DE102023112511B3 - Solid lubricant composition and its use, method for lubricating a chain - Google Patents

Abstract

The present invention relates to a solid lubricant composition comprising a solid lubricant mixture comprising or consisting of a fatty acid amide, a dicarboxylic acid or a salt thereof, and boron nitride. The solid lubricant composition further comprises a grease base and a solvent and/or a propellant. The present invention further relates to a method for lubricating a chain and the use of the solid lubricant composition for lubrication.

Description

FIELD OF THE INVENTION

The present invention relates to a solid lubricant composition, a method for lubricating a chain and the use of the solid lubricant composition for lubrication.

BACKGROUND

In many technical applications, lubricants are used particularly to reduce friction and wear. Depending on the consistency and physical state of the lubricant, a distinction is made between liquid lubricants (such as lubricating oils), lubricating greases, solid lubricants and also gaseous lubricants.

Solid lubricants, which can also be referred to as dry lubricants, typically contain particles or plates that slide easily on one another and can therefore reduce friction. Solid lubricants can be used in particular when you want to lubricate components but a) there is a dusty environmental condition; b) oily lubricants can easily be thrown off (for example when lubricating chains); c) you want to prevent clothing from being heavily soiled when touched; d) you absolutely want to prevent the lubricant from dripping; e) it is not easy to work with anti-friction coatings because there are many moving parts in contact with the lubricant.

Conventional solid lubricants, which can also be used in particular as chain lubricants, are usually based on waxes and contain black solid lubricants (eg MoS ₂ /graphite) as solid lubricants; PTFE; hexagonal boron nitride (BN); layered silicates (e.g. ceramic solid lubricants); Inorganic salts containing heavy metals (e.g. molybdenum dithiocarbamate (MoDTC)) or cerium trifluoride (CeF ₃ )) or polymers such as polyethylene or polypropylene.

However, waxes can only be used within a limited temperature range. Commonly used waxes include Alox 2213C or D. These are essentially oxidized paraffin waxes in which the carboxylic acid functionalities created by oxidation have been neutralized with alkaline earth hydroxides/oxides. To use dry chain lubrication at room temperature, waxes with a melting point around 40-50°C are often used. At low temperatures (e.g. not uncommon in bicycle chain lubrication down to -20°C) these waxes are extremely hard and have poor lubricating properties and can even limit the mobility of the chain links. At high temperatures (solar radiation; mechanical stress (e.g. motorcycle chains) the waxes melt and lose their consistency - there is a risk of the lubricant dripping or being thrown off during rapid movements.

But the solid lubricants used also have disadvantages: black solid lubricants such as MoS ₂ or graphite have a high contamination potential, PTFE is problematic with regard to microplastics and per- and polyfluorinated alkyl substances (PFAS); hexagonal boron nitride is very expensive; Layered silicates have poorer performance, inorganic salts containing heavy metals contain heavy metals and are usually not white, and polymers such as polyethylene or polypropylene are also problematic with regard to microplastics.

Microplastics are becoming an increasingly serious environmental problem due to their generally poor biodegradability. Microplastics also accumulate in the human body via the food chain and lead to health problems that have not yet been fully researched. Fluorinated polymers are particularly critical because they are extremely difficult to degrade. Chain lubrication usually leads to loss of lubricant. In the area of motorcycle and bicycle chains, this inevitably means a certain amount of pollution into the environment.

Lubricating grease compositions are known from the prior art, such as those described in, among others EP 2 824 166 B1 , US 2011/0306527 A1 , WO 2021/155968 A1 , EP 3 959 296 B1 , EP 2 891 702 A1 and DE 11 2017 001 618 T5 are described. PTFE or boron nitride are usually used as solid lubricants. Another example of a grease composition containing a solid such as boron nitride and additionally a soluble wax, an oil component and a volatile solvent would be: US 5,898,022 A to call.

There may therefore be a need for a solid lubricant composition that can reduce or ideally overcome the disadvantages described above.

OBJECT OF THE INVENTION

An object of the present invention is therefore to provide a solid lubricant composition that is particularly suitable for lubricating chains and can be applied particularly well and precisely, which is white and which is essentially free of microplastics and PFAS and still has a similarly good performance like existing PTFE-based solid lubricant compositions.

SUMMARY OF THE INVENTION

The inventors of the present invention have carried out extensive studies to solve this problem and in particular have found that a replacement for a PTFE-based solid lubricant composition can be provided by a combination of at least three light solids, a fatty acid amide, a dicarboxylic acid or a salt thereof and boron nitride, which not only offers properties similar to those of PTFE, but surprisingly has a much better performance in terms of lubricating effect that lasts much longer. In addition, very good corrosion protection can be achieved. Together with a lubricating grease base and a solvent or a blowing agent, a solid lubricant composition obtained in this way can be applied particularly well and precisely to a chain, for example.

The present invention accordingly relates to a solid lubricant composition (dry lubricant composition) comprising a solid lubricant mixture comprising or consisting of a fatty acid amide, a dicarboxylic acid or a salt thereof and boron nitride. The solid lubricant composition further comprises a grease base and a solvent with a boiling point at 101.3 kPa of less than 80 ° C and / or a pressure liquefied propellant.

Further, the present invention relates to a method for lubricating a chain, the method comprising providing a solid lubricant composition as described herein and applying the solid lubricant composition to a chain.

Furthermore, the present invention relates to the use of a solid lubricant composition as described herein for lubrication, in particular for lubricating a chain.

Additional objects and advantages of embodiments of the present invention will become apparent from the following detailed description and the accompanying figures.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

• is a photographic representation of the AU01 chain test bench used to determine the power loss of the solid lubricant composition.
• is a schematic representation of a chain drive.
• is a photographic representation of the chain drive as shown in the in Chain test stand AU01 shown is used.
• is a diagram showing the power loss as a function of time on the chain test bench for two exemplary embodiments of the present application.
• is a graph showing power loss versus time on the chain test bench for an exemplary embodiment of the present application and two competitor products.
• is a diagram showing the power loss as a function of time on the chain test bench for an exemplary embodiment of the present application and a PTFE-containing competitor product.
• is a photographic representation of test panels treated with a solid lubricant composition according to exemplary embodiments of the present application or with competitor products after a salt spray test DIN EN ISO 9227 .

DETAILED DESCRIPTION OF THE INVENTION

Further details of the present invention and further embodiments thereof are described below. However, the present invention is not limited to the following detailed description, but is merely illustrative of the teachings of the invention.

It should be noted that features described in connection with an exemplary embodiment may be combined with any other exemplary embodiment. In particular, features that are described in connection with an exemplary embodiment of a solid lubricant composition according to the invention can be combined with any other exemplary embodiment of a solid lubricant composition according to the invention as well as with each exemplary embodiment of a method according to the invention and each exemplary embodiment of a use according to the invention and vice versa, unless expressly stated otherwise is noted.

If a term is referred to with an indefinite or definite article, such as “a”, “an”, “an”, “the”, “the” and “that”, in the singular, this also includes the term in the plural and vice versa, unless the context clearly states otherwise. The terms “comprising” or “comprising” as used herein not only include the meaning of “include” or “comprise,” but may also mean “consisting of” and “substantially consisting of.”

In a first aspect, the present invention relates to a solid lubricant composition that is particularly suitable for lubricating chains.

The term “solid lubricant composition” as used herein can mean in particular that the lubricant composition forms a dry-feeling lubricant film after application to the object to be lubricated, i.e. that any solvent largely evaporates or any propellant largely evaporates. Accordingly, the solid lubricant composition can also be referred to as a dry lubricant composition.

The solid lubricant composition includes (or consists of) a solid lubricant mixture, a grease base, and a solvent and/or a blowing agent. The solid lubricant mixture in turn comprises (or consists of) a fatty acid amide, a dicarboxylic acid or a salt thereof, and boron nitride. Of course, several of the individual components can also be included, for example two or more fatty acid amides, two or more dicarboxylic acids or salts thereof or even one or more dicarboxylic acids and one or more salts thereof.

According to an exemplary embodiment, the fatty acid amide comprises an amide or diamide of a saturated or unsaturated, aliphatic or aromatic, linear or branched, substituted or unsubstituted fatty acid having 8 to 30 carbon atoms, optionally having one or more hydroxyl groups. The fatty acid can in particular have 10 to 28 carbon atoms, in particular 12 to 26 carbon atoms, in particular 16 to 24 carbon atoms. The meanings of the terms "saturated", "unsaturated", "aliphatic", "aromatic", "linear", "branched", and "unsubstituted" as used herein correspond to the respective established meanings thereof as they would be understood by one skilled in the art are known. The term “substituted” as used herein means that one or more, in particular 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 hydrogen atoms of the respective groups are substituted by a substituent. Examples of suitable substituents include hydroxyl groups, hydroxyalkyl groups (ethers), thiol groups, thioalkyl groups (thioethers), =O, ester groups, amide groups, nitrile groups and nitro groups, in particular one or more hydroxyl groups. When two or more substituents are present, they may be the same or different and may be linked together to form a ring.

According to an exemplary embodiment, the fatty acid amide comprises at least one from the group consisting of stearic acid amide (stearamide), oleic acid amide (oleamide), palmitic acid amide (palmitamide), erucic acid amide (erucamide), ricinoleic acid amide, distearyl ethylene diamide (stearyl stear diamide), dioleyl ethylene diamide (oleamidolein diamide), dipalmityl ethylene diamide (palmitamidepalmitindi amide ) and combinations thereof. Of these, stearic acid amide has proven to be particularly suitable for solving the problem of the invention.

According to an exemplary embodiment, the solid lubricant mixture comprises 1 to 80% by weight, in particular 5 to 50% by weight, in particular 10 to 40% by weight, of one or more fatty acid amides.

According to an exemplary embodiment, the dicarboxylic acid comprises a saturated or unsaturated, aliphatic or aromatic, linear or branched, substituted or unsubstituted dicarboxylic acid having 2 to 20 carbon atoms. The dicarboxylic acid can in particular have 4 to 16 carbon atoms, in particular 6 to 12 carbon atoms, in particular 8 to 10 carbon atoms.

According to an exemplary embodiment, the solid lubricant mixture comprises a salt of dicarboxylic acid. In particular, this can be a disodium salt, a dipotassium salt, a dicalcium salt, a diammonium salt, a monosodium salt, a monopotassium salt, a monocalcium salt, a monoammonium salt or a combination thereof. For example, the solid lubricant mixture can be a disodium salt of a dicarboxylic acid and a monosodium salt of the same or a different dicarboxylic acid. Combinations of different cations are also possible. A sodium salt, in particular a disodium salt, of a dicarboxylic acid has proven to be particularly advantageous for solving the problem of the invention.

According to an exemplary embodiment, the solid lubricant mixture comprises 10 to 95% by weight, in particular 30 to 90% by weight, in particular 40 to 85% by weight, of one or more dicarboxylic acid or salts thereof.

According to an exemplary embodiment, the boron nitride is a boron nitride with a hexagonal crystal structure. This allows particularly good lubricating properties to be achieved.

According to an exemplary embodiment, the solid lubricant mixture comprises 1 to 20% by weight, in particular 2 to 15% by weight, in particular 3 to 10% by weight, of boron nitride.

According to an exemplary embodiment, the weight ratio of fatty acid amide, dicarboxylic acid or salt thereof and boron nitride is as follows: $$\left(\text{fats}\ddot{\text{a}}\text{ureamide}\right):\left(\text{Dicarbons}\ddot{\text{a}}\text{ure}/\text{Salt}\right):\left(\text{Boron nitride}\right)=\left(5-15\right):\left(70-92\right):\left(3-15\right)$$

According to an exemplary embodiment, the fatty acid amide and boron nitride are contained in a weight ratio of 6:1 to 2:1, in particular 5:1 to 3:1, in particular approximately 4:1.

According to an exemplary embodiment, the solid lubricant composition comprises 5 to 20% by weight, in particular 7 to 15% by weight, in particular 8 to 12% by weight, of the solid lubricant mixture.

In addition to the solid lubricant mixture, the solid lubricant composition also includes a lubricating grease base and a solvent and/or a blowing agent.

According to an exemplary embodiment, the grease base comprises a soap grease. This can in particular be a fatty acid salt, especially a calcium sulfonate complex fat. A calcium sulfonate complex grease is characterized by a particularly wide temperature range, especially in the low temperature range.

According to an exemplary embodiment, the solid lubricant composition comprises 10 to 40% by weight, in particular 15 to 30% by weight, in particular 20 to 25% by weight, of the lubricating grease base.

According to an exemplary embodiment, the weight ratio of solid lubricant mixture and lubricating grease base is in the range from 1:5 to 5:1, in particular in the range from 1:3 to 1:1, in particular approximately 1:2.

According to an embodiment of the invention, the solid lubricant composition contains a solvent. In the context of the present application, a “solvent” is understood to mean, in particular, a chemical compound that is able to dissolve or at least dissolve other substances, in particular the components described above.

According to an exemplary embodiment, the solvent comprises a hydrocarbon. Combinations of several hydrocarbons or of one or more hydrocarbons and another solvent are also possible. It is preferably a halogen-free solvent, in particular a halogen-free hydrocarbon.

The solvent has a high vapor pressure or a low boiling temperature, namely a boiling point at 101.3 kPa of less than 80 ° C, in particular less than 60 ° C. In this way, rapid and essentially complete evaporation of the solvent can advantageously be achieved after the solid lubricant composition has been applied to the component to be lubricated, forming a dry-feeling lubricant film.

According to a further embodiment of the invention, the solid lubricant composition contains a pressure-liquefied propellant. In this case, the solid lubricant composition can also be referred to as a solid lubricant aerosol formulation. In the context of the present application, a “propellant” is understood to mean, in particular, a liquid or gaseous substance that is liquefied or compressed under pressure and is able to use its pressure to promote and, if necessary, also atomize other substances, in particular liquids or solids.

According to an exemplary embodiment, the pressure-liquefied propellant comprises a liquid gas, in particular propane and/or butane. It is preferably a halogen-free propellant, in particular a halogen-free liquid gas. The blowing agent can also additionally contain a solvent, in particular a solvent as described above.

According to an exemplary embodiment, the solid lubricant composition comprises 30 to 90% by weight, in particular 50 to 80% by weight, in particular 60 to 70% by weight, of the solvent and/or the blowing agent.

According to an exemplary embodiment, the solid lubricant composition is essentially free of plastic, in particular microplastics, and/or per- and polyfluorinated alkyl substances (PFAS). In the context of the present application, “essentially free” means that plastic, in particular microplastics, and/or PFAS, are contained at most in technically unavoidable quantities (due to the ubiquity of these substances) and in particular no plastic, in particular no microplastics, and/or no PFAS, as well as no starting materials for these, are deliberately added to the solid lubricant composition.

The production of the solid lubricant composition is not subject to any particular restrictions or requirements and can be carried out by a person skilled in the art using the components described in a manner known per se. Advantageously, the solid components are converted into liquid form (as far as possible) by heating in order to facilitate thorough mixing.

The solid lubricant composition can be filled and packaged in a suitable container, for example a bottle or a can, in particular a dropper bottle, a spray bottle, an aerosol can or an aerosol can, and thus made available for use.

In a further aspect, the present invention relates to a method of lubricating a chain, the method comprising providing a solid lubricant composition as described herein and applying the solid lubricant composition to a chain.

The solid lubricant composition can be applied to the chain in particular by dripping or spraying the solid lubricant composition directly onto the chain.

According to an exemplary embodiment, the chain is a part of a means of transport, in particular a two-wheeler, in particular a bicycle or a motorcycle.

In a further aspect, the present invention relates to the use of a solid lubricant composition as described herein for lubrication, particularly for lubricating a chain. According to an exemplary embodiment, the chain is a part of a means of transport, in particular a two-wheeler, in particular a bicycle or a motorcycle.

The present invention is further described with reference to the following examples, which are intended merely to illustrate the teachings of the invention and are in no way intended to limit the scope of the present invention.

Examples

Experimental data from embodiments of an exemplary solid lubricant composition according to the invention and from competitive products are described below. The power loss of the solid lubricant composition on the AU01 chain test stand and the anti-corrosion behavior in the salt spray test were examined for the samples examined DIN EN ISO 9227 determined.

Samples examined:

• Solid lubricant composition according to the invention:
  • Solid lubricant mixture:
    • 12% of a monounsaturated fatty acid amide (C16-C24),
    • 84% of a disodium salt of a short-chain dicarboxylic acid
    • 3% hexagonal boron nitride;
  • Soap grease from the class of calcium sulfonate complex greases as a lubricating grease base;
• Embodiment 1A) with solvent
• Embodiment 1B) with propellant as an aerosol
• Competitive product A: Wax with ceramic solid lubricants
• Competitive product B: melted wax with solids. Components:
  • Paraffin, MoS ₂ and WS ₂ (tungsten disulfide)
• Competitive product C: PTFE oil
• Competitive product D: Dry lubricant (without further description)
• Competitive product E: PTFE oil
• Competitive product F: Dry lubricant with PTFE
• Competitive product G: Wax with PTFE and ceramic solids

Chain test bench testing method:

is a photographic representation of the AU01 chain test bench used to determine the power loss of the solid lubricant composition.

With the help of the chain test bench, the influence of a chain lubricant on the power loss of the overall drive can be determined. From the measured values and their changes over time, conclusions can be drawn about the durability, quality and reduction in friction of the lubricating film.

To determine the power loss, a test run with defined measurement and load conditions is carried out over 20 hours. During the tests, the speed and torque on the drive (crank) and the output (pinion) are measured (see ). The effectiveness of the chain drive is assessed from the efficiency and power loss curves.

The test field is conditioned to a constant temperature of 22°C. The torque sensors deliver 4 signals per revolution and the deviation and repeatability accuracy is 0.03%.

is a photographic representation of the chain drive as it appears in the in Chain test stand AU01 shown is used.

Results on the chain test bench

• 1. Test run of a typical embodiment of the dry chain lubricant 1) according to the invention in various application forms:
  • In the in In the diagram shown you can see the dry chain lubricant 1) according to the invention twice - once as a liquid product in the dropper bottle 1B) and once as an aerosol 1A). In both During test runs, the difference between the start value and the end value is small, from which one can conclude that the lubricating film is intact until the end of the test run. The power loss of 5.2 or 5.9 watts is surprisingly extremely low for a dry chain lubricant and has never been found on this scale in a competitive product.

• 2. Comparison between a typical embodiment 1) according to the invention and typical very good competitive products:
  • In the in In the diagram shown you can see the exemplary embodiment 1B) according to the invention and two competitive products that have a typical dry chain lubricant loss run. Most lubricants in this category have an average initial value, but gradually the lubricant is lost in the chain drive until the lubricant film breaks completely (competitor product B). Competitor product A) lasts until the end on the chain test bench, but has a very high average power loss, which leads to high wear on the materials and to inefficiency of the drive.
• 3. Comparison with lubricants containing PTFE:
  • In the in The diagram shown shows the exemplary embodiment 1B) according to the invention in comparison with an oil that contains large amounts of PTFE.

Due to their lower internal friction compared to dry chain lubricants, oils tend to have lower coefficients of friction and long-term stable lubricating films - but in this case even larger amounts of PTFE do not help to generate similarly good power losses.

In addition to the disadvantage that PTFE is viewed as a microplastic and must be classified as PFAS, its performance in terms of reducing the coefficient of friction can be significantly exceeded by the exemplary embodiment according to the invention.

• Eine weitere geforderte Eigenschaft von Trockenkettenschmierstoffen ist ihre korrosionsschützende Wirkung. Um auch widrige Umwelteinflüsse zu simulieren, wurde u.a. der Salzsprühtest nach DIN EN ISO 9227 gewählt. In sieht man die Prüfbleche nach einer Testdauer von 24h. Erfreulicherweise hat der erfindungsgemäße Trockenschmierstoff gemäß der beispielhaften Ausführungsformen 1A) und 1B) einen sehr positiven Effekt auf den Korrosionsschutz des Gesamtsystems. Die Wettbewerber D) bis G) haben diesen Test nicht bestanden.

Corrosion-protective behavior in the salt spray test DIN EN ISO 9227 :

• Another required property of dry chain lubricants is their anti-corrosion effect. In order to simulate adverse environmental influences, the salt spray test was carried out DIN EN ISO 9227 chosen. In you can see the test panels after a test period of 24 hours. Fortunately, the dry lubricant according to the invention according to the exemplary embodiments 1A) and 1B) has a very positive effect on the corrosion protection of the entire system. Competitors D) to G) did not pass this test.

The present invention has been described using specific embodiments and examples. However, the invention is not limited thereto and various modifications thereof are possible without departing from the scope of the present invention.

Claims (19)

Solid lubricant composition comprising a solid lubricant mixture comprising a fatty acid amide, a dicarboxylic acid or a salt thereof, and boron nitride; a grease base; a solvent with a boiling point at 101.3 kPa of less than 80 °C and/or a pressure-liquefied propellant. Solid lubricant composition Claim 1 , wherein the fatty acid amide comprises an amide or diamide of a saturated or unsaturated, aliphatic or aromatic, linear or branched, substituted or unsubstituted fatty acid with 8 to 30 carbon atoms, optionally having one or more hydroxyl groups. Solid lubricant composition Claim 1 or 2 , wherein the fatty acid amide is selected from the group consisting of stearic acid amide, oleic acid amide, palmitic acid amide, erucic acid amide, ricinoleic acid amide, distearyl ethylene diamide, dioleyl ethylene diamide, dipalmityl ethylene diamide and combinations thereof. Solid lubricant composition according to one of the preceding claims, wherein the dicarboxylic acid comprises a saturated or unsaturated, aliphatic or aromatic, linear or branched, substituted or unsubstituted dicarboxylic acid having 2 to 20 carbon atoms. Solid lubricant composition according to one of the preceding claims, wherein the solid lubricant mixture comprises a salt of dicarboxylic acid, in particular selected from the group consisting of a disodium salt, a dipotassium salt, a dicalcium salt, a diammonium salt, a monosodium salt, a monopotassium salt, a monocalcium salt and a monoammonium salt. Solid lubricant composition according to one of the preceding claims, wherein the boron nitride is a boron nitride with a hexagonal crystal structure. Solid lubricant composition according to one of the preceding claims, wherein the solid lubricant mixture comprises: 1 to 80% by weight, in particular 5 to 50% by weight, in particular 10 to 40% by weight, of the fatty acid amide, 10 to 95% by weight, in particular 30 to 90% by weight, in particular 40 to 85% by weight, of the dicarboxylic acid or the salt thereof, 1 to 20% by weight, in particular 2 to 15% by weight, in particular 3 to 10% by weight, boron nitride. Solid lubricant composition according to one of the preceding claims, wherein the weight ratio of fatty acid amide, dicarboxylic acid or salt thereof and boron nitride is as follows: (Fatty acid amide):(Dicarboxylic acid/salt):(Boron nitride)=(5-15): (70-92): (3-15) Solid lubricant composition according to one of the preceding claims, wherein the fatty acid amide and boron nitride are contained in a weight ratio of 6:1 to 2:1. Solid lubricant composition according to one of the preceding claims, wherein the grease base comprises a soap grease, in particular a fatty acid salt, most particularly a calcium sulfonate complex grease. Solid lubricant composition according to one of the preceding claims, wherein the solid lubricant composition contains a solvent with a boiling point at 101.3 kPa of less than 80 ° C, in particular a hydrocarbon. Solid lubricant composition according to one of the preceding claims, wherein the solid lubricant composition contains a pressure-liquefied propellant, the pressure-liquefied propellant comprising a liquid gas, in particular propane and / or butane. Solid lubricant composition according to one of the preceding claims, wherein the weight ratio of solid lubricant mixture and lubricating grease base is in the range from 1:5 to 5:1, in particular in the range from 1:3 to 1:1, in particular about 1:2. Solid lubricant composition according to one of the preceding claims, comprising 5 to 20% by weight, in particular 7 to 15% by weight, in particular 8 to 12% by weight, of the solid lubricant mixture, 10 to 40% by weight, in particular 15 to 30% by weight, in particular 20 to 25% by weight, of the lubricating grease base, 30 to 90% by weight, in particular 50 to 80% by weight, in particular 60 to 70% by weight, of the solvent and/or the blowing agent. Solid lubricant composition according to one of the preceding claims, wherein the solid lubricant composition is essentially free of plastic, in particular microplastics, and / or per- and polyfluorinated alkyl substances (PFAS). A method of lubricating a chain, comprising providing a solid lubricant composition according to one of Claims 1 until 15 ; Applying the solid lubricant composition to a chain. Procedure according to Claim 16 , wherein the chain is part of a means of transport, in particular a two-wheeler, in particular a bicycle or a motorcycle. Use of a solid lubricant composition according to one of Claims 1 until 15 for lubrication. Use after Claim 18 for lubricating a chain, in particular the chain of a means of transport, in particular a two-wheeler, in particular a bicycle or a motorcycle.

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