1975 KTM MC5 250 prototype???

[John Doud]

Interesting reading on EBAY item #2483048272.

  The History.

In the Late 1980's I was hired to clean up a ranch in southern California. I found two motorcycle in a small lean-to shed. I asked the new owner of this ranch what he wanted to do with them, he said throw them away. So I loaded them into my truck and took them home. After cleaning them up, I discovered that only a few of the parts were missing from the desert bike, but more from the moto-cross bike. By using parts from the moto-cross bike I got the desert bike into good riding condition. I was riding this bike most every weekend, and broke two kick starters because of the high compression. I searched high and low for another kick starter, the few that I did find where not for sale at that time. After contacting KTM in Austria, I found out the history behind this motorcycle. The factory representative could not find the numbers I gave him in the regular production list. After he had done some research he called me back. He found the engine and frame numbers in the factory sponsored racing list. He told me that this bike had done very well in the Baja 500 and 1000 mile races. In fact they where so impressed with the speed and power of this bike, it was taken to the Bonneville salt flats. On the salt flats they made two runs at breaking the land speed record for 250cc motor cycles. If I remember right, the top speed was 147 mph - not quite the record but close. 153 mph was the record at that time.


For everyone to whom much is given, from him much will be required. Luke 12:48

[rob w]

Carl Cranke and Eric Jensen raced and won their class at the Baja 500 in '74 and the Baja 1000 in '75, both years on a Penton 125. This bike would have gone in 1976, does anyone know how to find out who rode good ole'number 47 was in '76?

rob/bob

[dirtbike]

The story might be right but can those speed figures really be correct?
The way I see it, the 1981 year KTM 495 is the fastest dirtbike ever tested and verified. It made a stunning 123.75 MPH which is pretty exact 200 Km/h. That is very fast!
I belive that the DirtBike magazine made another go for it last year or so with a Husaberg 650, Kawasaki KX500, KTM 540 and a Honda XR 650. They did just about everything but still couldn't beat the +20 year old 495 record. I don't belive that any single cylinder 250cc MX engine has power enough to break that speed unless mounted in a very slim roadracing chassi.

[firstturn]

Dirtbike,
  I was honored to work on a project that was directed by the late Woody Leone Sr. and he had a verified CanAm 175 that cracked the 150 mph.  It was in Road Racing trim.  This is back in the 80's and it would actually do over 160.

Ron Carbaugh

[rob w]

Carl Cranke and Eric Jensen raced and won their class at the Baja 500 in '74 and the Baja 1000 in '75, both years on a Penton 125. This bike would have gone in 1976, does anyone know how to find out who rode good ole'number 47 was in '76?

rob/bob

[dirtbike]

The story might be right but can those speed figures really be correct?
The way I see it, the 1981 year KTM 495 is the fastest dirtbike ever tested and verified. It made a stunning 123.75 MPH which is pretty exact 200 Km/h. That is very fast!
I belive that the DirtBike magazine made another go for it last year or so with a Husaberg 650, Kawasaki KX500, KTM 540 and a Honda XR 650. They did just about everything but still couldn't beat the +20 year old 495 record. I don't belive that any single cylinder 250cc MX engine has power enough to break that speed unless mounted in a very slim roadracing chassi.

[firstturn]

Dirtbike,
  I was honored to work on a project that was directed by the late Woody Leone Sr. and he had a verified CanAm 175 that cracked the 150 mph.  It was in Road Racing trim.  This is back in the 80's and it would actually do over 160.

Ron Carbaugh

[dirtbike]

Then I must be completely wrong!

In my mind, it would take at least 45+ rear wheel HP to crack 120MPH lying on the tank and slimmed plastic, cutted fenders and such.
I'm talking about a dirtbike...

A stock GP 125cc racer from 2002 (aprilia) raced by Chris Peris at Valencia (spain) topped out at around 125mph whereas the factory bike topped around 145mph. I assume it to be way faster than any 250 dirtbike ever made, not to mention a 175cc displacement.

[firstturn]

Dirtbike,
  The flaw in your picture is you keep comparing dirtbikes, road racers and rear wheel horse power and trying to mix them together and derive a formula for going fast.  When you were talking about the actual speed of a bike that performed on the salt flats you have to remember that one has a mile to get everything going and then you take a 5 mile average two ways, which is meant to take out any advantage that a wind may give to help your speed.  Since I don't have the test that is being talked about on the Phantom bike and how the speed was derived I don't know that tests parameters.
  Going back to mixing the comparisons, I was talking about bikes(CanAm 175) built in a R & D center in Beaumont Texas for the specific purpose of going fast in a straight line.  This is where the rear wheel horsepower part has to be examined.  If one questions the horsepower question look at NASCAR cars.  They atarted out with very poor aerodynamics and HUGE HORSEPOWER.  Now with low horsepower (relative to the old days) and great aerodynamics, less friction on all moving parts and a lot of $$$$$$$$$$ for testing you see cars that they are having to slow down with other modifications.
  I hope you take all this discussion as two people just comparing notes.  
Respectfully

Ron Carbaugh

[dirtbike]

Ron, We keep it cool but I'm talking about a dirtbike! The ebay item clearly was a dirtbike. 45+ horsepowers is for a dirtbike too. That bike at ebay was said to have run 147 mph. I would bet quite a substantial sum of money that it would (could) never ever had cracked 110mph. I don't belive it's even close to possible. I'd say that 100-105mph is absolutely the upper limit for a old 250cc DIRTBIKE regardless of gearing and with a rider of course.

You said that the can-am 175 was a bike too. What kind of bike? Certainly not a dirtbike I assume. A specifically designed slipstreamed aerodynamic bike could, of course crack 150mph with a 175cc engine.

Oh, with all respect, we just talked beside each other. Of course can that displacement go in that speed whereas I, in my mind only thought about a dirtbike. My comparison with a GP bike was just to make my point. Not even those can with much better aerodynamics, far more power and all travel in those speeds.

[Larry Perkins]

I am going to jump in and play with this.  

I agree that a 250 dirtbike from the old days in stock trim probably can't go 147mph.  However with proper gearing and the right aerodynamics a motorcycle can reach tremendous speeds at Bonneville. So I think you are both correct.

John Howard a famous bicyclist went over a 100mph on a BICYCLE at Bonneville and he has less horsepower than an 80cc bike.  The bicycle was geared so high he had to be towed to about 70mph.  Also any dirtbike of any displacement can do about 120mph if dropped out of a plane as that is approximate terminal velocity.  I wouldn't want to ride it, though.

As a side note I rode the bike for awhile that was the fastest dirtbike ever tested-The 495 in Dirtbike Magazine.  When Dirtbike was done with the test 495 it went back to KTM and was refurbished.  It then went to Letko Cycles in Kansas City.  I got it from Jim and Jim at Letko and raced it in the 1984 World Championship Desert Race put on by Casey Folks on the Nevada/California state line area.  Rough-Rocky-Brutal.  It was the bike I mentioned doing the High Speed wobble on in a previous post.  I was practicing bomb runs(starts) the day before the race and going about 80 or 90mph wicked off the throttle real fast.  I had heard the term head shake but finally understood the true definition making a mental note to never wick off a throttle like that again.  It was a real pants wee deal.  

Larry

[Steve Minor]

Nothing like a 90MPH "Tank Slapper" to get the ole heart pumping...huh Larry?

I'd never have the guts for 90+ in the desert.

1977 400 GS6 Original Owner
1977 125 GS6 Project
1978 400 MC5 Project

[firstturn]

Dirtbike,
  I doubt the bike you are talking about broke 100mph.  We are cool and I was just respomding to you post.  Have a great weekend.  The CanAm was a dirtbike sold in the 70's and built by in Canada and sold in different parts of the world.

Ron Carbaugh

[Larry Perkins]

Steve

Not sure if guts is the right word.  Lack of brain, death wish, or just the old, "Sticks and stones may break my bones but GLORY is FOREVER!"

Larry