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Electrix "Circuit" Review
Wednesday, August 11, 2010 at 11:34AM 
A few months ago, when Horizon Hobby told me that they wanted to re-invent the electric R/C truck market, I was more than a little skeptical. When they said they wanted to do to electric R/C trucks what they did with electric helicopters (the Blade Heli line), I all but laughed. And when we got the first of their new product line here in the store, I realized I was wrong.
While the brand name (“Electrix”) and truck name (“Circuit”) may be more than a little goofy, the product itself is no joke. It’s built like a tank, and has a number of features I imagine will be copied from here on out. But there is much on the truck that is familiar as well - in some areas, it more than borrows from Traxxas and Team Associated, as well as it’s cousin, Team Losi. But this isn’t a bad thing.
Let’s get started with the tear-down, shall we?
First of all, here is the list of things in the box:
The truck, pre-assembled
Transmitter
1800mAh 6-cell battery
AC-powered Charger
Stickers, Manual
Extra set of Crystals (nice!)
Optional battery hold down strap
AA Batteries
As you can see, there isn’t a single thing you need to buy separately. This truck is truly a one-box-purchase. 
We’ll get to the truck in a minute, but let’s break down some of the accessories it comes with.
The battery that powers the truck out of the box is an 1800mAh, 6-cell NiMH battery. Not an incredibly powerful battery, but it gets the job done. It is par for the course, given the electronics that comes with the truck. I would have loved to see a larger capacity battery here, something in the 3000mAh range, but I’ll take what I can get. And you can always buy a second battery.
Similarly, the charger is nothing to get excited about. It’s standard “we needed to throw something in the box” fare. According to the manual, it should take somewhere around six hours to charge the battery. I did the math, and I agree. However, your mileage may vary; it depends on how much you run the battery down. A faster charger would be a recommended upgrade.
The transmitter is functional. That’s about the only positive thing I can say about it. Like the battery, it does its job, but only just. And it’s the worst kind of tacky, aesthetically speaking. There’s no beating around the bush here - this thing is butt ugly. But the truck does come with an extra set of crystals - nice to have when you want to run this around with friends’ cars. I’d have liked to see a 2.4GHz system on the truck, but I imagine that Horizon had a certain price point in mind, and the higher-end radio system wouldn’t have made the cut.
Everything else is standard stuff. The inclusion of the AA batteries is nice. And the stickers and manual are fine. Not much else to talk about here.
The Truck
So all those negative things I had to say about some of the accessories? The truck more than makes up for them. This thing isn’t a re-purposed Losi truck. This is built with bashing in mind. The chassis is thick and rigid - there isn’t much chassis flex on the Circuit. The control arms are beefy, as are the front c-hubs and axle carriers. The construction of the truck is top notch, and it’s obvious that this was heavily influenced by the Traxxas Rustler. But there are some improvements to the formula that are significant.
First, and I couldn’t take a good picture of this, but the servo saver mechanism is built into the bellcrank. This is a great improvement to the standard setup of having the servo saver act as the servo horn as well. Traxxas has done this on their E-Maxx, T-Maxx, and Slash 4x4, but none of the entry-level cars have seen this upgrade. Surprising to see it on a truck at this price, but I welcome the improved setup.
Second, this truck is fully equipped with ball bearings! Not only in the transmission, but also on the wheels as well. This was one of the biggest surprises I found when I looked at the truck. While they aren’t rubber sealed bearings (the rubber seal helps keep dirt out of the bearing), I’ll take them. They are much better than bushings, and will significantly extend the life of the axles, not to mention improve run-time by removing the friction that bushings would cause.
The transmission is simple enough - just three gears internal, and two gears external. Essentially the same design we’ve seen on almost every 2WD truck since the stealth transmission on the RC10. The interesting thing to note here is that all of the internal gears are metal, and that makes the transmission “brushless-ready”. So upgrading the motor and ESC just became worry free. (Author's Note: After a customer disagreed with my metal transmission gears statement, I went back to my source in product development at Horizon, and he confirmed that the transmission gears are, in fact, plastic. The product support tech I initially talked to was incorrect with his information. November 5th, 2010)
It’s worth mentioning here that the spur gear is an 87-tooth gear (since they don’t tell you that in the manual - or anywhere else for that matter).
I like that the truck is easy to dis-assemble (I had the transmission off the truck and open in under five minutes - without having ever laid eyes on an exploded view). 
The Phillips hardware is decent quality, and doesn’t look like it will strip out on you the first time you’ll use them. The drive shafts look beefy enough. I like the battery hold-down that doesn’t use body clips (removing the chance for you to loose them). I really like how the suspension pins are captured - no e-clips! Two screws, and the front suspension pins are out. Two more, and the rear ones are out. Simple, fast, and efficient - the way a new car should be.
However, there are a few misgivings I have with the truck. The first, and most obvious is the absence of any steel (or aluminum, for that matter) turnbuckles on the truck. Both toe and camber links are all plastic bars - and the toe bars are so flimsy, I’m amazed the truck turns at all. Definitely an upgrade worth doing sooner, rather than later.
The slipper clutch hardware is a little dated as well. It reminds me of the older Losi or Associated cars. Unlike the newer Traxxas cars, you have to remove the slipper clutch to change the spur gear. Not really a big deal, but the Traxxas system is nicer.
I also wish that the differential output shafts were keyed, or flat on two sides. That just makes it easier to install the differential yolks. As it is, the shafts are completely round, forcing you to line up the screw holes. Again, no big deal, but just something I noticed.
Also, the suspension is set up much too soft out of the box, and they give you no extra shock pre-load spacers to stiffen it up. Mounting the shocks further out on the top, and closer in at the bottom seems to help, but stiffer springs and a heavier shock fluid would certainly help, especially in the front.
And, the tires are terrible. The compound is so hard that getting a good grip on whatever surface you’re running on, except maybe soft clay, is fruitless. On pavement, the front end wheel-hops so much that, in the back of my mind, I half-wondered if the thing was going to fall apart (it didn’t). This is partly because of the soft suspension I mentioned above, but also because the tire just doesn’t conform to the surface it’s riding on. I did have a marginally better performance on grass, but it still would push under power (meaning the truck didn’t want to turn while I was on the throttle).
And finally, the rims use 12mm hexes to lock on to the axles. However, they use a lip similar to the Axial hexes, and so you can’t use rims designed for Traxxas vehicles unless you also purchase Traxxas-style hexes. Not a big deal either, but worth noting.
The nice thing is that none of the complaints I have with regards to the truck are hard to fix. In fact, most of them are normal upgrades anyway. And the fact of the matter is, for the price of the truck, some sacrifices just had to be made.
The Electronics
The electronics package on board is a mixed bag. The Electronic Speed Control (or ESC for short) is a nice piece of hardware. It has a 12-turn motor limit, meaning that you can upgrade the motor without having to upgrade the ESC. That’s rare on any ready-to-run R/C car, regardless of skill level. The speed control also has no low-voltage cutoff, and thus is un-safe for Lithium-Polymer (or LiPO) batteries. I know there are conflicting reports on this on the web, but I got confirmation of this from Mark Reed, the senior product developer for all things surface-related at Horizon Hobby. So no LiPO batteries on the Circuit, as is.
The stock motor is a 20T motor from Dynamite. It’s a motor roughly equivalent to the old Traxxas Stinger motor - the motor that the Bandit, Rustler, and Stampede came with about four or five years ago. Compared to the current batch of competition, the Circuit is slow. If I had to ballpark it, I’d say somewhere in the 15-20 mph range on pavement, but that’s just a guess. Upgrading to a faster motor will probably be a recommended thing, unless speed isn’t an issue. Brushless is looking better and better.
The servo is a mystery. Try as I might, I couldn’t find a spec sheet for the servo at the time of this writing. So, all I can say is that it works, and it isn’t nearly fast enough for high-speed turns. But, it works.
How's It Run?
After the teardown, I charged up the battery and started my test runs. The idea was to get an accurate picture of what kind of run time could be expected out of the truck. First I tested the truck on pavement with the included battery. I averaged approximately 14 minutes per run over three test runs with the stock 1800mAh battery. Not too bad, and more than I thought.
Next, I tried an Onyx 3000mAh battery. I gave that three runs to try it out, and I averaged twenty minutes per run. So, you gain about six additional minutes of run time with the larger pack. Probably worth the investment. I also noticed a slight increase in speed as well, but it only lasted for about five minutes or so, then it was back to the stock speeds again.
I didn’t try the truck with a 7-cell battery, but the speed control will handle it, according to the specs. I just didn’t have any batteries with the right connector. For anyone that picks one up and tries it, reply with a comment here and let me know what you think!
On the grass, the truck didn’t fare as well. It didn’t take me long to realize I was getting only half the run time on the grass. Your mileage may vary, depending on how short the grass you’re running on is. But I’d say this truck is more at home on pavement and/or dirt.
I didn’t manage to break the thing during my time with it, though it wasn’t from a lack of trying. Short of intentionally running it into the back of the store, it did put the truck through its paces. At one point, I misjudged the distance, and drove full speed into a shopping cart sitting in the parking lot. I hit right on the passenger side control arm, and I was sure I had broken something. That kind of hit always breaks something. But nope; the truck was fine.
On the other hand, it probably doesn’t go fast enough to really break anything in the first place (by design, maybe?).
As far as handling, the truck was smooth on straight runs, and turns were passable. The tires just don’t have enough grip on the pavement to make tight corners possible, even if you slow down. Different tires will fix that. And, to my surprise, the plastic toe links didn’t effect the performance of the truck at all. I’d love to have a faster speed servo on board, as I mentioned. The servo on board seems to lag a bit, but a beginner wouldn’t notice it.
Conclusion
Overall, I’m impressed with the truck, keeping the price in mind. If this was priced any higher, I wouldn’t be as enthused. But with every complaint I can levy against the truck, I think about that price point, and my argument stops holding water. The fact of the matter is, you have many upgrades you can afford to do before you arrive at the price point of a similar truck from Traxxas. And, while it may not be for everyone, this is a great truck for kids and first-time participants in the R/C hobby.
Bottom line, I had fun testing this truck out. And if I had fun being careful with the truck, it stands to reason that anyone else will have a blast with it.
Check back in a few weeks, because now that I’m done testing and reviewing the stock truck, I’m going to upgrade this sucker. There are a slew of hop-ups that Horizon has in the production line already, and a few upgrades I have in mind that aren’t specifically for this truck. It’s going to be fun.
Reader Comments (13)
And don't forget, if you run into any trouble (or solid objects), we're here to help!
I have bought extra plastic tranmsision gear sets for the mean time, becuase it is so much fun, and so fast.
mattfunk@telus.net
As for everything else you said, they are good tips. I'm glad to see that you're enjoying your truck!
Brian
Roger's Hobby Center