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Aprilia SXRZ

217K views 590 replies 136 participants last post by  Dave..id 
#1 ·
Hi, guys, new to the site.

I'm starting a 2-stroke super moto build using an Aprilia SXV and a Yamaha RZ350 engine. The build is still in the planning stages, but yesterday I went ahead and ordered the Aprilia SXV frame, subframe, swingarm, rear shock, shock linkage, front forks, lower triple, upper triple nut, front and rear axles, rear wheel spacers, and rear swingarm adjusting blocks.

That should get me started on the engine conversion. The engine swap doesn't look easy, but if I'm not happy with the outcome, I'm going to use the RZ350 frame, and modify the Aprilia parts to fit. That way, I'll only be out the money and time I spend on the Aprilia frame.

Here is a custom motard using the RZ350 frame and engine with CRF450R bodywork:







Here is the bike that inspired me to build a 2-stroke super moto bike. This bike has a custom frame, and uses the RZ350 engine:

 
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#2 ·
Sounds like a cool project, someone on here is doing a bike with a banshee motor.

One question though, why the sxv frame? It seems like it'd be more expensive to acquire, and they are V-twins, so the frame will need more modifications. Other bikes using singles seem like they'd be less work to modify, like the examples you showed.
 
#4 ·
The others have already been done, and I'd like to do something original. I think the Aprilia frame and swingarm are straight-up exotic, compared to those bikes. Also, I don't usually like doing things the easy way. ;)

The Banshee engine is okay for the dirt, but I wouldn't use it for a street application. All modern 2-stroke engines for the road or track (not dirt) use some type of valve (usually on the exhaust port), which adds power lower in the RPM band and smooths out the delivery of power. The Banshee engine doesn't have a power valve system.
 
#3 ·
^ I was thinking the same thing. Why not use a yamaha WRX frame? Then you'd have a yamaha when you're finished, rather than a mutt.

Either way, it sounds like a sweet project and I wish you luck with it...
 
#5 ·
but everything can be modified im sure you know of duncan racing and trinity racing. trinity built my last motor for my banshee and tuned it to my exact request, then i had bills motocross development make custom pipes to suit my needs. i think it will be a bad ass bike good luck,
 
#9 ·
Actually, I prefer to premix. Most likely this motard will premix, too. Not sure, though.

Here's the clutch side casing from my other project bike. Notice there's no oil pump. It's an RZ engine, but this side casing is for a Banshee. I might do a custom dry clutch (on the other bike), and the casing will probably be polished, not blue. Designed my own featherweight oil cap, too. :)





 
#13 ·
By installing a brace that will go from the inside of one engine mount - over the intakes - to the inside of the other engine mount. The brace can either bolt onto whatever is left of the mounts after I cut them down, or welded to the aluminum frame itself.

I talked to a great fabricator about welding the cast aluminum frame. He has a lot of experience doing it and says that motorcycle castings in general, weld very well and that these frame pieces should be no problem.

There will also be drop-down brackets from the steel part of the frame to the front engine mounts on the RZ engine. I thought it might be cool to triangulate the brackets to the outside of the front mounts on the Aprilia frame. The brackets would probably be perfect for mounting a radiator, which could also brace the engine mounting brackets in the middle.

I know, I suck at photoshop! After I drew these brackets, I realized it might be better to use straight lines like the frame and swingarm.

 
#15 ·
Actually, it's the engine that tells if it's an offroad bike or on road bike. If I have a legal engine, I can put any frame on it, but If I have a legal frame - the engine still has to meet the EPA standards (for California).

The SRX engine wouldn't be street legal in California, But the '09RXV engine might be legal - not sure. The RZ350 engine that I'm using is from a bike that's not California legal, but I got it registered a few years ago when the regulations weren't so tight. So, the engine (and the entire bike it's on now) is registered and plated. :) Originally,I imported the bike from Canada.

The bike is definitely going to be street legal. It will still have the same RZ350 licence plate and engine but with a different frame. The Aprilia frame I bought is fully titled, as well.
 
#16 ·
Made a profile template of the RZ engine, grabbed my measuring tools and drove to the Aprilia dealer almost every day for a week. I calculated that it's going to be a bitch to transplant the RZ engine into the SXV frame. :headscrat





Someone that read about my project sent me this pic and said he thinks the RZ frame is the better way to go. If I had access to an SXV frame with no engine and an RZ engine, I might have chose not to do it! :lol:

 
#18 ·
I shouldn't have any issues with this bike being legal. The RZ350 is in my name, and is already registered and plated. The DMV doesn't know I'm turning the RZ into a motard. Later, I can have the bike inspected with the new frame. The DMV and CHP don't care if you change the frame, as long as you legally purchase the frame and have a title for it, which I will. It's the engine that the DMV and CHP don't want modified.

Another thing I could do is chop the head tube off the RZ frame (the VIN is on the head tube), modify it, and transplant it onto the Aprilia frame. Then, It's really a modified RZ350 frame - even though the head tube is the only piece that's original. The VIN number remains unmodified and matches the engine VIN. I could also weld over the numbers on the Aprilia frame and stamp the RZ VIN into the Aprilia head tube - and just say that I transplanted the RZ head tube onto the frame - but that wouldn't be kosher. ;)
 
#27 ·
[
Never seen an RG500 motard. The RG500 engine is quite heavy. I have an RZV500, and the weight isn't that different. Both bikes use a twin-crank engine.[/QUOTE]

yeah that's what I was thinking too. Bulky square 4 twin crank gonna be a packaging issue. Sure don't see many RZ500s, right on
good luck!
 
#30 ·
wow you got some cool stuff. I was in japan for year in 1991, and while I was kinda into bikes then, nothing like I am now. But I did see alot of badass 2 strokes. Wish I could do it again.
 
#31 ·
I competed in Judo for about 14 years, and fought at the Kodokan in Tokyo (that is where my screen name comes from). I was also a jammer for the U.S. All-Star Roller Derby Team, so I got to play for a week straight in the Tokyo Dome against the Japan All-Stars.

Man, I love visiting Japan and can't wait until I can go again. Next time I want to go to the factory motorcycle museums and race tracks!

I'm doing some frame mods to my other project bike, and tomorrow I'm going to pull the (RZ350) engine to see if it still fits through the mock-up frame rails. I'm going to leave the engine out, so I can test fit it into the Aprilia frame which should arrive Monday.

 
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