I want to help PENTON owners get information that has been gathered and saved over the years from many PENTON owners. PENTON motorcycles was always changing. So if you see something listed here that is not correct, please e-mail me. My good friend who has been collecting PENTON bikes for years helped me with this information. Thank You.
Frame Numbers: 1972 through 1977 all have eight numbers on the steering head. The last five are the searial number. The first three is a code for the date it was made. The first number is the year. The second number is the month. (20251030 would be February 1972). The 2 meaning 1972 and the 02 meaning the second month, February. Some even had a 7 or 51 or 54 ahead of all the other numbers. The 1976 - 1977 PENTON MC5 model and the 1977 GS6 model used something different. They started with 550 for the MC5 model and 701 for the GS6 model. But always remember the last five numbers are the serial number.
Engine Numbers: The engine case has the number stamped on it on the ignition side. The first number is the model year and the next two numbers tell the size of the motor. Once again the last five numbers are the serial number. (the first number 4 would mean 1974). The numbers went like this. 51 means 125cc & 52 means 175cc & 54 means 250cc & 55 means 400cc.
The Era of Steel Tankers:
First Year 1968 starting with serial number V001
Sachs 100cc motor with a 5 speed called the "Berkshire" Red in color on the air box, the rear shock body and the gas tank.
Sachs 125cc motor with a 5 speed called the "Six Day" Green in color on the air box, the rear shock body and the gas tank.
Every frame came painted silver.
All gas tanks were 2.5 gallon and made out of steel.
Small PENTON decals, white in color with the name and motor size on the upper front sides of the gas tank with the lettering being either straight or angeled.
The Sachs motors all came with a cast iron cyclinder (Known as the Iron Barrel) and a vertical finned head or a short finned Sachs sunburst high compression head or even a PUCH short finned sunburst head that overhung the cyclinder.
The Sachs engines came with a Bosch ignition that used points and had a 24mm Bing caruretor on them.
The air box was cast aluminum 10 1/4 inches in size tall enclosed frame style. Then later same year models came with a smaller shortened 7 1/2 inch tall version air box for better air flow.
The frames came without welded on fork stops if it was equipped with Ceriani steering dampener that contained an adjustable dampener knob on the triple clamp and self contained fork stops. Later that year same tear models came with the frame welded fork stops and no steering dampener unit on them.
The early model PENTON gas tank came with a twist off gas cap and the later models came with a flip top gas cap.
Their was a two piece engine mount on the front.
The exhaust pipe was chrome.
The seat was 15 inches long and the bike had 35mm Ceriani forks on it with the long rubber accordion boots for protection. The fully covered rear shocks were also Ceriani with the model year paint color on them and finished in chrome.
The rear sprocket assembly was a 4 bolt carrier hub assembly and had a 20 inch steel chain guard along the top. Also had a curved style center stand.
The controls were made by Magura in oval shape and then later in round shape.
Three inch narrow aluminum front fenders and a tubular style front fender brace was used.
A non high breather frame with a skid plate welded to it.
The exhaust pipe had a stinger tip on it.
Cast aluminum barrel style front and rear hubs were used.
The rims were either aluminum or chrome with chrome spokes.
The head lite was a large color coordinated long bullet shape being 5 3/4 inch in diameter and 7 3/4 inch long.
A lot of things were the same as the 1968 except the following.
The Ceriani rear shocks are now painted black with the chrome bell top.
Shorter chain guard made of aluminum and only 11 inches along the top of it.
New high breather frame with a 8 inch round air box with a plastic grey cover on it.
Now a 6 bolt rear sprocket carrier. The spokes are painted silver.
Center stand is straight with a flattened angled mounting area.
An experimental 175cc Jackpiner is unvieled. Bronze in color with silver side panels and a 175cc PUCH engine. Six speed with the Bosch ignition and a 27mm Bing carb. Also came with Cerani front forks and rear shocks and the Magura controls on it. Never was put in production.
A new second 175cc Jackpiner was introduced in a small quanity mounted with a blue gas tank and white side panels with a white PENTON Jackpiner sticker on the gas tank sides. Even some 175cc blue gas tanks were found with the 125cc Six Day stickers on the sides of the gas tank.
The Sachs motor used on the early 175cc Jackpiner was actually a 152cc Sachs cast iron conversion kit. They were actually Berkshire bikes converted over because the Berkshire was not selling well.
The Sachs 100cc and the 125cc motors are now aluminum and have the wide sunburst head for much better cooling.
Bosch ignitions were still used and they still had a 27mm Bing carb.
The exhaust now comes with a removable muffler.
The swingarms are made more sturdy with gussets welded on them.
The head lite is 5 3/4 inch bowl shape.
A lot of things were the same as the 1969 except the following.
They now come with a longer 20 inch seat.
The same 35mm Ceriani front forks without the rubber boots.
The center stand is straight.
A wider front fender brace.
A frame extension is put on to mount a moto cross down pipe.
Gas tank comes with holes to mount a leather tool bag on it.
Rear frame loop is strengthened.
The skid plate is now removable and the frame tabs are enlarged for the swing arm pivot bolt.