Trikke T12 geometry

[NormL1]

New to these forums, but, this looks like a great place for answers. I am in the process of converting my Trikke T12 to electric via a Magic Pie 4. One of the first steps that I have to do is create a new front fork that is wide enough and tall enough for the much larger wheel. The Pie is still in the sky, but, should arrive in the next few days and then i can add a tire and make some really good measurements of the combo. Until then I have laser scanned my Trikke to get some values for discussion.



I then dropped a plane through the asbuilt center of the Trikke


I come up with the rake at the front of the Trikke being 26.87° off of ground perpendicular and a 3.51" drop to wheel center from the main upright centerline. I also found the the two rear wheels toe out about 0.3°, which I thought would be more. The wheel center is 1.52" perpendicular to the main tube axis.

As I place the much larger wheel on it, the angle of 26.87° is going to get larger, by a lot. I would still like the carving feature to work after I am done, so, what am I trying to maintain? I do realize that switching the orientation to backwards would make it a better powered scooter, but, I am figuring the wheel is set inward for carving

The dimension that makes sense for me to maintain is the perpendicular to the steering axis to the center of front tire patch on the ground. I just measured it at 4.19 inches. Any input of experience, knowledge or guessing welcome.

 

[NormL1]

I still think that the offset from the steering axis to the center of tire patch is the important one. I modeled an inflated tire on a quick model of a Magic Pie 4 and added that to the model of the tubes and floor from the laser scan. I come up with the entire Trikke having to pitch backwards 3.6° which is not as much as I had thought it would be. I will also need to make the axle center closer to the steering axis than stock by about 1.1". This was done using a measured 1.26 foot diameter of the tire'ed Pie, which was a Kenda Kwest 16x1.50 100 psi tire. This tire does appear to be a low profile as the overall diameter is not really close to 16", so, I am assuming that bikes measure tires differently than cars do. I also find the center of Magic Pie wheel to be a 8.15mm offset from the center of mount for the 100mm mount to mount wheel I have

 

[NormL1]

I have been thinking this entire time that I was going to machine another fork, but, I took it apart and it is beautiful workable aluminum. So the dimensions for anyone following, move the hole down tube 1.82 inches, inward to the center of the tube 1.07 inches and move the left fork outward 10mm. This will place the wheel 1.8mm off center, but, I have serious doubts if that will be noticeable. Of course gusset the hell out of it including filling the inside



Of course this is based upon placing the center of tire patch at the same perpendicular distance from the center of shaft. I have had a mechanical engineer tell me that would be correct, but, neither he nor I have any experience with bicycle geometry