Hmmm RS550?

[Atitalongtime]

Let's shoehorn a new 550 V-twin into an ol' RS250 frame...  
tiny, fast, torque , and a handler!

I know the 50 hr service/rebuild schedule for the dirtbike would be painful, but with good clean air going through the motor you should be able to stretch that a bit.

Here's the story:

http://www.rsvr.net/pages/PROJECTRSVR550.asp


The next project is an R1 in a moto-X frame... oh the hill climbers already do that!

[DogBoy]

 


Bastards! How am I going to sleep at night?

[Tar Snake]

I'll take one baby Touno please..... to go!

[xdbx]

now, someone's just gotta shove an 450 motor into an SR50 body.  Talk about a sleeper....  

[hobbes]

I took a look at this, and had some questions about the quality of the build but everything looks up to snuff. I'm drooling over the potential of a bike like this, and I would realistically consider one if the suspension was quality.

I cant wait to read about how it is on the road.

[Mookie]

I still don't understand why Aprilia isn't building this  

[cyeager]

I still don't understand why Aprilia isn't building this  

50 hr service/rebuild schedule

[Mookie]

Well how much worse is that than an RS250?  (and I believe that 50 hours is in race only mode)

[cyeager]

Well how much worse is that than an RS250?  (and I believe that 50 hours is in race only mode)

Might not be all that different now that you mention it. Certainly neither bike makes much sense as a street machine, the RS250 makes sense as a race bike since the GP250 class is quite popular, but what purpose would the race only 550 2 stroke serve? Is there a race class that it would fit into?

[photomd]

That looks like fun.

There was a WR426 racing in SOS in AHRMA last July. It was tiny, with R6 bodywork and a custom GSXR front grafted on. This bike sorta takes that to the next level.  

[DogBoy]

Might not be all that different now that you mention it. Certainly neither bike makes much sense as a street machine, the RS250 makes sense as a race bike since the GP250 class is quite popular, but what purpose would the race only 550 2 stroke serve? Is there a race class that it would fit into?

The RS250 street bike is grossly underpowered and out of date for any 250 GP race class. The fast guys are on the latest Yamahas and Hondas with price tags in 20K range. You can race in some of the lightweight classes. The 450/550 engine's are four strokes. A theoretical sttreet legal RSV550 could race in any class where SV650s are legal.

[cyeager]

The RS250 street bike is grossly underpowered and out of date for any 250 GP race class. The fast guys are on the latest Yamahas and Hondas with price tags in 20K range. You can race in some of the lightweight classes.

Does the out-of-date aspect include chasis elements that would have to be fixed in order to be competitive, even with a new motor?

The 450/550 engine's are four strokes. A theoretical sttreet legal RSV550 could race in any class where SV650s are legal.

Thats what I get for assuming. I should have figured that they wouldnt start making a brand new 2-stroke. What kind of output does the motor have?

[DogBoy]

Does the out-of-date aspect include chasis elements that would have to be fixed in order to be competitive, even with a new motor?

Thats what I get for assuming. I should have figured that they wouldnt start making a brand new 2-stroke. What kind of output does the motor have?

I'm not sure what you're getting at. You can shoe horn almost any engine into and chassis, doesn't mean its going to work well. The new Aprilia 450/550 V-Twin in a street version of any later model 250 GP chassis would be a great bike if you could get it balanced. Maintenance would probably be a nightmare; as in pulling the engine for the frequent valve checks, etc.

The 450/550 took so long to come to market that I forget all the hp claims, but I think it was around 70hp for the 450.

[Atitalongtime]

They don't publish a HP figure, but I'd guess about 70Hp
It raps to 13,000 RPM
Won the Unlimited Supermoto World championship.
The AMA promply banned it in state side competition
and has electric start and fuel injection and looks like a Swiss watch.

It's da' bomb...

[Snowbird]

50 hours at 50 mph average = 2500 miles. That's more than the average bike gets annually in the US.

At that point, you pull the engine and send it off to the rebuild center. Shortly thereafter you receive an exchange engine.

Problem solved.