The Short Crank

I’m tall.  Six feet and three inches tall.  And a disproportionate amount of that is in my legs.  I had a hard time fitting into a velomobile.  When I went for a test drive at Bluevelo, they did every trick they could think of in order to squeeze me into one of their machines – and I still skinned my knees on the inside of the Quest’s body!  If I was going to become a velonaut, it was going to require extreme measures.  As I started considering the benefits of orthopedic surgery, Ray came to my rescue with a way to gain a few more precious millimeters: shorter crank arms – 155 mm instead of my normal 175 mm length.

Now I’ve been bicycling all my life and the mantra of “if it’s not upright, it’s not a bike”, “if your not wearing Lycra, your not a biker”, “lighter means faster”, and “longer legs, longer cranks” were firmly wedged into my tiny neanderthal skull.  But I was already making a huge leap of faith going directly from upright racer to velomobile!  I didn’t even bother with the obligatory evolutionary steps through the domain of open recumbents first.  So if this neanderthal was going to sail straight off the edge of a flat earth in his low, heavy bike wearing cargo shorts, he might as well do it with short crank arms.

Well I ordered my short cranked Strada and waited.  And worried.  When it finally came, I made the seat and bottom bracket adjustments with trembling hands and exhaled a huge sigh of relief when I slid into the seat.  My knees didn’t rub.  Disaster averted!  I put on my cargo shorts, gave my short cranks a push, and over the edge I went.

I’m now nearing my eighth month of velomobile bliss.  My upright bicycle muscles have become recumbent and all of the promised gains of speed and energy economy have been realized.  The shorter cranks don’t seem to have had any negative effect at all!  But the real surprise for me was the fact that uphills seem easier for me now!  Sure, they’re a little slower but they aren’t the energy drains that they used to be.

The Strada is 3 1/2 times heavier than my road bike was and going up steep hills at slow speeds robs the velomobile of every advantage.  Yet it still seems easier.  How can that be?!  Part of it, I’m sure, is that the upper body is taken completely out of the equation.  No more stress to keep the body from inefficient movement, no more rigid arms and shoulders or pulsating pulls on the handlebars – just keep the feet going around.  But I’m convinced it’s more than that…

I used to be a fencer – the kind with a sword, not a shovel – and we did a lot of squats and lunges for that sport.  I can tell you that I could do half squats or half lunges all day long but don’t ask me to do too many full squats or lunges in a row or I’ll be falling over pretty quickly.  The point is that it takes a lot less effort to push the same weight (me) if the legs don’t bend as deeply – the same reason hikers take smaller steps as the mountain becomes steep.  In the same way, the shorter crank is allowing me to take ‘shorter steps’ because my legs don’t have to bend as deeply to do the same amount of work.  Also, the short cranks don’t seem to offer any disadvantages when they aren’t climbing.  In fact, I’ve come to believe that the shorter cranks may allow me to do the same work, with the same muscles, with less energy, all the time – but especially up hills, where the resistance is greatest.

Perhaps I am taking an unrealistic leap of reason in this – especially since too many variables were changed in my little experiment – but I think I can safely conclude, at the very least, that the short crank shouldn’t be feared.