A little progress report (BEFORE > AFTER).
About the same done with Quad, Wayfarer, Faggio and Sport Motorbikes. Only Cross Motorbike (Sanchez) animation was fine.
UPD: I've decided to host 'raw' updates - some ready-made files will be available before the next confirmed release. At least, this is not a total conversion kind of a mod, so I think I can do such a thing. Keep an eye for a main topic post to get them.
The first update contains those bike seat fixes.