Originally Posted by
SethAZ
After some reading and thinking about things recently related to KOPS (knee over pedal spindle) and whether it's really the bee's knees, I experimented by setting my saddle back approximately 1.5 cm.
It was awful. I didn't also drop the seat post a tad, which I should have, and not doing so left my legs feeling much closer to overextending during the pedal stroke. The worst, though, was just the way setting back my saddle changed the angles of my knees and whatnot during the pedal stroke. I was now "behind" the pedals, and I didn't at all like how it felt. I was kind of shocked at how obvious it all was, and I'd assumed that ~1.5cm wouldn't be all that dramatic, and yet it was. I gave it several rides to see if I really felt that way because it was worse, or whether I just didn't like it because it was different than what I was used to. After several rides I still didn't like the effect it was having on my pedaling and my knees, and changed it back.
It can go both ways. In my case what I'd previously dialed in when I first got this bike was at least very close to an ideal for me (I'd used a plum-bob and did KOPS, which some will say is a rubbish technique, but it worked for me and was the "rule of thumb" for ages for a reason), and setting back 1.5cm from that made it worse. If you were in a worse position, of course, then a 1.5cm change might make a dramatic improvement. I'd say if you're not willing to pay a pro for a fit (I haven't paid anyone, just read and experimented and did it myself) then consider just starting out with KOPS and go from there. In my case I sat on the bike in my garage using one hand to hold onto my car while balancing on the bike, got one of my pedals to the 3 O'Clock position with my foot cleated in to the pedal, and dangled a thread with a little weight attached to it from my kneecap to see where in relation to the pedal spindle the weight hung, and adjusted my saddle until it was over the pedal spindle. It's possible that there's a better position for me than this, but I know for a fact now that 1.5cm behind my original position ain't it.
Well, let's see:
1) You managed to have your saddle way too high during the experiment. I would have thought that setting saddle height would be basic. The reason your knee angle changed was that you didn't reset your distance between saddle and pedals. Many riders find they climb better about 1 cm behind KOPS, which may be because they tend to climb in a more upright position.
2) You didn't adjust your hip angle. If you're going to close your hip angle like that, you need to open it back up with the bars if you expect muscle usage to remain the same. Maintaining hip angle is the reason that TT and tri riders move their saddles so far forward. One notices that this far forward position works for them.
3) Of course the other thing is to assume muscle usage will change and retrain your neuromusculsr system for the new position. This is the reason that racers have to train on their TT bikes, a lot. Different positions aren't wrong, they simply require one to train in them. That said, incorrect saddle height is certainly wrong.
4) If one ignores where the center of the earth is w/r to bike position, one sees that there is an angular relationship only between the body parts. There's upper arm/torso angle, hip angle, knee angle at full extension, and ankle/lower leg angle. These angles remain the same, no matter where the center of the earth is. We use the same position whether on the flat, climbing, or descending. Thus using a plumb bob is irrelevant. What matters is being accustomed to a particular set of angles. There are standard angles used by bike fitters which have been found, over the years, to maximize cycling efficiency in the average rider, though there's a good bit of variation in them, depending on one's exact location in the wide world of cycling sport. One notices that "pedal forward" bikes are designed to be ridden in an upright position.