I have been designing and building things since I was a kid, and the one thing that has always held true is that each design is a compromise. Consider the flying car as an example of compromise: If you make the world’s best flying car, it won’t drive as well as the best car, nor will it fly as well as the best airplane because you compromised those design elements to allow one vehicle to both fly and drive.
As I make progress on the next iteration of the XPO Trainer, I keep reminding myself of these points. It would be VERY easy to try to make it do everything and be all things to all athletes. But, it does a very good job of that as is, so the compromises involved would take away from the design rather than add to it.
While I continue to explore ways to make it more versatile and useful as a training tool, much of this round of design has been focused on making it a more refined product. It needs to be easier to assemble, easier to maintain, easier to transport, cheaper to ship, etc. And on those elements we are moving forward. When we have our next production run the XPO Trainer we produce will be all of those things, and we expect that it will open new markets to us and make the product more accessible to a wider audience.
Here are a couple of changes that are being ironed out. First, the front wheel will no longer have motorcycle-style axle adjusters for alignment and chain tensioning. The job of aligning the front wheel to cause the XPO to roll straight will be taken over by a device similar to this prototype I made from brass, visible in this picture. The production version will be a high density polymer or aluminum. Alignment is as simple as turning the nut.
Now what about chain tension? We’ll be going to a spring loaded chain tensioner that will maintain proper tension over the life of the XPO. Even as the chain stretches a bit with use, the spring will take up the slack and make sure that the XPO always works just as well as it did on day one! Also, as seen in this picture, we will be making the chain guard removable to give easy access for long term maintenance or future upgrades.