I picked up a 55t motor to try out on my cc-01 jeep. I've been slowly converting my truck into a scale rock crawler. I was debating what motor to replace the stock can that came with it (27t i think) I went with the axial 55t mostly because it was the least expansive.
First thoughts, it was slower than I expected. I knew it would be, but not that slow. The torque was also lack luster. I'm sure the motor would be better in a dedicated rock crawler. In my cc-01 jeep the stock gearing was just wrong. The front and rear diffs are locked and when you make a slow approach to a rock and slow crawl your way up it just doesn't have the balls need to climb. I think I'm going to go with a 35t and see how that works for me. Maybe I'll do some pinion swapping with the 55t but the number of pinions in my tool box is limited.