Aprilia 550 V-twin Sportbike!

[rbitra]

first

[seruzawa]

So, what's the point of a road bike that has to have it's engine rebuilt every 50 hours? For some people that might be 10 years of riding but for many it's only a few days or weeks.



I don't get these new MX 4-strokers with their delicate top ends. If one is a pro racer with support maybe, but the idea of rebuilding the engine every year myself is unacceptable. Guess I'll have to keep the old two-poppers.

[Patrick-of-the-Hills]

I was walking around for weeks with a twitchy throttle hand when we had the rumors of the RSV450 a few years ago. I've always thought that Ducati could sell a fleet of neo-Mach Is - light, agile Singles at newbie prices - if they ever had the drive to make one. I'm constantly irritated by the reality of (increasingly hard-edged, increasingly pricey, increasingly insurance-y) 600 Supersports being the first really desirable models in any of the Big 4's lineups.



Aprilia doesn't even have a decent entry-level bike, for God's sake. (At least until the Shiver comes online - let us pray....) Somebody - somewhere- please do the right thing!

[Holy_Kaw]

Sounds like great fun but < 3K rebuilds? That won't work for a street bike. If they could take 10HP off (that "Race" engine) and make it reliable/durable they'd be doing good. Still, sounds like it would be a fun bike.

[SmokeU]

That's why I stayed away from a Yamaha 450 when looking for an ATV.

[mitctho]

What's the point? Everyone knows any bike under 88, er, 96 cubic inches or 1800 cc on a metric bike is for girls.

[pdad13]

Maybe I missed something but I got the impression that this was supposed to be primarily a track bike. With the skills and resources these guys seem to have, doing a top end rebuild every now and then wouldn't be too much of a deterent.



I agree that it would not be a practical or economical street bike in any sense, but I'm sure it would be a kick on the track. If they've got the money and time to maintain it, I say good job.



But they've got to find another tailpiece. The ZX-10 unit looks wrong; it's just too big.

[Tigercub]

I really like projects like this and thanks for posting this one. But, having built and modified a few bikes I've found it's pretty easy to lose the goal of improving on what's available already. So for those of you who say, "what's the point of this when I can buy a supermotard from KTM, Suzuki etc. that lasts longer than 3k miles"... enjoy your smugness. For the gearheads among us I totally get the means of the project, but the endpoint sometimes requires shaded glasses.



Hey it's my ride and I'll do what I want.

[Gordy]

I agree, and it doesn't make any sense either. A Ducati 999 makes 120 hp from 2 500CC cylinders. That's 60 hp / cyl, and they certainly last more than 50 hours! Even my crappy Superhawk is over 50 HP / cylinder with mild cams and low compression and should be good for 100K miles. MX 450's only make 52 HP and they are grenades. Why?

[seruzawa]

The MX 4strokes use extremely light components in order to be able to compete with two strokes of half the displacement. This way they rev extremely quickly and keep the weight down. Streetbikes can get away with stronger valves and crankshafts since they don't require the extremely quick reving and weight savings.



It might be smart to pick up a couple of older open class 2smokers like CR500s or IT490s now. If things progress like they usually do all the offroad bikes will be using the new weakly built 4stroke engines soon.