|After the original engine from this racebike has surfaced, the time has
come for this piece of Danish motorsport history to resurrect.
Step one is to verify the originality.
Step two - setting a deadline: Classic race Århus - june 22.
|I´m not sure about those "Sterbenz" inscriptions to be found here and
there. Undoubtedly referring to the great Puch- racing engineer Albin
Sterbenz - could have been added for fun later on - to gain a little
top- speed :o)
Just like adding a Yoshimura sticker onto your Honda moped, which I
swear I´d never done myself - previous owner did that!!!
Turns out this that this engine in fact was prepared by Sterbenz himself!
I have been in contact with Herr Sterbenz, Graz, and he explains:
"During the day I worked with developing new models and engines,
and evenings I worked on the race- engines. As a matter of fact,
in 1965-66, I drove a similar bike in some races in Austria, so
when my old colleague in Denmark wanted a racebike, I knew what to do."
|Modifications to the Geländesport engines were a special close
ratio transmission of the pull- stud variety, a 22mm Bing carb
and an expansionpipe developed via dyno- testing.
Result was 10,5hp on the Schenck- engine dynamometer.
Seasons 1965 and 66
|Very interesting picture:
First? outing for the special built Puch- racer at Roskilde Ring 1965. A mixed field at the start line showing the Puch special in its initial layout:
fancooled engine and rubber- covered footpegs! The rider is Billy Kraul, the first to race the Puch and to the right is Dan Jeppesen, the second
and most successful rider, astride his CB72 Honda, on which he became Danish 250cc champion same year! The fairing seems to be different
from the Bultaco- type used later?
Notice how the footpegs in its original mounting keeps the driver sitting
upright, compared to Jørgen Nielsens driving position on the 12- speed
Fast forward to 1967 and Ring Djursland, where Dan Jeppesen outran a whole field of fast fiftees!
The first colour photo I´ve seen of this bike! Picture by Göran Kähler.
There must be a lot more out there???
|In a strong field of 50cc racers, Dan Jeppesen finished the two heats in just 13:42:7, second place 14:11:4.
From left: #4, Lasse Johansson- HM Sachs, #12 Dan Jeppesen- Puch, #15 Oluf Steffensen- Sachs, #7, #10 Jørgen Nielsen- Derbi, #3, #2 Hasse Larsson- Honda, #11 Chris Fisker- Tomos special.
Next race Ring Knutstorp:
The fast pace of the Puch were too good to be true, and protest were given.
Officials asked Sven Håkansson to check engine for size.
Another win for Dan Jeppesen!
Now forward to 1968 - a remarkable year for Dan:
Knutstorp - another win for Dan!
|Next race was a surprice for me!
Dan borrowed the Puch and went on to join the 1968 GP of Germany at
Nürburgring! Dan had driven on this track some years before on a 250
Honda, and liked the Südschleife enough to give it a try with the
fast Puch. A change of gearing was called for and as a result of this
Dan had to depart because of a loose rearwheel - axlenut completely
missing. The fun part: Dan was in fourths place when this happened!
A very rare DNF!
Can anybody contribute to this
Next race on a new Swedish track, Sviestad, Linköping.
"A race- long battle with Lennart Lindell, rubber on gearlever fell off,
causing a missed shift in one of the last corners, and he got away"
Dan Jeppesen 2012.
In 1969 Dan took the Puch "home" to an invitational- race in Austria.
In the landscape of hilly Groosraming, Dan experienced another protest
shortly after setting the pace in practise. The bike was put on a scale
and found grossly underweight! A ballast was prepared but the Austrian
Rennleiter intervened and deamed the ballast unnessecary!
Due to the tracks lengthy descents, it was necessary to drill holes in
the front anchor plate to enhance brake cooling.
Result of the 1969 Groosraming race:
1. Dan Jeppesen, DK, Puch
2. Hans Hummel, A, Kreidler
3. ? , A, Puch
4. Raimund Luritzhofer, A, Kreidler
5. Harald Bartol, A, Kreidler
A lot of press followed this victory and Dan and the Puch appeared
on the frontpage of the "Danish Motor Unions" monthly magazine!
In 1970 Dan appeared in Knutstorp again.
Here he was challenged by the 15hp Jamathi GP bike of Swede
Leif Rosell,and must have felt a little outdated on the 10,5hp Puch?
Taking second place behind Rosell had shown the sign of the times,
and to my knowledge, caused the retirement of this special Puch?
|To sum up the adventures of Dan Jeppesen and this Puch:
1967 Ring Djursland DK 1st place
1967 Ring Knutstorp S 1st place
1968 Sviestad S 2nd place
1968 Ring Knutstorp S 1st place
1968 Nürburgring D DNF (while in 4th place)
1969 Groosraming A 1st place
1970 Ring Knutstorp S 2nd place
Quite a record to say the least, having in mind that, to my knowledge,
the engine did not see any updates during three seasons of racing!
A big cadeux to the work of Albin Sterbenz, having developed a low rpm
(remember the crank- mounted clutch) high torque engine, connected to
a close ratio 6-speed, making it very easy to drive on all tracks.
To be continued...
|Doing a remake of this awesome machine demands a lot of research as
well as respect from my side. I feel it absolutely neccesary for it
to be correctly executed and maybe this will not happen within
deadline, but as a continuos update?
The original frame was from a series 1 Puch MC50- 1965 model.
The frame used for the replica is a series 3 frame with minor
alterations. Puch models Pioneer and Ranger got this frame.
|Trying to establish correct engine placement.
The engine was installed in a backwards rotated position as can be seen from the pic of the ISDT Puch. This awkward angle of the engine leaves a real tricky relationship between chain and shifterarm!
Modifying a VZ50 frontfork to resemble the one on the racebike.
Puch MC50 forktubes had different measurements, note total length
and placement of bushing. Head stock on MC50 frame were shorter so
lower triple- clamp had to be modified.
Rear fork/ swingarm had to be extensively modified demanded by
engine- placement and expansion- chamber routing.
Lower portion, including the side-to-side tube connection, had
to be removed, so a new tube had to be fitted.
And as you can see, now theres no room for the rear tire!
An old- fashioned and very different way of mounting a tank on a frame!
Secured by leather- straps and resting on rubber and felt.
Special curved brackets with pockets for the felt supported tank in front.
Used more than half a day to fabricate those brackets - only to discover
that due to the tank being lowered on the frame, they were not actually
used on the racebike! Bummer!
|Sponsored fairing had taken a fall - and a slide - at 100+ km/t!
Furthermore it was a very thin max-two-layer version, so I
didn´t mind giving it another layer, strengthening the
weakened structure. Made a wooden jig to keep everything in
check while plastering away.
|The premier race- date arrived and after a 42 year break, Dan was ready to enter the Puch.
In the beautiful surroundings of Marselisborg Castle, the Puch came to life and for some laps, the sharp clean sound of the Sterbenz- designed "Rennbirne" gave reminiscence of bygone times.
However, upon closing the throttle after the demo- laps, the cylinders chrome- layer decided to loosen with a resulting seizure.
Now the bike is being readied for the BIG Classic- event at RingDjursland 8- 9 September:
Enjoy the pictures by Trine Nieburh:
|Readied the Puch for a real race meeting which necessitated some upgrades:
Silencer, chainguard and sponsor- decals :o) Barrel returned with an .5
overborea and a fresh coat of Nikasil and fitted with a Puch ELKO race-
piston. The piston had a skirt some 2mm shorter on the intake, which
caused some reversion through the carb, and made starts difficult.
|An overall good experience to be able to race the Puch myself :o)
Very smooth and predictable in spite of the street rubber! The Sterbenz
designed 6-speed pullstud transmission were main reason for lapping faster
than the Honda.
Inside the Puch works engine:
Had to disassemble the engine to fix that annoying oil leak.
And I must admit that I was a little bit curious too :o)
The somewhat oversized axle(17mm) for the gearchange were sealed
by an o- ring squeesed in between left crankcase and a washer, and
held in place by a circlip. But the splines were cut a little bit to
deep, and o-ring leaked.
|Lots of space here - for the pull- stud to extend.
And note the primary drive with a high ratio: 1,56: 1.
|Roller bearings - three in all here!|
Can´t help thinking how easy this project has been, and how someone
could easily make a replica using the more common "Cobra" engine.
The Bultaco- type fairing hides engine completely, making the
racebike look like the real deal!
And now someone has done just that, Alexander Waldhart of Austria
has made this replica: