Rupp RMX 125 Questions.

[Mick Milakovic]

Hi Tom, I just saw this bike on Mark's MX Swapmeet page.  It looks like the one you're restoring.  You might contact him about information:

http://www.vintagemx.us/guestbook/Rupp.jpg

[pakala]

Rupp 125 MX

Robert Enders Jr was kind enough to send me some photos of this uncommon bike. Robert also told me about the bike, saying

" I purchased the bike new from a dealer in Linglestown (Harrisburg), Pa in either 1971 or 1972. I can't quite remember. I had only seen 2 other RMX's while I was racing and they were both 125's from the Allentown, Pa area. Rupp built this model in both a 100cc and 125cc version. For their day they were very fast and competitive with all the major Japanese bikes of it's era. It's a shame the company went out of business shortly thereafter. I think they had the right idea when they built this thing...combine the best the world had to offer into one simple well designed motorcycle. In a pure drag race, I could eat any Elsinore, YZ or RM that tried me.

This ain't no minibike!!!

Some specs:

Model Rupp RMX 125

Engine: Sachs 125/6B; 54mm bore and stroke; 10:1 compression ratio; 21.8 HP/8,800 RPM; Capacitive Discharge (Motoplat) ignition-breakerless w/ integral lighting coil; 6 speed constant mesh transmission. Large still air volume air box with washable foam element.

Chassis: Double loop Chrome Moly tubing; 31 degree caster; overall length: 81.7"; overall width: 35"; overall height: 45"; wheel base: 54.5"; ground clearance: 9.5"; seat height: 32"; dry weight: 198 lbs.

Aluminum conical hubs w/ drum brakes; Akront alloy rims and Carlisle Aggressor tires; 3.00 x 21 on front; 3.50 x 18 on rear.

All Magura controls: levers and throttle.

Compare it to a Penton?? They sure are styled alike. The Rupp gas tank could be a sister to the Penton 6 days Enduro...same engine. I don't know...no one can seem to tell me if the Rupp design was a copy or if John Penton had something to do with it. I think both companies were on the same track when they built them. If the Rupp had a weak link it was the brakes and spokes. I ended up relacing both wheels with steel spokes and tying them with wire to keep them from breaking. Problem taken care of. Brakes still don't match the Japanese bikes (installed a compression release).

I never had the privilege to ride a Penton but I sure spent many hours on the Rupp. I must have liked, I still have it (at least today). I really hate to part with it...but I need the space in my shed for the newest projects. As you can see from the photos, I installed lights for trail riding after I (and the bike) retired from racing. Believe it or not I actually flat tracked this thing for almost 2 years. Just had to fit a 19" front wheel and a Penton down sweep expansion chamber. The bike was plenty fast, the rider wasn't near fast enough!!!

Rupp 125 MX 118 K jpeg file
Rupp 125 MX 107K jpeg file

 This info was copy from //www.eurospares.com
               Paul(socal)

[firstturn]

Tom,
  This answeres my question;

Chassis: Double loop Chrome Moly tubing; 31 degree caster; overall length: 81.7"; overall width: 35"; overall height: 45"; wheel base: 54.5"; ground clearance: 9.5"; seat height: 32"; dry weight: 198 lbs.



Ron Carbaugh
Kerrville, Texas

[sixdazed]

Tom,Do you know if the rupps petcocks work on the penton gas tanks?the tanks look about the same.just wondering.Thanks,Ric

ric emmal

[bentrims]

Mick,
Thanks for that link! I think my bike is in better shape than the photo but if I know Mark, the bike is cherry now.

Rick, I will look into the petcock Q?

[bentrims]

Pakala,
Fantastic info..now we are getting somewhere. Ron: You've got mail.

[OhioTed]

Couldn't resist reading up on this post, when I saw the Rupp reference.  Never owned one myself, but there was several tearing around the old neighborhood, back in the day.  Also, feel kind of a kinship, as they were produced right over in Mansfield.  I've even met guys who worked in the mfg plant.  Taking a big step to one side, Tony's reference to "parachute braking after the checkers" reminds me of a funny situation, which occured some years back at a GNCC held near Lisbon, Ohio.  Freddie Andrews won, and after taking the checkers, came to a full stop at the scoring barrels.  I was videotaping the event, and kept the camera on Fred as he confirmed his finishing position with the checker.  Suddenly however, he and his bike lurched forward, so I zoomed back out and saw that two riders, fighting for position right down to the last few inches had run smack into the back of Fred's bike, and were now throwing punches at one another, while they were still on their bikes.  Fred remained on his bike as well, and had turned in the saddle to observe the fracas, while officials moved in to separate the combatants.  Those two guys were disqualified, as racing after the flag is a big, safety no-no, plus for displaying such unsportsmanlike conduct.  It was a pretty funny scene, all things considered.

                               Ted Guthrie
                               Salem, Ohio  

[bentrims]

Ted,
One thing is for sure; there is something about having these early motorcycles that turns back the hands of time to when life was simpler. :)If only we knew. I would have had a camera in my hands at all times. I still vividly remember our #1 rider (Tom Severson) on his Monark GS wheelying through the deep whoops way ahead of 2nd place. I had super 8mm footage of it but lost it in a family move[V].
Tom B

[OhioTed]

Couldn't resist reading up on this post, when I saw the Rupp reference.  Never owned one myself, but there was several tearing around the old neighborhood, back in the day.  Also, feel kind of a kinship, as they were produced right over in Mansfield.  I've even met guys who worked in the mfg plant.  Taking a big step to one side, Tony's reference to "parachute braking after the checkers" reminds me of a funny situation, which occured some years back at a GNCC held near Lisbon, Ohio.  Freddie Andrews won, and after taking the checkers, came to a full stop at the scoring barrels.  I was videotaping the event, and kept the camera on Fred as he confirmed his finishing position with the checker.  Suddenly however, he and his bike lurched forward, so I zoomed back out and saw that two riders, fighting for position right down to the last few inches had run smack into the back of Fred's bike, and were now throwing punches at one another, while they were still on their bikes.  Fred remained on his bike as well, and had turned in the saddle to observe the fracas, while officials moved in to separate the combatants.  Those two guys were disqualified, as racing after the flag is a big, safety no-no, plus for displaying such unsportsmanlike conduct.  It was a pretty funny scene, all things considered.

                               Ted Guthrie
                               Salem, Ohio  

[bentrims]

Ted,
One thing is for sure; there is something about having these early motorcycles that turns back the hands of time to when life was simpler. :)If only we knew. I would have had a camera in my hands at all times. I still vividly remember our #1 rider (Tom Severson) on his Monark GS wheelying through the deep whoops way ahead of 2nd place. I had super 8mm footage of it but lost it in a family move[V].
Tom B