Generation 4 Bike Pedal Testing

As we continue our journey to make great flat bicycle pedals, we want to document our successes and failures we have along the way. 

In our previous post - Generation 4 Bike Pedal Development - we outlined all of the work that went into brainstorming, designing, and building our Gen4 Flat Bike pedal prototypes.  Here in this post, we are going to show you some pictures and videos of the finished prototypes and talk about testing.

Below are some pictures of the finished Gen4 bike flat pedals on my e-bike.  These give you a great idea on what this pedal looks like:

Overall Bike Pedal Design Choices

For the overall design of this Gen4 pedal, we created a fairly long spindle shaft, and we kept the housing for the shaft circular.  We made this decision to allow for high rider weight and to create a robust and strong pedal.

You can see that we had a generous amount of pins for good grip on these pedals - these are actually not pins but m4 button head screws!  We decided to go this route to keep these easy to change out and replace.  Also, we used stainless steel screws vs. black oxide screws for these pedals to provide superior anti-rust performance.

For bike pedal material, we went with 7075 aluminum for its high strength and light weight.  We wanted to create a premium bike pedal that could stand up to a lot of abuse on roads and trails.  Of course, we decided to CNC machine these bike pedals vs. casting/forging for increased strength, and we don't have tens of thousands of dollars sitting around to purchase a mold!

For the sizing of this pedal, we went with a medium type of size for this prototype.  We thought this would be good choice to both demonstrate our machining and design capabilities as well as make for good prototype testing.  We eventually plan to have three total sizes of pedals to accommodate all bicycle rider shapes and sizes. That would be small, medium, large with sizes generally ranging from 90mmx90mm all the way up to 120mmx120mm!  We see many bicycle pedal customers requesting various pedal sizes with our competitors, and we want to serve the market in this area!

For the pedal bearings, we went with 3ea sealed bearings we purchased from Amazon.  These are installed towards the end of the pedal and held in place by our machined end cap.  We would like to go with professional NSK bearings for the final product as these offer superior performance and are regarded as some of the best bearings in the world.  But for this prototype, some quick no-name bearings will do the trick.

For the bushing (installed towards the crank arm end of the pedal) we intended to use IGUS bushings.  Except they did NOT arrive in time!  So, we got impatient and just assembled the pedals without these IGUS bushings for now.  I would have liked to get these installed on the pedals to get a true-to-life test, but we did not want to impact the timeline too much by waiting.

Finally, to seal up the bike pedal, we specified some generic rubber o-rings.  We made a small mistake here and ordered the wrong size, so these prototypes we tested are going without o-rings.  That should be OK for the summer (we thought).

 

Gen4 Bike Pedal Prototype Test - What Went Well

Overall the Gen4 bicycle pedal prototype test went well.  I installed them on my e-bike like what you see in the pictures above.  I gave them over 450 miles of testing on road surfaces to and from work (about 12 miles each way) over the course of several weeks.  

I liked the look and feel of these Gen4 pedals, and they have excellent gripping force!  I never once slipped off the pedals or had any concerns with losing my footing.

We learned a couple things we'd like to improve on for the next generation, so that's what making a prototype is all about!

Gen4 Bike Pedal Prototype Test - What Did We Learn?

There were a couple things we learned by building these Gen4 prototype bike pedals.  These are items that didn't go ideally, but we think we can learn from.

1- Machining time was too long

These pedals took over one hour each to run on the CNC.  That is WAY too long and will not allow us to get the price point on these pedals where we want to have them.  So, we needed to make changes to the geometry to speed things up.  The biggest time spender on the CNC program was the rounded shaft housing (the central part of the pedal).  If we can make this flat or beveled with the edges, it will save a considerable amount of machine run time.

2- Spindle and end cap hex geometry

The spindle and end cap hex geometry was not great.  We were using a drill on the six corners of the hex to get a good shape.  Because we used a larger tool diameter, this caused not enough surface area on the hex wrench, and these were prone to stripping.  So, going forward we will use a smaller drill.

3- Grease, grease, grease

When we first went to test these bike pedals, we did NOT lube the internal spindle up with grease.  This was due to a communication problem (each person thought the other guy was going to do it).  Obviously, we won't make that mistake again!

4- O-rings

Since we left out the o-rings (intentionally since we ordered the wrong size at first) we did see some seepage of grease around the spindle end which screws into the cranks.  This reminded us that we need to create a QA checklist during assembly to check for all of these items which could be easy to forget to install during production.

5- Screws as pins

I did have two screws (which we are using as pins) back out.  So, we'll need to use Loctite during assembly to ensure that cannot happen on future generations of these pedals!

6- Spindle threads had issue threading into cranks

The left-threaded spindle did not easily thread into my cranks.  This was because the thread on the spindle was a little poor at the very beginning.  Based on this experience, we are going to develop a fixture to check all the spindles for good threads before installing them into the bike pedals.

 

Video of the Gen4 Bike Pedal Prototypes in Action

Below you'll see a quick Youtube video of me installing and trying out the Gen4 bicycle pedals for the first time.  I do some riding around the neighborhood on the pedals and then a quick ride through the trails by our home.

 

 

Next Steps for Bike Pedals

Now that we've tested out the Gen4 bike pedals (I'm calling them our "Prime" pedal), we have a bunch of stuff to go iterate on for the development and production of our Gen5 pedal.  Click here to read about Gen5 pedal design and prototyping! 

 

In the meantime, if you're reading this several weeks or months from when this was posted, check out our PEDAL section of the Moongate Cycles store and grab your pedals now!