There are two main problems which I can see:
1) As Valy already pointed out, there is no provision for fitting a front brake.
(Which I consider to be an essential item!)2) Where the fork dropout and the compression stay both attach to the axle, they are designed to accept a standard round 10mm axle, so the elongated slots do not have to run parallel to each other. Unfortunately, the Magic Pie axle is 14mm diameter with 10mm wide flats, which would probably fit into the fork dropouts OK, but due to the different angles, it probably won't fit into compression stay slots at the same time, without filing the slotted hole to suit. The chrome finish will make this more difficult and the amount that may need to be removed will also weaken the hole in the stay.
But that's just my opinion.
hello I think it depends how long fork. you'll have problems if fork is long. and just brake.'s not easy to put brake on Springer and work well. that weight tends to rotate left or right fork. I took up this issue in my chopper when I had a long fork Springer. I had a wheel weight and had to change it with a light and went well after. I hope you got something I do not write English well 
Valy, what you experienced is more to do with the rake of the forks causing a large caster angle.
Using longer forks usually means they are slanted back at a much greater angle, and this adversely effects the caster effect which is designed to make the front wheel self-centre,
If an imaginary line is drawn through the centre of the fork steering tube, it should strike the road just in front of the axle centre line.
(see the attachment below) If this line meets the ground in the right place
(around 65mm in front of the axle, if my memory's correct), it should help to prevent the wheel from falling over to one side when you release the handlebars.
Alan
