Originally Posted by novetan .
I'd hv thought the mesurement of inseam shld be carried out wearing shoes, but the Lemond method mentioned is best done in bare socks. Isn't its more accurate to measure with shoe since each shoe has different ht.
Yes, but if you read Lemond's book his actual method is to measure inseam length without shoes, multiply that by 0.883 (which implies a universal perfect seat height which is not really true and assumes a common crank arm length as he measures to the BB center) but then adjust that up or down based on sole and cleat thickness measured with calipers which may have made some sense when his book was published using standard cleats and toes strap pedals but is less relevant today with pedal/cleat systems of varying stack height.
But his method will still get you into the ballpark and then you can fine tune.
There are other methods and they have strange caveats as well like measuring your Greater Trochantor height while wearing your cycling shoes and then setting your total saddle height (to the pedal spindle center so it accounts for crank arm length) somewhere between 96% and 100% of the measured height. So this method has you actually wear cycling shoes which may vary in sole thickness or cleat stack height but that's how the original studies that came up with the 96-100% recommendation were performed.
Or you can go with knee bending angles at the bottom of the stroke looking for something like 145 degrees plus or minus five degrees or so depending on hamstring flexibility. Ideally these measurements are made while actually riding under load as in with the bike mounted on a trainer and by shooting video (or using RETUL motion capture equipment). Making these measurements statically can be misleading as folks do things like drop their heels when posing and tend to toe down at least a bit while pedaling and that impacts knee bending angles.
Bottom line, all of these and other methods get you very close and then you fine tune based on guidelines like:
- Lower your saddle if you sense tightness or soreness behind your knees, especially tight lower hamstrings near the rear of the knee joint towards the end of longer rides
- Lower your saddle if your hips rock side to side as you pedal or you feel yourself reaching with your toes at the bottom of the pedal stroke
- Raise your saddle if you're experiencing pain or soreness at the front of the knee near the kneecap. This one can be tricky since things like poor cleat placement or pronation/supination issues in the foot or cleat rotational adjustment in non floating cleats can all contribute to knee pain even if your saddle height is appropriate but overly low saddles can lead to pain and soreness in the front of the knee joint.
IOW, get it close and then fine tune as suggested above....
-Dave