Chassis

The X-Factor 2's chassis assembly is a direct carryover of functionality from the original X-Factor, with twin nylon side plates forming the suspension and gearbox mounts, and a single 3mm-thick blue-anodized aluminum plate forming the chassis. All of the X-Factor's components mount to the chassis plate; the XTM 24.7 pull-start engine and radio box sit on the passenger side, while the receiver battery box, 125cc fuel tank, and Hitec HS-311 throttle servo occupy the left side. The chassis isn't countersunk, and with good reason: the XF2's chassis rides more than 5 inches from the ground, with the transmission case and transmission guard mounted on its underside.

Suspension

The truck's center-moutned transmission is protected by a metal skid guard. Spanning dogbones allow for constant drive no matter what position the suspension is in. Even though the bumper covers a wide area, you've got to be cautious with the steering servo mounted in such a prone position. For rock climbing you can cut the zip ties and remove the sway bars to let the XF2 achieve its maximum suspension articulation.

In true monster truck fashion, the X-Factor 2's solid-axle, four-link trailing-arm cantilevered suspension design allows for some gnarly articulation that becomes especially useful when climbing over curbs or crawling up a mountain of rocks. Four robust 7mm-thick aluminum push rods attach between the chassis and solid axles to form the XF2's suspension. Large triangular plastic cantilevers (or "shock absorber levers," according to XTM's instruction manual) attach the shock absorbers and push rods to the chassis. The cantilevers pivot on plastic mounts, with ball bearings in each to keep the cantilever rotation smooth. One of the X-Factor 2's multitude of upgrades is a set of four trick-looking blue-anodized threaded-body oil-filled shocks. The shocks feature 3mm shafts, aluminum caps, black rubber dust boots, and blue powder-coated shock springs. Anti-roll bars made of thick wire come pre-installed for increased high-speed handling capabilities, but they can be removed easily to add more suspension articulation if desired. The lack of suspension-adjustment mounting positions on all of the suspension components may seem odd to the average driver, but that's the norm for this style of truck. Optional weights of shock springs and silicone oil are available for suspension tuning.

Drive Train

A chassis-mounted gearbox forms the center of the X-Factor 2's drive train. XTM's own 24.7 pull-start engine sends power through a hardened-steel spur gear with a dual-pad adjustable slipper clutch, which in turn spins an adjustable lever-style two-speed transmission. A pair of large, chrome-plated, telescoping universal drive shafts deliver power from the transmission to the gearboxes, each of which is mounted on one of the solid axles. Inside each of the gearboxes sits a sealed planetary gear, 1/8-scale buggy-style differential, which can be tuned with silicone oil to alter the duff action. XTM says that they've addressed the original X-Factor's differential durability problems by casting the duff ring and pinion gears in a more durable metal alloy. Although the X-Factor 2 does not come with reverse capabilities right out of the box, XTM's clever design allows you to purchase an optional "XTM R-Box" reversing kit. Bringing the big X-Factor 2 to a stop are two drilled-out steel disk brakes with fiber pads.

Steering

XTM kept the X-Factor 2's steering system simple by mounting the steering servo directly to the front axle using a large, blue-anodized bumper/servo mount. The axle-mounted servo doesn't require a complex multiple-linkage mechanism because only two steering linkages (a right and left tie-rod) are needed to direct the front wheels. The installed steering servo, an XTM X-77 metal-gear servo, yanks the heavy front wheels with relative ease and is far more durable than typical RTR plastic gear servos. A spring-loaded servo saver fits directly on the servo to help protect it from jolts and shocks. If you are looking for even more steering, XTM offers a four-wheel steering option by incorporating an additional servo, mount into the rear bumper. All that's required is an additional servo, XTM's servo mount set, a servo saver, and a Y-harness.

Body, Tires, and Wheels

The X-Factor 2 received a big facelift in the form of a pre-painted color scheme and new Y-spoke chrome wheels. The body shell remains the same as the original X-Factor, as does the flame design, but the X-Factor 2 receives bright red flames to complement the black color of the main body. Large Chevron-tread tires come glued to the new Y-spoke wheels to add a little flair to the package. Although my truck arrived with empty tires-which are great for rock climbing, but not for jumping-XTM told me that all X-Factor 2 trucks will be shipped with foam inserts inside the tires.

Engine

With a displacement size just beyond 4cc (4.02cc to be exact), XTM's 24 pull-start power plant provides the X-Fact 2 with plenty of grunt. This mill has seen action in nearly all of XTM's vehicles, and deservedly so; the short-stroke 24.7 produces an impressive amount of power, especially when considering how inexpensive it is. The 24.7 features a two-needle carburetor, ABC construction with a five-port sleeve, a large blue-powder-coated cooling head with head button, and a pull-start mechanism. Although the blister-waiting-to-happen pull starter works well, most new vehicles on the market are ditching pull starters for more user-friendly rotary start or electric start mechanisms. Routing the exhaust gas out the rear of the truck is a large, dual-tipped exhaust pipe and tube header. The dual exhaust tips look trick out of the box, but the tips quickly get scraped into nubs after a few weekends of wheelie action. XTM claims they removed the wheelie bar from the stock truck to keep its cost down, but an optional wheelie bar is available to protect the exhaust and prevent the X-Factor 2 from flipping backwards during hard acceleration.

RTR Completeness

Out of the box, the X-Factor 2 includes a Hitec Aggressor AM two-channel radio, a full decal sheet, a complete set of instruction manuals, a four-way wrench, and the aforementioned pre-painted body. The truck arrives hilly assembled, with even the tires pre-glued and the body trimmed and ready for decals to be applied. You'll need to install eight AA batteries (not included) in the transmitter, and four more AA batteries in the receiver battery box before you hit the track. Before heading out, though, you'll want to check out XTM's highly detailed instruction manuals to familiarize yourself with the truck. Kudos go to XTM for including a spare parts manual, an engine tuning and troubleshooting guide with an exploded parts list, and an operating/tuning manual for the truck itself that will guide you through engine break-in, tuning, and even installing add-on accessories. The only thing missing that I would have liked to see is an exploded diagram with detailed part numbers for the truck itself, although with everything else here, it's a minor complaint.

RTR Gear
	Radio: Hitec Aggressor
	Servo(s): (St) XTM X-77, (Th) Hitec HS-311
	Receiver: Hitec HAS-2MB
Our Test Gear
	Fuel: O'Donnell 30%

Testing
I tested the X-Factor 2 on every surface that I could find, ranging from a baseball field, to a parking lot, to a vacant construction site. Before hitting the ground, I prepped the truck by breaking in the engine according to the manual and tightening all of the fasteners to make sure they were as secure as possible. Pay special attention to the cantilever screws that attach the black plastic cantilevers to their mounts; on my truck, the screws were almost half a turn loose, and that caused the cantilevers to flex.

Acceleration

With the engine tuned for performance, the X-Factor 2 bolts away from a standstill with a surprising jolt of energy. Wheelies are not a problem, assuming there's ample traction; on high-bite surfaces, such as concrete or grass, the XF2 flips itself onto its lid with ease, whereas on dirt you'll get a nice rooster tail from all four wheels as they claw at the ground. My truck wanted to lift its passenger-side front wheel first under throttle jabs, likely a result of the torsional flex from the engine mounted on the drivers' side. The 24.7 XTM engine has plenty of low-end torque, and that makes for great acceleration, even for this heavy beast.

Rating: 9

Top Speed

The two-speed transmission really comes in handy in the speed department, since the low first-gear ratio allows the X-Factor 2 to accelerate crisply without bringing the truck to a high speed. But once second gear kicks in, hang on-the X-Factor 2 jumps to what feels like warp speed and pushes itself to top speeds exceeding 35 mph. Factor in large tires and the tall ride height, however, and 35 mph "feels" more like 50 mph, which can be both exciting and nerve-wracking all at once.

Rating: 8

Braking

Bringing the X-Factor 2 back down from speed becomes quite a challenge, since even the dual metal disc brakes are outmatched by the big truck's weight and momentum. However, this flaw probably has more to do with the low-torque, standard Hitec throttle/brake servo than with a design flaw in the braking system itself. The X-Factor 2 is capable of full wheel lock under braking with a more powerful throttle servo installed, but in stock form, the truck could use more braking power.

Rating: 7

Low-Speed Handling

At low speeds, the X-Factor 2 feels very well planted and is totally predictable on all surfaces. On grass, the truck pushes but is easily convinced to turn with quick blips of the throttle. This method hops the front end of the truck around and makes wheelies an all-too-often occurrence. On concrete or dirt, the X-Factor 2's soft suspension leans into the turns but never gets hairy. With the anti-roll bars removed low-speed rock and curb crawls are an easy, entertaining adventure thanks to the solid-axle design.

Rating: 8

High-Speed Handling

Solid-axle, four-link suspensions are born for low-speed climbing and crawling, but are not very adept at highspeed maneuvering. When you bring the X-Factor 2 up to second-gear speeds, be sure to plan your routes well in advance. The truck tracks straight as an arrow and feels solid as long as you're not attempting to carve up a slalom course at high speeds. I flipped the truck a few times when turning on grass and high-traction dirt, but after you've flipped it once, you'll know the truck's limits and be able slow down before it flips again. The anti-roll bars help quite a bit at high speeds, but after I removed them for the low-speed crawling, taking the X-Factor 2 up to top speed became an exciting test of will power.

Rating: 7

Rough-Track Handling

Rough surfaces are precisely what solid-axle trucks are born to handle. The X-Factor 2 devours irregular surfaces for lunch and then begs for more. It's obvious that this is not a race truck, so the "rough track" portion of my tests involved a rock quarry, a trail-riding escapade through the woods, and some curb and stair climbing at my apartment complex. Suffice it to say that my apartment complex's maintenance crew nearly wrecked their golf carts and had to pick their jaws up off the ground after watching the X-Factor 2 wiggle and hop its way up an entire flight of shallow stairs. The XF2's massive suspension articulation-with the anti-roll bars removed-makes climbing and crawling over rough surfaces an easy task.

Rating: 9

Tuning

Tuning the X-Factor 2 is not difficult, since you are limited to making only a few adjustments. You can add or remove the anti-roll bars, tune the 1/8-scale differentials and shocks using various weights of silicone oil, and that's about it. Suspension tuning includes the regular array of toe-in and ride height adjustments, but camber and caster adjustments were left on the R&D studio floor. Although the solid-axle design inherently limits tuning options, the truck's layout makes it time consuming to adjust even the few options that are there. My suggestion: run the truck, have fun, and don't worry about it.

Rating: 7

Damage

I drove the XTM hard and made every attempt to break it once I got past the first tank. A few tanks into my testing, the rear-drive CV axle pin was ejected at light speed, never to be found again. A quick call to XTM/Global Hobby got me a new set of CV style drive axles in the mail, and I was back on the track shortly afterward. After that incident, I didn't break anything else through almost an entire gallon worth of test runs. I did, however, manage to grind the dual exhaust tips down to nubs and push one of the exhaust outlets into the pipe during the "jumping and wheelies" portion of testing. I was told by XTM that a wheelie bar was omitted to keep costs low, but this is the first upgrade that I'd plan to install on my truck. I'm nor sure what's more expensive, a wheelie-bar or a new exhaust pipe!

Rating:8



Conclusion
XTM's X-Factor 2 is a fast, fun truck that's sure to appeal to true monster truck fans everywhere. It is not a race truck, and it performs as expected on a racetrack-lots of bouncing, flipping, and wheelies. But take the X-Factor 2 to its native habitat and let it loose, and you'll be wearing a grin from ear to ear. Navigating the X-Factor 2 as it wiggles its way up a pile of rocks or jolts itself up and over a curb is something I could do for hours on end, and that's what "bashing" is all about. I'd like to see a wheelie bar included in the box to protect the exhaust pipe, as well as a rotary or electric starter for the engine, but those are my only complaints. The X-Factor 2's price is right in line with its competition, which means that there's never been a better time to go shopping for a solid-axle nitro-powered 4x4.