Saturday, November 1, 2008

Jeinkel-Heimer the story On the Fritz


Since little is known about the origins of Ernst ‘Fritz” Jeinkel and Heinrich “Heinz” Heimer I would like to take this opportunity fill in some background information.

Legend has it that the boys Fritz and Heinz grew up best of friends. As children they were impressed by the two American brothers who developed flight: Wilber and Orville Wright. What impressed them most was their ability to argue back and forth about a project and come together with a plan that both approved. The boys also thought that being bicyclists was a great advantage to their understanding of the basic principles of physics. This idolization would serve them well in their future endeavors.

When they first got bicycles of their own, at ages seven and five respectively, they jokingly referred to themselves as the Wrong Brothers since their first experiments with the bikes did not go to well. A classic problem was trying to ride more than one person on one bike. Inevitably one would fall off, the handlebars, rear axel, top tube, rear rack or seat with the usual bumped head, scraped knee or other injury. Sometimes the bicycle would even get damaged. This led them to start wrenching on their equipment. Again these early attempts were fraught with problems. Wheel truing was virtually impossible for the youngsters, as was brake alignment.

Since the boys were raised in a neighborhood that was let’s say less than affluent, some of their early vehicular experiments used only three wheels. “When that’s what you got that’s what you use!” The test runs for these coasters was in a field down the side of a hill they dubbed “Kill-Devil Hill” in honor of the Wrights. Again many experiments went bad part way down the hill. But they did not give up.


They rode together a lot and time passed. As a teen Heinz acquired a part time job at a local bike shop. His tutelage there would serve him well for the rest of his life. Meanwhile Fritz in and out of service jobs was having difficulties finding a vocation. It occurred to him that a stint in the military would give him some direction so he enlisted. Because of a difference in ideology that turned out not to be a good idea.

The boys had, as they grew up, developed this concept that people should do what is right not necessarily what you are told to do. And what could be more right than combined human transportation? When they first saw a tandem cycle they thought they had found it. Riding tandems was something they totally enjoyed. The climbing power, the acceleration, the speed and even the look were the great parts but they noticed that it was difficult to talk to each other and hard to take anything along with them.


For a time an injury Fritz had sustained kept him from cycling but Heinz found a tricycle, single front wheel, covered seat at rear (a Bicycle Rickshaw from Asia ) and the boys could cycle together again. The problem with the big trike was that it was big, heavy, hard to pedal, hard to handle and hard to find a place to keep it. This led to brainstorming by the boys. Some of the things they wanted were a lighter vehicle, more standard parts, closer location for passengers and bigger payload.

After formulating an idea for transporting people who couldn’t walk Fritz took some old bikes and parts to Victor a metalworking friend and said “Could you weld these together so I can put a chair between them.” Victor in his usual relaxed tone replied “Oh, yea I could do that but when I got done it would look like crap.” Fritz rephrased his request, “Victor” he said “Would you consider these parts sacrificial and give me a platform beside my bike that is about five inches off the ground, four feet long and about twenty-six inches wide”. Victor replied “Sure I could do that”.


A platform bike was built. It consisted of a bicycle with an expanded metal floor to the right and an outside wheel to the right of that. Also there was a fold-up loading support so it wouldn’t tip when weight was put on the back of the bed. Unpainted and fresh from welding it was kind of ugly but it worked. Riding it around was fun but what ever you put in it stood a good chance of falling out and it was difficult to tie things in. The stock gears were too high to be practical and the stock wheels especially the outside wheel started to develop problems immediately. Heinz’s experience at the bike shop gave him the insight to build a set of heavy-duty wheels and develop a super low gear train. After riding the sidecar bike for a while it went back to Victor and got side-skin, tie-down loops and a grey paint job.

That bike now referred to as OLD GREY or PROTO I was used be the boys for many years and whenever any who saw it claimed “I always wanted to do something like that” the boys said “Go for it” hoping that the concept would grow. You see that Victor had done an amazing job of frame construction but was not interested in doing more.


It was years later that a close relative Eric had someone try to copy the original. It had some nice features but didn’t work quite as well. Heinz and Fritz saw the problems, offered suggestions and some materials. Eric used those and with some ingenuity of his own got the sidecar bike the White Wizard AKA PROTO II completed.


Now came the fun part. Using the experience gained from years of riding Old Grey and seeing how the White Wizard was made Heinz and Fritz ‘argued’ about the relevance of every detail on a sidecar bike. They argued about height, weight, wheel size, tubing size, closeness of cage, front and rear cage connections, pedal protection, and entrance and exit ability. In order to develop it Heinz made a miniature wire model. Eventually they agreed on a design. They then learned to bend tubing and to tack weld. After cutting shaping and tacking parts together they took their project to a welder (still unable to trust their welds) for frame completion.

Finishing the skin, filing the welds, painting the frame and installing the components went quickly after that. Now the sidecar bike the Blue Ferry or PROTO III was done. The Blue Ferry has turned out to be more comfortable and easier to handle than either of the other bikes.

Not satisfied to rest on their laurels a set of dished washers were added to the outside wheel of the Blue Ferry allowing the outside wheel to be micro adjusted for camber and toe in. Adjusting toe in turned out to be difficult because the cycle would not track without a severe steering oscillation. By adding a steering dampener the oscillation was virtually eliminated and Heinz was able to coast the Blue Ferry on level ground and adjust the dished washers to make the bike track straight. The scrubbing of the outside and rear wheel when turning was significantly reduced. And as an added bonus the steering damper also reduced handlebar pull when traveling over uneven surfaces.

The dominant belief now is that even though the steering damper they used limits the steering travel, keeping you from being able to turn around in the length of the bike, the benefits far outweigh the minor disadvantages.


This brings you pretty much up to date with JEINKEL-HEIMER development. From here the next step will be to pursue further development by creating PROTO IV. PROTO IV will be constructed of aluminum it will have a 24” outside wheel (as opposed to a 16” for PROTO I and 20” for PROTOS II and III) and hopefully a detachable sidecar. Projecting further out than this is difficult but so far bike frames have been just rugged standard bike frames. It is now only a matter of time before a custom sidecar specific frame and matching car are made. It is our belief that this cycle PROTO V will be a pre-production model.

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