by Andrew G » Mon Nov 12, 2007 5:59 pm
[quote="Sylv Frischknecht"]I hadn't touched my seat position for ages, but just had a look and on the mtb the distance top of saddle-to- bb axle is 68cm (175mm cranks), and 69 on road bike (170mm).
I've always seemed to have had it at 70 to 70.5cm though, I don't know when that has changed as the saddle doesn't seem to have slipped on either bike (had some marking tape on one). But I've raised them to 70 and am now keeping my fingers crossed this will do the trick, as a too-low saddle is symptomatic of this type of pain below the kneecap.
A saddle that is too low can cause knee pain, although you can only have the same height from saddle to BB on different bikes if the cranks and pedals are the same length/type. Different length cranks obviously alter the overall height but so do pedal/cleat combos as they have different stack heights. The pain will tend to appear after a while in to the ride rather than instantly as your saddle may only be a tiny bit out.
Also make sure you take the measurement from BB (assuming same size cranks and pedals etc) to the top of the saddle, in a line with the seat tube, as different saddles are different heights from the rails to the top.
Sorry, if this is SOTBO.