GB-01S
The GB-01S chassis is an evolution of the GB-01 chassis; Tamiya upgrades the bathtub chassis (introducing several improvements) while keeping all other shared components unchanged between models equipped with the GB-01 bathtub chassis (shown on the left in the image below) and the GB-01S bathtub chassis (shown on the right in the image below). With this chassis, Tamiya introduces new accessories and spare parts that are compatible with models belonging to the GB-01, GB-01T and GB-02 series.
The following factory pre-assembled models, complete with transmitter, integrated receiver with electronic speed control and steering servo, are part of the GB-01S TamTech-Gear family by Tamiya:
– The Grasshopper Mini, model number 56714, released in 2021 and available on the market until 2022; 1/14 scale model. Scaled-down reproduction of model 58043 – The Grasshopper
– Mighty Frog Mini, model number 56715, released in 2021 and available on the market until 2022; 1/14 scale model. Scaled-down reproduction of model 58041 – The Frog
– The Hornet Mini, model number 56716, released in 2021 and available on the market until 2022; 1/14 scale model. Scaled-down reproduction of model 58045 – The Hornet
The chassis has been widened to accommodate either a battery pack consisting of four AA cells (image on the left) or an LF1100 6.6 Volt battery pack (image in the center). Replacing plate A2 with plate A5 is sufficient to switch from the first to the second configuration.
A new feature of the GB-01S chassis is the system that allows the assembly of a battery pack consisting of four AA cells. This battery holder is made up of several components.
These are the instructions on how to use it.
Technically, the GB-01S chassis has the following features, starting from the rear and moving toward the front:
– The first major difference from the GB-01 chassis is the wider bathtub chassis, designed to better accommodate a standard-size front servo, the AA battery holder system (shown on the left in the image) and the new electronics (shown on the right in the image), which integrate the receiver and electronic speed controller into a single unit. All electronics are perfectly installed within the chassis, leaving no unused space. The plastic used for the GB-01S chassis feels softer to the touch compared to the material used for the GB-01, GB-01T and GB-02 chassis tubs. Despite these differences, the overall wheelbase of the GB-01S chassis remains unchanged compared to the previous GB-01, GB-01T and GB-02 models.
The chassis also includes a safety fuse for the electrical system, a first for TamTech-Gear models. The fuse rating is 10 Amperes for the factory-installed 370 motor and the optional 370 Torque Tuned motor and 30 Amperes for the optional 370 Sport Tuned motor.
– New planetary gear differential, more durable than the ball differential used in the GT-01, GB-01, GB-01T and GB-02 chassis. This new differential is compatible with those installed in previous chassis and is also used in the GB-03 chassis. Part number SP-1685 or 51695, described as TamTech-Gear GB-01S Spare Gear, highlighted in the second row of the image below.
– Rear-wheel drive powered by a 370-type motor with a Teflon pinion gear (four factory-supplied pinions with 12, 14, 16 and 18 teeth). Technical specifications of the RK370 motor at maximum efficiency: 10,600 RPM, torque 5.4 Nm and current draw 1.8 Amperes. For improved performance, install accessory number 54860 described as “TamTech-Gear Sports Tuned Motor SPT”
– Transmission equipped with an anti-hop clutch. The slipper clutch consists mainly of two discs held in contact by a spring loaded with a bolt. The slipper clutch serves two functions to compensate for the lack of traction between the surface and the wheels.
The first function is to protect the drivetrain during jumps. While airborne, the model does not touch the ground and the drive wheels spin without resistance: the wheels tend to increase their rotational speed. During long jumps, the motor’s RPM is modulated by the operator to maintain the model’s attitude and control the landing angle. In both cases, when the model touches down, the wheel RPM must quickly align with the actual speed of the model, causing a sudden change in rotation speed. This puts stress on the transmission gears.
The second function is to protect the gears from premature wear when the motor, during sudden acceleration, increases its rotational speed faster than the wheels can respond. The same occurs during sudden deceleration. The clutch prevents loss of traction and avoids unnecessary stress on the gears.
This dual role of the clutch ultimately preserves the drivetrain components inside the gearbox, where the motor pinion gear is the most stressed part.
To achieve optimal performance, it is necessary to adjust the slip by setting the calibration value (indicated as “BA9” and highlighted in red in the image above on the left). Follow the instructions by compressing the spring until reaching a total length of 4.2 mm to establish an initial operating point for the slipper clutch.
Place the model on a table or flat surface, power on the electronics, hold the rear wheels with your hands and apply a short burst of throttle. There are two possible outcomes: the model tends to move and the front end lifts off the surface (following the red line shown in the image below), or a sound is heard from the gearbox indicating that the clutch is engaged and the front end remains on the surface. The image shows the hand holding the rear wheels and the expected movement of the front axle in response to the throttle burst (highlighted by the red arrow).
The optimal configuration is when the front end and front wheels lift slightly, losing contact with the surface; this serves only as a starting point. The best setup depends on the track surface conditions and its grip level; calibration must be adjusted accordingly.
The two worst configurations are the extremes of adjustment: an overly compressed spring or an overly loose spring. In the first case, the gears are directly and rigidly connected to the wheel axle and the clutch loses its function entirely. In the second case, the spring is so loose that it fails to transmit any motion to the wheels, preventing the model from moving. In the Tamiya universe, the first slipper clutch, named TTC (Tamiya Torque Control), was engineered for the Super Astute, which was released in 1991.
– Unlike previous TamTech models GT-01, GB-01, GB-01T and GB-02, the GB-01S chassis is not equipped with a full set of ball bearings. The gearbox contains ball bearings, while the front wheels and rear axles use bushings. To reduce wear and increase system efficiency, extending runtime, eight 1280-size ball bearings are required for the front and rear wheels.
– Four independent suspensions with four black mini coil-over dampers, which are long and thin, accurately replicate those used in 1/10 scale models. For improved performance, replace the factory-installed coil dampers with set number 22011 described as “TamTech-Gear GB-01S CVA Damper Set (4pcs.)” This set features yellow-colored dampers.
– Most of the screws used in models equipped with the TamTech-Gear GB-01S chassis have M2.6 thread size.
– The radio and receiver use 2.4 GHz technology; the transmitter is identified by code Fine Spec 2.4 TTU-08 and the receiver by code TRE-01, which integrates the speed controller. The TRE-01 unit is programmable (refer to the table on the right in the image). With the chassis modification, the steering servo has standard dimensions and is identified by code TSU-03. The servo is mounted on a plate and to install it, the side tabs must be trimmed.
List of all parts that are accessories for performance enhancement or components not included in the factory package of the GB-01S chassis; some accessories are shared with the GT-01 family and other GB-01xx families:
22008 33x6mm Steel Flanged Screws (5pcs.)
22010 TamTech-Gear GB-01S Full Ball Bearing Set; bearings are size 1280
22011 TamTech-Gear GB-01S CVA Damper Set (4pcs.). The set includes 4 dampers with yellow bodies and 12 yellow plastic ball joints for use in the steering system (4 pieces; 2 per arm) and upper suspension arms (8 pieces; 2 per arm). To assemble the arms, add threaded rods to screw into the ball joints (a total of six threaded rods are needed: two for the steering arms and four for the suspension; see set number 22017)
22012 TamTech-Gear GB-01S Setting Spring Set
Here is how to install the springs from accessory number 22012 according to their color, which corresponds to their stiffness: lighter-colored springs are stiffer than darker-colored ones.
22013 TamTech-Gear GB-01S Wheel Collar (Blue) & Bolt Set
22014 TamTech-Gear GB-01S Aluminum Wheel Hubs (Blue, 2pcs.)
22017 TamTech-Gear GB-01S 26x29mm Aluminum Turnbuckle Shaft (Blue 4pcs.)
22018 TamTech-Gear GB-01S SC Front Tire
22019 TamTech-Gear GB-01S SC Rear Tire
22020 TamTech-Gear GB-01S Bumper Set
22021 TamTech-Gear GB-01S 05 Hard Coated Aluminum Pinion Gear (16T)
22022 TamTech-Gear GB-01S 05 Hard Coated Aluminum Pinion Gear (18T)
54919 “Torque Tuned Motor,” equivalent to RK-370-SD-3265; technical specifications at maximum efficiency: 15,000 RPM, torque 6.8 Nm, current draw 2.1 Amperes
54860 “Sport Tuned Motor,” equivalent to RK-370-SD-4045; technical specifications at maximum efficiency: 21,000 RPM, torque 7.7 Nm, current draw 3.3 Amperes
51679 TamTech-Gear GB-01S Front Wheel (S Type)
51680 TamTech-Gear GB-01S Rear Wheel (S Type)
51681 TamTech-Gear GB-01S Front Wheel (D Type)
51682 TamTech-Gear GB-01S Rear Wheel (D Type)
51683 TamTech-Gear GB-01S Front Grooved Tires
51684 TamTech-Gear GB-01S Rear Spike Tires
51685 TamTech-Gear GB-01S Spare Gear Set
54928 Metal Cross join
To install set number 54928, which becomes necessary when using motor 54860 “Sport Tuned Motor,” follow the specific instructions provided with the accessory.
It is possible to install tires and wheels from the GB-01T Wild Boar and Suzuki Jimny SJ30 chassis:
– Set number 54831 described as GB-01T Wild Boar front wheels, to be completed with
– Set number 54830 described as GB-01T Wild Boar front tires
– Set number 54833 described as GB-01T Wild Boar rear wheels, to be completed with
– Set number 54832 described as GB-01T rear tires
