Do you know if the 6L has a 5mm shaft. I heard the feigao motors have weak 1/8" shafts.

No the 380 size motors only come with a 3.17mm shaft, and it isn't hardened. You best bet is with a lehner BASIC of some sort (XL would be better for your application)

i would think the xl4200 would be about right.

Well, the truck is not that heavy, I don't think the xl will be needed. I'm not looking for fastest, I'm more interested in a top speed at least 28mph and a runtime around 12-14 minutes. Maybe over 15 if I can manage.

If I gear down the 4200 basic I think I'll be satisfied.

You think I can get away with the smaller motor?

not sure. i would personally go for the xl.

4200xl is too hot for offroad, but its great to send your tc3 70mph

As a temporary solution, do you think a 13T pinion, instead of the 15T would help at all?

I was also thinking of using a 550 motor instead for longer track times, still at 9.6v.

Both of these have a 5 mm shaft

540 7s
http://cgi.ebay.com/Feigao-Brushless...QQcmdZViewItem

540 9s
http://cgi.ebay.com/Feigao-Brushless...QQcmdZViewItem

I'd go with the 9s. The 7s may draw too many amps.

Wow, thanks for those links

Keep us updated if you get one of those motors.

I bought the 9s, it'll take a while for me to get it. I also just bought a 13T pinion too. It seems like a great motor to use.

I bought a pinion form mike and it came in less than two days (being about 40 miles away doesn't hurt either). I ran it with the 13T still with the 9L and it definately ran cooler, still too hot to touch after about 4 seconds though and the runtime was aboout 9 minutes. The ESC was less than burning too. And the bettery temp was in check.

I assume the 9s will give faster speeds and longer runtimes. It's weird to think that it will. The 9L was just overall slow and innefficient.

Yeah, it's all about the rpm/V. With your 8 cells, the 9L was only running at 26,000 rpm unloaded. The 9S will do 37,000 rpm with the same number of cells, so it will be much faster.

Of course, if you crammed four more cells on there like me, you'd be hitting 39,000 rpm unloaded with the 9L and going about 50mph without overheating. :p

Less weight the better for me. I noticed that I've chipped some teeth off the front internal diff gears by braking too hard, weight it definately not what I want. The gears usually don't wear, I have 0 wear on the ring gears and the internal gears only stop working when you crack them. It not like a "over time it will wear" thing.

I've seen some hardened ring gears crack too in the RCU forum.