I remember the first TOUR long term tests of carbon forks where most of them passed the tests in sound condition with more than 100,000 kilometres (62,140 miles). I’ve been riding my carbon fork since 2004 (20,000 kilometres/12,430 miles); a material test revealed an "increased failure risk". And my manufacturer Canyon recommends the replacement of carbon components after three years or 15,000 kilometres/9,320 miles. Do I really have to worry about, even if I’ve tightened the stem to the indicated torque values and haven’t experienced any falls?
Reply by Dirk Zedler, TOUR technology expert and bicycle expert
If the manufacturer supplies a properly made product and the bike is completed with suitable add-on parts and serviced at regular intervals, carbon components last nearly forever. Carbon breaks, however, easily if inappropriately mounted and in the case of riding errors or falls. The damage is not always visible at once. Although a material testing with screening procedure or impulse thermography shows defective spots, the pictures must be compared to the pictures of the state as new to allow a decision. To only test a used component brings no reliable result.
Manufacturers are understandably cautiously, as they cannot know whether the user will mount a sharp-edged stem to the fork steerer tube or whether he has cycled already over a kerb at high speed. In this case the fork would fail much earlier. Whoever is in doubt, whether the fork, the seat post or the handlebars are still safe, due to an incident or visible damage, should replace these components to be on the safe side.
