The background to the growing need to test both the front and the rear wheel are the constant changes in operation due to the ‘E’ in all bicycle categories.
High-torque motors with more traction on the chain, higher brake forces due to disc brakes in combination with trailers or cargo bikes, not to mention when combined with an anti-lock feature, heavy e-bike types and new, often neither lightweight nor sporty user groups, put far more load on the wheels than before.
In the experts reports department we learned that hub flanges can shear off; in a dealer forum where we are members we followed reports about broken spokes and cracks in the rims intensively, and recently we all learned from the press that in some hubs even the brake disc mount can shear off abruptly.
All these real cases of failure, some with unforeseeable consequences for life and limb, are our incentive to develop the tests and the testing systems in such a way that this can no longer happen to wheels in future. Countless wheels, some known to be weak, some known to be very proven, were destroyed by us in order to verify the test criteria.
It goes without saying that we are again performing the tests according to the bike categories, from gravel via the classic e-bike to the transportation bike, in combination with the well-known Advanced, Advanced Plus and Advanced Plus XXL weight classes introduced by us.
However, what we still don't do, is putting fully-assembled bikes or transportation bikes on the roller. There is still no indication that structural defects cannot be detected during component or, rather, cleanly structured component assembly tests in the bicycle, e-bike and transportation bike categories that we work on, if the work is properly regulated.
Clearly rattling cables or their grinding marks, loose bolted connections of mudguards etc. are however not tested when, for example, a fork undergoes a pneumatic or hydraulic fatigue test, with overload and impact testing for fatigue strength. Experience has shown that it is easier to evaluate these functional tests, that can only partially be reproduced by a roller, during test rides. We recommend test rides for many reasons. The important thing is to always activate GPS and use a log book.
Apart from that, documented test rides have always been a good argument in our practice in court and in countless accompanied market surveillance proceedings
Photo: © Zedler-Institut
