats why they came out of corners faster and were fast down the straights.