WORDS & PHOTOS LITO REYES

Size: px

Start display at page:

Download "WORDS & PHOTOS LITO REYES"

Merilyn Allison
6 years ago
Views:

1/8 SCALE ELECTRIC RTR Type 1/8-scale RTR electric motorcycle Top speed 22.5mph Price $230 (varies with dealer) Requires 8 AA alkaline batteries venom-group.

1 1/8 SCALE ELECTRIC RTR Type 1/8-scale RTR electric motorcycle Top speed 22.5mph Price $230 (varies with dealer) Requires 8 AA alkaline batteries venom-group.com QUICK SPECS BEHIND THE WHEEL MORE ONLINE! rccaraction.com VENOM GPV-1 RTR RTR Two-Wheeler Promises to Bring Bike Racing to a Track Near You WORDS & PHOTOS LITO REYES Venom is ready to bring RC bike racing to the masses with its new 1 8-scale GPV-1 motorcycle, patterned after the popular MotoGP-style racers. Even though RC bikes have been around since the 1970s, the ones currently marketed for proper racing are larger 1 5-scale models that require a huge 1 5-scale car track to run them at their full potential. Venom is confident that a 1 10-scale touring-car track is a perfect venue for racing its new machine and set out to put together a reasonably priced package that makes it easy for anyone to start racing on two wheels. The learning curve of running a bike is a bit higher than of driving an RC car; it can be compared to flying a heli a steady hand and precise control work are a must! One of Venom s goals, however, was to make the package docile enough for beginners and fully capable of being tuned for experienced bikers as well. DRIVE TIME PREPPING FOR THE TRACK As the GPV-1 is an RTR package, the only thing needed to get going is a set of 8 AA batteries for the transmitter. The included charger is a slow wall-type unit, so for more track time I recommend getting a peak-charger. The battery is mounted on a plate on the underside of the chassis with a hook-and-loop strap, and a neoprene pad keeps it from sliding around. As an alternative, I pulled some adhesive-backed Velcro from my parts bin and used that instead. Ideally, a cinch strap along with the Velcro should be used. TEST SPOT FREEDOM PARK CAMARILLO, CA ROADRUNNERSRC.COM 90 MORE FROM THIS ISSUE AT RCCARACTION.COM TAKING IT FOR SOME LAPS The first thing I noticed was that the GPV-1, like all RC bikes, is quite responsive to steering input. Fortunately, the included computer radio has a programmable dual-rate thumb switch to toggle between multiple steering dualrate settings. So while getting accustomed to the bike, I ran it with 60% throw. At its top speed of 22.5mph, the bike is fairly stable, requiring minimal steering inputs to keep it on track. Approaching tight turns, I gave a quick stab of the brakes to slow the bike down and then some wheel input to drop it into a lean. I was able to complete the arc of the turn by accelerating out of it to bring the bike back upright. The weight of the deceptively heavy (and very durable) foam rider helped get the bike leaned over quickly. Once I was more comfortable with the handling (and more confident of the GPV-1 s durability), I increased the dual rate and tightened up the spring tension on the steering rod to get the bike to feel more like my larger 1 5-scale race bikes, with a quick side-to-side transition speed and more cornering speed at the expense of low-speed stability. The bike responded to my adjustments just like I had hoped, and it felt much more raceworthy to me. All the electronics worked very well as a package.

PUTTING IT IN THE HANDS OF BEGINNERS Throughout my testing in various locations, I let racers of a wide range of experience levels try out the GPV-1.

2 PUTTING IT IN THE HANDS OF BEGINNERS Throughout my testing in various locations, I let racers of a wide range of experience levels try out the GPV-1. From on-road car drivers who were afraid of breaking it to off-roaders who had never even seen an RC motorcycle up close, I gave them all a chance at the wheel. In every case, it only took a few minutes for them to get comfortable with the GPV-1. I even had the off-roaders driving laps around the track well enough to race. Of course there were incidents, especially with the wall surrounding the exit from the front straight. I constantly had to remind the newbies that a bike has to be slowed down before it will turn, but amazingly, not a single part broke during any of the testing. TURNING UP THE VOLUME I ve raced bikes for a few years now, so I just had to see how the GPV-1 worked with a hotter powerplant. The stock Venom Fireball motor is perfect for spec racing, but I really wanted to push the GPV-1 harder. So, after first checking with Venom s Chris Nicastro, the designer of the GPV-1, I threw in a Castle Creations Mamba Micro Pro brushless speed control, a 5400kV motor and a 2000mAh 7.4V LiPo pack for power. To keep things from getting completely out of control, I replaced the 12-tooth front sprocket with an 11-tooth one. With the stock Mamba programming, not only was top speed ballistic, but the GPV-1 was also transformed into a wheelie machine. I was able to lift the front tire both at will and when I didn t want to. Now we re talking! A few tweaks of the Mamba programming, such as increasing the punch control, and the GPV-1 felt really close to my big race bikes. I can t wait until some of the upgrade parts come out, such as the carbon chassis and aluminum forks, so I can tweak it even more. FEBRUARY

With a more than 7-inch wheelbase, the GPV-1 is 1 8 scale, but it is still small enough to run on the average 1 10-scale track.

6mm black fiber-reinforced plastic material (FRP) and are separated by plastic standoffs. The plates are rather stiff and are all fastened together with Metric hex-head screws.

A battery mounting plate is attached across the bottom of the chassis, and that also helps make a stiff structure. The GPV-1 is designed much like its larger 1 5-scale cousins but with more realism.

3 With a more than 7-inch wheelbase, the GPV-1 is 1 8 scale, but it is still small enough to run on the average 1 10-scale track. Chassis Like its larger cousins, the GPV-1 has a multiplate ladder-type chassis. The chassis plates are made of 1.6mm black fiber-reinforced plastic material (FRP) and are separated by plastic standoffs. The plates are rather stiff and are all fastened together with Metric hex-head screws. The upper plates incorporate a servo mount designed to accommodate microservos or miniservos. A battery mounting plate is attached across the bottom of the chassis, and that also helps make a stiff structure. The GPV-1 is designed much like its larger 1 5-scale cousins but with more realism. Check out the swingarm with sponsor logos, the "carbon fiber" exhaust pipe, the simulated brake rotors even the stands are realistic! Wheels and tires The stock front and rear tires are made out of a natural rubber compound designated with a 45-shore rating (hard). Optional tires are also available: a medium 45-shore synthetic compound and a soft 35- shore synthetic compound. A solid rubber front tire insert helps with gyroscopic stability, while the rear tire s insert is made of molded foam. The Y-spoke-design wheels are made of hard plastic. 92 MORE FROM THIS ISSUE AT RCCARACTION.COM

SPECIFICATIONS VENOM GPV-1 RTR venom-group.com Scale 1/8 Price $230 (varies with dealer) DIMENSIONS & WEIGHT Length 10.6 in. (270mm) Height 7.1 in. (180mm) Wheelbase 7.4 in. (188mm) Width 3.9 in.

33; final 10.7 UNDER THE HOOD Steering The GPV-1 steers with a rod from one side of the upper triple clamp that floats between two springs at the servo-horn end.

The servo just has to pivot the forks enough to get the bike to lean over into a turn.

And to minimize head shake at high speeds, where the front wheel wobbles back and forth, a friction damper comes attached to the opposite side of the upper triple.

The steering rod floats between the two springs to let the bikefind its upright balance point naturally. A tunable O-ring damper setup helps minimize any high-speed head shakes.

4 SPECIFICATIONS VENOM GPV-1 RTR venom-group.com Scale 1/8 Price $230 (varies with dealer) DIMENSIONS & WEIGHT Length 10.6 in. (270mm) Height 7.1 in. (180mm) Wheelbase 7.4 in. (188mm) Width 3.9 in. (100mm) Weight as tested 22.4 oz. (652g) CHASSIS Type Multiplane 1.6mm fiber-reinforced plastic DRIVETRAIN Type Chain-driven RWD Transmission Pinion/spur gear Gear ratios Primary 4.6; internal 2.33; final 10.7 UNDER THE HOOD Steering The GPV-1 steers with a rod from one side of the upper triple clamp that floats between two springs at the servo-horn end. The floating action, combined with the angle of the forks, allows the front wheel naturally to find an upright balance point when up to speed. The servo just has to pivot the forks enough to get the bike to lean over into a turn. To increase steering response, the springs can be moved closer to the sliding mount, or the fork rake (angle) can be decreased. And to minimize head shake at high speeds, where the front wheel wobbles back and forth, a friction damper comes attached to the opposite side of the upper triple. Basically a sliding rod and tube, the damper can be tuned with greases or different size O-rings to get the effect you want. The steering rod floats between the two springs to let the bikefind its upright balance point naturally. A tunable O-ring damper setup helps minimize any high-speed head shakes. SUSPENSION Type (F/R) Adjustable rake USD fork/dual-sided swingarm SHOCKS Type Threaded-body composite with 3mm shaft Upper shock positions 3 Lower shock positions 1 BODY, WHEELS & TIRES Wheels F/R 2.25 in. (57mm) / 2.4 in. (61mm), black plastic Y-spoke Tires (F/R) 3.1x0.73 in. (78x18.5mm) /3.4x0.9 in. (86x23mm) 45-shore slicks Inserts (F/R) Solid rubber/foam Body Printed polycarbonate Rider Painted foam Suspension Up front is a set of realistic-looking upside-down (USD) forks, held by a pair of molded-plastic triple clamps. The composite fork bodies are fluid-filled, sealed and fully adjustable. The 6mm lower shafts are made of smooth hard steel. Upper and lower Teflon pistons provide the damping action, though only the lower pistons sit in the oil bath. Extra pistons come in the package. Straight from the package, they feel a bit sticky, but after only a few runs, they break in perfectly for smooth damping. Three sets of holes are drilled in the chassis for setting the fork rake, and Venom designed it so the wheelbase does not change with different rake angles. In the rear, a realistic dual-sided swingarm made out of a very stiff composite is supported and damped by a threaded compositebody fluid-filled shock. The swingarm pivots on a 3mm steel shaft supported by hard nylon mounts attached to the main chassis plates. A travel-limiting setscrew on the rear of the battery mount can be used to limit the range of swingarm extension. The internally sprung fluid-filled USD forks are fully functional and leak-proof, with dual O-ring seals and Teflon guides. The rear shock has a threaded body for easy preload adjustments. Extra pistons for the front and the rear are included in the kit for performance tuning. Drivetrain Attached to an aluminum motor mount on the right-side main chassis plate is the Fireball 370 stock motor that has a 14-tooth mod 0.5 pitch brass pinion mounted. Multiple holes in the motor mount allow the use of motors with different screw mount spacing. The pinion drives a layshaft forward on the swingarm pivot shaft that has a 64-tooth spur on one end and a 12-tooth brass chain sprocket on the other. A finepitch steel chain passes over and under the swingarm to the rear sprocket, which is amazing for two reasons. First, the sprocket is incredibly detailed, with the look of a lightweight racing sprocket. Second, it s made out of a very hard and low-wearing plastic that shows absolutely no wear, despite some very hard running. Chain tension can be adjusted with keyed eccentric cams that the layshaft and its bearings are supported by. A steel chain connects the brass front sprocket and the composite rear sprocket. Keyed eccentric cams on the layshaft are used to adjust chain tension. FEBRUARY

VENOM GPV-1 RTR INCLUDED ELECTRONICS & ACCESSORIES Venom VR3T computer radio system This is one of the nicest RTR radios I ve seen with some very high-end functions.

It has 15-model memory, digital trims, exponential, model naming, a programmable dual-rate thumb switch and extensive brakemixing settings.

V-Series 18R ESC and Fireball 370 motor The 18R speed control can handle up to 160A of peak current, so it is more than sufficient to power the 1.4 lb. GPV-1.

5 VENOM GPV-1 RTR INCLUDED ELECTRONICS & ACCESSORIES Venom VR3T computer radio system This is one of the nicest RTR radios I ve seen with some very high-end functions. Though it s only available in 27-band, it is a 3-channel FM unit that can output standard PPM or PCM signals. It has 15-model memory, digital trims, exponential, model naming, a programmable dual-rate thumb switch and extensive brakemixing settings. The steering servo is a plasticgear Venom 308 Mini that features 34 oz.-in of torque and 0.14-second transit time at 6 volts. V-Series 18R ESC and Fireball 370 motor The 18R speed control can handle up to 160A of peak current, so it is more than sufficient to power the 1.4 lb. GPV-1. The Fireball 370 motor isn t the fastest brushed motor around, but it does a great job and is perfect as a spec class motor for bikes. Venom 1200mAh NiMH battery and charger The battery is a standard 6-cell stick pack of the same size as used in many 1 18-scale cars. The charger is a wall-type trickle unit. I experienced about 20 minutes of run time from one charge. Tools and spares A round box wrench and an open-ended wrench come in the package. The front and rear jack stands even have urethane-look wheels. Multiple optional rear shock pistons and multiple sets of fork pistons let you play around with damping with out purchasing more parts. And spare O-rings to fine-tune the steering damper round out the spares. Rider and body It wouldn t be a proper race bike without flashy bodywork and a suited-up rider, and this is where Venom s attention to detail shows through. The polycarbonate cowl and tank/seat come painted and stickered in a variety of color schemes. The rider is made out of foam and is surprisingly durable and hefty. It s a dense foam compound, and the color on the urethane is actually a skin that becomes part of the foam itself, so it doesn t rub, flake or wear off very easily. And even after all my testing, the metallic blue paint on the rider s helmet still looks perfect. For those of you who have your own paint scheme in mind, Venom also offers the bodywork in clear to paint yourself and offers a white rider you can customize. Both ends of the bike have realistic-looking brake rotors and calipers, but they are decorative and look really nice painted. The durable rider is mounted on the tank/seat from a post molded into his torso and secured with a body clip. His feet stay on the pegs by pressing them down onto sharp posts. Note the position of the fingers on his right hand: they re ready to apply the brakes! ON THE BENCH WEIGHT WHERE IT COUNTS The weight of the stock NiMH pack helps keep the GPV-1 stable at all speeds; but if you switch to LiPo batteries, the vertical center of gravity changes dramatically. You can do two things to get back that same feel with lighter batteries. First, add ballast to the bike low on the chassis to bring the weight back up. Second, drop the ride height by sliding the fork tubes 2mm up in the triple clamps and drop the rear by using less preload on the threaded shock body adjuster. SET THE CHAIN TENSION RIGHT Most bike newbies run a much tighter chain tension The GPV-1 was designed to be easy for bike novices to drive out of the box yet still be tunable enough for more experienced drivers. Here are a few tips to help you get beyond the initial learning stages. than is necessary, so it s worth mentioning here. Because the swingarm pivot point is behind the driven layshaft, as the rear shock compresses, the chain tension gets slightly tighter. Always check the chain tension when the bike is fully loaded with the rider and battery installed. The top portion of the chain should droop slightly, and the rear wheel should spin freely for several revolutions when spun by hand. QUICKER STEERING RESPONSE One thing that you can t get around is having to slow down to turn a bike, but you can increase the lean transition speed very easily. There are multiple ways to tune the GPV-1 s steering response, but the easiest thing to experiment with is the steering spring tension. First, take off the tank/seat and rider to expose the steering-servo linkage and fully tighten the setscrews on the two collars that retain the steering springs (this will create marks on the rod to be used later). Then loosen the setscrews and slide each collar towards the servo arm, using the indentation on the rod from the previous setscrew position as a guide. Start by moving the edge of the collar to that indentation; this should be about 2mm. Keep moving the collars closer until you get the snappy response you want while keeping some low-speed stability. FACTORY OPTIONS Clear body set item no. VEN Alloy triple clamp set VEN-0300 Carbon race chassis set VEN-0328 Front brake kit VEN-0355 Soft front and rear tires VEN-1167V1, VEN-1168V1 Find a complete list of factory options at rccaraction.com YOU LL NEED WE USED Batteries 8 Rayovac alkaline AA cells; rayovac.com TO READ THE INTERVIEW WITH VENOM GROUP S CHRIS NICASTRO, DESIGNER OF THE GPV-1, GO TO RCCARACTION.COM Rating the Venom GPV-1 RTR Venom s goal was to bring the excitement of RC bike racing to the masses, and I firmly believe they ve done their part to accomplish this. The package as a whole is a great way for anyone to get started, and as it comes out of the box, it is fully raceable on touring car tracks. Of course I m excited to see what the upgrades look like the front brake set in particular but rest assured, I will race it in its stock form with other GPV-1 owners as soon as possible. The GPV-1 RTR package makes getting into RC bikes easy. I think a new generation of motorcycle racers can at last share the excitement of what we hardcore bikers have been experiencing for years. + - BEST FOR Easy for beginners to drive Lots of tuning adjustments Surprisingly durable Battery securing method could be better Anyone who wants an RC motorcycle and existing RC bike enthusiasts who don t have large-scale facilities to race on. 94 MORE FROM THIS ISSUE AT RCCARACTION.COM

TIPS TO FINAL ASSEMBLY Radio installation. The Electronic speed control (ESC) and the receiver need to be mounted onto the chassis, using double sided

TIPS TO FINAL ASSEMBLY Radio installation. The Electronic speed control (ESC) and the receiver need to be mounted onto the chassis, using double sided tape (not supplied.) Mount the ESC first on the chassis