Quote:
Originally Posted by Naushad
Terry has kind of covered this on tamiya club forum
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As searching on TC seems harder than it was, here's a cut and paste of it.
The first Lazer was the ZX, released in 1989, with a 2 piece top deck and belt cover that was also the chassis stiffener. It was also fitted with a centre ball differential on the layshaft and gear diffs front and rear. The centre diff had a one way clutch built in which meant it only worked when the front wheels were turning faster than the rears (so while cornering if it was full 4WD the front wheels could turn faster) which meant if the front wheels lost grip when accelerating all power went to the front end. The top deck was in two strips either side of a plastic moulded belt cover which also acted as a chassis spine which added a lot of stiffness to the chassis, a lot of people removed the belt covers then discovered the two piece top deck meant the chassis flexed way too much. Shocks were mounted on black anodised alloy shock mounts and the rear wing mounted on the shock tower support using Optima Mid wing mounts. It came with gold short front shocks and 2" wheels and tyres, the same wheels and tyres as the Mid Custom. All other cars came with 2.2" wheels and H pattern tyres. No turnbuckles, straight centre steering link and 0.6 module 88T spur gear. Battery straps held down by body posts with body clips, all later cars used posts which the straps clipped on to and you squeezed to remove the straps.
The ZX-R was released in 1992 with a one piece top deck, medium length gold front shocks, ball diffs and a slipper clutch instead of the centre diff. The change to a slipper also included a change of spur gear to a 48dp 100T spur. The suspension geometry was the same as the ZX as the front top link used a special long ball joint to attach it to the outside hole on the front uprights, but it now included turnbuckles. A new centre steering link with the ends angled forwards improved the ackermann settings to give more steering than the straight ZX link. Shock mounts were now fibreglass and the wing was mounted on the shock mount using Triumph wing mounts instead of the Optima Mid wing mount that was used previously. It was also the first Kyosho 4wd to be fitted with 2.2" wheels and the H pattern tyres.
1992 also saw the release of the ZX-Sport. It used the same body as the ZX-R and was a low cost version. It had the same alloy shock mounts as the ZX but without the anodising to harden them. To cut costs it had a moulded flat plastic chassis and top deck, Kyoshos standard plastic oil shocks and the 0.6 module ZX spur gear screwed to a plastic mount which replaced the slipper. It also had an MSC.
1994 they introduced the ZX-RR. The obvious difference was the teflon coated Ultimate shocks instead of the gold ones, with different fibreglass shock mounts as well. The slipper clutch was also a different design which Kyosho called the hyper clutch, with a coil spring to tension it and the spur gear bolted onto outside of the clutch itself instead of being fitted in the middle of the slipper clutch. The suspension geometry was also redesigned, new front uprights with a second pivot pin hole drilled through the upright to increase castor and the front top link fastening to a bolt through the top kingpin instead of the outboard mount used previously. To balance it out the rear suspension had bolt on extensions to the uprights to change the geometry as well.
The ZX-RR also has a redesigned chassis that moves the batteries further back to improve the weight distribution. This also meant a new top deck, new bulkhead in front of the motor that is similar to the original but with a curve cut out to clear the motor, new U shaped rear gearbox brace that wraps around the motor and a new shorter motor mounting plate as the bulkhead just in front of the motor was moved back. The motor also bolted straight on to the mounting plate, previous cars had a small slotted motor mount that bolted to the main plate as a spacer.
Some markets got the ZX-R Mark2 instead of the ZX-RR. It was the ZX-RR without the expensive parts. It had the ZX-RR chassis, top deck and bulkhead to move the batteries back, the ZX-RR kingpins and rear suspension mods and the ZX-RR shock mounts, but was still fitted with Kyoshos gold shocks. It still also had the ZX-R slipper clutch, not the ZX-RR hyper clutch, but the ZX-R slipper clutch spring washers were replaced with a coil spring.
In 1996 the ZX-RR was replaced by the ZX-S, a car that was only available to order in Japan. Very few parts remained of the ZX-RR with only the general layout the same. Complete new gearboxes and transmission, one piece carbon chassis with a kick up moulded in, Losi shocks and Yokomo wheels. The wishbones (now carbon reinforced), uprights, driveshafts and diffs are the only parts connected with the Lazer ZX-RR.
In 2000 they updated the ZX-S with the ZX-S Evolution. The biggest difference was the 3 piece chassis with the front kick up being a separate alloy plate which dovetailed into the front of the chassis, much cheaper and easier to produce than a built in kick up. Also had new suspension uprights. It came with Kyosho Pro shocks and wheels.
There was also the budget models the Lazer Alpha and Lazer 2000. These weren't part of Kyoshos line of race buggies. They kept the same chassis and suspension layout, but had a moulded tub chassis and all plastic parts were replaced with softer budget versions with the parts not being glass reinforced like the race versions were. The drivetrain was the same as the ZX-Sport, one piece plastic layshaft with gear diffs and back to 2" Mid wheels and tyres.