SRB

SRB stands for ‘Special Racing Buggy’ and is perhaps Tamiya’s best-known chassis. Three models use the original version of the SRB chassis:

– Rought Ride, item number 58015 released to sale in 1979 and available on the market until 1984,
– Sand Scorcher, part number 58016 released to sale in 1979 and available on the market until 1984, and
Ford F150 Ranger XLT, article number 58027 released to sale in 1981 and available on the market until 1984.

These three models represent a very important novelty for Tamiya, there are several advertisements that Tamiya or the various importers around the world have published in the trade magazines; in the image below are some examples of advertisements concerning all models equipped with the SRB chassis.

The biggest difference between the three models is the body, the chassis anchoring system and the wheels with rims; the rest of the chassis consists of the same parts that are interchangeable between one model and another. There have been several re-releases of the Rought Ride model and the Sand Scorcher model over the years, until now (2023) the Ford F150 Ranger XLT model has not been re-released.
These are the specifications of this family.

– The chassis is only two-wheel drive (rear-wheel drive).
– Two-wheel steering.
– Independent rear suspension for purely off-road use with torsion bar suspension.
– Independent front suspension for purely off-road use with springs assisted by oil-filled shock absorbers.

In the image all the parts that are needed to assemble the three models equipped with the SRB chassis are neatly shown.

The central body of the chassis consists of a fibreglass plate; at the two ends of the plate are installed:

1 – a) the double-arm suspension system + front steering. The double-arm front suspension was inspired by the front suspension system of the VW Beetle-based buggy of the 1970s.
b) The single-arm suspension system with torsion bars + rear drive train. The rear drive system is very realistic: two axles Both these assemblies are made of metal.

2 – Centrally installed is the box for the receiver, servo and battery; the box is made up of several parts of transparent plastic. In the intention of the designers this part was to be water-proof, in reality it is very effective against splashes and mud; it can hardly protect the electronics from too much water. It is better not to submerge the model completely in puddles.

The weight distribution is shifted towards the rear and this helps to ground the motor power. The front bumper is very effective, which is why it is difficult to find one that has not suffered impact and damage. The rear gearbox guard assembly is very exposed to impacts and being made of plastic tends to break easily.
Over the years, Tamiya has continuously evolved this chassis and several improvements have been introduced. Of the first series from the late 1970s, two families Mk1 and Mk2 can be distinguished. These families differ in several points. The changes were not all introduced at the same time, so it is difficult to give a date when Mk2 replaced Mk1. Here is a non-exhaustive list of the differences that can also be seen from the assembly instruction manual.

The pictures on the left show the parts of the Mk1 family and on the right the parts of the Mk2 family. Starting at the front and moving towards the rear of the chassis, these are the differences for:

Hardware
The hardware on the first Mk1 version was shear-headed and then became cross-headed in the later Mk2 versions. Beware that this modification was not made later by owners to update hardware that was lost during routine maintenance.

Front bumper
The front bumper for Mk1 is black, while the front bumper for Mk2 is grey. Please note that the black bumper is also present on the reissues, the latter can be distinguished from the early versions (on the left in the photo) because it is marked “>ABS< 58015/0979050-00 1979-2009 TAMIYA” (on the right in the photo).

Buggy abbreviation
In the front bumper and on the bodies of the Rough Rider and Sand Scocher in the early Mk1 versions appears the inscription TAMIYA 1/10 RC RACING BUGGY later corrected to TAMIYA 1/10 RC RACING BUGGY in the Mk2 by adding the missing G.

Front suspension arms
Front suspension arms differ in diameter between Mk1 and Mk2. Arms are thinner in the middle part for the Mk1, which is why it was easier to bend them.

Front Suspension
Different spring retention systems for the front suspension. The front springs are held in place by screws in the Mk1 version, the front springs are held in place by die-cast pins in the Mk2 version. Obviously this modification also leads to differences on the inside of the suspension support arm where in the Mk1 there are two cylinders to tighten the screws.

Centre plate
The fibreglass plate of the Mk1 version is about two millimetres shorter than that of the Mk2 and has holes to fix the larger diameter screws. The green frame could be an Mk1, the yellow frame could be an Mk2.

Servo and receiver  box
The almost watertight electronics box and motor-receiver covers have changed colour over time from a clear transparent to a dark transparent as if blackened by smoke.

Gearbox
The gearbox casting has several points where there is a difference between fins and reinforcement points. The first difference is at the point where the gearbox attaches to the fibreglass frame, in the Mk1 version (left in the photo) there are two remnants of the casting which are two small cylinders that are missing in the MK2 (right in the photo).

The second most visible difference in the casting of the gearbox is at the rear where the suspension is attached (left on the Mk1 and right on the Mk2).

Rear suspension arms
In the rear suspension arms of the Mk1 version there is machining to install another bushing, which is not present in the Mk2. The arms of the Mk1 version are devoid of the ‘1’ and ‘2’ marks that are present on the Mk2 version.

Ford F150 body wheel arches
The MK1 version of the Ford F150 has wheel arches that are approximately 80 mm long compared to about 95 mm for the Mk2 versions. This modification was necessary to better allow the wheels to interact with the body when working the suspension.

Ford F150 wheels
The front wheels of the Ford Mk1 (left) allowed the wheels to be installed further away from the car’s axis; with the introduction of the body with enlarged wheel arches the wheels moved 2 mm closer to the centre of the car. The photo shows the difference in the position of the bushing holder, which in the Mk1 is in contact with the ruler and in the Mk2 version is about 2 mm away from the ruler. Obviously the other two parts that complete the rim are also different between the Mk1 and Mk2 models with different depths. The Mk2 rims were later replicated on Subaru Brat model 58038.

Further differences were then introduced in the re-release versions, just think of the motor speed regulation system, which in the 1970s and 1980s was a mechanical regulator with an electrical resistor and in the 2000s an electronic regulator.

The original 1970s version

Pictured from left to right are parts of the Rought Rider, Sand Scorcher and Ford F150 Ranger XLT. Starting from the front and moving to the rear of the chassis, these are the differences for:

Front locking system of the body to the chassis
The front locking system of the body to the chassis is different in all three models. The metal column is low for Rought Rider, high for Ford F150 and has an intermediate height for Sand Scorcher.

Tyres
Rought Rider and Sand Scorcher have different front tyres than the rear tyres, and the tyres are different between the two models. Sand Scorcher has sand rear tyres, while Rough Rider has knobbly tyres
Ford F150 has a more homogeneous configuration and has the four identical tyres in the treaded version. The rear tyres on the Rought Rider model are identical to the four tyres on the Ford F150.

Rims
The difference in tyres is also reflected in the front (F) and rear (R) rims. Sand Scorcher has 1.5-inch rims, while RoughRider and Ford F150 have 1.6-inch rims. The rims are highly sought-after and each wheel consists of three parts.

Rear body locking system to chassis
The rear locking system of the body to the chassis + rear bumper is identical between Sand Scorcher and Rought Rider (highlighted in red); but it is different for Ford F150. The Ford F150’s structure has a square section to allow installation of the rear column (highlighted in blue).

All three models have different body, some of which have been used on other chassis families.

Ford F150 body
The rarest is definitely Ford F150, which shares part of the body with Black Foot model 58058.
There are some substantial differences between Ford F150 and Black Foot, the most obvious being:

– transparent windows for Ford F150 while they are transparent black for the Black Foot
– Ford F150 has two holes to fix the body to the chassis while the Black Foot (right) has three holes to fix the body to the chassis.
– the Black Foot also has the roll bar complete with three lights.
– the antenna position is different between the two models.

Sand Scocher body
The most famous is certainly Sand Scocher, which shares the body with several later models starting with the Monster Beetle model 58060 and the Blitzer Beetle model 58122. The bodies of the Monster Beetle and the Blitzer Beetle are virtually identical, differing only in that the former is made of red styrene (plastic) and the latter of black styrene (plastic). Sand Scocher first version and following have always had white styrene (plastic) body.
There are some substantial differences between the Sand Scocher and the Monster Beetle, the most obvious being:

– The nose of the Monster Beetle lacks two holes to install the turn signals.

– The holes for the pins that attach the body to the chassis are single in the Sand Scocher (pictured left) and three in the Monster Beetle (pictured right).
– In the Sand Scocher, the rear attachment of the body to the chassis is a plate with a hook that fits over the bumper – rear roll bar. In order to attach the body to the chassis, the Sand Scorcher’s rear window is missing. This plate has two holes in the roof that are used to pass the screws that secure it to the body.
– The hole for the front tower pin to attach the body to the chassis is moved forward in the Sand Scorcher than it is in the Monster Beetle. Left Sand Scorcher and right Monster Beetle.

– The handle of the Monster Beetle is integrated into the body (in the Sand Scocher it is a separate piece which is very rare because it often comes off and is lost).
– The number plates of the Monster Beetle is a sticker (in the Sand Scocher the numbers and wording are cast from the number plate itself and are in high relief).
– The front and rear wheel wells on the Monster Beetle are slightly different in shape and size from those on the Sand Scocher, the picture shows the Sand Scocher and the black line marks the area that has been cut off in the Monster Beetle.

Re-releases:

There are several differences between the original and the re-edition of the Sand Scocher and Rought Rider model. The pictures on the left show the parts of the original and the pictures on the right show the parts of the re-edition. Starting from the front and moving to the rear of the chassis, these are the differences for:

Front Bumper
the re-release bumper is black like that of the Mk1 and is marked “>ABS< 58015/0979050-00 1979-2009 TAMIYA”, obviously this information (2009) could not be present in the original version.

Oil shock absorbers
Oil shock absorbers are different in shape and performance, the modern version is better performing and leaks less oil. Check the shape of the eyelet, which is the part that differs the most.

Front suspension arms
The castings of the front suspension arms in the most modern version bear markings to help with assembly. The image shows LL and RL.

Bearings, bushings
The original version installs bushings, which later became plastic bushings in the re-edition.
Centre frame
The fibre base is light-coloured in the original version and becomes carbon fibre black in later editions.
Motor speed control
In the re-edition there is no mechanical speed controller + ceramic resistor, but an electronic speed controller.
Servo box and receiver vibration dampers
The two rubber buffers that secure the electronics box have changed from the original version to the 2010 re-edition. The photos show three views with the original version on the left and the re-release version on the right. The original version differs mainly in the less thick base and the view from below (see last photo).

Servo – receiver box
There are several details that change in the modern version. The plastic used for the electronics box has returned to being as clear as that of the Mk1, in the picture are the base of the electronics box of the three versions: from left to right are in order Mk1, Mk2 and re-release.

Nella versione moderna lo scatolotto anteriore per contenere la ricevente è più compatto.

The lid has two holes, which was not present in the original version.

Stickers
Body stickers are slightly different, due to intellectual property laws that have evolved. Today, no well-known, registered trademarks can be displayed without the consent of the company in question.
Body number plates
The re-issue number plates are stickers, whereas in the original Sand Scocher the numbers and wording are cast from the number plate itself and are in high relief.

In addition to the above for the Sand Socher alone there are differences in the body, starting at the front and moving towards the rear of the chassis, these are the evolutions introduced for:

Rear view mirrors
The rear view mirrors are different between the two versions.

Door handles
The door handle is a separate part to be glued in the original version, while it becomes part of the body in the following edition.

Headlights
The rear lights are in two pieces in the original version and are in one piece in the later edited version.

Later evolutions of the SRB chassis

Speaking of this family, we cannot forget to introduce the Super Champ model, model number 58034 put on sale in 1982 and available on the market until 1986.

This model is an evolution of the SRB, so it’s hard to know what to call it. It shares the suspension + steering + front bumper assembly and changes for the other parts.

 The pictures on the left show the parts of the original SRB chassis and the pictures on the right show the parts evolved on the Super Champ model. Starting from the front and moving to the rear of the chassis, these are the differences for:

– body
– tyres and rims
– servo saver – steering column servo saver is improved on the Super Champ model to better absorb shocks on the front wheels. Left is that of the SRB series and right is that of the Super Champ

– double system of central fibreglass plates (the transparent plastic box is completely missing). This system does not protect the electronic part from water like the box in the SRB family. It does, however, allow for faster battery replacement and better cleaning after use on dirt roads.

– rear suspension system with central oil reservoir with spring-loaded single shock absorber + drive system + rear bumper

universal joints are no longer made of brass (left in photo), but of steel and dark green (right in photo)

The differences between the first three models and the Super Champ are so marked that one can speak of a different chassis.
There are several advertisements that Tamiya or the various importers worldwide have published in trade magazines; in these documents, Tamiya emphasises the evolution of the chassis.

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