No sync-loss...Using a Castle-Creations Phoenix-ICE 75A at 24V (Ebay $90)
http://www.castlecreations.com/products/phoenix_ice.html
Its nice that this ESC has the data-logging, and it also has a built-in BEC to power the E-Sky ST as a throttle (no separate 5V power supply needed), and also it can run 8S (28V)...but the big question for me was will it suffer sync-loss at 24V? and
I couldn't get it to stumble under any conditions (sudden full throttle being the worst culprit). I used the factory default settings, worked right out of the box.
I don't know if its the hardware or the software, (also it has an donut-inductor on the throttle wire), but their secret sauce works. Its almost a moot point, because the available motor-kVs for the 63mm diamter motors work better at 36V, also I could hear and feel that the drive ran better on hills at 36V. In fact, in an earlier post I posted that the Hobbywing HV-70A ESC ran good at 36V, but had sync-loss at 24V.
If you live on relatively flat terrain and don't mind only 20-MPH using the highest kV 63mm motor (Exceed 295-kV), this model of CC ESC will do the trick for a simple 6S system. However, any interest that has been expressed around here has been for help on the hills, plus there's always someone who wants to go a little bit faster (higher volts than 6S will help both of these).
At 36V (10S) there are many motor-kV choices in the commonly desired speed ranges. At 22V-24V (6S) theres really only a couple that are useful, unless you want lots of choices that only go at the slow end of speed ranges. edit: The smaller 50mm motors are likely to be well suited to the task of driving a small 1.0" roller on flattish terrain, and kVs are available from 270-to-400+ for up to 30-MPH on 6S. However, the shafts are only 8mm, but they are an option...
edit: also had a thought today, another option might be to use a 63mm motor with a fatter 1.5" roller (which will fit my drive) but the fatter roller might require a higher 100A Phoenix ICE ESC (only $25 more than the 75A). The fatter roller would give the available kVs of 63mm motors a good top-speed selection-spread while using only 6S.
I haven't tried the inexpensive servo-signal speed-adjuster yet, it sounded like Adrian had enjoyed some success with that, and it may prove to be beneficial here.
Kepler and Adrian use the 63mm motor-shell as the roller, which is about 2-1/2" in diameter (the smaller 50mm motors run a little warm as a shell-drive, and most avoid them). Their 85A ESC ran a little hot, but several makes of 100A ESC have worked well for those drives. 75A may sound light for my drive, but I am only using a 1.0" diameter roller (optional 1.25"), and Todd has reported his similar drive was using 60A peak, with about 10A during cruise, so I am confident the 75A (100A peak?) is more than adequate (never got warm). The data-logger link will be here soon so I can verify my guesses.
A while back I read up about 36V (Todds original pack) and 28V cordless drill packs (Makita, Milwaukee) and several of the manufacturers have a long term committment to continue producing the 28V packs. Oddly, the 28V packs are configured to output more amps than the 36V packs, and the 28V system was designed as a response from customers who like the 36V power, but found the packs too bulky. They are expensive, $150 each and $100 for the charger, so three packs would be around just under $600 for only 9aH of range (3 X 3aH). Each battery has a 5-LED "fuel gauge", and the CC-Phoenix-ICE range of ESCs will run at 28V.
Now that I've settled on 36-ish volts, I'm ordering two 5S LiPos to continue testing. I'm really glad the weather got better this week!
(edit: just found out Zippy is now producing 4S, 5S and 6S packs in 8000MaH, so two of these bricks would provide 8aH of 28V for $120, or...8aH of 37V for $148) http://endless-sphere.com/forums/viewtopic.php?f=14&t=25700