9 Reasons to Upgrade to Short Cranks

If you want maximal power when climbing or sprinting, there is no crank length better than 145mm. If you need more reasons to upgrade, keep reading.

Below are nine reasons why you should upgrade to short cranks.

Many of these benefits also apply to standard (legacy) bicycles, not just your Cruzbike.

 

  1. Short crank arms make the bike more aerodynamic (they actually make the RIDER more aerodynamic on the bike). 
    With shorter cranks, your knees don’t pop-up as far into the clean airflow, nor do your heels drop as low into clean airflow; thus reducing turbulence and drag.
  2. Short crank arms make fitment easier (more knee clearance).
    Because your feet are making slightly smaller circles, your knees travel less and there is more room for your knees in front of the handlebar.
  3. Short cranks make more power (Watts).
    A study performed at the University of Texas at Austin by J.C. Martin and W.W. Spirduso found that 145 mm cranks made maximal power higher or equal to longer cranks. Many people erroneously assume that longer cranks make more power because long cranks allow more torque for the same force. It’s much more complex than that.  https://pubmed.ncbi.nlm.nih.gov/11417428/

    Short cranks increase power on a bicycle


  4. Short cranks benefit both tall and short riders.
    The study above found only a weak correlation (R2 = 0.205) between taller riders with longer legs making more power with longer cranks. Even tall riders can reap benefits from short cranks.


    Crank Length to Leg Length Power Production

  5. Improved handling while pedaling through corners, because the mass of your feet are rotating with a smaller radius.
    Angular momentum at the crankset is directly related to mass (feet/shoes/pedals, etc.) but increases by the square of the radius (crank length). The difference is subtle, but you may notice a feeling of more precise control as you pedal through corners.
  6. Shorter cranks allow higher cadence with less foot-speed, which is a biomechanical and physiologic advantage (high cadence = good, high foot-speed = bad).
  7. Short cranks are lighter.
    They also work better with smaller, lighter chainrings. Switching to shorter cranks may require a change in your gearing because it increases the Gain Ratio (the ratio of how far the bike moves vs. how far the pedal moves). For example, switching from a 170 mm crank to a 150 mm crank has the same effect on Gain Ratio as switching from a 46T chainring to a 52T chainring. If you use a 50T chainring with 170 mm cranks, you would use a 44T chainring with 150 mm cranks to achieve approximately the same Gain Ratio. Therefore, shorter cranks use smaller, lighter chainrings.
  8. Short cranks are stiffer.
    All crank arms flex, but given the same material and design, a shorter crank arm will flex less than a longer one. The stiffer the drivetrain, the more efficient it is (less mechanical energy loss).
  9. Short cranks reduce pressure at the patellofemoral joint, a common source of knee pain.
    The more the knee is bent during contraction of the quadriceps, the more pressure is exerted on the cartilage behind the kneecap, which may cause pain and injury. Short cranks reduce the amount of flexion at the knee during quadriceps contraction. This is also another reason to have your boom extended as much as comfortable so that your knees are not too flexed.
    Short Cranks Reduce Pressure on Knees for Cyclists

Ready to switch? Check out the high quality 145mm crankset upgrade that we custom ordered here.


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