Could have, would have... Exactly, the bicycle chain! If you want to make metres on your bike, no component is more important than the drivetrain and, above all, the more than one hundred links of the chain. In the end, each chain link consists of exactly 5 elements:
- Outer flap
- Inner flap
- Bolt
- Sleeve
- Role
Although not a game changer, the chain lock (not in the picture) was added at some point, which replaced the irreversible pressing out of the bolt.
The efficiency of a bicycle chain can be up to 98 %. Of the 200 watts that you hammer into the pedals, 196 watts go into propulsion - theoretically. This is because the hubs, the gear shift rollers and the bottom bracket are also involved with additional friction, even if the chain is optimally lubricated. Maintenance of the entire drivetrain is the be-all and end-all!
But opinions are divided on this - probably since the invention of the bicycle chain, certainly with the advent of of different lubricants.
What do you use for the chain? Oil, wax, spray oil, spray wax? Olive oil?
What lubricates the bicycle chain best? The AU 01 chain tester shows it mercilessly
In the search for the best lubricants, Wolfratshausen-based manufacturer Tunap Sports thought: The only way to test how well a chain is lubricated is under the most realistic conditions possible. To this end, the AU 01 chain test bench has been at the company headquarters in Upper Bavaria since 2018, reeling off kilometre after kilometre. It is estimated to have travelled around 200,000 since then, and we have now visited it at work.
The device was built in collaboration with a Swiss drive specialist from motorbike racing - what exactly is hidden in this box the size of about 4 fridges remains secret and, above all, unphotographed. What we do know: It contains two electric motors. One generates the torque for the drive on the chainring, the other the braking power on the rear cassette. Sensitive sensors are installed between them, measuring the difference with an accuracy of 0.3 watts. Alfons Urban from the development team at Tunap and responsible for the chain test bench answers our questions.
Same parameters, only the bike oil makes the difference
On the AU 01, everything can actually be replaced in order to test it, including the chainring or derailleur. However, as it is important to create absolutely identical conditions when comparing the lubricant, the test bench is usually always run with a Dura-Ace drivetrain and a new KMC chain for each test.
The decisive factor when testing a lubricant is the running time or kilometre performance. To ensure that this is also comparable and realistic, the test protocol at Tunap is also always identical: a test lasts 20 hours and includes 20 one-hour cycles. Each includes 50 minutes of "driving" under full load at 1000 watts and 10 minutes at 500 watts. During these minutes, the power loss through the chain is measured; 4 times per crank revolution. If required, the external influence of water and/or dirt can also be simulated.
It would even be possible to "retrace" certain stages of a cycle race, including the gear changes. However, Tunap normally tests statically, as described above. In the end, a few watts are lost - or more.
Fun fact: Olive oil achieves very good values in a test. An internal Tunap measurement showed a power loss of just over 6 watts. Unfortunately, vegetable oil is not stable enough under heat and sunlight to seriously consider it as an alternative. And not even for the exercise bike, because it quickly turns rancid and smells in the air.
In fact, Tunap Sports chain oil is said to perform so well (even better than olive) that the German national track cycling team uses it to lubricate all their chains. Tunap has been an official supplier to the German Cycling Federation in the area of product development since 2020. The manufacturer became a cooperation partner of the Institute for Research and Development of Sports Equipment (FES) back in 2019.
Alternatives to the chain test bench
We have already co-operated with other test laboratories in our own BIKE tests of chain oils. The SRV test, for example, was recently used there: the oscillating friction wear tribometer. Here, a transverse steel cylindrical roller, a vertical steel ring or a steel ball is moved in an oscillating motion on a stationary steel plate. In between the respective lubricant.
Others put their oils through the so-called Brugger test, in which a fixed test cylinder is pressed onto a rotating test ring for 30 seconds. With both tests, it is also clear that the greater the wear, the worse the lubricant's properties. SRV and Brugger measure the wear, but only the SRV measures the coefficient of friction.
But a chain is much more complex than a cylinder, and the duration of the test on the Tunap chain test bench also shows the qualitative change in the oil or wax over time, including the effect on the realistic test object. According to Tunap, the assessment of a lubricant in terms of power loss is not valid without such a chain test bench.
Information about Tunap GmbH & Co. KG
Tunap has a total of more than 700 employees worldwide. The company operates three production sites, namely Wolfratshausen, Lichtenau in Saxony and Märstetten in Switzerland. Around 180 people are employed at the company headquarters in Wolfratshausen. "Only" around 7.4 million units of oils, other lubricants and additives for the automotive industry are produced there each year. Lichtenau, on the other hand, is Tunap's main production site, with a production of 76 million units per year. Around 85 people work here. The 3rd site, Märstetten in Switzerland, employs a further 75 people. In 2023, Tunap achieved a turnover of around 243 million euros.
The products
Tunap Sports is a division of the company that specialises in bicycle care. The lubricants and cleaners, for example, are sold in retail outlets. Tunap also supplies dealers and workshops with larger containers and accessories. Tunap Sports also offers products for body care - which is perhaps not so well known: Seat cream, sun cream and shower gel.
Marc Strucken
Editor
