The shock absorbers included with the RB5 are high quality alloy units, with threaded height adjustment and a re-buildable cartridge system in the bottom containing the seals.
The shocks look pretty much identical to those on the ZX5 to the passing eye, but the real difference is in the cartridge.
The seals are now inserted from below. From top to bottom:- o-ring, spacer, o-ring, spacer. The bottom of the cartridge is sealed with an alloy cap and the last spacer extends through this cap slightly and holds the shock shaft stable. The seals on the ZX5 were held in place with a clip - so this is a distinct improvement in terms of ease.
Shock cartridges are easy to assemble
A tool is provided to install cartridges
the finished shocks!
Bleeding the shocks is a breeze - with the filled shock body upturned, the cartridge is slowly inserted and screwed in place most of the way. The cartridge has a groove in which allows excess air and oil to escape as the shaft is slowly pushed in, then the cartridge can be finally nipped tight with the supplied plastic tool.
Four different pistons are included in the RB5 kit and these are slightly more confusing than what you’d find from Losi or Associated. Those other manufacturers stick to the same number or holes in the piston, and only the hole size varies.
The pistons included with the RB5 come in 2 and 3 hole varieties, with two different hole sizes in both versions.
The shocks are incredibly smooth when built. The spring height adjusters have a large o-ring installed to prevent accidental movement, but even when lightly oiled as per instructions, these height adjusters are quite tight.
Silver springs are included in the kit and are fairly soft. You can use Associated springs which are a slightly smaller diameter, but while the shorter fronts are OK, the rears tend to rub on the shock body – not ideal. Kyosho have a range of springs available but we didn't have any to use on this review car except the kit supplied items, so we ended up opting to go with the Associated springs.
The pistons in the RB5 kit come on plastic trees and need cleaning up with a scalpel. Here you can see the four different pistons - from left to right: 2B - 2C - 3A - 3B. The holes are progressively smaller from left to right whilst the last two have three holes instead of two.
The shocks mount top and bottom with plastic balls, the top being longer with spacers moulded-in. After putting one of the balls from the shock bottom in the top of the shock cap by accident, I found it very difficult to remove without damage - so make sure to get it right first time is the lesson.
You can see the contact with the front shock tower
Stu filed the corner of the tower for more clearance
With all four shocks securely fastened in their 'default' locations - something unusual is apparent (See above). The front shocks rub on the shock tower! This is using the middle hole on the shock tower. Were we to move to the inside hole the shock would be well and truly clamped against the shock tower. The offending item is really the large diameter spring height adjuster which is actually further back than the leading edge of the shock tower. oOps on the part of Kyosho there. We ended up putting a slight bevel on the edge of the shock tower to allow us to use the middle hole without any contact.
The near-finished chassis looks unique, but clearly has a mix of influences from the other two main manufacturers. The front end is slightly 'Losi' style, whilst the rear end has a more 'AE B4' flavour to it. Overall though, the car is far from a copy of any one car out there - more an evolution of the original Ultima Type-R than anything.
The wheels on the RB5 are, as previously mentioned, HEX fitment. This places the RB5 as the only top-level competition 2WD to use such wheels.
The rear wheels are from the ZX-5, but the front wheels are new for the RB5 and are quite wide - such is the current trend toward wide front wheels on 2WD buggies.
The wheels don't come with any holes pre-drilled, and you'd be a fool to use them without holes as this can really help keep the wheels on the ground. You can either use a body reamer like I have or a craft knife to make a couple of decent sized holes.
Tyres are not included.
Fitting electrics in the RB5 is relatively straight forward, and starts with the steering servo. Plastic servo mounts are included, along with shims to get the right positioning. Three different servo horns are included to suit the three main fitments, Hitec, Futaba, Sanwa. Since we were using one of the latest Blue Bird servos, we used the Futaba horn, since they share the same fitting.
A short link needs assembling between the servo horn and the bell crank - once assembled the length shouldn't need changing so it's best to glue this part together to stop it failing at some point.
This link needs snapping onto the bell crank ball stud - this can take a lot of pressure, so we braced the bell crank with a driver under it whilst snapping on the link. (Don't want to snap that steering assembly before hitting the track!)
There are actually 2 sets of battery posts in the kit, the 'proper' ones - item 89 in the manual, and some which are left overs from the ZX5 which are slightly longer. The artwork in the manual shows the longer (incorrect) posts being used even though the part numbers are correct.
The battery tray in the RB5 is longer than a pack of cells, to allow position changes, to affect the balance of the car. A long battery strap tucks under the rear shock tower and clips in mid way down the chassis on the battery posts. A small square of dense foam is supplied to hold the cells in position at either end of the chassis.
The ESC and receiver sit on opposite sides of the main chassis - the receiver on the right and the ESC on the left. There seems to be plenty of room for even large brushless ESCs, with the high sides of the body shell. We fitted the Mtroniks system, coupled with their latest motor - the ESC is very large and comes with a monstrously large capacitor which we mounted on the shock tower (not in the photos). The shell has bulges which should accomodate the highest ESC's with integrated fans.