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.

[Dodgy]

I heard a rumor that the tigcraft one was closer to 80.

Nah, that sounds like the trailling F3 racers trying to make themselves feel better :doh: Even the 600 singles would struggle to get to 80hp (hey, I have tried to squeeze max out of a 600ccc single and know it aint easy if you want to finish a race too
Jason made it look like it had 80hp cause he can ride extremely well!

[koba]

hey, I have tried to squeeze max out of a 600ccc single and know it aint easy if you want to finish a race too


I know exactly what you mean with that.

[onearmedbandit]

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.

In 2002 (the first year of the 4 strokes) the RC211V of Rossi was putting out 220hp. The 499cc V4 was capable of over 200hp, so the difference is not as big as you would think.
4th Paragraph (http://www.motorcycle.com/news/news549.htm)
4th Paragraph (again) (http://powersports.honda.com/the_story/heritage/heritage_milestone.asp?Decade=1980&TargetUrl=Milestone/Milestone_Model_0114.asp&PrevPageTitle=)

[cowpoos]

In 2002 (the first year of the 4 strokes) the RC211V of Rossi was putting out 220hp. The 499cc V4 was capable of over 200hp, so the difference is not as big as you would think.
4th Paragraph (http://www.motorcycle.com/news/news549.htm)
4th Paragraph (again) (http://powersports.honda.com/the_story/heritage/heritage_milestone.asp?Decade=1980&TargetUrl=Milestone/Milestone_Model_0114.asp&PrevPageTitle=)
thanks bro...ya saved me going searching...

another Major difference between the engines in the two strokes had a lower weight internals..so getting them to spin up to speed to accelerate required less HP from the engine..

Does anyone know where to get trap [speed trap] speeds from on the net...I'm curious to see the difference in teminal velocity at the end of straigh aways between the 2st and 4st bikes.

[onearmedbandit]

The original 'Faster' DVD had a comparison, and in 2002 the 4st's were faster in top speed than the 2st's, but at that stage the teams were fully developing the 4st's. I'd have to rewatch the DVD to get the actual speeds.

[k14]

You can get it off motogp.com under results.

[k14]

thanks bro...ya saved me going searching...

another Major difference between the engines in the two strokes had a lower weight internals..so getting them to spin up to speed to accelerate required less HP from the engine..

Does anyone know where to get trap [speed trap] speeds from on the net...I'm curious to see the difference in teminal velocity at the end of straigh aways between the 2st and 4st bikes.
I think that a good example of the difference is philip island qualifying the first year they had 4st. McWilliams (i think?) put the proton 2st on pole (last time a 2st was on pole). I think this shows that on a fast flowing track you can get the 2st going faster, but on a stop/start track the 4st will always win. Because of the very steep power band of a 2st they will always loose out on a circuit that requires lots of braking and accelerating. Whereas a 4st will loose out on a high speed flowing circuit (eg Philip Island).

I guess it will be an argument only solved in a few years time though.

[F5 Dave]

And may they litter the racetrack with valves & all sorts of other unnecessary engine componentry.

Veckin' tree huggin wankers & Honda themselves. Lets all ride sanitised 2 wheeled Volvos.:argh:

[scott411]

this will triple the cost of running a 125gp bike,

thats what happened to mx bikes, the four strokes will become as fast, but will be 3 times the price to run,

long live the 2 strokes, fast, fun and cheap

[steveyb]

Y'all also miss the point about capacity.
Noting that the 4st needed 990cc to compete effectively against the 500cc 2st and that only a FACTORY 250cc single 4st engine is competitive against a 125cc 2st. If MotoGP had really been serious about opening the playing field rather than pandering to the big 4 factories (but also Ducati as they don't build 2st engines) they would have allowed 600 or 650cc 2st in the premier class. Some privateers such as maybe Roberts would have gone that route.
It would be interesting to see a good 500 against the new 800cc bikes, but the level of development on the 800 exceeds that of the 500 so it cannot really be compared that easily.

Remember what it really means: Factory engine, not available to public, only lasts one meeting then needs rebuild, all the most expensive materials and add-ons, Ti, Mg, Carbon etc etc.
The customer 250 GP Mono is not competitive against 125GP bikes. We will not see competitive 4st bikes until they go to 200cc twin as argued for by Harald Bartol, and he knows what he is talking about.
(He argues for 200cc and 400cc twin 4st to replace 125 and 250 bikes)
Green technology for 2st is already in place. Some new 2st designs produce fewer emissions than 4st.

Enjoy it while you can.

Steve

[diesel pig]

In 2002 (the first year of the 4 strokes) the RC211V of Rossi was putting out 220hp. The 499cc V4 was capable of over 200hp, so the difference is not as big as you would think.
4th Paragraph (http://www.motorcycle.com/news/news549.htm)
4th Paragraph (again) (http://powersports.honda.com/the_story/heritage/heritage_milestone.asp?Decade=1980&TargetUrl=Milestone/Milestone_Model_0114.asp&PrevPageTitle=)

Over 200hp is myth making nonsense, GP Reporter Alan Cathcart testing the last NSR 500 in 2002 was told by the Honda top joker it made 195hp. I read that report in No 124 Classic Racer but it would of been in other mag's from 2002. Your bloke rounded it up in his paragraph to make it sound better.

220hp for the 990's was what the factories talked about limiting the bikes because they thought the 990's would destroy rear tyres. When they started racing they just dialed them up to max power. That comes from Stanko's book on the 990 motoGP racers by Mat Oxley, An other GP reporter who knows the right people to find this sort of info out.

[gav]

I think the figures posted by Diesel Pig are closer to the truth......

[Dodgy]

Yeah, but did Dorna/FIM whoever was in charge (Honda??) stifle the future of 2 strokes by banning direct injection. If the 500s had no development restrictions, the emissions et all could have been sorted out by direct injection

Remember when Itoh first did 200mph on the injected 500? Not much different to 199mph he reckoned...

Steve's point is interesting. If 500s had not had development blocked and had progressed it would have been interesting to see how they compared to the 800. F5 Dave and I went to PI the last year of the 500, which was when the 1000s came in. It was pretty cool to see the likes of McCoy one lap down (he pulled in on the first lap with a duff rear tyre) but doing the business on the 500!

[F5 Dave]

Yeah, they are all a bunch of ghey softcocks impotently trying to stuff their flaccid members up each others backsides.

Prevent development & sanitise the racing machines. Unleaded petrol killed off the V-twin 500s. Bring in Diesels, but let them be twice as big & remove their noise restrictions. :argue: Gee aren't 4 strokes great?

Doohan on a screamer NSR. Now there was something impressive to watch.

[Badjelly]

Green technology for 2st is already in place. Some new 2st designs produce fewer emissions than 4st.

I'd like to know more about that. Can you post a link?

[onearmedbandit]

I think the figures posted by Diesel Pig are closer to the truth......

Cool, could you inform every site on the internet that they are wrong then. Because every search I've done on the 2002 RC211V shows a max power output of 220hp, from Honda's own info through to tests done by magazines at the end of the 2002 season. In the later years of the RC211V they were getting 240hp...... (edited because I forgot the '......')

[xr-rider]

there is no way in hell the honda 250 motor is going to be competitive. as for emmisions on a 2st they would probably be less than a F1 car or something like that, i say BRING BACK THE BIG 2ST

[Dodgy]

Doohan on a screamer NSR. Now there was something impressive to watch.

yeah man, remember that year we saw him lose it on turn 1. Shit, that was cool!

Anyways, 2 strokes still have their uses - Hyaundi have the worlds largest and most powerful engine - huge ass 2 stroke diesel powering some supertanker.

Shame some riders may never experience the thrill of a 2 stroke driving hard - and the pucker of feeling it seize up!

[Cleve]

there is no way in hell the honda 250 motor is going to be competitive.

just wondering... in off road isn't the 250 4st quicker than the 125 2st? Why could this not happen in road racing.

[F5 Dave]

125MX bike with nice power spread say 32hp (rear wheel not brochure hp). 250 MX 4 stroke, about the same with a better spread. Compromise is the 250 is sailing closer to the edge of reliability & revs harder.

125 GP is near edge but reliable if fed parts at correct intervals. Revs about 3000 rpm higher than MX bike. A customer 125 2008 Aprilia I dunno 45hp? (50+ for factory bike).

How high is the 250 going to have to rev to match the power?
Factory bikes may run up there, but. . .

OK on the other side the 990s had almost 250cc cylinders, but these are set up as multis which are intrinsically smoother & designed for higher revs. I think the 250MX engine would be a poor base to try to rev higher. A twin or phantom twin (Duc supermono) would be a better basis.

[cowpoos]

250mx engines already rev at 13,000rpm...these engines will definatly be tuned different for GP type racing...

So comparing MX engines to Roadrace GP engines won't be a relivent comparison... and if it were...the 250 fourstrokes are making more power everywhere in the rev range...which I suspect will be the case in a GP chassis.

I seriously doubt the people instigating this change to 4stroke bikes would contemplate it if they didn't have a good product to sell...I doubt its all about tree hugging emissions levels...

[avgas]

Moriwaki still exist?!
Wow thats awesome.
Now all we need is new Harris frames

[gav]

Cool, could you inform every site on the internet that they are wrong then. Because every search I've done on the 2002 RC211V shows a max power output of 220hp, from Honda's own info through to tests done by magazines at the end of the 2002 season. In the later years of the RC211V they were getting 240hp...... (edited because I forgot the '......')
No, thats fine, but the 500's weren't putting out over 200.
Don't think Dorna/FIM killed off the two strokes, in fact the 500's were eligible to race with the 990's, and have only been disallowed with the change to 800cc.
What would be interesting would to see how the latest tyres would perform on the 500's along with the latest electronics. Probably why they have been outlawed from racing with the 800's. :rolleyes:

[xr-rider]

just wondering... in off road isn't the 250 4st quicker than the 125 2st? Why could this not happen in road racing.

but in off road a 125 really needs the power all the way through the rev range and cause its a small motor it doesn't have much power. with a 250 4st it puts out more power all the way through and plenty of bottom end so they have an edge on stop start tracks. in road racing a 125 2st puts out more than the standard 250 4st motor honda are using and the 125s will have it all up top while the 250s wile have less power up top and weigh more.

[quallman1234]

Give em a year i hate too say it because im a 2 stroke fan, but unfortunately if you look at a 2 stroke engine, you can quickly figure out that no 2 stroke engine can be two times more efficent than a 4 stroke of the same capacity. For instance in Beach racing they class that two strokes are about 1.8 Times more powerful than a 4 stroke the same size. Even the most tuned 2 stroke engines, will still loose some because of simpleness that it is shoving unburnt gas out the exhaust port before the spark occurs.

Direct Injection Could be a goer but this would require heaps of petrol to be put into the cylinder at precisely the right time and very quickly. Essentially a rather large compressor/pump/whatever capable of shoving fuel in at around about 500psi (That's what the Yamaha High pressure direct injection engine use on the marine engines). - Trust me i have researched alot.

But then again with low capacity engine's 2 stroke's might still have a fighting chance.

[gav]

I'm picking the 250 four stroke will "grunt" off the line, and beat the two stroke to the first corner, then park its fat arse in the way, hold up the two stroke and then fark to the next corner etc.
This what happened to the likes of the Aprilia 400 and Team KR with the V3, theoretically it could lap faster, but never got the chance.

[cowpoos]

but in off road a 125 really needs the power all the way through the rev range and cause its a small motor it doesn't have much power. with a 250 4st it puts out more power all the way through and plenty of bottom end so they have an edge on stop start tracks. in road racing a 125 2st puts out more than the standard 250 4st motor honda are using and the 125s will have it all up top while the 250s wile have less power up top and weigh more.

So you don't think they will tune the 4 stroke for circut racing??
I think they definatly will....but if they don't...I really don't think it would matter...the 4 stroke will still beable to pull taller gearing with better over acceleration!

And don't get me wrong people..I love 2 strokes..I have raced dirt bikes of both genre's...infact I was racing a xr280..when my peers were on 125 two strokes..so I was against the trend at the time..The two strokes had a definate acceleration advantage..and weight..for some reason..I placed very highly on the xr280 at times..as soon as I got a kx125..piffft..shit..I placed crap..different riding style,etc but mainly..so much more work to do!! I mean your working the clutch..banging through the gears..correcting the tail wagging because she didn't hook up to well when the engine was on it!!..and it seems I wasn't that adaptable....but I realised...the smaller two stroke..while less physically demanding it was to ride..you were just so dam busy on the thing..and you couldn't bully it around as much with your weight..the four stroke was more physical to ride..heavier..brakes wern'tr as good..made heaps of power everywhere[well at the time it did]..and it was easier to ride..you got away with more..you had less to do to ride the bike..making mistakes less frequent..and when you made one..no big deal..riding techqunic was easier [IMHO] even though is require more grunt to push it around..you did less of it..and you could bully it with your weight!!

And the reflection I see with road racing is the same..less to do..not as busy..gives you more time to think what your doing!..mistakes are less of a disadvantage..promotes More modern riding styles on the track..[<--now thats going to get a few reply's..maybe I should start a new thread on that..lol]..having a motor that is well built with a nice power build..plenty of mid range and not massive abruptness in power increases as you go though the rev range make a bike easier to ride..I have learnt this in my first 2 seasons club racing in F1..
But thats enough from me for a bit..

[steveyb]

Heh.
Now here is a blast from the past. Was looking for some info and this thread came up.
Quite amusing to read ones opinions from the past and how they were shaped by the current climate and ones own agendas.
At the time I had a vested interest in 125GP 2-stroke machinery.
That is quite different to now I guess.
Also very interesting to see how the Pre-Moto3 and Moto3 bikes are now eclipsing 125GP bikes (other than perhaps factory Aprilia machines).

[BMWST?]

Give em a year i hate too say it because im a 2 stroke fan, but unfortunately if you look at a 2 stroke engine, you can quickly figure out that no 2 stroke engine can be two times more efficent than a 4 stroke of the same capacity. For instance in Beach racing they class that two strokes are about 1.8 Times more powerful than a 4 stroke the same size. Even the most tuned 2 stroke engines, will still loose some because of simpleness that it is shoving unburnt gas out the exhaust port before the spark occurs.

Direct Injection Could be a goer but this would require heaps of petrol to be put into the cylinder at precisely the right time and very quickly. Essentially a rather large compressor/pump/whatever capable of shoving fuel in at around about 500psi (That's what the Yamaha High pressure direct injection engine use on the marine engines). - Trust me i have researched alot.

But then again with low capacity engine's 2 stroke's might still have a fighting chance.
easy.modern crd diesls operate at higher pressures than than and have injection systems that fire multiple times.Prolly a fraction of the speed tho!