TOUR: What criteria do you use to choose the right crank length?
Franziska Schmidt: We work with saddle pressure measurement. It's about stability on the saddle, the hip angle and the pedalling movement.
TOUR: The customer's proportions don't play a role?
Franziska Schmidt: That's right. We look at the pedalling movement. If the overall position is right, the seat height and seat length are right and there is still visible instability, we look at the crank length. Of course, there are customers who come with problems in the hip flexor or with knee problems; then we immediately take a closer look at the crank.
TOUR: What do you do with customers who don't bring a bike with them and want size advice? What crank length do you start with?
Franziska Schmidt: We have a Fitbike with adjustable crank length. This allows us to test everything from 155 to 175 millimetres.
TOUR: Is a 2.5 millimetre difference in length noticeable?
Franziska Schmidt: Some athletes already notice the difference of 2.5 millimetres, sometimes we can see it in the movement in the video. From five millimetres, the difference in crank length can be clearly felt and seen.
TOUR: Are cranks generally too long or too short?
Franziska Schmidt: It often makes sense to work with shorter cranks, especially when it comes to sporty riding positions and time trials in triathlons. Shorter cranks open up the hip angle and improve stability and power transfer.
TOUR: Are you noticing a trend towards shorter cranks among customers?
Franziska Schmidt: In any case. Demand has increased significantly as a result of the reporting.
TOUR: If you take 20.5 per cent of the crotch length as a criterion for the crank length, it seems that the bikes are offered ex works with cranks that are a little too long for men. And for women, who are a bit off in the size spectrum, anyway.
Franziska Schmidt: We can confirm this. It has never happened that a purchased bike was equipped with cranks that were too short. If you are not very tall, the cranks are usually a tad too long. This applies particularly to small frame sizes between 48 and 52 centimetres. Very small frames are often fitted with cranks that are much too long.
