29" wheels did and still do seem like a ridiculous idea, that to be honest I don't even notice the difference with when it comes to a 29er hardtail or a 4" travel 26" (i prefered the 26). But they sell like flu vaccines. To be honest, I think in a niche market like street/park/dirtjump, with so many different styles of riders, it makes sense to have the same number of styles of bikes. While the need for such an innovation seems a bit lacking, i.e. I have seen people flick a 26 like a 20, or people who could barely ride 26 or 20 shred on a 24. That doesn't mean that it won't be the absolute perfect fit for someone somewhere, which is all you can really hope for.
As far as the design of this particular bike goes. I have only three real concerns:
1. Holy overkill dropouts batman.
2. Walmart called, they want their cable routing back.
3. The interrupted seattube makes little sense as it clearly adds weight without probable cause.
I was thinking about this again because of another thread. So, a 26" MTB rim has a beat seat diameter of 559mm. A true 25"er (imagining the same height of tires) would therefore be 559mm - 25.4mm = 533.6mm.
The traditional sizing systems are based on a measurement of the outside diameter of a tire. This would usually be measured in inches (26", 27", etc.) or millimeters (650, 700, etc.).
Unfortunately, evolution of tires and rims has made these measurements lose contact with reality. Here's how it works: Let's start with the 26 x 2.125 size that became popular on heavyweight "balloon tire" bikes in the late '30's and still remains common on "beach cruiser" bikes. This size tire is very close to 26 inches in actual diameter. Some riders, however were dissatisfied with these tires, and wanted something a bit lighter and faster. The industry responded by making "middleweight" tires, marked 26 x 1.75 to fit the same rims. Although they are still called "26 inch", these tires are actually 25 5/8", not 26". This same rim size was adopted by the early pioneers of west-coast "klunkers", and became the standard for mountain bikes. Due to the appetite of the market, you can get tires as narrow as 25 mm to fit these rims, so you wind up with a "26 inch" tire that is more like 24 7/8" in actual diameter!
A second number or letter code would indicate the width of the tire. (26 x 1.75, 27 x 1 1/4...650B, 700C...)