SRB Cage-Racer

JMo

V.I.P. Member
Prompted by a comment on one of my build threads recently, I thought I would summarise one of my favourite builds over the years (and it did take years, over three from start to finish), and what is still pride of place in my collection albeit not a true 'scaler'* in the traditional sense perhaps...

*are we allowed to use that term here on the SBG?


photo. The SRB Cage-racer - essentially a 2-seater Tamiya Rough-Rider/Twin Hammers mash-up.

I'll include a detailed specification list below, but in summary: I consider this to be my take on the 'ultimate SRB' - arguably Tamiya's most iconic chassis/model combination over the years.

The high proportion of metal components in the standard/donor kit prompted me to continue that theme using as much aluminium as I could, together with the plastic roll-cage which essentially created a two-seater version of the original 1979 Rough Rider.

The scale VW engine and other branded detailing (shocks, seats, seat-belts, tyres, wheels, lights) all help to add scale realism, while still keeping the overall effect recognisably Tamiya.

The original intention was to leave as much raw metal on display as possible (the only painted parts are the Knight Customs 3D printed engine, and the driver figure) - however it turned out the original Tamiya Pajero Wheelie Dakar style racing decals were an almost perfect fit for the Twin Hammers panels, and I feel finally tie the whole project together.


photo. 1983 era Dakar Rally Pajero decals trimmed to fit Twin Hammers panels - race cars need bright colours after all!


photo. original front track width increased to more closely match the rear - for stability, plus so that the cage would fit between the shock towers and closer to the chassis.


photo. Vanquish Method Roost wheels with Locked-Up RC scale hardware and SLW hubs - freewheel/bearing type in front.


photo. custom chassis (cut from 2mm thick aluminium) folded at the rear to create rear inner aches to follow the cage.


photo. clear Tamiya gearbox covers painted aluminium silver to match the rest of the scale engine.


photo. custom engraved licence plates... because this is a heavy metal hammer.


photo. Tamiya BFGoodrich Mud-Terrain tyres (approx. 86mm diameter).


photo. Kelly Osbourne driver figure repainted, and Sand Scorcher helmet shaped to fit.

cont.
 

JMo

V.I.P. Member
cont.


Specification in more detail, and brief build summary:

model name: SRB Cage Racer (aka. Mjolnir)

driver: Krazy Kelly (Kelly Osbourne figure, modified with Sand Scorcher driver helmet and to steer with her left arm)

body: Vaterra Twin Hammers roll cage (customised) and aluminium panels

chassis: Tamiya SRB front & rear suspension subframes, with custom aluminium chassis

wheels: Vanquish Method Roost 1.9 (internal bead-locks removed)

tyres: Tamyia BF Goodrich Mud Terrain 1.9s (86mm diameter)

motor & transmission: standard Tamiya 540 motor and stock SRB transmission - RWD

suspension: 70mm RC4WD super scale shocks (Old Man Emu) front & rear

wheelbase: 262mm

track width: f: 185mm / r:195mm

overall width: 222mm

overall length: 395mm

overall height: 155mm


custom features:

Custom designed and hand-cut aluminium plate chassis to mate SRB front and rear subframes together with a 262mm wheelbase.

Front suspension track width widened, and direct servo steering. 70mm internal-spring shocks.

Custom rear suspension mount/bulkhead and twin 70mm internal spring shocks.

Twin Hammers cage modified at rear, alloy body panels fitted together with custom roof and rear deck cover (styrene covered in self-adhesive carbon-fibre ).

Axial Corbeau bucket seats and Yeah Racing seat-belts.

Axial light buckets front & rear and custom LED harness.

Graphics are original Tamiya Pajero Wheelie decals, modified to fit.

Knight Customs SRB scale VW engine (custom painted with modified air-filters and further detailing).


photo.driver Kelly Osbourne shaped to fit in the Axial Corbeau bucket seats, and her left arm is free to rotate in the shoulder socket with the steering.


photo. rather than use a separate servo, Kelly's animated arm is actually connected to the steering servo via a working steering column.


photo. Knight Customs scale VW flat-four engine - with added HT lead and pod airfilter mesh details.


photo. spare wheel is mounted to cage with a custom spinner (made from a wing-nut and two short lengths of aluminium tube).


photo. classic Tamiya SRB cambered rear suspension - it might not handle all that well, but it looks kewl!


photo. Custom alloy chassis to connect the SRB subframes together. Additional Tamiya bracing plate incorporated to increase rigidity of the rear shock tower upright/gearbox mount.



photo. the body can be easily detached (with just two M2.5 screws along each sill) for battery changing (or charged in situ) and the chassis driven bare.

And just for fun, a short (and admitted pretty poor quality) running video in the carpark of the RC4WD event last October (2019) - donuts for breakfast!


Toot toot!
 
Last edited:

dagabba

Supporting Member
Love this, very cool and super clean!

Definitely makes me want to do an SRB build too...
 

JMo

V.I.P. Member
Love. This.

Not knowing anything about the srb transmission, what kind of speed are you getting w that 540 can?

Hi rshackleford - I've not actually measured it, but generally speaking an SRB is pretty rapid - certainly fast enough for it's limited handling... it's probably not quite as fast as a modern buggy in a straight line, not least due to a little extra weight (and more in the build with the extra metal chassis and body panels), but if you watch a video of a Sand Scorcher/Rough Rider/Super Champ on Youtube it ought to give you a fair idea?

The nice thing about the SRB is it's distinctive sound, and how smooth it is (this example running on full bearings of course).
 

JMo

V.I.P. Member
only thing i dont like is that camber in the rear

Ah, but that is quintessentially what the Tamiya SRB is all about no less!

It actually squats under power so that the wishbones are essentially level when driving - it - just gives you a little extra droop travel as the suspension moves through it's arc...

...coupled with a locked rear diff - SRBs have always been known for their 'quirky' handling of course - it was the 80's baby!
 

Small Factory

Fancy-Walkin'
This is so well thought out. Did you have a reference of a 70's two-seater VW dune buggy, or was this just done from your imagination?

The rear camber certainly gives it that vw feel. I do wish that tamiya did rear trailing arms like the 1:1 vw bugs.
 

JMo

V.I.P. Member
This is so well thought out. Did you have a reference of a 70's two-seater VW dune buggy, or was this just done from your imagination?

The rear camber certainly gives it that vw feel. I do wish that tamiya did rear trailing arms like the 1:1 vw bugs.

Hi Small' - thank you for your kind words! - yes it did take some working out originally, and was probably the longest project I've had (a little over three years from start to finish, since other more immediate projects kept getting in the way!)

As I mentioned in the intro, the idea was to essentially make a two-seater [Tamiya] Rough Rider - so basically a wide-body Bel-Ray Bullet kind of thing - although the overall body shape was dictated by the Twin Hammers cage of course, even though I was able to dock the tail to try and mix things up a bit there and emphasise the VW engine hanging out the back.

Like you say, I really like the rear wheel camber too - although I do also have a set of [aluminium] trailing arms from a Kyosho Beetle, together with another SRB front end - and another back-burner project is to make more of a scale Class 5 racer with a traditional Beetle (Sand Scorcher) shell at some point after I've exhausted my current 4x4 fixation.

Stay tuned as they say!
 
Top