RZ500 vs RG500

[MAPonce]

I would like to create a personal bike project over the next few years. I'd
like to make my own 500 gp bike (of sorts). Ultimately, I'd use a Harris frame
or the like, but in the mean time, would like opinions on the
superiority/inferiority of the RZ500 and the RG500, both engine and
chassis-wise.

TIA

[Ryan John Cousineau]

map...@aol.comQQ (MAPonce) writes:

>TIA

Up in Canada where we got both bikes, the RG is widely regarded as the
superior machine. Both are high-strung, and not great street rides. The RG
is much lighter and has a better (cast aluminum vs. square steel tube)
frame. The RG may also have a little more power, though I think they're
roughly even.

Both bikes are way behind current suspension trends: narrow 16" wheels,
skinny forks, anti-dive. A popular upgrade for the Gamma is to add
a late-model GSX-R front end and rims.

The RZs seem to be more common and slightly cheaper.
--
Ryan Cousineau, rjco...@sfu.ca
"Even if animal research resulted in a cure for AIDS, we'd be against
it." -- Ingrid Newkirk, PETA founder and insulin-dependent diabetic,
Vogue, September 1989

[Michael Abercrombie]

There is a aluminum version of the Yamaha called the RZV.  It's a Japanese version, but a number have made it over to the states.  I have one with a late model FZR front end and rims among other modifications.

I can't speak for the RG since I've never ridden one, but the RZ is a blast to ride.  I suggest you research as much as you can before deciding.  Here are a few webs sites for the RZ and RG.  Some of them have real good technical data.

 RZ/RD 500 OWNERS GROUP
 Petes RD500LC Pages  - This one has a lot of good technical data
 Mats' RD500LC pages
 French RD 500 LC Home Page

 Suzuki RG500 GAMMA Web site

[scotus]

Okay, I ride a gamma and strongly believe it to be superior to the RZ, but
I'll do my best to be objective. Since you speak of an aftermarket frame
I'll limit my discussion to the powerplants. Right off the bat the RZ
engine is a LOT heavier than the RGs. It is well over 20 lbs. heavier. The
engine also needs a balance shaft, whereas the gamma has natural primary
balance from its firing order. The RZ engine is reed inducted, which is
actually an advantage over the rotary valved RG, in that you do get better
tractability out of the engine, particularly in the lower RPM range off
pipe. The rotary valves of the RG though, permit intake tuning without
having to grind the cylinders. Your intake time area becomes independent of
piston position. The RZ employs a guillotine style exhaust valve, which at
first glance is less reliable than the RG's exhaust chamber method of
improving performance off the pipe since it (the guillotine valve) can clog
up more readily. However, this form of exhaust pulse management works
better with water injection, which is the single best thing you can do to a
2 stroke engine (apart from getting your pipe tuned length right) to make it
really useful. The RZ's carburetors, though, are grossly inferior to the
RZ's, and can not be readily modified due to their location. A fad now for
gammas is to fit 35mm TMX carbs. It works, actually, but others like myself
are boring their stock carbs to 30.25 mm and doing just fine. The
transmissions and clutches are comparable. The RG's transmission did have
weaknesses in the gears, but by the 1986 model year these issues had been
resolved. Another problem for RZs is hoses. The gamma's coolant packaging
is far more sano with only two hoses (and a 2 inch long bridge hose between
cylinder pairs). The RZ I believe has better tuning data published.
Yamaha, unlike Suzuki, wasn't afraid that the RZ 500 would hurt their
production GP bike production so they published porting data freely, which
can be found on a number of Web sites. The gamma was so close to the RGB
production racer in design that Suzuki did not publish these specs. Today,
though, the 'package' for the RG is widely known and the bikes regularly get
an honest 110 hp at the rear wheel and don't grenade. One bike is making
126 hp at the rear wheel. I've ridden it and it's not a joke. One final
note on the RG engine. It can not be used as a stressed member due to its
rubber front mount bushings. I don't know if the RZ engine is a solid mount
or not, or if the mounts are all on one crankcase half, but I wouldn't
expect the gamma engine to help stiffen the frame.

All things said and done, I think the gamma's engine is the best project
starting point at the end of the day. It's a lot easier to work on, it's
lighter, and it made more power in '85 and can still spank the RZ after both
lumps have had the same dosh tossed at them. The Bonneville speed record
for a 500 cc stock bike is held by a gamma. The general packaging is also a
lot cleaner, which facilitates mounting in aftermarket frames. The RZ has
some good features as mentioned above, but its balance sheet just doesn't
come out quite so much in the black.
MAPonce wrote in message <19981116094342...@ng133.aol.com>...

[morten_...@my-dejanews.com]

Hello Get hold of a UK magazine called Performance Bikes, they have had a lot
of articles about this in the past. Get a copy and contact them for back
issues, or copy of articles. Or you can mail direct to me, and i will get the
addres for you. I have seen some very tasty jobs, Spondon makes really tasty
ones, singel side swingarm and all that dribbel dribbel. reguards. Morten B
Johansen Denmark ´97 GSX-R600rider move the X´es from the addres. mail :
XXMB...@Dancall.dk
...........................................................................
In article <19981116094342...@ng133.aol.com>, map...@aol.comQQ
(MAPonce) wrote:

> I would like to create a personal bike project over the next few years. I'd
> like to make my own 500 gp bike (of sorts). Ultimately, I'd use a Harris frame
> or the like, but in the mean time, would like opinions on the
> superiority/inferiority of the RZ500 and the RG500, both engine and
> chassis-wise.
>
> TIA
>

-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

[Dave Dal Farra]

I remember the RZ500 having a pretty bad front end and have heard
several stories from guys who could never dial it in.

Performance Bikes did a piece on a real tasty RGV250 with a Gamma 500
engine stuffed in. The guy went through hell to make it work, and was
still sorting out the carberation, but it was an interesting concept. My
fave special has always been the Canadian that stuffed an H2 triple into
an early 90's Ninja. It looked beautiful, and apparently drop scads of
weight and gained a lot of aceleration.

Dave Dal Farra

[Don MacPhail]

Dave Dal Farra wrote:
>
> I remember the RZ500 having a pretty bad front end and have heard
> several stories from guys who could never dial it in.

Yup, so I took the direct route - replaced it with the entire front end from a
YZF600.

Not _quite_ a bolt-on; had to grind the face of the lock tower ~ 1/8", plus
moving the tanks outboard ~ 1/2". We'll see how well it works come the spring. .
.

> Performance Bikes did a piece on a real tasty RGV250 with a Gamma 500
> engine stuffed in. The guy went through hell to make it work, and was
> still sorting out the carberation, but it was an interesting concept.

That was Youngie's, wasn't it? Didn't he wind up suing the shop that was
supposed to do the work?

> My
> fave special has always been the Canadian that stuffed an H2 triple into
> an early 90's Ninja. It looked beautiful, and apparently drop scads of
> weight and gained a lot of aceleration.

I've seen that! It was in an issue of Cycle Canada a few years back. Think I've
still got it at home, somewhere. . .

cheers,

Don

Remove my brain to reply

[Williams]

Dave Dal Farra wrote:

> I remember the RZ500 having a pretty bad front end and have heard
> several stories from guys who could never dial it in.
>

> Performance Bikes did a piece on a real tasty RGV250 with a Gamma 500
> engine stuffed in. The guy went through hell to make it work, and was
> still sorting out the carberation, but it was an interesting concept.

That's gotta be Youngie's bike.

A bike I would like to see built would be a TZR500. The '89-'90 TZR250 used a reverse
design with the exhausts exiting directly through the tail cowl. It seems to me you
could squeeze an RZ500 engine in there since the reverse design took up a lotta room
anyway.

I have a Japanese friend who stuck a CR500 engine into an NSR250 frame. He never got
the carbs dialed in though.

I have another Japanese friend who got a Walter Wolf RG400, then added a cylinder to
boost it up to 500. I think that math works, or maybe I'm just remembering that part
wrong. Anyway, he then stuck a new Ohlins shock out back, added wheels from a Gixer
1100 so he could use modern wide rubber, then hung an '89 Gixer 750 front end on it.
He told me it handled loads better than a stocker.

These kinda bikes are a riot, I wish more people would build'em.

Rick