Parts matching, 3d printable motor mount

Hi there, this is actually my first post so let me know if I'm following the proper etiquette for this forum.

I have all my parts in hand but I have a few concerns about what I've actually ordered, the overall assembly and mounts.

Here is my parts list:

2 x 4200maH LiFePo4 Batteries (https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14070)
1 x 2750W / 193KV Brushless Outrunner DC Motor (https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18129)
1 x Speed Controller (https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10944)
1 x UBEC (Universal battery eliminator circuit (https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6320)
1 x Austin David's Modified Wii-mote (http://austindavid.com/jm3/index.php/hardware/3-wiiceiver)

Here are some of the concerns I have regarding my configuration:

(1) The LiFe batteries are proving to be a pain in the ass, not much support for them and I'm concerned on finding a good charger for them. (I'd eventually like to make a charging port on the board)

(2) The total voltage on the batteries is 26.4 V, will this affect my top speed? I was told I should be supplying the maximum voltage to the motor (44V) Will the ESC take care of this?

(192 RPM/V) * (26.4 V) * (pi * 8e-5 m) * (14/36 gearing ratio) * (60 min/1hr) = 30 km/h ( I could probably fix with gearing ratios but I don't want to make my own gears)
(192 RPM/V) * (44 V) * (pi * 8e-5 m) * (14/36 gearing ratio) * (60 min/1hr) = 50 km/h

(assuming no losses so probably * 0.75)

If the ESC doesn't handle this, is my only real option to add more batteries in series? Also, since LiFe have a different nominal voltage compared to Lipo, I don't think I can actually reach 44V with 4s packs.

(3) I need a proper motor mount. I've done some sketches and I think I could cnc one to be welded onto the truck, but a screwable mount would be preferable for prototyping. (Perhaps a 3d printable model? If someone has one)

(4) Lastly, are all the parts appropriate?

Is the motor overkill? Is there a smaller motor that could supply me with 35km/h speeds in practice (a 50mm if possible)
Should I switch to LiPo or can I solve these issues with Life?
Is the ESC a good match? The BEC?


Sorry if this is a lot of questions, I just am trying to finalize the prototype and could use the guidance of someone with experience.

Any help would be appreciated! Thanks for input!

What is your wheel diameter ?
Given the data you have posted this is what I calculate (new tool I'm writing so YMMV):
Assuming:
- your two battery packs in series (8s)
- drive pulley 16 teeth, wheel pulley 44 teeth (so ratio 2.75)
- wheel dia = 83mm

Battery voltage = 26.4V nominal (29.2 max) (LiFePO4 chem)
RPM = 5095 unloaded = 3566 likely (assuming 70% efficient through motor and drivetrain)
Pulley ratio = 2.75
Duration (minutes) = 24.2 @ 26.4V
topspeed = 20.3 Km/h (12.6mpH) on 83 mm wheels
max dist = 8.0 km
(Using peak voltage calculation - you get 2 more minutes)
(At 16/40 teeth pulley) you get 2 more Kph

This is trying to be realistic rather than max on-paper performance. I'm still working the kinks out though.

I do not know that ESC but would point out two things:
Firstly - it is an aircraft ESC, so probably no nice progressive brakes
Secondly - I would have gone for a higher current one. It may be OK but not much headroom.

Motor is a good choice.

Batteries - I presume you are running in series but are going to charge single or in parallel. This would make finding a charger cheap and easy. An 8S charger would be more problematic.

I can send you a few files of motor mounts I used for prototyping when I get home as well as some gears for 83mm wheels. Although I ended up CNCing one from some aluminum. I can also almost guarantee that you will need a metal mount that is welded to the truck. My first attempt at the hole with a rod in it was too loose.