Losi XXX-SCB Review

Posted:  Wednesday, July 20, 2011
Written By:  Gary Katzer
Copyright:© 2011 Horizon Hobby, Inc.

      Short course trucks have reinvigorated the 1/10-scale off-road scene over the last few years, drawing more and more people into our wonderful hobby. Like anything that gets mega-popular though, you eventually reach a level where it starts to burn itself out or leave people longing for the next new thing. Losi is hoping to have the answer in something that is different enough to catch your eye, but still familiar enough to provide a connection to something wildly fun. I'm of course talking about the new Losi XXX-SCB, or short course buggy.

      The XXX-SCB combines the looks and feel of a 2WD buggy with the size and handling of a short course truck. This is a combination that Losi hopes will help the appeal of this new platform as it shares most of its parts between both vehicles, making it easier for someone to own one of each and not have to carry around unique parts. The narrow chassis and lower profile front shock tower gives the XXX-SCB a different look and stance, along with the potential to provide a different feel in the steering department. I had a chance to drive one at RCX 2011 in Pomona and was really looking forward to heading to the track with one to test out. The wait is over as I now have a XXX-SCB of my own and am ready to hit the track.

Speed Specs
Part Number(s): LOSB0107 (Stronghold); LOSB0110 (Rockstar); LOSB0112 (ReadyLift)
Vehicle Class/Type: 2WD Short Course Buggy
Target Audience: Short Course Enthusiasts looking for an open-wheeled experience
Completion Level: RTR

Notes from the Bench
Since this was an RTR, getting the XXX-SCB up and running was really quite easy. The included electronics are the same as the XXX-SCT RTR, so I knew I was good to go there. One thing I did do, however, was to tighten the stock servo saver about 2 turns. From the box, the servo saver is set loose to help protect the gears inside your servo, but having a looser setting also affects the steering somewhat, potentially making it feel soft or unresponsive. This was the only change I made before heading out to our local track, RJD Hobbies and Raceway in nearby Lincoln, IL.

Before I headed to the track, I also needed to add one piece of equipment to the puzzle. The XXX-SCB does not include a battery pack, but I had a perfect one in mind. I've been running the new Xcelorin 60C, 6000mAh LiPo packs in my TLR 22 and XXX-SCT lately, and I thought it would be the perfect pack to use in the XXX-SCB. The ESC features EC3™ connectors while the battery utilizes bullet or Corraly-style connectors, but that's not an issue as the battery actually includes an adapter harness that I could simply solder an EC3 battery connector onto. In a matter of minutes I was ready to get charging and hit the track.

Out-of-the-Box Setup
I was expecting the XXX-SCB to drive a lot like my XXX-SCT with better jumping characteristics due to the reduced surface area the narrower chassis and body provides, and I was right. The first time the XXX-SCB took to the air, it showed that it was an improved jumper. The parachute effect of the truck body was totally eliminated with the new, narrower chassis and body that the XXX-SCB is outfitted with. I'm not saying that the XXX-SCT is a bad jumper, quite the contrary. However, I will say that the XXX-SCB doesn't require you to be nearly as precise on your approach and take-off. It's hard to explain, but if you drive one of these cars you will absolutely notice the difference instantly.

One thing that cannot be overstated is how smooth and efficient the driveline of the XXX-SCT is. Anyone who is familiar with the XXX-family of vehicles should be surprised by this as the transmission is proven and durable, capable of handling the hottest of brushless motors. Not only that but, compared to most of the other short course trucks, the XXX-SCT is virtually silent around the entire track. A quiet transmission is an efficient transmission, which improves both acceleration and top speed.

The stock LM-32K motor works quite well and delivers a decent amount of pep. Under these conditions, the stock motor was capable of kicking the rear end sideways if I got on the power too hard, but overall it was easily controllable. There were a few jumps that I actually found myself over-jumping initially; trying to overcome a perceived horsepower disadvantage that didn't exist. I found if I backed off on my approach I wouldn't over-jump obstacles, particularly the doubles before the back straight, and I was able to run a better line downside the jump and get lined up for the next corner even better. Clearly, this was a perfect example of the adage "slow-is-fast" and, at least with the stock setup, the smoother I drove, the faster the car went.

On-track, the XXX-SCB drives a lot like its truck cousin, but the buggy felt more nimble. The fact that the front shocks are more laid down than the truck did provide more steering into and out of the corners. I was curious if this would affect the jumping characteristics at all and was pleased to see that it didn't. All-in-all, the XXX-SCB felt like a more refined short course vehicle from the box. It was confidence-inspiring, and I see a lot of potential here.

Top Speed/Acceleration
The transmission and stock motor of the XXX-SCB are identical to what comes with the XXX-SCT, and to no surprise the performance is virtually identical as well. The top speed of the XXX-SCB is near 30MPH out of the box and the motor has plenty of get-up-and-go when you stand on the power. I was a bit surprised that the motor's performance faded towards the end of the day, but will admit that I did torture it pretty solidly in those 95-degree plus temps and dusty conditions. After I returned from the track, I sprayed the motor out with some motor spray and the discharge was, well, funky at-best. The motor had gotten downright filthy, which no-doubt contributed to its reduction in performance.

The one area of handing that the XXX-SCB really shines over short course trucks (not counting jumping—more on that later) is how the car enters a corner off-power. The different front shock towers and shock geometry changes on the front end really helps the XXX-SCB enter a corner with more speed. Not only that, but the XXX-SCB also felt like it held a tighter line around a corner. I never felt like the chassis was lacking rear grip when I got on the binders and overall, felt confident that I would be able to turn-in under the competition without much effort.

With the included gear differential, the XXX-SCB has rock-solid acceleration; unlike a ball diff, a gear diff physically cannot slip. This provides you with positive acceleration when you get on the power with the XXX-SCB and lets you get off the line even harder. With the stock setup, the XXX-SCB was pretty locked-in when I got on the gas, although it was possible to kick the rear sideways if I got out in the marbles or got on the power too aggressively. There was a slight on-power push with the initial setup, but by moving the battery pack forward I was able to get rid of most of it.

The one area where the XXX-SCB was different was in the air. The one thing that every single short course truck has in common is the fact that, depending how you launch off a jump, it can be prone to what's called the parachute effect. If you don't know what this is, it's really simple. The body of a short course truck has a ton of surface area to it, simply because it's so wide. While it has to be wide to cover the wheels, it also traps a ton of air which can cause blow-overs. The body basically acts like, you guessed it, a parachute. With the narrower chassis and body of the XXX-SCB, it doesn't trap air like a truck does, thus eliminating the parachute effect and making the XXX-SCB a more precise and predictable jumper.

While the XXX-SCB was a more refined jumper, it wasn't as good on the landings as I would have liked. Specifically off of larger jumps, like the one on the back straight, the XXX-SCB tended to bottom out quite a bit. Adding some preload and/or using a thicker shock oil would help address this issue and will be one of the first changes I make.

Short course trucks are popular for a very good reason and Losi may very well have the next big thing when it comes to short course in the XXX-SCB. I love the fact that the XXX-SCB uses almost all the same parts and pieces in its design as the XXX-SCT, this way I don't need to bring separate parts, tuning options, springs or anything else. That will make for a much lighter pit box! The fact that I can also use the same wheels and tires between both chassis makes it less expensive for me to be able to run both my XXX-SCT and XXX-SCB at the same time.

The XXX-SCB could very well be the start of the next big thing in off-road. It provides an improved driving experience when compared to short course trucks and the open-wheeled nature of the chassis makes this a different animal. Without full fenders side-by-side, running gets a lot more interesting with a buggy as leaning on your opponents can lead to some rather exciting battles. There's a very real potential that short course buggies could do for 1/10-scale buggies what short course trucks have done with stadium trucks—completely reinvent the class. The XXX-SCB is a super-fun car to drive and I am looking forward to running one at the upcoming Short Course Nationals. This could truly be the start of something new and big.


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