SPD pedals for EUC

Modern electric unicycle riding centers on the interaction between the pedals as the primary contact point and power pads that lock the rider's legs to the chassis. By pressing their feet into the pedals while leaning their weight against pads, riders gain the leverage necessary to command heavy, high-torque machines. In professional usage, this locked-in stance is critical for high-speed racing, where it provides torque for aggressive cornering and stability to prevent wobbles. Pro riders also utilize jump pads to physically lift the wheel off the ground during stunts or jumps, ensuring they remain connected to the machine while airborne, across technical obstacles and extreme off-road terrain. Yet, this setup remains imperfect as feet can still shift or creep during the ride or even get yanked out on violent turns.

I’ve always wanted to overcome this deficiency and, having some MTB experience, felt this could be achieved with SPD. So one day I bought a 3D printer and made myself a pair of SPD pedals for my EUC. Now, many iterations later, with over 3000km and one year of experience riding them I've decided to share the project with you. For me the goal is accomplished and there is no going back to normal setup.

This guide describes the build process of a pair of electric unicycle pedals that you clip into with your shoes. This solution completely eliminates foot slip and ensures that your feet are always in the optimal position. It eliminates the need for toe and heel pads, while maintaining shin and calf pads. Currently, my design is for LeaperKim hangers only, and there is no angle adjustment.

Ride feel

Since heels are free to move, riding SPD sometimes feels like dancing on your toes. This is so nice when climbing uneven terrain on the limit of traction. I never have to correct my stance between jumps. The control over the wheel is superb. I can lift it faster and with better precision than ever. I can better and quicker counteract sudden twisting of the wheel. This opened up an entire category of saves I can now pull off. Being locked-in also gives you great leverage to push on the pads and maximize power transfer.

SPD concerns

I completely switched to SPD over a year ago and I have never had an injury related to SPD. No sprained ankle, not even a strained muscle. And I’ve done some crazy things - see my insta @kaos.euc. My feet were never trapped when they should have been let go. And they’ve never been let go unexpectedly. If I crashed at slow speed my feet remained clipped in. Thanks to that, I stopped hitting my legs with my wheel completely. And if I crashed at high speed my feet would always get released. Surprisingly, SPD pedals seem safer to me than a set of normal pedals and pads. Once I learned how to dismount SPD quickly, I found it more reliable than with traditional toe and heel pads tightly locking my feet.

Mud can clog up the mechanism and prevent clipping in. It can be cleaned easily, but you’ll need a moment. The best you can do to prevent it is just don’t step off your wheel, ride on.

Mounting an EUC with SPD pedals takes longer than with standard flat pedals, you can’t just jump in. Unless you can pendulum you'll need a little run-up after you clip in the first foot to add the other one and check the binding. SPD is not good for starting on a very uneven terrain or just in front of an obstacle. It’s not good for sprint start races or for races with slippery, unstable surfaces, where falls are expected. You also can’t just jump out and back in, so doing tricks is not possible with SPD. Long distance and seated riding can be tiring. While you can unclip mid ride and rest your feet you will be in a tight spot in case of emergency.

None of these things matter to me, as my element is singletracks and bike parks.

Design durability

Parts that wear out over time are cleats and shoe inserts. Fortunately, these are inexpensive and easy to replace. Cleats tend to fret at the rear edge. If the binding doesn’t hold as well as it did initially, it’s probably time to replace them. Shoe inserts wear at the threads.

While SPD mechanisms never caused me any issues, I did experience some problems with the durability of my pedals. These issues occurred during testing of early prototypes, as they were subjected to increasingly greater forces. Me and my buddy Adam broke a couple of plastic-only pedals. The current design with steel braces has never failed. It certainly has its limits, but those remain unknown as with most pedals, so use at your own risk. If you crash you will most likely just scrape or chip off the plastic part. For better durability you can try printing from PCTG or PA - without fiber additives.

Shoe selection

Proper shoes are the vital part of a good experience riding SPD pedals for EUCs. They need to have: A flat tread for good contact with the pins under your heel. You dismount the pedals by raising your heel and twisting it outwards. If your shoe has large tread blocks you won’t have good contact with pins and risk unclipping unexpectedly. A flat tread is also beneficial for that short time when you’re off your EUC, walking. A stiff sole for leverage and acceleration. While pressing on shin pads will remain the default way for aggressive acceleration, you will also use just your feet to accelerate by raising your heels. On the other hand the sole can’t be too stiff, as you still need some flexibility to clear pins while clipping out. The shoes I've tried that worked very well for me are Shimano SH-GE900 and its GTX winter version. The nice thing about them is they have an extra cut out in the tread for the SPD mechanism, so you can unclip and lay your shoe flat on a pedal. Boa closures are also a plus. If you buy new shoes, you may find it difficult to clip in at first. Give them time, they will break in.

Cleat selection

You can use cleats from the VP X92 set, but they have angle adjustment. If they ever loosen, dismounting will be very difficult. I recommend Shimano SH51 cleats. Both of these are single-release cleats, which means they only release through a twisting motion. Multi-release cleats, on the other hand, also release with an upward motion. In practice, though, single-release cleats do release upward too — you just have to yank hard (for example, during a crash). This is actually desirable, since you don’t want cleats to release unintentionally during a jump. If you want extra safety, you can start with multi-release cleats, like the Shimano SH56.

Assembly precautions

Drilling through hard and soft materials simultaneously can cause sudden bit grab, deflection, or rapid plunge at the interface where the materials meet - ease pressure and maintain control. Always wear eye protection when drilling metal. Use thread glue for every part with a thread on it (screws, pins). Repeat all steps for both pedals if not directly mentioned.

Assembly

Print the attached pedal model and its mirrored copy. Use 100% infill for the best strength. The pedal can be printed standing on its back or laying flat if you don’t have problems removing large prints from the bed. Enable supports, disable “supports for small overhangs”. Internal cutouts for shafts and braces don't need to be supported. Printing a pair takes me about 38 hours. After printing is completed clean all supports, brims, etc.

Cut four pieces of the attached brace profile from a 10mm 304 steel (or similar) on a CNC machine. A precision of ±0.2mm should be enough. Insert them into the pedals and make sure they are all the way in.

Secure the pedal in a vice. Use an 8.1mm drill bit and ream the 8mm shaft hole from both sides. Drill the full depth of the hole through the steel braces. Repeat the same for the 5mm shaft hole, using a 5.1mm drill bit. This time, you don’t need to drill the full depth of the hole, just past the braces.

Keep the pedal in the vice or put it on the floor. Hammer the 8mm and 5mm shafts in. Use nail punch for last strokes to dig the shaft under the surface. Check from the other side if the shaft is centered. Hammering in the 5mm shaft should be hard and irreversible. The 8mm shaft should not need much force to get in. If it does, redo the reaming process from the previous step. Make sure there are no filings left from drilling and the hole is clear.

Place the pedal flat side facing up. Hot press inserts into their holes. M4x12 inserts are meant for the two through holes, while M4x8 inserts are meant for the 11 blind holes. Turn the pedal upside down. Clear bottom of M4x12 inserts from any molten plastic and screw in two M4x12 screws tightly.

Remove a pedal from the VP X92 pedal set and place it securely in a vice with the SPD mechanism facing up. Unscrew the two screws on the top, you’ll need them later. They are locked with a high strength thread glue. You need to use PH2 bit, be very careful, apply as much downward pressure as possible and turn the driver slowly. Otherwise you risk damaging the screws’ sockets and rendering the whole part useless. You can also heat the pedals up beforehand to break the glue bond.

Take the two screws from the previous step along with the SPD mechanism and screw it onto the pedal. While screwing in, take the same precautions as in the previous step. Screw 11 of your M4 pins into the pedal.

Remove toe and heel pads from your unicycle. Remove pedals. Remember to unscrew the two set screws from the bottom of the hanger. Mount the SPD pedals on your unicycle. Use a hammer and a nail punch to push the 8mm shaft all the way in. Secure the shaft with the two set screws. Screw cleats to your shoes. Allow 24 hours for all glue to set before riding.

Learning

I find the default release tension on X92 mechanisms just fine for learning. You can use the 3mm allen key to adjust the tension. On flat ground, clip in by placing your foot on the pedal and pressing forward and down until you hear and feel a click. Pull your heel up a little and test if the binding holds. Make that a habit, false clip-ins happen. To unclip, raise your heel to clear pins and twist it outward. If you have problems, check if the cleat is aligned and screwed tight. Practice clipping with both feet separately before you start riding. Learn in a safe, open area and expect a few slow tip-overs at first - this is normal. Also, I’d suggest crashing once or twice at a moderate speed before trying anything too crazy. Don’t go all in right away. Riding off-road fast in SPD needs getting used to. Remember that time you were learning to ride on an EUC and discovering muscles you had no idea existed in your body? I had that with my feet while using SPD as well. I think it took me about a month to learn it well. During that time I had many close calls I just had to pull off because there was no option to bail. With time I learned to dab, and even bail.

You need full commitment to learn and ride SPD.

Stay safe and enjoy!