RS250-CR500

[gpracer15]

I am considering using a RS250 rolling chassis and a CR500 motor. Any body want to comment on this? Any one have experience in something similar? This is all for personal fun and dont expect to compete with it unless it works well.

[This message has been edited by gpracer15 (edited 08-10-2001).]

[TwoCycler]

I have an RS250 frame and SS swingarm I would sell you if you don't already have the roller.

[biaggibaxter]

Good luck. I am finally finishing my XR600/TZ250 special. If I can answer any questions drop me a line. Darryl

[rob]

bare bones machine in colorado make sos racers using tz250 chassis, an rs chassis should be just as good. they use mostly 4-stroke hondas and rotax. but i was thinking of putting a cr500 motor in my gs500 chassis as well; a mechanic who did some work on my tz also suggested this, not knowing i was considering it. he said the cr500 motor is really fast. you can buy a new motor with electrics from honda for around $2200. or so. lots of used ones around, have not changed in years. the hardest part may be designing an expansion chamber for it. no idea where to start on that....also do not know if the ports are enlarged at all. i have seen at least one other cr500 race bike advertised in roadracing world a year ago, maybe, so someone else has done it. do it!

[Jack]

Actually, I've been thinking of doing a CR500 motard road racer myself, ever since doing my little KX mini. Motards are great fun, cheap than the GP frame alternative, and can be competitive. It ain't like this road hasn't been traveled before, either. I know this guy named Culpepper was pretty successful in CMRA with one and there's a guy now that Lindsey and Derek say ran them off the road in the barn turn and Henderson this year. Haven't seen that one run, but I know Culpepper was fast and finished well in "lightweight sportsman" in CMRA. Actually, I think the bike is legal in "GP singles" in CCS, which is mostly 125s. These things are a blast to ride, motards, and one with the kind of power I could get out of the big CR motor would be AWESOME! I've not researched the classes it'd run in WERA, but would before I took on such a project. You could get a LOT of track time and be competitive in CCS, though. BUT, I'd REALLY miss the GPs. I'm not sure I wouldn't rather just take some time off from 125s and save the bucks and hope to find a competitive RS by 2003 season. Of course, in the meantime, the kid's school expenses could suck it out of me before I could save it, but I'll try to rat hole it. I'm pretty good at that.

Putting a CR in a 250 chassis would be a challenge, but it could produce the ultimate fun, great handling GP for less than the cost of a new RS. If you decide to do it, keep me updated. Wish I hadn't given away my old 250 chassis now, but it was a BIT out of date, like 24 years, LOL.

Jack

[gpracer15]

I need a motor for this monster!!!
I heard that the 88 has a wide ratio tranny and more power than new ones.

[tattoo guy]

Originally posted by TwoCycler:
I have an RS250 frame and SS swingarm I would sell you if you don't already have the roller.
I might be interested.What are you asking for it?

[Stumpy]

I am looking into this same kind of setup, except I'm using a hawk chassis instead of an RS. The people I've spoken to about it say the main problem is fighting the vibrations from the big single. Keep me posted on any problems you encounter.

[moto_dan]

Originally posted by TwoCycler:
I have an RS250 frame and SS swingarm I would sell you if you don't already have the roller.

I may be interested in your roller. What's your asking price. Thanks.
Dan

[Team Road Rage]

I have an extra frame from a 98 NSR 250. I have been thinking of putting in a CR500 motor also but, a few of the people I spoke with said the vibration would be too much. I haven't started this project yet. Has anybody out there tried it yet?

[Jack]

Originally posted by Team Road Rage:
I have an extra frame from a 98 NSR 250. I have been thinking of putting in a CR500 motor also but, a few of the people I spoke with said the vibration would be too much. I haven't started this project yet. Has anybody out there tried it yet?

One more reason to go the motard route. Yeah, a TZ chassis would be cool, but I know some folks have said this about putting the KX80 motor in a 125 frame, had all sorts of vib problems and went with a smoother motor. My KX doesn't shake all that bad. A CR with that huge slug HAS to buzz pretty good. I'd be wary of that. Besides, the motard route is cheaper, less to sort out. Just some rims and spokes, a suspension revalve/springing/lowering and some gearing, maybe something for more braking on the front. Motards are way fun to ride, too.

JMHO

Jack

[emerge racer]

I have thought about an rs125 with a Yamaha 426. Not sure it would fit but am thinking aout trying it. Something about putting the RS on the rear whell any time that you wanted sounds intresting. I have called BBS but they are not intrested in helping with the frame work. Any ideas of who else out there may be able to help?

[tattoo guy]

Originally posted by emerge racer:
I have thought about an rs125 with a Yamaha 426. Not sure it would fit but am thinking aout trying it. Something about putting the RS on the rear whell any time that you wanted sounds intresting. I have called BBS but they are not intrested in helping with the frame work. Any ideas of who else out there may be able to help?
Hey Tony,Take a look at the website for Bare Bones Machine(www.barebones.net).They do custom TZ250/Rotax and honda powered racers and say they are willing to take on projects.Or call (719)687-0431 and ask for Jay


[This message has been edited by tattoo guy (edited 08-16-2001).]

[gpracer15]

Call Elias Corey with GPStar.net in Cali. They can do the mounting.

[werase643]

here's a dumb question(or questions)?
CR500 C/S on left...last one I saw
93-up RS250(not shure of year) C/S on right?

is this a concern?

somebody already installed the 426 in a YSR chassis.

anybody ever heard of the TULDA??????
home made chassis(TZ suspension) with a CR500 motor!!!!!

two things rob would NOT discuss...
RPM....just how high would it go
and
EXHAUST....had 8-10 pipes made before he got it correct.

[tattoo guy]

[QUOTE]Originally posted by werase643:
[b]here's a dumb question(or questions)?
CR500 C/S on left...last one I saw
93-up RS250(not shure of year) C/S on right?

is this a concern?
That is a problem.93-up RS250s do have there c/s on the right CR 500s are on the left.The NSR250 (street bike)has a left side c/s so that would work.I will soon be working on a RS250 framed project but I will be using a Rotax or KTM four stroke engine.They both have right side c/s.


[This message has been edited by tattoo guy (edited 08-27-2001).]

[This message has been edited by tattoo guy (edited 08-27-2001).]

[EMathy]

Just passing through. http://www.wera.com/ubb/wink.gif

For more information from folks who've done this sort of thing, try the MC-CHASSIS-DESIGN e-mail list. It's run by Michael Moore of Eurospares in SF. Great guy, good list.

For more info:
http://www.eurospares.com/maillist.htm

Enjoy,
- Erik

[gpracer15]

Yes you guys are right and I totaly looked over that issue. The chassis/motor combo will work if I us a RVF swing arm but I am putting the chassis up for sale. It is complete bike minus the motor and electrics for $2300. I have pics.

[bryan norton]

Culpepper was fast, could be me, but not impressively fast. He rode an older steel framed CR500. Watching the rear end hop around corners was frightening. He was at Cresson this weekend, but spectating.

Randy White is da man right now for super retard, er motard bikes. He has an aluminum framed CR500 that smokes it around Cresson, his home track. He crashed twice, but still never missed a beat. He knows how to sort out the suspension, he previously had a YZ426 and a husaberg 600 4 stroker.

I bought a Hawk chassis, was gonna do the CR500 thing. BIG PROBLEM- The rear sprocket holder is too large, you can't fit a small enough rear sprocket to make it work well enough for the fast tracks.

Cr-500 in a TZ frame, thats the ticket probably-just look at the older tul-da which was similar idea.

How about welding up two CR-500's into a vtwin, 1000cc two stroke in a bike frame like a gixxer or duck...its just sick to think about...(well, thats similar to the Tul-aris I guess)