I’ve been given an old style Tacx Turbo trainer so I can turn some peddles while my badly sprained ankle recovers. The front fork goes onto a QR, then there is a vertical post (height adjustable) with a rubbery top around the BB area. Is this supposed support the BB? or just go infront / behind it? If it supports it then I guess it will change the amount of weight from the bike & rider that is placed on the roller thingy at the back.

Hi, i’ve got one of those still in my dads loft. Yes the bb does sit on rubber bit. Mine also has a T shaped threaded bar which sits over your two rear frame tubes just behind bb and you then screw tight from below bb (hope that makes sense). It all works really well but does make quite a racket from the fan when at full chatt.