Quelltext der Seite The Heidemann 30-inch-wheel bicycle

The Heidemann 30-inch-wheel bicycle from 1988
Nearly one hundred years before the Heidemann 30-inch-wheel bicycle came on the market, Wilhelm Wolf published his book “Fahrrad und Radfahrer” (Bicycle and Cyclist) in 1890.<ref>Wolf, Wilhelm: Fahrrad und Radfahrer, Leipzig 1890, Reprint: Die bibliophilen Taschenbücher Nr.106,   Harenberg, Dortmund 1980, p. 43</ref>  In the chapter about wheels he wrote: “At the lower bicycle we usually find two wheels of the same size; 30 inches, 76 cm in diameter.” But from 1900 onwards, the wheel size of 28 inches had become standard. From 1926 onwards, no more 30-inch tires were available in German bicycle part catalogues.  
A hundred years after Wilhelm Wolf´s book, in 1986 and 1987, we find several advertisements in the Radmarkt magazine (“Bicycle Market”) for tall bicycles for tall people.  The height of the frame of the Heidemann 30-inch-wheel bicycle was 64 centimetres, but the company Zweiradtechnik Thumel advertised an even higher frame of 69 centimetres for a 28-inch-wheel bicycle. (Fig.1) 
The frame maker Kwadie from Bielefeld advertised 61 centimetre frames for a 24-inch-wheel bicycle and 66-centimeter frames for 26-inch-wheel bicycles. Kwadie asked the Radmarkt readers : “Are you looking for bicycles for our young generation – young ladies and young gentlemen - , who will grow up much taller?” (Fig.2)
These examples show that a demand for tall bicycles for tall cyclists was in the air at that time.
Professor Fieblinger from the Technical College in Kassel was a promoter of the Heidemann 30-inch- wheel bicycle. He emphasized the need for taller bicycles. However he argues against the combination of high frames and 28-inch wheels. In his “scientific” essay of five pages in the Radmarkt issue no.2 of 1987 2 he wrote: “For a frame size of 63 cm upwards a bicycle with 28-inch-wheels looks out of proportion, problematic and ugly.” (Fig.3)
The idea to build a 30-inch-wheel bicycle for the group of very tall people came from the chief journalist Johannes Lübeck (Fig.4) of the journal Radmarkt. The bicycle journal Radmarkt has provided the German speaking bicycle dealer and bicycle producer community with bicycle news for 125 years. Johannes Lübeck promoted his idea of larger wheels in the magazine. 
In a personal conversation, he convinced the owner of the Heidemann-Werke-Einbeck,  Gerhard Heidemann (in his last year as owner and chief) of the virtues of the new wheel size 30 inches. Willi Kellner (Fig.5, Fig.6), the frame designer for the Heidemann bicycle factory, told me that he was asked to join the conversation when Gerhard Heidemann and the chief Radmarkt journalist Johannes Lübeck met in Heidemann`s office.  Willi Kellner was intrigued with the challenge of the new task.
Willi Kellner (Fig.5) had learned the profession of draughtsman/technician before he became chief bicycle frame designer at the Heidemann Company. He left the declining Heidemann bicycle factory in 1988, ironically soon after the Heidemann 30-inch-wheel bicycle came on the market.  He then started his own bicycle business BTG Bike Tech. 
The Trading and Marketing chief for Heidemann, Bruno Henke (Fig.), invented the names Super 30 (Fig.7) and High Touring (Fig.8) for the new top-class bicycle with the big wheels.
The word High was supposed to show that the bicycle had a high frame, it was intended for tall people and also had big wheels. 
The word Touring was meant to imply that it was a bicycle for tours, but definitely not a mountain bike, racing bicycle or city bicycle. The German word “Tourenfahrrad” was at that time associated with the cheapest and simplest product of a bicycle factory. By using the English word “Touring”, the name sounded much more exclusive. At the same time the East German DDR company, IFA-Mobile in Nordhausen, produced a bicycle called Touring as well. Their cheapest bicycle model, type 102, a very simple 26-inch-wheel bicycle, had to be given more prestige by the English name “Touring”. It is on display in the “Tabakspeicher” local museum in Nordhausen in Thüringen. (Fig.9)
Heidemann also used the name Super 30 for the 30-inch-wheel bicycle (Fig.10). A beautiful Heidemann Super 30 is in the collection of Heinz Fingerhut, owner of the Velo Classic shop in Hüllhorst (Fig.11). The Super 30 was advertised as a “world novelty, noble and sporty, for tall people, who want to ride easily, safely and relaxed.” The High Touring and Super 30 had the HWE sticker on the head tube, meaning Heidemann-Werke-Einbeck (Fig.13).
Another name used for the 30-inch-wheel bicycle from Heidemann was the Diplomat. The Diplomat was produced for sales through department stores and other big dealers. Diplomat had been the original name given to small motorcycles with 98cc motors produced by Heidemann in the 1950s. Most consumers were not aware that the Diplomat was in reality a Heidemann bicycle. The head tube did not have the HWE sticker.  Instead a blue letter D was displayed on the head tube.

Frame design
The prototype of the new 30 inch-wheel-bicycle was introduced in the offices of the Heidemann factory in Einbeck on a so called bicycle-dealer-day (Fig.3). It was a concept-model with only one top tube. The frame was 68 centimetres high. Professor Fieblinger wrote an article in Radmarkt issue 2 in 1987 about the new concept.2 On the bicycle-dealer-day, some dealers commented that the 30-inch-wheel frame was too flexible. They asked for a second tube top tube as a reinforcement. Also they wanted a smaller frame as 68 centimetres was too high for many customers. The circle of potential buyers should be made wider, they felt.
The designer Willi Kellner shortened the height of the seat tube and the head tube by two centimetres and added a second horizontal top tube. This second prototype was described in the Radmarkt in June 1987 (Fig.5, Fig.14).3 However some dealers still found the frame too high. Kellner had to reduce the frame size by two more centimetres. But now the head tube was not long enough for three lugs. So Willi Kellner created the final frame design. The second top tube now did not go to the head tube but was connected to the down tube. Now the height of the frame was 64 centimeters. The construction of the frame had to be adjusted to the lugs, that were available only in certain angles and sizes. The lugs were not made at Heidemann in Einbeck but were bought from Karl Zech at Hückeswagen in Sauerland. At that time a “beautiful” bicycle had to have a horizontal top tube. This made the design even more difficult. The bottom bracket had to be one centimeter higher than for the 28-inch-wheel bicycles. This additional centimetre did not fit with the concept of the 30 inch-wheel bicycle. The extra centimetre had to be accepted if only the standard lugs were available. The crank arms had the normal size of 170 millimeters, the same as on 28-inch-wheel bicycles. 
In the catalogue the fork is advertised as reinforced. It looks slender but the metal is thicker than in normal forks (Fig.15).

Frame numbers
All Heidemann bicycles have a three digit number on the bottom side of the bottom bracket (Fig.16). Because of that, the author assumed that perhaps less than a thousand 30-inch-wheel bicycles were produced. But Willi Kellner explained the meaning of the three digit number: the number in fact indicates the frame type for the production process. All the Heidemann 30-inch-wheel bicycles show the number 305 on the bottom bracket. Heidemann had nearly 1000 different frame constructions in their program. Sometimes the only differences were the brackets soldered to the frame for the fixation of pumps or Bowden cables or chain guards, depending on whether a big dealer wanted to equip the bicycles with long expensive pumps or cheap short pumps. The frame designers again and again tried to reduce the number of different frames.6 
The ESGE plate, also called the Pletscher Platte, on my bicycle shows the number PG 88006207 (Fig.17). The Pletscher Platte is a part of the frame and it is widely used in German bicycles to fix the back carrier with screws to the frame. The ESGE plates were not made in Einbeck at the Heidemann factory. They were bought from Pletscher at Marthalen in Switzerland, the well known bike rack manufacturer, and the ten digit numbers were consecutively pressed into the plate in the Pletscher factory. All ESGE plates for all types of Heidemann bicycles were the same. From the serial number on the ESGE plates we cannot find out the quantity of 30-inch-wheel bicycles produced.
In 1963 Heidemann was the biggest bicycle producer in continental Europe. The ten-millionth bicycle was celebrated in 1968.  In the 1980s the production cost for a normal frame was only 8.50 Deutsche Marks.6 
There were 30-inch-wheel bicycles with three different gear systems available: Sachs three-speed hub, Sachs five-speed hub and Shimano Positron PPS six-speed derailleur. They all had the same simple rear drop-out built-in to the frame. 

How many 30-inch-wheel bicycles were produced by Heidemann?
The tire company Continental had to develop the new 30-inch tire for Heidemann. Continental demanded a minimum quantity of six thousand tires and six thousand inner tubes. Otherwise the construction of a new vulcanization mould would have been too expensive. Maybe only three thousand Heidemann 30-inch-wheel bicycles were produced. Willi Kellner estimates a maximum number of five thousand 30-inch-wheel bicycles.

The 30-inch tires 
When the first prototype of the new 30-inch-wheel bicycle was introduced  to the public with only one top tube the new bicycle was already equipped  with 30-inch  tires  by Continental. Therefore there was no longer a possibility for the Heidemann company to step back from the 30-inch project because six thousand 30-inch tires had been ordered.  The journal Radmarkt wrote: “An unusual sight – to see the tire size 700-37 on the side of the 30 inch tire by Conti. The dealer will have to stock up his warehouse with this new dimension.” (Fig.18)
30-inch-wheel tires have been out of production at least for the last 10 years. Sebastian Moos, Product Management for bicycle tires at the Continental company, wrote in an internet forum in 2012 (not anymore accessible ):
“The 30-inch size tire is a heavy burden for our factory. A tire tool in size ETRTO 700 does not fit into our standard moulding machines. The largest size possible is 630 and 635 mm. The 30” size was formerly made with an old machine. The machine does not exist anymore because it cannot meet the safety standards any more. Some years ago, it was decided that the remaining demand for 30 inch tires did not justify the expense required to invest to adapt the existing machine or to buy a new special purpose piece of equipment. And the circumference of a 30 inch is quite near the circumference of a big volume 28-inch tire that some people call 29 inch. Our old 37-700 (tire) has a diameter of 774 mm, our big volume mountain bike 29-inch tire has 722 mm and the very big tire 55 mm wide has even 732 mm. So the trend to big volume 28 inch tires has not helped the development of the market for 30-inch tires. So I apologize as a cyclist to you that we cannot offer 30-inch tires any more for economical reasons.”

The 30-inch wheels
The hollow rims in the size 700x20 came from the Alesa company and the Weinmann company, both in Belgium (Fig.19). Producing rims of the new 30-inch size was technically not a problem compared to making the new tire in that size.  For the production of a rim an aluminum profile has to be rolled to the correct radius and then cut to the correct length for 30-inch wheel rims. Then the two ends are fixed with pins and welded. The 30-inch-wheel rims have only 36 holes for the spokes. More spokes would have made the wheel more stable, but then special hubs would have had to be ordered with additional holes. The holes for the nipples in the alloy rims had special eyelets, so that tightening the nipples of the spokes was easier.
The 30-inch-wheel bicycle was trialed on a test stand according to Deutsche Industrie Norm 79100 (Fig.20). The Heidemann engineers found out that imbalance of the new 30-inch wheels developed much faster than in 28-inch wheels. The tension of the spokes of the 30-inch wheel diminished much sooner.  The reason was that the number of spokes had not been increased according to the increased diameter of the wheel. And the width of the axis had not been increased according to the increase in diameter. The wheel had become instable by the increased diameter. 
Heidemann did not have machines for lacing and adjusting the wheels. This was done by several subcontractors in homework, mostly families who worked for very low prices for the Heidemann factory. One of the Heidemann subcontractors for lacing the wheels was the jail in Einbeck. The problem with the stability of the new 30-inch wheel was solved by the subcontractor family Reimann: The ready wheels with spokes in full tension and correct adjusted rims were artificially made older by bending. Reimann built a special hand driven wheel bending machine that simulated the wear of thousands of kilometers. After the bending in the machine the imbalance of the wheel was adjusted again and all the nipples of the spokes were re-tensioned. All 30-inch wheels came from the subcontractor Reimann.
Nowadays this procedure is standard in good bicycle wheels. Heidemann introduced it to the world for their new 30-inch-wheel size. Artificial wear by bending the wheel and re-tensioning of the spokes was kept as a secret in the Heidemann factory at the time. Heidemann did not want the problem of unstable 30-inch wheels to become public in the world of the bicycle industry.6

Brakes
The front wheel was equipped with a Sachs drum brake for effective wet weather braking (Fig.21). In the 1980s, only expensive bicycles were equipped with drum brakes. Compared to modern disc brakes the efficiency of the Sachs drum brake of 1988 is not as good, but it does not fade like chrome rim brakes in the wet. The models with three-speed and five-speed Sachs hub gears had back-pedal coaster brakes. The models with the Positron PPS six-speed derailleur gear had the drum brake by Sachs in the back wheel instead.

Colours
The frames were available in the colours light blue, dark grey and light silver grey, the mudguards and the chain guards were always red (Fig.22, Fig.23).

Equipment
The red chain guards were made of aluminum (Fig.22.) They came from the company Horn in Gottmadingen as the model SL23 and were specially made for Heidemann, because they had to be three centimeters longer than for normal 28-inch-wheel bicycles. The stylish red Bluemel Olympic plastic mudguards came from the SKS company (Scheffler-Klute Sundern) in the Sauerland (Fig.23). They were the best quality available at that time, they had an interior inlay of chrome foil and could be pulled, wrapped, compressed without getting torn or bended.
A rare and stylish specialty was the black plastic combination lever of the handbrake lever and the lever of the three-speed Sachs hub gear (Fig.24). This combination was not more expensive than the two single components. On my 30-inch-wheel bicycle the plastic gear lever was broken. I ordered a new one from Heinz Fingerhut`s Velo Classic shop. The lever on the handle bar for the Sachs five-speed hub was the same one as for all the five-speed hubs from Sachs. 
The black polyurethane foam saddles (Fig.11) were at that time the trend in bicycle mass production, even for good quality bicycles. At that time the better gel saddle was not yet offered. High quality leather saddles were added by the purchaser. The original polyurethane saddles are only in good condition on bicycles that have been seldom used. On my 30-inch-wheel bicycles they fell apart and had to be replaced by a similar ‘typical of the time’ saddle.  
In some Heidemann brochures we can see photos of handle bars equipped with safety handle bar grips, that have a knob on the ending. It secures the hand from side slipping and it protects the driver from getting hit in the stomach by the sharp handle bar end if he falls. Only some of the high priced 30-inch-wheel bicycles were equipped with the safety grips, not the other Heidemann models. 
Depending on the order from wholesale dealers the bicycles were equipped with a sturdy wheel combination lock with six digits from Basta or with a simple spiral lock, which was transported in a saddle tool bag. Some wholesalers ordered an additional front carrier from Pletscher. All bicycles had back carriers from Pletscher It was a custom build of the Pletscher Safari III model, with three stays on each side - made wider, longer and higher for Heidemann, with rubber straps for securing the load (Fig.25).
The handle bar had the traditional shape of a touring bicycle handle bar. Some call this design the ‘German handle bar’.  In the 1980s there had been problems with broken aluminum handle bars. Heidemann wanted no risk for the heavy two-metre tall cyclists, who were the customers for the 30-inch-wheel bicycle, so they chose steel handle bars.  Other Heidemann bicycles were equipped with aluminum bars. The stem for the handle bar came from the Friko company and others (Fig.26). The upper part of the stem is made of aluminum and pressed into a shaft made of steel. Unfortunately, the pressed connection of steel and aluminum sometimes disconnects and the steel shaft breaks. That is why the stems of many 30 inch wheel bicycles are replaced by a better all-aluminum stem. 
In Germany, all bicycles (except pure racing bicycles) have to be equipped with a dynamo powered light system of 3 Watt power, in the front and rear. The 3-Watt dynamo and the 2.4-Watt front lamp U70 with a 70 mm reflector came from the Union company. The bulb of the headlight was a normal 2.4-Watt 6-Volt incandescent light bulb, not even a halogen bulb. Only in the brochure from the last production year 1993 the headlight was advertised as a halogen beam. The backlight of 0.6 Watt had already a reflector and its protective cover was advertised as a special quality.  At that time the electric litz wire of bicycles normally was braided from 7 wires. Heidemann used litz wires braided from 11 wires. It was a one polarity system. The metal parts and the frame of the bicycle were the second pole. The price for the one pole wires was under 10 pfennig. The wire passed through the tubes of the frame and through the bottom bracket. If a broken wire had to be replaced, the bottom bracket axle had to be removed for the repair. The cost of this repair was over 50 marks. In many times these costs were avoided by fastening the electric wire on the outside of the frame. Willi Kellner is still angry about the bad electric bicycle light systems of that time: “The lights only needed to be working in the bicycle shop, when the bicycle was sold.” His proposals for better electric bicycle wiring and light systems never prevailed in the Heidemann company.
The kickstand was a high-quality two leg ESGE stand from Pletscher. It folded to the left side when not in use.

Price
The Heidemann 30-inch-wheel bicycle was very expensive at that time. The author’s bicycle was sold on the 17th of April 1991 by the bicycle dealer Pott in Oyten near Bremen to the seventeen-year-old two metre tall man Arnd Willem for 1100 Deutsche Mark. (Fig. 27) For comparison: The price for the small 50-cc Simson motorcycle imported from the German Democratic Republic was, at that time, only 1300 Deutsche Mark in Western Germany. 
Accurately the dealer noted in the bicycle passport all the high quality equipment, the colour of the frame and of the mudguards, the standard shape of the saddle, the Pentasport five speed hub, the size of the tires, the Safari carrier, the Sigmasport speedometer, and even the black color of the Bowden cables (Fig.28).
I bought my 30-inch-wheel bicycle two years ago from the first owner for 50 Euros. The most important to look at if you buy a Heidemann 30-inch-wheel bicycle is the condition of the tires because they are no longer available as spares. The tires of my used 30-inch-wheel bicycle were nearly new, the thin rubber moulding marks on the running surface were not yet worn off. 
The German Ebay Kleinanzeigen is presently (May 2017) offering a Heidemann 30-inch-wheel bicycle for 295 Euros and another one for 500 Euros. Two years ago the auctioneer Dorotheum in Vienna sold a blue Heidemann 30-inch-wheel bicycle with the five speed Sachs hub for 938 Euros and a frame without wheels, handle bar and saddle for 250 Euros.
Seldom can one find 30-inch tires on the German Ebay site. A friend bought recently two new tires  on Ebay for 45 Euros each. Often the owners of 30-inch-wheel Heidemann bicycles give the machines to the bulk rubbish, because they cannot buy new tires. 

Other big-wheel bicycles
In America at Walmart, 32-inch-wheel Genesis beach cruisers with 48-spoke wheels were offered for only 199 dollars. They were not made for very tall people, but had a low frame. They were a lifestyle gadget for ‘everybody’ (Fig.29).
The frames of the 36-inch-wheel monster cruiser by Kiwibike from New Zealand are sized for normal people as well (Fig.30). They use the same 36-inch wheels with only 36 spokes as unicycles with the tire size 36 x2,25 (Fig.31).
These 36-inch wheels and tires are also used for the Gentlemanbike, a small high wheeler with a free wheel drive (Fig.32).

History of the Heidemann company
The predecessor company in Einbeck was the Stukenbrok company, a bicycle factory and technical department store and mail order business since 1888 (Fig.33). Stukenbrok became insolvent in the world economic crisis in 1932 and closed down. The Heidemann bicycle factory moved in 1937 from Bielefeld into the empty Stukenbrok factory in Einbeck. 
In the 1960s the Heidemann factory became the largest bicycle factory in continental Europe.  Some well known bicycle brands were badge-produced in the Heidemann factory, for example Adler and NSU. The bicycle production of NSU had been sold from Neckarsulm to Einbeck to make room for the automobile production of NSU in Neckarsulm.  From the 1960s on Heidemann added the production of automobile parts. The manufacturing of car parts brought a lot more money than the bicycle production (Fig.34).
In 1961 Heidemann created new jobs in Rotenburg near Bremen for the unemployed workers of the Borgward car factory in Bremen. Borgward had gone bankrupt in 1961 and closed forever. In the 1980s Heidemann went into an economical crisis. In 1986 Robert Stafflage (Fig.37 and Fig. 5) took over as managing director and owner from Gerhard Heidemann during the crisis. He strengthened the departments of the company that were involved in the production of automobile parts and divided them form the bicycle production. In 1993 the bicycle production department went bankrupt and was sold to Asia. From then on Heidemann produced only car parts for VW, Ford, BMW, Audi, Porsche and others (Fig.34).
Robert Stafflage writes about himself: “The intelligent manager transformed the provincial Producer of bicycles and car parts into an automobile system developer and into a global player.”7 In a conference of managers Stafflage illustrated the situation of the Heidemann group in the crisis of the 1980s in a sketch (Fig. 35, Fig.36). It shows what he achieved between 1987 and 1999.5,7
Stafflage sold the Heidemann group to British investors in 1997. From 1999 on the company belonged to the American car parts producer DURA in Michigan. DURA was later taken over by Patriarch Partners with a worldwide volume of 8 billion dollars. The owner is Lynn Tylton. There are internet sites with a lot of photos of her. She writes about herself that she ‘saved many American jobs’.<ref>https://www.patriarchpartners.com/lynn-tilton/</ref>

Closing remarks
Although the Heidemann 30-inch-wheel bicycle design is hardly 30 years old it is a wonderful collector`s item. I have seen it in several German private collections and in museums. It will be a ‘must –have’ one day.  If you look for one on the internet do not type ‘Heidemann 30-inch-wheel bicycle’ because there will be no good results. You get the best results with “High Touring”, “Super 30” and “Diplomat”. Do not go to an auction in Vienna!  You will find your rarity in the German ebay.de or in ebay-kleinanzeigen.de for a small part of the original price. 
If you are a tall person and you want to ride the bicycle, buy one with good tires. If you do not want to ride it, if you only need it for your collection or to look at it, you can take a very cheap one with bad tires. 

Sources:
1.	Wolf, Wilhelm: Fahrrad und Radfahrer, Leipzig 1890, Reprint: Die bibliophilen Taschenbücher Nr.106,   Harenberg, Dortmund 1980, p. 43
2.	Fieblinger, Günter: Große Fahrräder für große Menschen, Radmarkt, issue no.2, pp. 39-44, 1987
3.	Radmarkt, issue no.6, pp. 73-75, 1987: Durch Zurückschneiden zu besseren Erträgen
4.	Hannoversche Presse: Größte Fahrradfabrik auf dem Kontinent, June 4th 1963
5.	Conversation with Heidemann managing director Robert Stafflage in 2014
6.	Conversation with Heidemann chief designer Willi Kellner in 2017
7.	http://www.insm.de/insm/Themen/Arbeit/Robert-Stafflage-eine-Unternehmer-Biografie.html 
8.	https://www.patriarchpartners.com/lynn-tilton/


== captions for illustrations ==
Belongs to the paper: Heidemann 30-Inch-Wheel Bicycle from 1988
Short caption for each illustration that tells the reader what the illustration is all about:

Fig. 1   	A high quality bicycle with a 69-centimetre frame was advertised in        1987 for tall cyclists by Thumel.
Fig. 2   	Kwadie advertised tall frames for 24- and 26-inch-wheel bicycles.
Fig. 3   	Fieblingers “scientific” article of five pages about the need for 30-inch-wheel bicycles.
Fig. 4   	Chief journalist Johannes Lübeck of the journal Radmarkt convinced Gerhard Heidemann to bring a 30-inch-wheel bicycle on the market.
Fig. 5   	The makers of the Heidemann 30-inch-wheel bicycle, from left side: 37-years old designer Willi Kellner, chief manager Robert Stafflage, sales manager Bruno Henke with the second version of the frame design. The second top tube was meeting the head tube and the height of the frame, 66 cm, was still too high. 
Fig. 6   	Most of the information for this essay was given by chief frame designer  Willi Kellner, now 67 years old.
Fig. 7   	A price tag of the Super 30 Heidemann bicycle for use in a bicycle shop. It was fastened on the handle bar in the bicycle shop. “The bicycle for the long ones. Special frame, reinforced, with double top tubes. Height of the frame 64cm. For body sizes upwards 1,85 meters (73 inches). …..”

Fig. 8   	HEIDEMANN HIGH TOURING was one of the three names.
Fig. 9  	The counterpart: East German low quality bicycle called Touring in the “Tabakspeicher” museum in Nordhausen.
Fig. 10  	The bicycle for tall basketball players. A catalogue from 1990.
Fig. 11  	The Heidemann Super 30 in the Fingerhut collection with the original black polyurethane foam saddle.
Fig. 12  	------------
Fig. 13  	Super 30 and High Touring had the Heidemann logo HWE on the head tube.
Fig. 14          The second prototype 	had a 66-cm frame and two top tubes connected     to the head tube. 
Fig. 15          Frame designer Willi Kellner´s drawing: The reinforced fork
Fig. 16  	The three digit number on the bottom side of the bottom bracket  indicates the frame design, not the production number.
Fig. 17  	The frame numbers were pressed into the Pletscher plate in the Pletscher factory in Switzerland.
Fig. 18  	“An unusual sight – to see the tire size 700-37 on the side of the 30 inch tire by Conti. The dealer will have to stock up his warehouse with this new dimension.”
Fig. 19	Alesa and Weinmann produced the new 30-inch rims.
Fig.  20	The test stand according to DIN 79100 showed severe problems with the stability of the 30-inch wheels.
Fig. 21	Sachs drum brakes in the front and the back wheel were high quality and quite expensive brakes in 1988.
Fig. 22	The red aluminum chain guard was specially designed for the long 30-inch bicycle. The pedals came from Union.
Fig. 23	Bluemels Olympic mudguards, always in red.
Fig. 24	Combination lever for front brake and Sachs three-speed hub. 
Fig. 25	Advertisement in the Radmarkt 1986 for the high quality Safari III carrier. “Globetrotters` opinion: First class”
Fig. 26	Friko stem, made of aluminum and steel.
Fig. 27	Receipt for the 30-inch-wheel bicycle from the first owner in 1991.
Fig. 28	Bicycle passport from 1991.
Fig. 29	32-inch-wheel Genesis beach cruiser from Walmart.
Fig. 30		36-inch-wheel Monster cruiser by Kiwibike from New Zealand.
Fig. 31	36-inch-wheel unicycle with the tire size 36 x2,25.
Fig. 32	36-inch-wheel Gentlemanbike highwheeler.
Fig. 33	Stukenbrok bicycle factory in Einbeck in the 19th century.
Fig. 34 	“Everything firmly in one hand”.  Heidemann´s self-presentation as an automobile part producer in the style of the seventies. Bicycles are still a part of the portfolio. 
Fig. 35 	Long time before nine-eleven: Robert Stafflage prevented the Heidemann crash. Stafflage used this sketch in a presentation in the 1990s for managers to demonstrate his success. 
		I. Fall into the crisis. II. Financial recovery and revitalizing. III. Stop of the downside trend. Stabilizing. Rise. 
Fig. 36	In 1989 when the 30-inch-wheel bicycle was in its second year of production, the proportion of the bicycle branch had gone down to 25 percent. Automobille parts had grown to 75 percent in the Heidemann factories.
Fig. 37	Robert Stafflage, owner and managing director of the Heidemann group from 1986 to 1997.

==Quellen:==
<references/>