Assembly Guide
DIY
Build your own SmartSpin2k
This page is for builders. It tells you which parts to buy, which files to print, and where to find the build manual for your version. You should be comfortable with a 3D printer. For Version 2 you'll also need to solder.
Rather ride than build? Get a fully assembled SmartSpin2k, ready to mount on your bike.
Table of contents
- The build at a glance
- Check the fit
- Pick a version
- Parts list
- Print the parts
- Build guides
- After the build
The build at a glance
Measure your bike so you print the right arm, mount, and knob insert. Check the fit
Version 3 uses a ready-made board. Version 2 is a board you solder yourself. Pick a version
Motor, power supply, bearings, and hardware-store bolts. Parts list
The case, gears, and knob cup, plus the three parts sized for your bike. Print the parts
Follow the manual or video for your version and your shifter. Build guides
Flash the firmware if needed, then set it up like any other SmartSpin2k. After the build
Check the fit
Make sure your bike is compatible before you buy anything.
Take three measurements, with calipers if you have them:
- Back of the head tube to the center of the resistance knob. This sets the arm length. Measure at a right angle to the knob’s axis.
- Smallest diameter of the knob and largest diameter of the knob. These pick the knob insert.
Arm length is about your head tube measurement minus 65 mm. Arms come in 5 mm steps from 20 to 155. The Arm readme lists the arm length for each tested bike. To make a length that isn’t there, use the arm customizer on Thingiverse.
Version 2 needs at least 49 mm from the back of the head tube to the center of the knob. The compatibility page has photos that show where to measure.
Pick a version
- Uses the SmartSpin2k PCB kit. The board comes ready-made, so you don’t solder any surface-mount parts.
- The only version that connects to the original Peloton Bike’s sensor cable.
- Built from the Version 3 assembly manual.
- You solder a through-hole board that holds an ESP32 dev board and a TMC2225 stepper driver.
- Needs the extra Version 2 parts on top of the common parts.
- Built from the Version 2 build video.
Parts list
Every build needs these parts.
| Qty | Part | Where to buy |
|---|---|---|
| 1 | PCB and wiring harness kit (Version 3) | Official resellers |
| 1 | 38 mm NEMA 17 stepper motor | Amazon, AliExpress |
| 1 | 12 V to 15 V power supply, 1 A or more | Amazon, AliExpress |
| 2 | 608 skate bearings | Amazon, AliExpress |
| 1 | 5/16” x 1-1/2” hex head bolt | Hardware store |
| 1 | 5/16” washer | Hardware store |
| 2 | 5/16” nuts | Hardware store |
| 4 | #8 x 1.75” countersunk wood screws | Hardware store |
Power supply: anything from 12 V to 15 V works, as long as it supplies at least 1 A. The PCB kit needs a 5.5 x 2.1 mm barrel plug. Don’t go above 15 V.
Shifter
Pick one.
| Shifter | Qty | Part | Where to buy |
|---|---|---|---|
| PCB shifter | 1 | Shifter PCB kit | Official resellers, or build it from the files |
| Hand-wired shifter | 2 | Tactile switches | Amazon, AliExpress |
| 1 | Stereo RCA to 3.5 mm headphone Y cable | AliExpress |
Version 2 parts
Extra parts to solder your own board
Version 2 builds use these parts in place of the PCB kit.
| Qty | Part | Where to buy |
|---|---|---|
| 1 | ESP32 dev board | Amazon, AliExpress |
| 1 | TMC2225 stepper driver | Amazon, AliExpress |
| 1 | JST-XH connector kit | Amazon |
| 1 | 3.5 mm stereo headphone jack (for the shifter) | AliExpress |
| 1 | 5.5 x 2.1 mm DC power jack | AliExpress |
| 1 | Version 2 PCB | PCBWay |
| 1 | Recom R-78E5.0-0.5 regulator | Octopart |
| 1 | 10 µF 50 V capacitor, 6 mm diameter or smaller | Octopart |
| 1 | 100 µF 25 V capacitor, 6 mm diameter or smaller | Octopart |
| 1 | 0.1 µF 50 V capacitor | Octopart |
| 1 | 1 kΩ resistor | Octopart |
Print the parts
Print settings: ABS, CF-Nylon, or PETG, with 4 perimeters and 40% infill. Print the shifter strap in TPU.
Parts for every build
| Part | Files | Notes |
|---|---|---|
| Case, both halves | V3 Case | Left and right, each with or without the logo |
| Window | V3 Case | Translucent or clear filament, so the LEDs show through |
| Knob cup | KnobCups | Looks best in an accent color |
| Gears, 11T and 40T | Gears | Looks best in an accent color |
| Shifter strap, single or set | Shifters | TPU |
Building Version 2? Print the case from V2 - Through Hole instead of V3 Case. Direct Mount is the recommended case. Each case folder has a readme with its own notes, so read it before you print.
Parts sized for your bike
| Part | Files | How to choose |
|---|---|---|
| Arm | Arm | The length from Check the fit. The file name is the length, for example armWithHook85.STL. |
| Bike mount | Bike Mount | Named by bike. The folder has reference photos. |
| Knob insert | Inserts | Named by bike. Generic sizes such as 50mm.STL and 60mm.STL fit many unbranded bikes. |
Bike not listed? The Inserts folder has the reference photos and CAD files behind each design, and the Arm and Bike Mount folders have CAD too. Start from the closest match and adapt it.
Build guides
After the build
From here, your SmartSpin2k sets up the same way as one that came assembled.
A board with no firmware won’t show up in the Companion App. Flash it over USB with the SmartSpin2k Flasher.
Mount it on your bike and run Guided Setup in the Companion App. Getting Started covers the same steps.
Once you’ve ridden, calibrate so SmartSpin2k knows how far your knob turns.
Something not right? Start with Troubleshooting.