Old 03-17-20, 10:51 AM
  #12  
Russ Roth
Senior Member
 
Join Date: Dec 2019
Location: South Shore of Long Island
Posts: 2,762

Bikes: 2010 Carrera Volans, 2015 C-Dale Trail 2sl, 2017 Raleigh Rush Hour, 2017 Blue Proseccio, 1992 Giant Perigee, 80s Gitane Rallye Tandem

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1073 Post(s)
Liked 999 Times in 710 Posts
They give you F in the piece above. Measure the diameter of your wheel to the outside of the tire, my wife's as an example measured 340mm, take that and crank length and subtract from F which is 557 for a medium in the chart above. For me that would leave 47mm. Measure from the where the spindle sits below the cleat to the front of the shoe, whatever that happens to be taken from the remainder is your overlap. This won't be perfect however unless you ride with your heel down as you pedal so that on the upstroke your foot really is in line with the crank at the closest point, this is the case for a few riders. Mostly people ride heel up or flat when so that when the crank is at the closest point you will gain a few extra mm that might made the difference.
Personally everything I have read says that a longer crank length doesn't make a significant difference, it'll matter more if you mash vs. spin and unless you're taller can even harm your pedal stroke by causing more rocking at the hips. I would be inclined to find better things to spend the money on then a marginal improvement. Though if you're above 6' I'd be more inclined to try longer.
Russ Roth is offline