Moped tuning
As a moped tuning (traditionally before the advertising language found its way into the youth jargon, fudge moped is called), the tuning of motor-assisted bicycles with a maximum capacity of 50 cc and a maximum design speed of 25 km / h (in Germany), 30 km / h (in Switzerland) or 45 km / h (in Austria). These vehicles can be brought to top speeds of more than 100 km / h through tuning measures. The simple construction of the two-stroke engines and their high tuning potential make this possible.
To ensure that the operating permit is retained despite such modifications, a re-registration with the TÜV is possible and of course required under certain conditions. In addition, a driver's license is required to drive these vehicles and the moped test certificate is no longer sufficient. If the modified vehicles are only driven away from public road traffic, the reassignment at TÜV is not necessary. However, not every modified moped can be rededicated.
Colloquially, the term “ hairdressing” is used when objects are upgraded through targeted modification; one then speaks, for example, of a souped-up moped.
Tuning measures
Resonance exhaust
The original, simple exhaust system can be replaced by a resonance exhaust . This consists of cones arranged against one another and partly reflects the exhaust gas wave emanating from the cylinder. As a result, part of the design-related fresh gas escaping into the exhaust pipe in the two-stroke engine (called scavenging loss, see: reverse scavenging ) is pushed back into the combustion chamber.
Bigger carburetor
It is possible to mount a carburetor with a larger passage cross-section so that more fuel-air mixture gets into the cylinder if the inlet port in the cylinder has also been adapted. A more cost-effective variant, which, however, requires some manual skill, is the so-called boring out of the carburetor. The cross-section of the carburettor is increased by mechanical processing and a larger main jet is used. It is important to ensure that the direct attachments such as the intake manifold and the air filter are dimensioned larger accordingly. Only a larger carburetor without a suitable intake manifold has no effect on the engine performance and makes tuning the carburetor considerably more difficult. A racing air filter is not always necessary, often very nonsensical. The standard air filter pulls, the prerequisite is a clean filter insert, usually more than enough air for tuning a 50 cm³ cylinder. It also has advantages such as the attenuation of the suction noise.
If there is not enough air, it is also widespread to drill holes in the original air filter box and filter them with textile fabrics over the air filter.
Change the translation
The easiest way to change the speed or the acceleration is to change the gear ratio from the motor to the driven wheel. A distinction must be made between different types of drive. On the one hand there is the chain drive . Both the sprocket and the chainring can be exchanged here. The larger the sprocket compared to the chainring, the higher the resulting top speed at the expense of acceleration; the smaller it is, the greater the acceleration at the expense of the top speed. Exactly the opposite is true when changing the size of the chainring.
There is also the belt drive , but a distinction must also be made between mono drive and variator drive. In principle, the same applies to the mono transmission as to the chain drive, but here the pulleys are replaced. It is not possible to replace the belt pulleys on motor-assisted bicycles with variator gears; the variator or the entire assembly must be replaced here.
Machining the piston
Since the control of inlet and outlet times in two-stroke engines is mostly done through slots in the cylinder wall that are closed or released by the piston, it is possible to influence these processes by machining the piston. There are basically two different approaches. Either the piston skirt, the part of the piston that slides along the wall of the cylinder, can be shortened by the correct amount at the relevant points in order to open the slots for the inlet earlier and longer. This results in a change in the running properties and a shift in the maximum power to mostly higher speeds. Due to the shortening of the running surface of the piston, however, it now tends to tip over and its stability decreases, which in some circumstances can lead to engine damage. The second way to modify the piston is to machine its top, which, paradoxically, is called the piston crown. The procedure is basically the same here. In some engines, the piston does not completely open the exhaust and transfer slots when it is at the lowest point of its career, the bottom dead center. Material is now removed from the corresponding points on the piston crown so that the piston can completely clear the slots.
Machining the cylinder
On cylinder many modifications can be made, which mainly relate to the transformation of control slots in the cylinder wall. It is possible to change the shape and size of these slots in order to adapt and optimize the timing and thus the running properties of the engine. Most of the time, these changes affect the outlet and inlet so that they can be opened earlier and, by enlarging them, improve the flow of fresh and exhaust gas. In this way, the maximum power of the engine is usually placed in higher speed ranges. The overflow ducts are rarely modified because they require the use of special tools because of their difficult accessibility. Another possibility is to increase the compression by turning the cylinder or the cylinder head . An increase in performance is to be expected. After this change, a fuel with a higher knock resistance may also be necessary.
Cube sets
Another possibility to tune is to increase the displacement with so-called "cube sets". The cylinder and piston with a larger bore diameter achieve a larger piston crown area on which the combustion pressure acts. Due to larger inlets and outlets, racing carburettors with a larger cross-section and exhausts with a larger pipe are required. In most cases, additional transfer ports (boost ports) are incorporated into the cubic sets. With such cylinder kits, a very high power output of around 14–35 hp is possible.
Optical tuning
To beautify the moped, parts of the moped are often repainted or special add-on parts (due to the now larger range, more and more from the scooter tuning scene) such. B. side stand, other handles, etc. used. So-called "underfloor lighting" (neon tubes in different colors) are also being installed more and more frequently. Another type of optical change is the chrome plating of various parts such as B. the tank.
Frame parts are often painted with so - called flip - flop paint, which creates a multicolored effect in the light. It is also common to remount the rearview mirror on the handlebar so that the mirror hangs down on the handlebar. As in the motorcycle scene, aluminum flame models are also mounted on the exhaust and tank (see picture on the right). Also handlebars of other designs, e.g. B. "M-handlebars" or slightly curved, almost straight handlebars are mounted. Side-mounted insurance labels are also popular. Some technical, non-registrable or registered changes can invalidate the vehicle's operating license.
Legal consequences
Anyone who "fudges" a moped has to have it re-registered with the TÜV, provided that one wants to use it on public roads. However, this is usually relatively expensive and time-consuming and the applicable requirements for the vehicle, which are always strictly observed during acceptance, must be observed very precisely. Even minor deviations can prevent a successful re-registration. Most of the time the project fails because of the braking system and the chassis, as these are not designed for higher speeds and therefore have to be reinforced or modified. Furthermore, the maximum speed of only 25 km / h for mopeds determined by the legislator is set relatively low, which means that many young people but also adults dress their mopeds and thus participate illegally in public road traffic. If you are caught by the police for the first time, the criminal proceedings are usually suspended against conditions. The conditions can be traffic education or social hours. The termination of proceedings is based on the division process. This presupposes that the perpetrator shows insight and regrets his actions. The only thing the police usually do is send a report to the driver's license office. Until the process has been completed and the requirements have been met, you are banned from further driving test. If you are caught the second time, basically the same thing happens as the first time, only that a hiring according to the division procedure is no longer practiced. If you are convicted, you will most likely continue to receive social hours, but there are an additional 6 points in Flensburg. If you are noticed twice by the driving license authorities for driving without a driving license, this means that you have to go to the MPU (medical - psychological - examination) before applying for a driving license. The costs incurred for this can range from 300 to 700 euros, depending on the state and city.
Insurance and tuning
In the event of an accident, the vehicle owner's insurance must pay the opposing damage, but there is an exception: If the tuning can be proven to be responsible for the accident, the motor vehicle liability insurance has the option of reclaiming up to 5000 €. A comprehensive insurance does not have to pay for the damage to the moped in such a case. Due to driving without a driver's license, insurance cover and expiry of the operating license, the driver takes part in public road traffic illegally, which is why it is not uncommon for high fines or monthly or one-off compensation for pain and suffering in a traffic accident in which people have been injured Drivers are attached - in the worst case, there is even a risk of imprisonment because the tuning was negligent. This can even happen if the driver is only partially responsible.
Tolerances
The manufacturing tolerance is 10%. This is based on the design- related maximum speed of the vehicle. With a moped, the tolerance is around 3 km / h - which results in a maximum top speed of 28 km / h.
Individual evidence
- ↑ a b c d Moped tuning, hell ride for youngsters. In: Thomas Soltau, Der Spiegel GmbH & Co. KG, Hamburg, www.spiegel.de. November 25, 2008, accessed November 6, 2019 .
- ↑ a b c d Hairdressing the moped. In: Einbock GmbH, Hanover, www.fachanwalt.de. 2019, accessed November 6, 2019 .