A decent idea but looks to wobbley. Although mine is perhaps over the top for track dayz its great for the garage and is fully adjustable !, What is it I hear you clamour? well....... A trusty garden spade ,simply lie it on the floor with the handle pointing towards the front wheel and bring it forward or backwards and due to the shape of the back of the spade it acts like a wedge and when you have done you can go and dig up some spuds whilst everyone is riding around .
Watch this space. My brother has made me a wooden wedge mounted on some plywood with grip tape on, works a treat. Will post photo once I get my back wheel back tomorrow after tyre change. It's so easy to use you wouldn't believe it.
Sorry for the late reply post on this thread, only just remembered after seeing photos on my phone I took. Here we go:- Slacken spindle and wind adjuster bolts in enough to remove chain off sprocket when wheel is pushed forward. Remove chain and hang on end of swinging arm. Insert wedge fat end forward. Remove spindle and wheel the wheel back down the wedge removing the caliper and carrier as you go hanging them over the swinging arm too. (pushing the pads in slightly also helps.) Leave the wedge where it is and reverse the procedure for refitting, works a treat see attached photo of this super inexpensive tool