Hand Bikes are Formula 1 cars under the wheelchairs. For this reason the modern sports equipment disabled people have supplanted the traditional wheelchairs at City Marathon. This is all the more, the more the sporting competition in the foreground. On wet roads but this fellow get in the curves already problems. The Dutchman Ad Aarts has developed such a hand bike especially for artificial and natural ice rinks. Easy to see that he also had massive problems when cornering, to keep on ice the course. These problems are due to the Dampers by ACE Shock the past.
Anyone traveling by car on icy tracks knows the unpleasant feeling when cornering. This refers to the feeling that you do not have your car under control and that you are at risk of under- or oversteering when accelerating. Technical aids such as ABS or curve assistants have defused these situations a bit, but the speed is significantly reduced in such circumstances. The term "adapted driving" is no coincidence.
That's what you had to imagine when Ad Aarts was traveling with his Ice Handbike. As long as he drove straight, he could put a constantly high speed on the ice. As soon as it went into a curve, it was only at 13 to 14 km / h. Every km / h made it happen that his homemade handbike broke out. For someone like this model athlete, who wants to spend less than 200 h on ultra-long distances of 11 km, this is unacceptable.
Not only did Aarts lose time in the corners, but accelerating out was also a limiting factor - in two ways. Because it takes not only a while until his subset reaches the optimal speed again, but on the way he also unnecessarily squandered forces. The same applies to the almost ten pit stops that Ad Aarts plans for tours around the 200 km. In contrast to Formula 1 races, new tires are not wound up, but batteries are replaced, protecting the paraplegic athlete from frostbite on his legs. Although this process takes place as fast as a tire change in the Formula 1, he still lowers the average speed.
Design optimized with oil brakesSince Ad Aarts dealt with ice-hand bikes, cornering was problematic for the above reasons. That's why he had technical support during his first conversion of a standard handbiked model for trips on the ice. At the time, he relied on industrial gas springs, such as those used to open small hoods, lids or flaps. Without them, even his cornering speed of up to 14 km / h would not have been possible. But Ad Aarts wanted more. Because he could not like the unstable cornering when using the gas springs.
For this reason, he turned to the ACE shock absorber GmbH, more precisely to their own sales in the Netherlands. Local expert Han Titulaer suggested two oil brakes with separating pistons. Normally, oil brakes serve to provide a constant feed rate along their stroke, unless high impact speeds occur. Depending on the different sizes, the closed, hydraulic and adjustable brakes cover large force ranges. They range from 50 N to 1800 N. Normal applications of these machine elements are z. As the drilling of thin sheets or sawing aluminum and plastic profiles to avoid tool breaks in the rule. The type used in the Netherlands, on the other hand, is a special model of a gas-filled oil brake, which is listed by ACE under the name "HB-22-150-EE-NT-200N".
Normally the abbreviation "HB" stands for "hydraulic brake cylinders" at the Langenfelder company. Because of their similarity to these machine elements, the special solutions for oil brakes are frequently also listed under this product name. Why is this solution so suitable in the present case? It is due to the possibility to compensate an inclined plane in the horizontal area again. Because in the curves, the seat of Ad Aarts tends to 10 to 15 degrees. The subsequent return to the horizontal range allows exactly the combination of oil brakes and gas filling, because the oil brakes dampen in this case when retracting. The gas then pushes the piston rod outside with a force of 200 N.
Higher cornering speeds realizedAlready a first test showed how well the new combination solution works as a stabilizer. Ad Aarts ad hoc managed to negotiate the curves in an ice rink without any problems with 21 km / h. But the ambitious athlete hoped even more: "That's because artificial ice is harder and smoother than natural ice and the curves on natural ice rinks have a slightly larger radius," said Aarts.
To explain: Its annual climax takes place in the open air. Because in the Netherlands in the last few years, apart from the winter, 2012-2013 was too hot for closed ice sheets at the so-called "Elfsteedentocht", a tour that links the eleven historic towns of the province of Friesland, became 2013-2014 in winter an alternative on the Weißensee in Austria held. In January, 2014 was supposed to exploit the full potential of the new solution, but even in 930 m altitude in Carinthia, the weather did not bother Aarts. Because of too heavy snowfall, the race was only one day ahead at short notice, then the snow made the track too slow. In the given time limit of 11 h it was not possible to think of a driven distance of 200 km.
Nevertheless, Ad Aarts was able to gain something positive from the day: "The cornering was great, my Ice Handbike was 100 percent stable. Still, the 200 kilometers must come out of my arms. And that just did not go by the additional resistance of the snow. But for the January 2015, we are optimistic and will be back at the foot of the Gailtal Alps. "And if it is snowing again, so the sympathetic Dutchman, then maybe there will eventually be a technical solution to this problem of ACE, a built-in snow shovel for example.
Picture above: Ad Aarts on the Weißensee in the Austrian Carinthia