The cover of "SAZ Bike" reads: "Once again, a test by 'bike' magazine causes a stir: Out of eleven carbon handlebar models, five failed a massive breakage test. Were the wrong standards applied? Were the handlebars subjected to too much, for example 'crashed' handlebars were worked on several times? In any case, they were deliberately screwed on with excessive torques. (...)". Correct! Because this is what the European standard EN 14766:2005 stipulates: "4.3.2 Minimum defective torque: The minimum defective torque for bolts intended for the attachment of handlebars, stems, bar ends, saddles and seat posts should be at least 50 per cent greater than the torque specified by the manufacturer."
It is clear that emotions run high when it comes to torque. In our test, we tightened the stem clamping bolts 1.5 times tighter than the maximum specified by the manufacturer. The reason for this is obvious: on a tour, nobody reaches for a torque spanner to optimally adjust their handlebars - the frequent result is over-tightened bolts. Such "normal misuse" must not have any dangerous consequences, as stipulated by the European standard. Furthermore, a manufacturer cannot expect every customer to be experienced in handling the material. At the Eurobike trade fair, the trend towards carbon handlebars as standard equipment was evident, and not just on expensive bikes. Will buyers all go to the shop if something is wrong with the handlebar setting? We have our doubts. SAZ-Bike quoted Thomas Wilkens from Titec importer Grofa on a second point of criticism: "Drops and jumps are not necessarily part of the repertoire of an XC or marathon racer". Perhaps such manoeuvres are not everyone's cup of tea, but they certainly can't be ruled out. Especially as the majority of riser handlebars tested in our test are even fitted to enduro bikes. The fact is: our series of carbon breakage tests makes the bike world safer in the long term and exposes black sheep. This is the trend: numerous manufacturers are now investing a lot of money in their own testing machines.
That's what our experts say:
Dipl. ing. Matthias Blümel, TU Munich
"On safety-relevant components, such as handlebar/stem units, which are definitely also tightened by hand, operational safety must be guaranteed even at 150 per cent of the nominal torque."
Jan Talavasek, Head of Development at Specialized
"150 per cent of the torque is part of the new CEN standard! It requires that every screw used for safety purposes must be able to withstand at least 50 per cent more than the specified torque. I think it would be negligent to ignore that."
Christoph Listmann, BIKE Head of Test & Technology
"Manufacturers must realise that breakage tests improve products and ensure greater safety in the saddle. This can only be in the interest of the customer! We do not destroy wilfully or with inappropriate methods!"
