Bioaccumulation

The cleat on my left foot was about 1mm further to the center line than the one on my right foot. My saddle was about 1cm too high, and the angle of my bars was about 5 degrees off the ideal. As a result, I was only a little uncomfortable. Over 20k, I only noticed a little, but over greater distances, the little bits of discomfort accumulated into a sore knee, an achy back and numb hands.

The slow build up of pain left me thinking about grade school biology and the lesson on bioaccumulation. The classic example of bioaccumulation in an ecosystem is DDT, the pesticide that leached into ponds, lakes and rivers in the 1950s after being used to treat nearby crops. As small organisms absorbed the poisons in minute quantities, scientists were tempted to declare the substance safe, but as those same small organisms were consumed by larger predators and the poison accumulated in their systems, what was once viewed as a miracle cure for insect infestation, became an infamous cause of environmental disaster.

Think of a badly adjusted saddle as DDT. Sure, you’re only a centimeter off, nothing over the first ten thousand pedal strokes, but eventually the damage accumulates. That little rock in your hips that is the tell-tale sign of too much seat post turns into a week off the bike. Likewise a marginally misaligned cleat, which will give you ITBFS (illio-tibial band friction syndrome) over the space of a fortnight, can ruin your riding for months at a time. Believe me, I know.

Handlebar angle can also be quite important, not just for aerodynamics and comfort, but also for blood flow and nerve health. Ride with bars too narrow or too acute to your posture and you can get ‘handlebar palsy’, a condition similar to carpal tunnel syndrome that will leave your hands numb. Narrow bars can also cause carpal tunnel syndrome itself, by encouraging you to rest the center of your hand/wrist on the bend of the bars above the hoods.

What makes injuries like these so frustrating is that their causes can be hard to pin down. Because you’re only very subtly uncomfortable, it can be hard to make the connection between bike fit and injury. Really, it’s so much better to confine your cycling-related injuries to the road rash incurred by a touch of wheels in a town-line sprint. Sure, it hurts like hell, but the cause-and-effect of it is so much easier to diagnose … and correct.

I notice that when I am tired, I will let my left knee fall inward, which gives me a little more down stroke power, but derives that power from an unnatural torquing of the knee joint. Form counts nearly as much fit.

As a nobody (a proud nobody, thanks), I don’t have a coach or a trainer or a masseuse or a mechanic to help me along. My “season” is a thing called a “year,” and my off-season is a thing called “injury.” If I want to stay in the saddle, I have to be acutely aware of all these little forces accumulating in my body, the bumps of the road dissipated through my lumbar spine, the reach of my cranks carrying joints and muscles forward inertially. The thing about bioaccumulation is that you seldom know it’s even occurring until the system breaks down.

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5 comments

  1. Robot

    Well, Bryan. It really depends on your preferred seat height. If you’ve had ITBFS issues, you probably shade it low, as I do, and then you just constantly wonder whether you’re at maximum comfort/power height, always sure it’s not quite right, but never sure how far to go.

    So yes, a whole cm. I didn’t know you guys were on metric up there in Maine.

  2. Randomactsofcycling

    Robot, I am with you on this one? As a very keen footballer, I was a religious ‘stretcher’ after every training session. When cycling took over from football I let that habit lapse as suddenly I didn’t have the time after a two hour ride to spend half an hour stretching. Now three years later I am really feeling it and have begun my routine again, sacrificing time in the saddle to ensure I can spend my time in the saddle much more comfortably.

  3. grolby

    Long-term knee issues due to improper fit have derailed my last two seasons of riding. Even after getting a good fit and my cleats adjusted, getting back on the bike was still enough to tweak the injured parts and get them good and unhappy after an hour or so of pedaling. Now that I’m too busy to think about riding so much of the time, things seem to be gradually working themselves out, but undoing the harm from the accumulated damage of a mis-fit bike can take an extremely long time.

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