Now always looking for a bargain it seems theres always plenty of shorter length cranks in the bargain bins. The Duo FSA set are 170mm and I’ve had good success with them and no adverse reactions so I was wondering what the “reasoning” was behind why we all seem to religiously use 175mm cranks in the mtb world.
Macinehead who sem to be cycling engineering geeks have a calculator, putting my 32″ inside length in, gives an optimum of 166.6mm, more confusing? The cycling guru Sheldon Brown has a good info as usual and one phrase that caught my attention was “Too long cranks cause excessive knee flex, and can cause pain/injury if it causes your knee to flex more than it is used to” So what is the prinipal behind different crank lengths.
Bike fitting specialists Bike Dynamics have some blinding science all about knee angles too, and as I do have weak kness from early life abuse I’m drawn to going shorter on length. Another factor is that I like to spin the pedals as much as possible and while using single ring setups more recently it all seems to point to shorter being best.
Will this reduce power though, you still have the slow grinding climbs, especially using 1×9 and running out of the smaller gears even in this relatively flat area of the country. The people who deal in power meters should know. Powercranks have a interesting study. They talk about crazy short lengths that I didn’t even realise people rode, and back them with power readings, but one section bears some truth.
So, using shorter cranks will usually give the rider: 1. More (or, the same) power. 2. More ground clearance. 3. Better aerodynamics. What is the mountainbiker not to like?
The Anthem with its definate low bottom bracket and 170mm cranks are the way to go for me, sold! the order is in.