Knee discomfort from bike fit

How likely is it that a proper bike fit causes knee discomfort in the short term from the new position but isn’t a sign that the position is wrong? By knee discomfort I mean around the knee cap area of my left leg, very faint pain but more just feels wrong like something that will get worse if I don’t stop. (don’t know if it will get worse) Is that a bad sign that the discomfort will grow or is it something that can happen when changing positions from what I’m used to?

I had a bike fit go bad a few years ago when the insole they gave me pressed into the ball of my foot (the arch support was too far forward) causing foot pain that took a few months of limping to recover from so don’t want a repeat, but don’t want to just assume the fitter is wrong.

See I’m trying to get my position better adjusted from a fitter and was doing this by measureing my biomechanics with a leomo device by raising and lowering my saddle from the baseline which is my previous position. Purely based on the numbers the leomo device gives I do see that I’m more stable with the saddle lower. But also feels like I’m bouncing a bit on the saddle like the saddle is too low and the knee discomfort.
In case you want to look at the numbers with the laps labeled of my saddle position:

It seems like my foot has excessive movement at the bottom of the pedal stroke and lowering the saddle fixes that. Is that worth fixing? is the side effects of fixing that worse than the problem?


From my experience: If knee pain arises from changing anything. Go back, full stop.

Test: take a video of yourself on the trainer normal posture. Asses if you feet are horizontal in that position at the lowest point of the pedal stroke. Now go into that position while on the trainer and see if you can move your knee cap around with your hand. If so: lower your saddle until you cannot.


Its hard to say, the pain could be caused as its a bad fit and you shouldn’t continue but on the other hand it might be the ideal position and a good fit and the pain is your body trying to adapt to it. If its a large change from your previous position you may try moving to the new position incrementally, say 2-5mm change at a time.

If low enough that you feel like you’re bouncing on the saddle isn’t that too low?

I don’t understand what you mean. My kneecap didn’t move around with my hand no matter what the saddle height

Could be, perhaps that movement is causing the pain, which might mean its not the right fit, but I am no expert and its especially hard for me to guess of the linked graphs :neutral_face:

Was hoping more people would have experience with this :slightly_frowning_face:

Happened to my mate after his bike fit. I was fitted by the same guy and didn’t experience any issues whatsoever - it’s highly individual. I definitely think you should go back (without additional charge) and get it adjusted. As someone pointed out above, revert to your previous settings meanwhile in case it felt fine before.

  • It depends (sorry, just the truth). First question is have you talked to your fitter about this?
  • “New” discomfort can happen, but depends entirely on the type and amount of changes that were made in the fit vs how you came in. If I make huge changes to a rider’s position, I caution them about potential issues and recommend the “take it slow” approach for rides right after the fit.

  • In any event, I tell them to contact me if there are any significant issues, whether we discussed them specifically or not.


The data shows this is the better position so implies just trusting them and will take awhile to adjust (this is a remote fitting so they have seen as much about me as you (the link above) I’m not doing the bike fit because I had pain before, I’m doing it to maybe get more efficient. Getting an injury with a bad fit like what happened to me before isn’t something I want to do. Granted when I said my knee had discomfort when lowering my saddle 8mm and over then went with 4mm even though saying the data shows I should be 20mm lower (tested baseline, 4mm lower, 8mm lower, 12 mm lower, 16mm lower and 20mm lower)

No pain before any adjustment, only adjustment is lowering saddle.

On further playing with the device and using my cell phone for video I noticed when I pressed down on the sole of my shoe with my toes and so sort of arching my feet in the bike shoes (carbon fiber specialized torch) I noticed that the DSS score drops to 0 which is good and the foot AR in q1 also decreases but the video of my foot looks basically the same.

To me this seems to indicate the source of the numbers looking bad is not from saddle height but from the way my foot fits in the shoe. I have custom-molded retul insoles currently which feel like they keep my arch from collapsing. I don’t think its an issue with my arch collapsing but more that my foot has two ways of taking load where my foot either slightly tilts to the outside so weight is on metatarsals 2-5 with 1 being mostly unweighted which is usually more when not under load. The other position mostly loads 1 but also 2-3 and 4-5 have less load. Arching my foot in the shoe keeps me in the first position so more stable in the shoe so the sensor sees less movement. Lowering the saddle means I’m less toe down at the start of the down and up stroke so less transition between the two positions.

This seems to be supported If you look at my insoles the stop under metatarsal 1 (big toe) has a nice indent in it from use and the rest of the ball of my foot makes less of an impression. But when lightly putting my foot down it always feels like the big toe has the least load. When pressing on the bottom of my foot my big toe moves more than my other toes which makes it seem to have more give than my other toes which could be why it takes more load as load increases

Is this something that should be fixed? (moleskin to build up the area under my big toe so I won’t switch between the two positions?

Me overthink?..

Was 20mm the max you tested? My gut feeling is, don’t trust that data. Bearing in mind I know very little about bike fits, but maybe a little bit about measurements. It’s odd when only one parameter changes, but goes right to the end of the measured range.

Also usually when you lower your saddle, your reach also gets shorter (because of the seat post angle), so you might need to check if you need to change that.

Personally, I’d put the saddle back up and forget about it.

Personally, if an app tells me that a position is more ‘optimal’ but it causes me pain, I’m going to listen to my body. Comfortable = more riding = better fitness = getting stronger / faster. Uncomfortable / pain = less riding = worse fitness = getting slower.