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  LRP Shark 18 Monster Review, Part 1

 Small-sized offroad(-cult)
 

"Micro racing is fun!"
"Truggy-driving  is cool!"
"Monster Trucks are the greatest!"

These are the three biggest trends that you could experience as an R/C car driver in the last five years. All of them brought loads of more or less sophisticated models to fill the new classes and add some colour to the R/C car world.

LRP-Electronic seems to aim at combining all those trends into one single car. How? By building a small 1/18th scale truggy and naming it "Monster"!
LRP offers their Shark 18 Monster in two versions: You have the choice between the completely assembled (ARTR-) Truggy without any rc-gear for about 149,90 Euros or you could go for the full RTR-Package that includes anything you'd need as a hobby starter for 229,90 Euros.

For the this review WR-RC-Racing hooked me up with the RTR-version of the LRP Shark 18 "Monster"
The following remarks therefore refer to the test sample and especially the measured values cannot be unrestrainedly generalized due to serial dispersion.

Although "RTR" might sound like "unwrap and go" such models should always be disassembled and checked. This can be easily done thanks to the well illustrated manual which is also a good reference for future maintenance work.

TECHNICAL DATA
Length:     263mm
Wheelbase:  168mm
Width:      196mm
Height:      92mm
Weight:     730g

SUPPLEMENTARY EQUIPMENT
27MHz transmitter
servo, receiver
380-size motor, ESC
batteries for vehicle and transmitter, charger

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 Shark 18 Monster: The package
 

As expected, LRP will not let down their customers when it comes to funky package design. The compact box features a ‚see-thru’ window while the coloured cardboard is used to promote some spare- and hop-up parts. A small photo gallery affirms to a still undetermined consumer that this product has been developed and tested by some of the swell in the (international) R/C car scene – well, then!

What has always counted more for us are the ‚inner values’. The RTR kit is (nearly) absolutely complete: The Shark 18 has been equipped with a Phaser 27 MHz (AM) receiver and an A.I. micro ESC – meaning no cheap ‘RTR-edition’ components but regular, off-the-shelf LRP products.
The transmitter is all standard: charging jack, trim and servo end point adjustment for the steering are included and should be enough for a start.
The additional equipment consists of a 600mAh battery to power the Shark 18 Monster, a wall socket charger and eight (non-rechargeable) AA cells for the transmitter.
While shopping, all newcomers should equip themselves with a set of rechargeable transmitter batteries plus charger.

 
 
  

 Shark 18 Monster in details
 

"solid"... "overcrowded" ... "cute!"
Guess those were my first thoughts when I had delivered the little truggy from its bodyshell.
Luckily, the crowded look only comes from the standard components that the Shark 18 Monster is fitted with. Using mini-components (micro servo, small FM-receiver from a slow-flyer) the chassis would certainly look more orderly, but parts in standard size are quite tough and budget-priced.


The chassis actually debuted with the Shark 18 buggy – which LRP promoted as a scaled-down 1/8th buggy. Just as well, because the dimensions of the chassis remind more of a gas powered vehicle than of a frail electric car. The construction itself is a clever mix of both types with some intriguing details. The chassis hasn’t been changed for the Monster model, but the suspension has been made wider, featuring a PBS-suspension at the front.

The electronics can be (apart from the taped-in servo) quickly removed from the chassis because they are mounted onto the battery strap. Down below you can see much more of the chassis. It's of a ‘tub-type’ with lots of things moulded to it, hence the Shark 18 Monster consists of a surprisingly small number of parts.
The chassis comes with the lower halves of the gearboxes, all supports for the drive train and the inner hinge pin mounts.
If it weren’t only twenty centimetres long you could think of a 1/10th scale chassis because the thickness of 2.5 millimetres seems quite beefy with the small scale. The plastic is reassuringly stiff and light – it seems to be fibre-glass reinforced nylon. All stressed parts are secured with 2.6 millimetre tapping screws.
 

The design of the front suspension is very close to the 1/8th scale buggy concept. Due to the pivot ball suspension the upper arm has to support the steering arm and can therefore not use a tie rod. The whole steering construction reminds of the bigger-scale ancestors as well. The double linkage of the steering itself is more of the 1/10th standard again, while the servo –deprived of its mounting lugs- is held in place only by a patch of double-sided adhesive tape.

The cast-aluminum motor mount is a firm base for the 380-size motor and also quickly dismantled by loosening two screws. The construction of the Shark 18 would make it quite tricky to adjust the meshing between pinion and main gear, hence blue anodized adaptor plates with fixed mounting holes are used. This way, five different pinion gears can be used. (11, 13, 16, 19 and 21 teeth)
A precisely fitting gear cover protects everything from dust and also stiffens this critical part of the chassis at the same time.

Why be complicated when there’s an easy way? Instead of attaching frail hinge pin holders, LRPs’ Shark 18 Monster uses all of the tub chassis and integrates the hinge pin mounts into it. The rear end uses a ball-type design which makes everything more crash-proof and allows the use of different toe-in blocks.


 Suspension
 
The Shark 18 Monster comes with a PBS-system at the front and conventional hub design at the rear suspension. Four oil filled shocks provide remarkable 3 centimetres of travel (depending on the position of the shock on the lower arm and the shock tower)
PBS-systems are a little trickier to set up due to their construction but LRP found a clever solution to compensate this: The arms got a little ‘peephole’ – when the thread of the pivot ball is half way in, the setup is OK. Fly, huh?

PBS-systems are a bit more sensitive to crashes because of the bigger leverage forces (like on the pivot ball thread which is screwed into the suspension arm)
Hence these suspensions are normally built more ruggedly than conventional c-hub systems. The Shark 18 Monster is no exception here: Its steering arms could compete with a Team Losi XXX-4 (1:10) buggy.
 

What is a pivot ball suspension?
At the front the suspension has to allow movements in two ways: up and down for the shocks, left and right for the steering.
With conventional c-hub systems these two directions of movement are performed by two separate parts: The c-hub allows vertical movement and inside of it you find the steering arm which can move horizontally. 
The pivot ball suspension uses one single suspension part that is able to move in both axes which is realised by using, well, balls

The steering arm contains two massive ball supports which can be set up without any play by the help of aluminum inserts. Depending on how far the steel balls are screwed into the suspension arms you can adjust the caster – and with a three-ball PBS even the toe-in at the rear suspension.
More on this in the R/C-clopedia!

The suspension arms are made of a more flexible material but this shouldn’t have any negative effects on the whole construction. In order not to overstress the shocks, the arms have lugs on the underside to limit the maximum suspension travel.

Now that we’re talking about shocks: Luckily LRP equipped the Shark 18 Monster with full-fledged oil filled shock absorbers. Alas, they cannot keep up with the excellent quality of the chassis as they are sloppily filled.

But filled correctly (the diaphragm could be a bit bigger too!) they’re really smooth and soft. Unfortunately the manual doesn’t tell about the actual oil that the shocks have been filled with but 20WT/200cps should be just about right.

Also the spring preload needs a bit of help: one clip at each front shock and two at the rear will make the suspension arms stay level to the ground and provide for remarkable 15 millimetres of ground clearance.

As you can see on the pictures on the right the whole suspension can do without e-clips: the hinge pins are kept from falling out by the front bumper or the rear plate respectively. The rear-hub pins are held by a (really firm) press fit.

 



You can be quite inventive when setting up the Shark 18 Monster: The shocks have two positions on each suspension arm and three at the shock tower in order to master any surface that you can think of. The caster of both front and rear suspension can be adjusted while the toe-in remains fixed.

 

 A Centershaft, two diffs, four universals and a few ball bearings
 

Unlike in bigger scale 1/10ths’ or even 1/8ths’ everything could be quite simplyfied for this mini-truggy: Thanks to the stiff chassis there was no need to separate the bevel gears from the main shaft but simply stick them onto the 5-millimetre aluminium shaft. The bearing of the central shaft is realised by the bevel gears and the spur gear so that there remains a bit of flexibility from the plastic chassis.  


Simple and rugged: Thanks to a lot of plug-connections (also at the diff-outdrives) the whole driveline is quickly dismantled. The diff outdrives are made of plastic as well, but thanks to their closed design they do not need any outdrive-saver rings.

 

The bevel gears run smoothly out of the box and without being notchy. Gears and diff innards are packed tightly with sticky grease (which has been removed for the photos, as far as possible)

Contrary to the good impression that the Shark 18 Monster has made so far, you have to ask yourself what LRP might have had in mind while designing their universal shafts: Compared to the four-millimetre aluminum main shaft these three millimetre plastic shafts (which have to transfer three to four times the torque) look rather ‘provocative’ - to put it in a nice way.

The only metal part in the shaft is the drive pin; even the cardan joint is made of plastic and engages with a nearly one-millimetre lug. There would be enough space to make the prop shafts 50 percent bigger.  

"And that works?" – more of a rhetorical question, but we will see!

I definitely like the idea that LRP decided to use the widespread 12-millimetre wheel hex for the Shark 18. So it is no problem to use 1/10th sedan tires when the track allows it. However you will need a screw with a bigger head or a small shim to attach it securely.


 Checkpoint!
 

LRP's Shark 18 Monster – a 1/18th scale truggy with lots of clever details, supreme quality in assembly plus material and ...
… universal shafts that don’t want to have anything to do with the rest of the car; or at least make you want to believe that..

The whole truggy is purpose-built: as simple as possible without compromising stability or suspension geometry. So it doesn’t come as a surprise that the Shark 18 can be almost completely disassembled in about ten minutes.
The quality of the RTR assembly is excellent for the most part: Every screw is tight, the suspension is set up and also the wiring leaves nothing to be desired.
The sloppily filled shocks are a nuisance and with the wing stay I had to find a damaged thread – annoyingly, in the chassis.

Text and pictures by Aaron Banovics
Translation by Markus Simon
This review has been published on www.offroad-cult.org on 02-10-2007.