“Can’t feel sit bones or IPR when seated” … I experienced and worked through something very similar to this over the course of the summer. Though this lengthy response is purely anecdotal, the key themes therein might help isolate your own particular issue.
- Hip angle/tilt:
Prior to my love for cycling, I spent a great deal of time gaming (these were my foundational years, 8-16)
I’m now 32, and like many of us on here, I work a desk job
- Saddle height
Observing professional cyclists gives the impression that a high saddle height is ideal (of course this turns out to be greatly affected by the amount of power being displaced, and conditions you’re observing them in which is nearly impossible to control for as an observer)
Knee angle as observed while riding ones own bicycle is not a good indication of ‘actual’ knee angle. I.e., high speed or slow-mo footage under sizeable load (80%+) IS the ideal and probably only way to accurately measure this angle without a third party observer
- Saddle fore/aft
- KOPS is largely irrelevant as the foundational factors (sit bone engagement + saddle height) are largely deterministic unless your bike is completely the wrong size or you have funky limb proportions
- More often than not, this is a compensatory mechanism
- Saddle size
- Often overlooked but easy to measure!
So here’s the big picture:
Due to my ignorant ‘past’, my pelvic/hip angle has over the years naturally tilted forward (anterior pelvic tilt). This has led to weaker glutes (VERY low/no activation), tighter hip flexors and naturally, a tendency to rotate forward taking the load completely off my sitbones and onto the soft tissue. Before i understood this, and while observing myself cycling (video), i noticed my knee angle was less than optimal, so my solution was to jack up the saddle height to correct. This led to excessive ankling, excessive anterior pelvic tilt, and in turn forced me to position the saddle further forward to compensate. While progressing through these gates of trial and error, at no point did i pay attention to the real issue; my sit bones were NOT engaged. The setup was not optimal, and although i was managing to put down solid power and was able to maintain endurance for extended periods, i suffered from poor control of the bike, and a general lack of comfort which i simply accepted as fact.
Here are the steps i took to remedy:
Measure sitbones and obtain an appropriate saddle width (I’m @ 125mm, and was originally on a 138mm wide saddle. Followed the +20 method and scrapped it for a 145mm wide Aeolus)
Reduce saddle height incrementally to 1) mitigate ankling (If this is an issue) and 2) help reposition your sitbones back into the saddle
Because of this reduced saddle height, i now began to feel myself sitting more upright and this ultimately influenced the amount of weight distribution over my sit bones. As i began to feel them engaging, i pivoted my attention to…
Saddle fore/aft. Using Steve Hogg’s balance technique, i found a saddle position that allowed me to unweight my hands almost completely at 80% threshold. I mention above that KOPS is largely irrelevant- if you follow this technique to balance your weight over the BB, you’ll realize your knee position over the pedals almost naturally aligns. Ride enough to see how your knees feel, and adjust according to any pains that develop (bearing in mind that you may now be activating your quads MORE than before in this new position, which may bring about some initial aches (top of patella) while you acclimate)
What i’ve come to realize throughout this process is that ‘hallmark’ methods for sizing up a bike-fit almost organically fall into place; things like heel on pedal method for correct saddle height are only effective if your sitbones are properly engaged in the saddle, and this becomes apparent once you nail that down.
As a quick test: while on the trainer, sit upright, hands off the controls and rotate your pelvis back (think of sucking your belly button in). Feel your sit bones engaging then try the heel method for saddle height and observe how much you sway and which side you may be favoring. Then, try to reach for the controls while maintaining this sit bone engagement and see how your body reacts.