With the extremely rapid success of the RC rock crawling sect people have grown to require more from the industry. 5 years ago "those crazy RC crawler fans" only had a handful of viable donor trucks to pull from to build a rock rig, and dreams of a truly scale trail truck was just that, a dream. Thank God the dark ages of the crawling world have come and passed! Now with the mainstream corporate support of this beloved hobby behind it one man would be hard pressed to own one of every crawler out there. What I aim to do is to educate you on the four main types of trucks and to list the top models in each class and to shed some light on the woes of the bottom models.
The Four Main Classes.
The first class being Large Scale competition rigs, which comprise of the Tamiya Clodbuster type and the XTM's X-Force and Rock Force type axles. The main differences in the two types of axles being the 'Clod type is a transaxle design requiring a separate motor for each axle whereas the traditional solid or straight axle design of the X-Force type axles have to be powered by a chassis mounted power-train. These rigs run roughly 6-8 inch tires from popular monster trucks such as the Traxxas T-maxx and the HPI Savage. The biggest draw back for these as an entry vehicle into the hobby is the fact that there are few RTR (ready to run) trucks available. So they have to be made from several other trucks and custom built. Also their size requires more powerful motors and electronics to allow them to properly navigate large rock courses without being under powered, resulting in a higher sticker price.
The Second Class is the 2.2 competition rigs. These rigs are built in the same manner as the Large Scale rigs excluding the large tires and the option for the 'Clod axles due to their size. The name 2.2 comes from the fact that these rigs run 2.2 inch rims that would be shared with trucks such as the Traxxas Stampede, with a tire that is at best 6 inches tall. Because of their size many people see it as a much more viable option for an entry level crawler simply because they can use electronics from older models they have laying around. They just don't require as much power. They are 20-30% smaller but are still able to complete the same courses as the Large Scale, just with less ease.
The third class is the 2.2 Scale or Trail Trucks. These trucks by and large are the same as the 2.2 comp rigs, just with less articulation and a more realistic body. When done right the average on looker would be hard pressed to see in a picture that it was not in fact a real trail truck. Before trucks like the SCX-10 came out from Axial, some people even made trucks that had frame rails just like those found on full size jeeps and other off-roading warriors. This truck is roughly the same start up price as a 2.2 comp truck, but the time, effort and in some cases money that is put into the detail on the truck body will often surpass the cost of a comp truck. These trucks are rarely capable of completing the same course as either of the two rigs listed above, but the driver will often have more fun finding "scale" obstacles to navigate.
The fourth and final class I have in the Small to Micro Indoor and Novelty Crawlers, such as the Losi Micro Crawler. These little guys are simply the best possible way to get your feet wet in the hobby and to fully allow yourself to fall in love with it. Most of these crawlers are no more than 6 inches long, and most of them don't even have 2 inch tall tires. Although they are by no means capable of completing courses anywhere near as big as the others they are still very capable on equally scaled courses. These trucks run very small and very inexpensive electronics. Almost all of them come completely RTR, even down to the truck and radio batteries. Most people buy this size truck for indoor use as I mentioned, and they really shine in the winter months where most RC'ers do not want to be outside in the freezing cold rain or snow. Garage and basement clubs are sprouting up all over the country just for these little buggers.
I hope that this has been of some help to you in identifying what type of crawler you would be interested in acquiring. And I hope it may have answered some questions. In the coming days I will post a new article comparing some of each of these classes in price and longevity along with capability . So keep an eye out!