Manufacturing & Shipping Update #6

Manufacturing & Shipping Update #6

Hey Everyone,

Happy New Year. I hope everyone had a great Holiday season and everyone is being safe and COVID Free.

First, please do not hesitate to email me. I am not using any money from the wheel project to fund the development of the Hollow Wheels. Only the cost to actually make the final wheels. This comes from my own pocket. I have healthy streams of income so don't worry about me going homeless and having to give up. I never give up.

Lots of productive work going on since last update:

  • Made a small tooling change to the core. Already completed. More below.
  • TPU Upgrade. New wheels being made right now.
  • Testing. Notice no deadline, but more on that below.
  • Final retail box
  • Final printing of logo on wheel

This is the timeline of when things will be complete.

We also have Chinese New Year around the corner wherein China takes a break from Jan 15 to Feb 7th or so. So I am racing against the clock to get this done, but don't want to sacrifice anyone's safety. This is important because it can add more delays. Just being honest.

Tooling Change:

We elected to make a tooling change to the core of the wheels. We wanted to make sure there was enough surface area on the core of the wheels to grab on to the soft TPU (the tread). We wanted to both increase mechanical grip between the two compounds as well as provide more surface area for the chemical adhesion (for more on what this is refer to the last update). Sorry for the small, low rest picture. Just need to protect my work from the copy cats as long as I can.

TPU upgrade:

The latest batches have been coming in at 95A and 89A, respectively. All the prototypes have been at 80A, so we're slowly changing the formula to get to that baseline. The wheels are still very comfortable at 89A though. Moreover, we adjusted the formula with more bonding agents so it can get the chemical adhesion that we need.

We're also adjusting the core chemical composition to aid in chemical composition too.


I am no plastic injection molding expert, so I hired a third party plastic injection molding consultant. So we have the TPU factory, the Injection molding factory, and a third party consultant working on getting the chemical composition.

Each new sample, we performing more and more tests to make sure we have chemical composition. We were testing in the beginning, but we're just learning more and more and applying these lessons learned to make sure we can minimize downtime. Some additional tests include cutting wheels apart and measuring the amount of force it takes to peel away the soft TPU from the core TPU. Then continue adjusting parameters.

There are a lot of variables including, but not limited to mold temperature, TPU temperature, Core TPU temperature, injection pressure, chemical composition. We just have to control variables and pull one lever, then test. Just using data to make the best decisions.

Not hard. Just takes time and attention to detail. So I'll keep you up to date, but this project is of high priority. We are able to inject a new wheel and test per day, so we have a lot of testing parameters to go through. My estimation is about 2 weeks before the test is complete. Perhaps less. They work 6 days a week and 10+ hours a day. Beasts.

Retail box: 
It is looking beautiful, but maybe I'll leave that as a nice surprise when you all get the wheels. 

Logo Printing:

No major challenge here as far as I am aware. But you all know how it will look.

Off topic: My room mate got COVID and so I wanted to get tested. Do not take the quick test 80% accurate COVID ($150); it is a waste of money... I thought I would try to save some money since I was feeling fine. Go for the PCR test (supposedly 99% accurate) and spend the extra money - it is $350 w/o insurance ($250 w/ insurance). Anyway, I took the 80% accurate test and it gave me a false positive. Huge mind F**K. I convinced myself that I got sick. Anyway, I took the PCR test and it came back negative.  



Back to blog


Thanks for the update!! Hope you’re staying safe and that you are healthy!


Hey Doug,

Thanks for the updates! Glad you came out negative and New Year Year!

Johnny Chan

first off, I’d like to wish you a happy new year! Sorry you had to go through that with covid, what a sucky thing to deal with.
Ive been keeping up with your newsletters for a while now, and while I haven’t yet pre ordered due to financial constraints, but once I do I’m jumping on the train asap! Look forward to the development of hollow wheels and wishing you and your loved ones good health in this coming year!!

Aaron Hau

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