What I used
- A file
- TM-13 Drive Hub Set
- LA-45 Alcyon’s Shapeways ZX-Sport pulley [link]
- TM-12 Slipper Plates
- TM-19 Wave Washer Set (or an M8 sized alternative or spring)
- LA-5 Limiter Collar
The Lazer ZX-Sport has always been a favourite of mine for modifications. Although the Kelron chassis is underrated, the majority of parts is shared with the Lazer ZX-R. It’s a fantastic based if you’re going to get for example a Fibre Lyte carbon chassis, shock towers and other plates. The other part you’re probably going to update is adding a slipper setup.
While the parts are getting hard to find, my first foray into modifying the ZX-Sport is documented here.
The standard ZX-Sport layshaft setup
The Lazer ZX-Sport uses the Triumph layshaft with a different pulley and a plastic hub. The pulley is a single piece double pulley where both front and rear belts hook onto. It slots directly onto the flat piece of the Triumph layshaft. The plastic drive hub also slides over a flat part of that layshaft, with the LA-2 spur being directly bolted onto the hub.
These plastic parts form a fairly weak part of the setup. The torque can be a bit much when using a very strong motor, and the lack of a slipper will have jolts from landings and rough terrain transferred quite abruptly through the parts. The flat parts of the plastic can be worn out quite quickly.
Slipper setup using the improved parts
Although the parts needed are quite limited, and you could just go with adding the Triumph slipper setup, I would recommend replacing the Sport pulley with the above suggestion. The Sport pulley is, as mentioned, a weak spot: the flattened part only runs halfway up the part. Alcyon’s pulley has a flat part that runs 10mm further inside, making it a lot stronger.
Of course, this means you will have to extend the flat part on the Triumph shaft by 10mm. Get your file ready. I did this by hand.
Slipper pads
TM-12 slipper pads are a wear item on this setup but cutting your own is an option. In this case I’ve used a vinyl cutter to cut the right shape out of 0.5mm compressed Artein gasket paper. I’ve also tested cork which is quite thick, but the blue paper doesn’t need a lot of tension to grip quite well so it’s easy to adjust.
