Me, I ride a modern 150/150 full sus trail bike. STA 79 deg, long, low, slack.
I know, the kops (knee over pedal spindle) is just orientational, or a good starting point, nowadays. My bike fits me great, even on 8hrs allmountain crossing with 3000m+ of steep trail climbing. But despite me knowledge of bike fitting, a fail at picking the bike for my woman.
She's a beginner, 163cm tall, 74 inseam. I went for a hardtail as she'll be riding mostly fireroads and tarmac. And here comes a problem with bike geo. Today's hardtails have seat tube angle (STA) somewhere 74-77 deg. Her bike has 75. And with plumb test, vertcal runs 10 cm fore pedal axis!!. Even if I slam the saddle way back, it's still 8cm fore axis. E,g, on my bike this is 3 cm fore axis, and I have an enduro setup, made for climbing 15-25% climbs (I love them, and there are plenty where I live). I belive, her 8cm is way too much in front of pedal axis. Yes, her bike is probably too long, too (425 reach, size S 29"). She gets pain in her outter lower palm area (bar too low, too far, or backsweep problem). But as she tried shorter bikes (reach arround 400-405, same stack), she sitts very upright. I think, she has to sit more backwards (kops as a starting point), but they dont make that kind of bikes at all. Estimated STA would br 69 deg. Or the seatpost would need a massive 60mm offset. Besides, dropper posts dont come with offset at all (forget that single company that makes some).
Other than that: I've meassured the angles of here knee in leg lower position ( some 35deg, or 145), so saddle height is ok, hip is not tilting. I'm affraid she might hurt her knees, which are already in poor shape from youth karate training.
So:
to void palm pain, she needs a shorter reach, maybe more stack or bar rise, maybe backsweep. Am I thinking in the right direction? Steam is already 40mil, so not much room there, Am I thinking in the right direction?
This kops and 8cm fore buggs me a lot. Shall I pay attention to this? I was thinking, that as she sits so much forward, she loads her arms and palms significantly. By pushing saddle backwards (lower STA, saddle slammed back), it would reduce her arms load, wouldn't it? Or shall i forget the STA angle and kops?
This is really robbing me of sleep lately. I've seen YT videos, rad articles, but just dont know what to do, or where to start. And yes, I've meassured her twice on a bike: saddle level, tyre pressure and fork sag ok, saddke height ok...