Joints... Joints... Meets Kinematic

I got a game 2.5D basicly my biker runs along z axis only

i got my biker as a ragdoll always enabled with both feet and hands Kinematic to respective bike handle bars and bike feet base.

my problem is when my bike is in motion biker lower leg moves back away from the feet a little bit taking around 0.3 seconds to (reatach) to biker feet. any ideas how to do it

Im using configurable joints

if i drop ragdoll from the skyeverything looks smooth

also if i Kinematic my hips instead of my feets and hands to see if problem was with feets and hands the problem passes to the hips and feet and hands look great, so i came to the point joints dont like Kinematic, any work around?