Its quite easy to take a off the shelf vehicle and a proven combination(such as a castle motor/esc combo) and make it work, and find gearing that works.
However, when you build a custom vehicle from scratch, you have nothing to go by. You can ballpark it, and judge weight and get close. But, most of these were smoked before anyone was running brushless, in any ground vehicles. In 1999, you couldnt go on a forum and ask what gearing to run. We had to start somewhere. Chances are most of you guys wouldnt be running brushless had we not spent all the R&D for the various companies. We brought the cheaper Feigao motors to the market. Before that, you couldnt buy a brushless motor below $150. We have been pushing the limits to push the industry further. We are the reason ultramaxxed gears came to be, we did the R&D for them and we gave the specs of what they needed to be.

I agree, try to avoid a thermal at all cost to prevent a failure. But you are giving false information reguardless if you believe it or not.

I dont know you from Joe Schmoe, I dont have a thing in the world against you, or anyone here. I see some good info you give, and some that I know are false...and this one will cost some kid hundreds of dollars if he trusts your theory. So I felt the need to correct it. Sorry to get off track Hippie.

As far as saying I need help gearing....I am sure HiAmplidude,305997,EmaxxJeremy and Promod need the same advice. We have all smoked similar systems at about the same time. We did get an e-maxx to 40,50,60, and 70mph before anyone else though.