Hello humans 
I’ve been working on 3D printable hubs for a while now. Here are a few sets, free to download. Most of these designs are tested and work very well. This has been verified in test prints by other members of this community (thanks @Lionpuncher, @Arzamenable). If you want to support what I’m doing or send me a coffee to survive the day, there is a tip jar at the bottom of the post.
These hubs will fit tires from MBS, Trampa, Evolve. Most other tires will also probably fit (like Clever 2x6" or whatever flipsky is offering for example). I also included matching 3D-printable pulleys and spacers.
Hubs:
Y-Type:
Files:
Y-Type - Medium (6001,16100,638).stl (2.1 MB)
Y-Type - Wide (6001, 16100, 638).stl (2.1 MB)
Y-Type - Wide (Imp) (R6).stl (2.1 MB)
Detailed information:
Versions: wide (60mm), medium (47mm)
Face-to-face bearing distance: wide 31mm, medium 26mm
Hardware needed (per wheel):
5x M4 25mm socket head screw
5x M4 lock nut (for non-driven wheels)
OR 5x M4 ≥12mm Hex spacer (for driven wheels)
5x M4 washer
2x 6001 bearing (12mm axle)
OR 2x 16100 bearing (10mm axle)
OR 2x 638 bearing (8mm axle)
OR 2x R6 bearing (3/8 axle)
Printed:
This is an example picture, yours might look very different depending on you printer settings and filament!
Assembly instructions: press bearings into hub halfes, install tube into tire, slide valve through hole in front hub-half, slide front hub-half into tire, pull valve-side front hub-half slightly backwards, slide front hub-half fully into tire, slide screws through holes, put spacer in empty space between the bearings, install back hub-half onto screws, put washers onto screws, screw lock nuts (or hex spacers) onto screws, inflate tire with periodic stops to seat tire evenly onto hub.
R-Type:
Files:
R-Type - Medium (Lager 6001).stl (2.7 MB)
R-Type - Wide (Lager 6001) [MBS Pattern].stl (2.9 MB)
R-Type - Wide (Lager 6001).stl (2.9 MB)
Detailed information:
Versions: wide (60mm), medium (47mm)
Face-to-face bearing distance: wide 31mm, medium 26mm
Hardware needed (per wheel):
5x M4 25mm socket head screw
5x M4 lock nut (for non-driven wheels)
OR 5x M4 ≥12mm Hex spacer (for driven wheels)
5x M4 washer
2x 6001 bearing (12mm axle)
OR 2x 16100 bearing (10mm axle)
OR 2x 638 bearing (8mm axle)
Printed:
This is an example picture, yours might look very different depending on you printer settings and filament!
Assembly instructions: press bearings into hub halfes, install tube into tire, slide valve through hole in front hub-half, slide front hub-half into tire, pull valve-side front hub-half slightly backwards, slide front hub-half fully into tire, slide screws through holes, put spacer in empty space between the bearings, install back hub-half onto screws, put washers onto screws, screw lock nuts (or hex spacers) onto screws, inflate tire with periodic stops to seat tire evenly onto hub.
V-Type:
Files:
V-Type Medium (6001, 16100, 638).stl (1.8 MB)
V-Type Wide (6001, 16100, 638).stl (1.8 MB)
Detailed information:
Versions: wide (60mm), medium (47mm)
Face-to-face bearing distance: wide 31mm, medium 26mm
These wheels have non standard mounting points, so you’ll NEED the 6x pulleys to drive them!
Hardware needed (per wheel):
6x M4 25mm socket head screw
6x M4 lock nut (for non-driven wheels)
OR 6x M4 ≥12mm Hex spacer (for driven wheels)
1x pulley size of your choice for driven wheels
12x M4 washer
2x 6001 bearing (12mm axle)
OR 2x 16100 bearing (10mm axle)
OR 2x 638 bearing (8mm axle)
Printed:
This is an example picture, yours might look very different depending on you printer settings and filament!
Assembly instructions: press bearings into hub halfes, install tube into tire, slide valve through hole in front hub-half, slide front hub-half into tire, pull valve-side front hub-half slightly backwards, slide front hub-half fully into tire, put washers on screws, slide screws through holes, put spacer in empty space between the bearings, install back hub-half onto screws, put washers onto screws, screw lock nuts (or hex spacers) onto screws, inflate tire with periodic stops to seat tire evenly onto hub.
S-Type:
Files:
S-Type Medium (6001, 16100, 638).stl (2.9 MB)
S-Type Wide (6001, 16100, 638).stl (2.9 MB)
S-Type Wide Special Edition Right.stl (2.6 MB)
S-Type Wide Special Edition Left.stl (2.6 MB)
Detailed information:
Versions: wide (60mm), medium (47mm)
Face-to-face bearing distance: wide 31mm, medium 26mm
Hardware needed (per wheel):
5x M4 25mm socket head screw (medium version)
OR 5x M4 30mm socket head screw (wide version)
5x M4 lock nut (for non-driven wheels)
OR 5x M4 ≥12mm Hex spacer (for driven wheels)
5x M4 washer
2x 6001 bearing (12mm axle)
OR 2x 16100 bearing (10mm axle)
OR 2x 638 bearing (8mm axle)
Assembly instructions: press bearings into hub halfes, install tube into tire, slide valve through hole in front hub-half, slide front hub-half into tire, pull valve-side front hub-half slightly backwards, slide front hub-half fully into tire, put washers on screws, slide screws through holes, put spacer in empty space between the bearings, install back hub-half onto screws, put washers onto screws, screw lock nuts (or hex spacers) onto screws, inflate tire with periodic stops to seat tire evenly onto hub.
JE-Type:
Files:
JE-Type UW (6001, 16100, 638).stl (3.8 MB)
Detailed information:
Versions: ultra wide (77mm)
Face-to-face bearing distance: 31mm
Hardware needed (per wheel):
10x M3 8mm socket head screw
10x M3 6mm heat-set insert
13x M4 80mm socket head screw
5x M4 40mm socket head screw
18x M4 lock nut (for non-driven wheels)
OR 13x M4 lock nut + 5x M4 ≥12mm Hex spacer (for driven wheels)
5x M4 washer
2x 6001 bearing (12mm axle)
OR 2x 16100 bearing (10mm axle)
OR 2x 638 bearing (8mm axle)
Assembly instructions: press bearings into hub halfes, melt inserts into front hub half, install tube into tire, slide valve through hole in front hub-half, slide front hub-half into tire, pull valve-side front hub-half slightly backwards, slide front hub-half fully into tire, put washers on screws, slide screws through holes, put spacer in empty space between the bearings, install back hub-half onto screws, put washers onto screws, screw lock nuts (or hex spacers) onto screws, install front flange with long onto front hub half, inflate tire with periodic stops to seat tire evenly onto hub, screw hub cap onto hub.
Pulleys:
Files:
HTD 5M 56T 6x.stl (4.4 MB)
HTD 5M 56T.stl (4.3 MB)
HTD 5M 62T 6x.stl (4.8 MB)
HTD 5M 62T.stl (4.7 MB)
HTD 5M 66T 6x.stl (4.8 MB)
HTD 5M 66T.stl (4.7 MB)
HTD 5M 72T 6x.stl (5.3 MB)
HTD 5M 72T.stl (5.2 MB)
HTD 5M 78T 6x.stl (5.9 MB)
HTD 5M 78T.stl (5.9 MB)
6x means 6 mounting holes instead of 5. Only needed for the V-Type.
Spacers:
Files:
Spacer Medium 10mm (A8).stl (53.4 KB)
Spacer Medium 10mm (A10).stl (44.6 KB)
Spacer Medium 10mm (A12).stl (46.8 KB)
Spacer Medium 10mm (Imp).stl (44.0 KB)
Spacer Wide 15mm (A8).stl (56.7 KB)
Spacer Wide 15mm (A10).stl (51.4 KB)
Spacer Wide 15mm (A12).stl (53.3 KB)
Spacer Wide 15mm (Imp).stl (50.8 KB)
Ax stands for the axle Ø in mm, match wide or medium to the chosen hub. Imp is 9,8mm Ø, only Trampa uses those.
Parametric files:
Files:
step files pile.rar (12.8 MB)
PSA: Don’t change critical dimensions without testing.
Template files for making your own hubs:
Files:
hubsraw.rar (5.7 MB)
Some rudimentary fea analysis:
click here
Print recommendations:
click here
I recommend to print the hubs (and pulleys) in PETG with a 0.4mm nozzle (0.6mm works too, but you loose some fidelity and the text), a 0.2 or 0.3mm layer height on 
100% infill or 10+ perimeters with automatic support generation in the following orientation:
If you want to use PLA, don’t use black colored filament, as it could soften in hot weather. DO NOT use matte filament, filaments with weak layer adhesion or filament with a lot of additives (for example Bamboo PLA), as this may pop off the rim flange due weak layer adhesion. I strongly recommend the use of PETG, as it is more impact resistant than PLA. Furthermore I suggest painting the hubs, as this increases UV resistance. Annealing is also not a bad idea, especially if you’ll print in Nylon. Sanding the bearing seat helps if it’s too tight. Using too much force while inserting the bearings WILL crack the seat.
All recommendations are optional, you can print these however you like. However, if you ignore my recommendations you are in unknown territory and on your own.
Attention dumbass
I will take absolutely no responsibility if a hub unexpectedly breaks and you streetface!! I have tested them thoroughly, but I have no control over your filament, your printer and your skills on how to use it.
Do not use the medium sized hubs for tires over 160mm (6.3in) unless you have really good layer adhesion. It’ll create a lot of excess force on the sidewalls of the flange and maybe even pop it off. Use the wide versions for bigger tires.
I’ve tested all my prototypes with a dynamic pressure of 3bar (45PSI). Although the hubs can withstand tested static pressure of up to 7bar (100PSI), higher than 3bar of dynamic pressures may still result in failure.
As with all pneumatic wheels, these need to be balanced. Otherwise you will experience vibrations and wobbling!
You are free to use and modify these files for non-commercial use however you like, but please give credit or link to this post if you publish them.
If you don’t have a printer, you’ll find lots of people on here who might be so kind to print something for you. 
Or just ask a friend! If you want to test the hubs in more extreme circumstances, for example heavy offroading or high jumps please share you findings, as those are some use cases I can’t test. Thanks!
