There are more options for your new mountain bike than ever! Both wheel diameters and suspension have more choices for you, and there is always color.
Traditionally, mountain bikes had twenty-six inch wheels. Twenty-nine inch wheels have been around since the ninety’s and have been very strong the last few years. The newest size is a diameter with an identity crisis. It has three names: 584mm; 650b; and 27.5 that are all the same size. It is approximately half way between 26” and 29”.
The larger the diameter of the wheel the better it will roll over obstacles such as rocks and roots. The smaller diameter will allow the frame designer to have a shorter wheelbase resulting in more agile handling.
The best wheel size for you will depend upon many factors. It seems to be that larger wheels are better for fast riding on less technical trails. Smaller wheels are better with more suspension travel. It seems intuitive to me that rider size would be a factor. I am tall, so I do not have personal experience with big wheels and small rider, but it seems to make sense that the size of your body should be one consideration in the size of your wheel. The new middle size might be the best option for many riders. However, each size requires a unique size of tire, rim, fork and frame. In the future it may be hard to get replacement parts for a size that has fallen out of favor. I will not predict the future!
Mountain bike suspension has evolved and is a very technical part of the bicycle. Suspension started with the invention of pneumatic tires by Dunlop in Scotland. Yes, tires are suspension. The wider the tire, the more air volume there is between the tire and the ground resulting in more suspension.
It is generally accepted that front mechanical suspension is important for technical riding. Having a lock out feature on the fork is a real benefit. Rear, or dual suspension is a major benefit for fast downhill riding on uneven surfaces. Whether it is necessary for Midwestern riding is up for debate. I find riding is more fun with rear suspension.
Fat bikes with tires about four inches wide were originally designed for winter riding. They have been evolving into more general riding machines. Some mountain bike riders like the simplicity of no mechanical suspension, while the big tires give the rider enough suspension for some.
You have to consider wheel diameter, tire width, front suspension fork, and rear suspension design. Maybe it does just come down to color……