Frankenbikes?

[Zombie]

I was wondering if anyone out there has tried to make a extra superlight RZ 350, like a TZ-250 sized bike with the RZ engine crammed in it. I am in the VERY early planning stages of this, and if anyone else has tried, and has had success (or failures) please advise me of any potential pitfalls. I am imagining a Spondon aluminum frame (did they ever make these?) R6 forks and brakes up front, a single-sided swingarm using a R6 shock and brakes out back, and possibly carbon fiber wheels. All hardware would be aluminum, titanium and magnesium as I could find. I intend for the bike to be a good weather ride with an odd trip to the track. Any tips, tricks, or advice (or better frame option) would all be appreciated.
Also, has anyone tried using a RZV or TZ750 engine in a modern frame with modern suspension and brakes? I seem to remember someone was making R6/RZV hybrids a few years back..
-Zombie

[Questo vecchio rz]

There quite common, best start searching posts, there everywhere on here & other bike sites, Simple as "Googling".
Theres months if not years of available reading/research of others projects here and on other sites.

All I'm willing to say is build what you want, as almost anything is possible. As far as budget double or triple your inital cost projections.
A bike like you describe above, I'd estimate (realistically) costing one around around 15-25 k depending upon level of detail and fabrication skill.

Good luck on your endevors.

[oldestschool]

And for that 15 to $25K,you can buy a complete TZ250.So it is a labor of love.The best looking ones I've seen are the Aprilia RS250 ones but the FZ400 based ones of years ago were also light and nimble.
In street spec,anything under #300 wet is light.
Here are a few frame ideas
http://www.tz350.net/aftermarket_frames.net.htm" onclick="window.open(this.href);return false;

[evan_calgary]

Aprilia RS250 Frames can be had for $300 landed. These were described as the very closest to a GP race bike you could get in a frame. Just start there. Brembo wheels/brakes. Lots of aftermarket bits. Full kits available for engine cradles using RZ.

[two-stroke-brit]

Aprilia RS250 Frames can be had for $300 landed. These were described as the very closest to a GP race bike you could get in a frame. Just start there. Brembo wheels/brakes. Lots of aftermarket bits. Full kits available for engine cradles using RZ.

http://www.fastfromthepast.com/hybrid-frame-engine-kits" onclick="window.open(this.href);return false;

this looks tidy

[evan_calgary]

Fast kit looks nice but wow is it expensive! There are other cheaper options out there. But really...the RS hybrid is the best bet unless you think you are special and know better than everyone else. Definitely see it occassionaly and if that's the case go for it and let us know when youve blown your budget and get stuck.

[Zombie]

The fastfromthepast kit looks like just like what I'm looking for! But could I remove the engine if I weld that new cradle in?..
-Z

[evan_calgary]

Yes, the cradle bolts in like most of the late 80/early 90's sport bikes before they completely hung motors. The rear engine mounts have to be cut off and rewelded with engine in cradle to align. Figure its a couple grand with the fast kit after welding to put in the RZ motor.

[Zombie]

Aprilia RS250 Frames can be had for $300 landed. These were described as the very closest to a GP race bike you could get in a frame. Just start there. Brembo wheels/brakes. Lots of aftermarket bits. Full kits available for engine cradles using RZ.

Who imports & sells the Aprilia RS250 frames in the US? Does anyone make a single-sided swingarm for them? Are rolling frames available? I would spring for an Ohlins rear shock, but I would also like inverted forks for the front. I'm basically after a GP bike with lights and turn signals.
=Z

[Questo vecchio rz]

Aprilia RS250 Frames can be had for $300 landed. These were described as the very closest to a GP race bike you could get in a frame. Just start there. Brembo wheels/brakes. Lots of aftermarket bits. Full kits available for engine cradles using RZ.

Who imports & sells the Aprilia RS250 frames in the US? Does anyone make a single-sided swingarm for them? Are rolling frames available? I would spring for an Ohlins rear shock, but I would also like inverted forks for the front. I'm basically after a GP bike with lights and turn signals.
=Z

No one really imports them per say, you just have to get the word out and search accociated websites.
A single sided swingarm, does you absolutley nothing for your bike, its 99% cosmetic bling, unless your a endurance racer.
If you really want it thats plenty good, They do look nice. I spent 2 years researching & accumulating parts to do mine, then decided I didnt like the look on a RZ as much as a conventional.
Price for a single sided arm would realistically be around $2500.00 for arm & wheel either specificlly fabricated by a firm, lets say "metachex" or to source one from a existing model NC30 etc..and pay to have it modified by someone such as "RGVSteve", you'd have to pay him handsomly I'd imagine for him to come out of retirement. Unless of course you can handle the suspension linkage design and fabrication needed yourself, then your golden on that issue.

There as far as I know, NO specific frame kits currently avail for the RZ/YPVS. Although a while ago a gent on the 500 side was selling his custom built 1 of 1 TIGCRAFT frame built specificlly for a RZ, it was a stinking good deal @1/4 the price of his orig price too! Just a few weeks ago there was a 3ma ir 2maTZR frame there for under $300.00 bucks.
To be honest there really isnt too much of a problem w a stock frame, regardless if intenet forum myths, not so much that the frame cannot be modified to handle whatever "within reason" you choose to throw at it. I've watched some pretty fast guys race RZs w basiclly stock frames & they were likley faster than you, I, or most on this forum would ever hope to be.
If you want a hybrid frame, thats great, they look awesome & would work for a expert level rider or hsrdcore trackbike. There are a few options that others have done.
NOTE*** THEY ALL require fabrication, same as the "prilla" RS250, its just the RS has a popular following due to its fairly straight foreward install and avail cradle kit.
I've viewed RZ motors in FZ, FZR, NSR,TZR250, old 80s. Nico Bakker frame kits,TZ350,and 89 reverse twins TZ250s-
& later TZ250s as well. MBSteves and AXRacing. If your looking for a realistic replika the a TZ-TZR based build would be the most accurate. There all doabl with enough careful thought and fabrication. Below are a couple examples of AxRacing & MBSteves. I've viewed one up close several times , This conversion requiring the actual engine case to be shortened is not for the feinght of heart & not practical on the street, but they look "factory" and hard to beat as far as a " All Yamaha" race replika. The RS250s also look good and there are several examples posted here latley as well. IMI the RS250 appears the easiest steaightfireward and documented as to convert, but the TZR & TZs look much better.
It's all what you want to spend, chassis choice and fabrication costs or skills.

[Zombie]

I like the look of the RS250 conversion, and while I like how the single sided swingarm looks, something needing stupid amounts of fabrication as to be a 1-off just isn't worth the hassle for me. The "banana" style swingarm (like on the silver bike above) would be my second choice, and probably not need nearly as much screwing around with.
While I have nothing against the original steel frame, I have ridden bikes hard enough to feel frame and fork flex. Yes, I know they can be reinforced, but why not upgrade to modern ergonomics, controls, suspension and brakes too?
-Z

[Questo vecchio rz]

I like the look of the RS250 conversion, and while I like how the single sided swingarm looks, something needing stupid amounts of fabrication as to be a 1-off just isn't worth the hassle for me. The "banana" style swingarm (like on the silver bike above) would be my second choice, and probably not need nearly as much screwing around with.
While I have nothing against the original steel frame, I have ridden bikes hard enough to feel frame and fork flex. Yes, I know they can be reinforced, but why not upgrade to modern ergonomics, controls, suspension and brakes too?
-Z

If I were you (which Im not) I would look for a complete RS250 not just a frame or swingarm. If you go the route of buying all components separately, your bound to end up
spending way more than you should. Unless of course you intend to modify everything with upgraded aftermarket components anyways, there are some really good build threads regarding the RS250/hybrids that will inform you of most all you will need to know.
As far as frame its totally up to you, I'd like a hybrid framed TZ/TZR build myself, but I also know the definitive cost of such a build (roadbike) is around a min of 15k done as I would build such a toy w my ability. For me, no point in building a hybrid race replica if I didnt build it w all new/restored quality components.

Back to the stock steel frame, Theres no way (In my situation) I'll find its limits on the road nor my personal trackday pace, If I need to go that fast I'll certainlly use a diffrent bike for me a 60-75 h.p RZ is just perfect for reliving a GP influenced youth. My bike with converted front/rear w more power than stock on modern wide sticky rubber or slicks is certainlly capable of exploiting any potential weak areas (if pushed beyond) that said range. I'll have to ride it within those limits, which frankley, I'm honest with myself is FAR faster than I should or would ever ride on the street or trackdays, I aint goin racing! Every bike I've ever owned has some quirks or suspension, frame issues just gotta ride em as they are deal with what each dictates.
But In your case, I'd recomend the RS as you like it already, and its the easiest of the conversions, you could go hog wild or build it, ride it & modify it as you go.
It will be a fine looking & excellent handling machine if done right. I viewed many RS250 cup races, the bikes really wete quite fast in 250cc form, nowhere near TZ250 levels but still darned quick it would be awesome with another 25-40 h.p. the average RZ350 based motor provides. Im sure a few of the guys here who have done it would be glad to help you out or even help you locate a bike or rolling chassis, or even a bare frame & swingarm. Your total cost, obviouslly depends upon how you source parts and the level of components, I'd estimate the cheapest build w bigbore at around 7k to well into the upper 20k possibly 30k range if commissioned with top shelf components and build quality.
Great project, hope to follow your build.

[Questo vecchio rz]

Zombie...This may or may not intrest you. But there is a project bike advertised right now in the for sale section that fits (alot of your criteria). Its a Hybrid "Frankenbike" it could seriouslly jumpstart your build.

Its states:
Cheetah big bore (fresh rebuild). 80 possibly100 h.p depending on state of tune. Its the CPI cylinders
Hybrid FZR400 alym deltabix frame w cradle.
Ducati, single sided swingarm conversion.
Ducati front end conversion.
All new race fiberglass.

The guys asking about $4.5k

THAT LESS THAN JUST THE COST OF THE ENGINE BUILD!

[Zombie]

I saw it, it looks good, BUT, it is all the way down in Florida. I am in the Pennsylvania/Maryland/Delaware area.
If I had my truck back, and he was closer, I'd be looking at it in person.
-Z
PS- Im currently looking at a 570cc engine..

[evan_calgary]

Miyabee on eBay sells frames for RS250 quite commonly for around $180 plus the same for shipping. No clue on the title deal in the USA but it is not a big deal in Canada. 1999 MK2.

Rear frame mounts have to be moved and rest of the kit can be found from Fast. I have a line on subframe/new wheels but no suspension at this point but again can be brought in from Japan. All depends on what you are looking to do.

I have a RS250 frame sitting here if you are interested for whatever I paid (already landed). I will get around to building one at some point but it is a long haul.