I would like to have bike fitting session but I am not sure how they can use trainer on my Speed TR... with Dual Drive & Click box.... Is there a way around it? (other than maybe installing some other 20" rim, etc)

YEA remove the click box and shifting rod from the hub, or put a common 20" wheel needs to be with a 135 wide axle in it,
but why bother with a bike fitting, just change the stem length to what feels better,
If what came out of the box is not satisfactory, unless you just like hanging around in bike shops..
Nature of folding bikes [other than BF] is they only make one, but adjustments of stem and saddle position compensate.

FWIW I liked working in a community bike shop where the regulars came by. WABAC ..

I would think they could fit you on any bike. Then take the dimensions and implement that on your Speed TR. No?

Not exactly.... Fit parameters on a Speed TR are going to be severely limited. Saddle position, saddle height, and a tiny range for handlebar height are all you've got.

I'd expect that the wheel size may be a bigger issue. Regardless, I'd bring the TR so they know exactly what they're dealing with.

gonna be difficult........ as folding bikes are ridden very different than full size bikes the regular sizing methods are not working for folders usually....
different ridden I mean that you hardly ever get out of the saddle, usually higher cadence while keeping the butt firmly planted is the much prefered method of climbing for example......

you just need to find the most comfortable position and than just use your bike
dont worry about small details

thor

Depends on the folder. I had zero hesitation about standing while climbing with a Swift, for example. The real issue is that most folders are "one size fits all" and have minimal fit options.

However, if you can't get the fit you like on your own, I say get some help with the fit. Even if they can't get the TR onto the trainer I'm sure they can figure something out.

Also you don't want a situation where they spend half an hour figuring out a good fit for you, only to find that for some reason you can't achieve that on the TR. Definitely bring the bike.