I built cheap pedal platforms for Shimano PD-520/540 clipless pedals. I use proper bicycle shoes off road but they are not the most comfortable footwear during the occasional trip to the super market. I had some scrap plywood available and decided to build pedal platforms so that I can use regular shoes with clipless pedals.

This project takes about an hour (or likely less, if you are familiar with the tools) of active building time plus the time it takes for the glue and varnish or paint to dry. Material cost should be minimal. I happened to have everything in stock as leftovers from previous projects, so practically these cost me nothing.

Material list:

4 pieces of 10x10cm plywood (6mm thick is fine)
4 T-nuts with 5mm thread
Cleats
Glue
Varnish or paint (optional)
Some skateboad grip tape

Tools:

Saw
Hacksaw
6.5mm drill bit
Jigsaw

Step 1: Declaw T-nuts

I removed the spikes from the T-nuts by bending them a few times back and forth with pliers. They snap off quickly. The nuts I have happened to have just the same inner diameter and threading (M5) as the fastening screws that come with the cleats. If you can't find ones with fitting threading, just get something that is close enough and use regular countersunk screws that match the nuts and adjust the drill bit diameter to match the outer diameter of the nut.

Step 2: Cut Plywood

First I cut the plywood to four 10x10 cm pieces. Two of the pieces are the platform pieces and two are for reinforcement. If you have thicker plywood or if you pedal lightly you can do with only two platform pieces.

I drilled two 6.5mm holes two both platform pieces. The centers of the holes are on the centerline and they (the centers, that is) must be 14 millimeters apart from each other. The cleats are fastened to these holes.

Use the jigsaw to saw a 5x6,5cm opening to the reinforcing pieces. Note that the reinforcing pieces are not symmetrical! The opening is 5mm closer to the back of the pedal. See attached drawing.

Step 3: Glue & Cleat

If you only use one platform piece and no reinforcing pieces, then you obviously do not need to bother with gluing. I glued the reinforcing pieces to the platforms using PVAc-emulsion adhesive (wood glue). Note that since the pieces are square it is easy to glue the reinforcing pieces sideways. Measure twice, glue once.

After glue had dried, I applied some varnish to the platforms, because I will use them during the winter too. After varnish had dried I fastened the cleats. I pressed the T-nuts to the holes, using brute force, and screwed the cleat tight.

Step 4: Apply Grip and Test

My last step was to apply pieces of skateboard griptape to the platforms and take them for a test drive. I ride my pedals so loose that I can install and remove them with my hands. If you ride your pedals tighter, you can install them by pressing them of with your foot. Removing them might be trickier, though.

These pedals are not as comfortable as proper pedals. They rotate sideways a bit under the foot, just like the bicycle shoe does in the PD pedal. The only major annoyance is that when I take my foot off the pedal, it immediately rotates upside down.

Step 5: Improve Grip

I have been riding these pedals on snow in slightly below freezing temperatures. As such these pedals are useless in snow because the skateboard griptape collects quite a bit of snow and the shoe compresses it into ice making the pedal very slippery. I took inspiration from regular mountain bike pedals that have small studs on the pedal surface to improve grip and drove six screws to each pedal.

First I drilled holes that were slightly smaller than the screw core, opened the holes with countersinking bit and screwed in the screws. Driving wood screws right into plywood can make the plywood crack, so always drill holes first. Then I flattened the pointy ends of the screws so that they don't puncture my shoes. I did this with a hacksaw but if you have shorter screws a metal file might be a better tool.

If you don't wish to use a reinforcing plywood piece under the platform, it may be a good idea to use round headed screws instead of countersunk screws.