More Honda RN01 speculation...

[Ryan]

Apparently what I'm about to tell you comes from an early-release copy of the latest Mountain Bike Action. Don't take it as gospel, but MBA have had the best of the recent coverage on the new Honda bike...this is all stolen from Ridemonkey.com btw
MBA says that with the increase of more and more strict air pollution rules we will soon see the end of motorcycle dirt bikes as we know them. First it was the pressure to switch from two stroke motocross engines to the more enviromentally friendly four strokes. The next ruling proves to be a much harsher blow. By 2006 it will be unlawful for engine displacement to exceed 50cc on any dirt bike sold in the United States. This of course would mean the end motocross racing unless something drastic took place. H.R.C., Honda's motorcycle racing division has always been on the cutting edge when it comes to innovation so it comes as no suprise to learn that they have planned all along to install the popular xr50 mini bike motor in the Honda DH bike chassis. The clues were obvious considering the recent name change of Honda's smallest dirt bike to the official racing label of crf 50r. Interviews with Team Honda's Ricky Carmicael reveal his utter disbelief in the incredible performance of the new machine. (note: by 'new machine' they mean a working RN01 / CRF50 hybrid) Check your news stands for the latest issue of Mountainbike Action.

The weight for this crazy-hybrid-50cc-DH bike-come-crosser is 67lbs. No lightweight by MTB standards but crazy light for a motor bike, the new 50cc Honda engine has apparently grown some serious nuts and the whole bike according to Ricky Carmichael goes like the clappers.

Now once again, this IS in MBA and they ARE quoting Ricky Carmichael who is like some sort of God to sponsor whores so don't necessarily treat it as fact. Interesting idea though, 67lb moto's for full grown people, beats the shit out of tarting up a kid's bike to be able to deal with the weight.

[Cave Dweller]

Hahahahaha :lol: :lol: :lol: :lol: :lol: :lol:

That is so funny. This is the mentaliity of americans

"Lets ban the 400 cc four stroke bikes and limit them to 50cc....... but lets all drive around in big chevy pick up trucks that chew as much fuel as three normal cars and throw out 3 times the pollution."

What a bunch of dumb arses. Really.......

[Ride_Guy]

Honda have got some crazy design people workin for them :shock:

Makes you wonder if they actually produced the RN01's for mtb'ing or for this purpose...

Or maybe they now want to be dominant in another market who knows??

[kalem]

that seems pretty crazy...

[Ryan]

They produced the RN01 to investigate 'technology' that might be applicable to dirt-bikes, that's always been their reasoning behind it...speculation was it was light-weight frames or SPV technology for moto's but it looks like the whole bike might be the 'technology' they were talking about, crafty buggers ;)

[shmity]

That would also explain the reference to manufacturing the gear box on the rn01 patent too.

[CHEWY]

Pffft, 50cc restrictions on dirtbikes by 2006, what a utter load of crap... :roll:

Only gonna what, put 5 million people out of a job...

[Wattsy]

for 1 of the only countrys not in the kyioto [sorry bout the spelling] agreement, they sure are harsh with the pollution rules. i dunno bout you guys but i could see someday this was gonna happen, like cars.

[floody]

Pffft, 50cc restrictions on dirtbikes by 2006, what a utter load of crap... :roll:

Only gonna what, put 5 million people out of a job...

I agree, my money is that its a load of bullnuts. Nobody I know in the moto industry knows anything about it.......

[Ryan]

Yeah, I'd have to 'third' that call that the motor restrictions coming into force is a load of shit...the whole idea still intrigues me though.

I don't have any experience with real motocross bikes other than the occasional fang about on a mates so...is there anyone on here who does and who could comment on whether this is a feasible idea or just a gee-up?

[CHEWY]

Well.. Carmicheal can't really come out and say the thing rides like a peice of shit now can he?
I'd have to hear it from a reputable, unbiased source before I'd believe anything.

The reason the thing apparently rode so damn well would be cause its light as piss! Its a 1/3 the weight of an open MXer.. Aint never gonna get 250 balls out of a rice cracker..

[floody]

This wasn't perhaps the April issue of MBA, just wondering?

[Ryan]

Nah, it was either the June or July issue, only just came out in the USA so we won't be seeing it for a while.

So could an engine with 1/5 the capacity of a crosser power a bike that weighed 1/3 of what a moto weighs to any reasonable speed? Honda are the masters of getting big performance out of small engines and I'm assuming that 67lbs would have to be pretty close to what a standard Fiddy weighs anyway...with a CVT whacked on you'd have a pretty sweet recreational bike that accelerates like it's nobodys business.

[S.]

Nah, it was either the June or July issue, only just came out in the USA so we won't be seeing it for a while.

So could an engine with 1/5 the capacity of a crosser power a bike that weighed 1/3 of what a moto weighs to any reasonable speed? Honda are the masters of getting big performance out of small engines and I'm assuming that 67lbs would have to be pretty close to what a standard Fiddy weighs anyway...with a CVT whacked on you'd have a pretty sweet recreational bike that accelerates like it's nobodys business.

Have to keep in mind that you're gonna need a much higher power-to-weight ratio from such a light bike, because the rider is now gonna make up 3/4 of the weight instead of 1/2.

[floody]

Nah, it was either the June or July issue, only just came out in the USA so we won't be seeing it for a while.

So could an engine with 1/5 the capacity of a crosser power a bike that weighed 1/3 of what a moto weighs to any reasonable speed? Honda are the masters of getting big performance out of small engines and I'm assuming that 67lbs would have to be pretty close to what a standard Fiddy weighs anyway...with a CVT whacked on you'd have a pretty sweet recreational bike that accelerates like it's nobodys business.

Have to keep in mind that you're gonna need a much higher power-to-weight ratio from such a light bike, because the rider is now gonna make up 3/4 of the weight instead of 1/2.

You hit it on the head, S., thats a very very good point! A 450cc four stroke bike weighing 110 kg and making ~50hp and a lot of torque is not going to be nearly as badly affected by plonking a 80kg rider on top, as a 30kg bike with 5 hp and stuff all torque is. A rider included power to weight ratio of 190kg:50hp (just less than 4kg per 1hp) is substantially better than 110kg:5hp (22kg per 1hp).

Also looking at a 50cc , well put it this way, a typical 400-600cc four-stroke MX bike is making between 45 and 60hp. A 50cc motor could only hope to make 5-10hp, and let me tell you, if it made 10hp, it would be making roughly 200hp:litre of capacity - it would be in an extremely high state of tune.
Theoretically that is possible, however in a 50cc engine, to turn the sort of RPM that output requires, would need parts which would have to very very light, and in an engine where everything is already going to be humourously tiny (of necessity), this means MASSIVE expense, exotic materials, very tight tolerances, and extremely short service intervals. It would make stuff all torque also, and a good MX motor is a torquey and flexible one. But of course the CVT could always keep the motor close to its torque band but thats another story....

Sorta OT....
The final thing I'd like to add is that the two stroke engine just may be on the verge of a comeback - my understanding is that they aren't banned, per se, rather emissions standards have put the squeeze on them. I think you'll find things like Aprilia's orbital-concept engined scooters are still on sale over there. There is a lot of potential for emissions reduction if enough development money is thrown at it, and being lighter, smaller, less mechanically complex and more powerful for a given engine capacity, IMHO this is where the factories should spend their money. Orbital engine company's older concepts and Honda's EXP 2 stroke experiments have shown that power, economy AND low emissions are possible... And one also has to consider that the two stroke engine has had much less development time thatn the four stroke - most major developments in 2 stroke tuning have occurred in the last 40 years (ie Ernst Degner at MZ/Suzuki introducing the expansion chamber oin the early 60's) , and especially in the last 20 (Reed Valves in mass production, Power Valves and so on) , whereas the four stroke has been fiddled with for about twice as long.

[2 smooth]

Typical americans...They make some of the biggest cars known to man, but they complain about 450-600cc moties. If its not big, its not worth letting it stay as part of culture...For fuck sake, honestly. :roll: