The plain prefabricated building near Schweinfurt's main railway station looks more like a transhipment station than a bicycle laboratory. Noisy goods trains shunt a few metres behind the building. A white and blue sign at the front reads "velotech.de". Inside the large main hall, the atmosphere is also dominated by machine noise and clattering. It's a different story in the next room, where a handsome gentleman with light-coloured hair and glasses listens quietly and intently to a wheel. It is clamped and lashed down in a test rig. Powerful machine arms push and pull alternately on the cranks. The man wears a stethoscope on his head. He proudly explains: "Almost every frame makes a noise when you ride it." He listens to various points like a doctor. The only difference to the white coat wearers: the rear triangle, shock absorber and seat tube are the critical points. The man is Ernst Brust, he examines bicycles - not people. "We can simulate and test everything with our test benches," says Brust, owner of Velotech GmbH and recently appointed noise doctor for bicycles.
Unpleasant noise has been around since the invention of the bicycle. Cracking bottom brackets, squeaking disc brakes and creaking saddles are annoying companions and spoil the fun of cycling. They are also often a harbinger of impending defects or material fatigue, so they are also a warning sign that you should keep in mind. But mostly they are just one thing for the rider and companion - annoying.
"Last year, courts appointed me as an expert witness to provide expert opinions. It was about creaking noises on a 5,000-euro bike," says Brust in his friendly, original Franconian dialect. The result: Brust and his team found the noise on the bike in question. But only after several tests: "The problem was that it only occurred at higher speeds. We searched for hours."
Brust has a wide range of options at his company: drum and brake test benches, laser measurement and self-built machines that simulate pedalling or handlebar forces. But specialised equipment is one thing, experience is another. This is why he is approached by many dealers who are unable to help their customers eliminate annoying noises themselves. Noise Doctor Brust is on the side of the dealers: "They are usually let down by the manufacturers in this respect: Customers won't accept a cracking noise on a bike costing 5000 euros. That's understandable. But dealers are often at the end of their tether."
A noise analysis at Velotech costs 300 euros. But before you send your bike to Schweinfurt, you can often make sure it's quiet yourself. Before he reaches for the stethoscope, noise doctor Brust also works through the following steps systematically during his eavesdropping attack:
To roughly localise the noise, all you need is silence. Firstly, check all the screw connections on your bike and tighten them with a torque spanner. Check whether your quick releases are correctly closed. If this still doesn't give you peace of mind, we will show you four simple tests on the following pages that should help you discover most of the problem areas. If you are still unsuccessful, look for specific areas or parts while riding. Firstly, when riding slowly, then without pedalling and finally while pedalling in the saddle. And if none of this helps, you may have to go to the noise doctor after all ...
You can find out how to search for noises yourself in the PDF download below (including a table with FAQs "Where, when, why it cracks and what helps").
