Arrow Launches New X2 Cadet / Rookie Kart
TweetArrow has launched their much anticipated X2 Cadet/Rookie kart. The new chassis has been twelve months in the making and incorporates the best of the two previous X1 models by introducing an adjustable wheelbase. The new machine carries the popular aggressive X2 look.
"In 2010 we offered the market two variations of a Cadet-Rookie kart" DPE Research & Development Manager Bart Price said.
"This was to cater for the vast difference (in size) between Cadet and Rookie drivers, but this lead to many customers believing that they had to have both the 900 and 950 wheelbase models to be competitive at different tracks and conditions.
"We believed that this was an unacceptable requirement for the karter and the decision was made to develop a single model capable of delivering the results of the previous two karts."
ADJUSTABLE WHEELBASE
Forty millimetres of adjustment in the wheelbase allows the kart to cater for a vast variety of drivers, from eight year old Cadets through to bigger Rookie drivers.
Above: Wheelbase can be adjusted by moving the rear axle. There are three 20mm increments allowing adjustment in a wheelbase from 905mm to 925mm and 945mm.
"These drivers can vary by over 40cms in height and 15kgs in weight" Price explained. "We have found that the adjustable wheelbase enables you to extract the most performance from the kart all the way through ones Cadet and Rookie driving career.
"It’s not only with various driver sizes that the adjustable wheel base has seen improvement, but also when setting up for various track layouts. During development we have significantly improved performance of the kart by adjusting the wheelbase for tight & twisty tracks versus fast open flowing circuits.
"The shorter wheelbase makes the kart change direction faster using a smaller arc resulting in a sharper and more direct turn-in for a late apex, which is required on a tight & twisty track. By extending the wheelbase this makes the kart much more stable on faster corners, thus allowing the driver to keep the kart's momentum for optimum speed and lap times."
Above & Below: Arrow’s unique quick-change rear sprocket hub, adjustable wheel base & black 30mm rear axle
RAIL POSITIONING & TUBE TENSILE STRENGTH
Changes to the rear rail position and material played a major part in reducing the amount of track the kart uses by offering better side bite which enables a narrower exit off the corner. "In fact, when compared to the X1 models, we found the new X2 used up to 2.65m less track around a circuit like Todd Road" Bart said.
Whilst the new bearing hanger system looks softer, Arrow has moved to a stiffer steel that is imported from Japan and offers two and half times the strength of the previous material.
"We also now have mounts placed on both sides of the bearing flange as compared to the X1 model’s single sided mounting. This places the new X2 bearing flange mounting in double shear and improves the overall strength."
Above: The centre cross rail, which is in a different position, retains the split section from the previous model as it helps make the kart more forgiving for the smaller drivers.
FRONT END GEOMETRY
The front end geometry has changed with increased caster to improve turn-in, which was a significant goal during Arrow's development.
"We have also improved the exit speed off tight corners which is very important when dealing with the low power of the Cadet and Rookie engines. At first, the changes made the kart a little nervous on entry to the corner but by fitting the new steel 17mm stubs axles we have been able to eliminate the nervousness by decreasing the ackerman that occurs when you increase the steering lock on turn-in."
Above: Multiple steering arm pickups on the stub axle allow variable ackerman effect and steering rates
Above: The X2 has a removable front bar
Above: There are two pedal positions available on the Cadet/Rookie X2. The pedals are fitted behind the main front rail in this photo, but there are holes in the front crash hoop to locate them in the traditional position for when the driver grows taller.
BRAKE SYSTEM
Arrow has decided to use a new smaller brake caliper & brake disc on the Cadet/Rookie X2.
"Our development drivers all reported better feel than the previous brake system, enabling better modulation during the braking phase. Also, moving to the smaller brake disc has reduced rotating mass and reduces the risk of the disc being bent in the event that the driver drops a wheel off the track."
Above: X2CR braking system with a redesigned caliper and smaller brake disc. Significantly, the caliper is mounted to the alloy bearing flange, meaning no adjustment is needed when the wheelbase is changed as the brake moves with the axle.
STEERING
The Cadet/Rookie X2 comes with the new design KG steering wheel used on the other X2 models. This new design is slightly larger diameter than the previous model at 320mm vs 330mm and has been proven to improve the steering input by the driver due to less physical effort.
Above: Wider diameter, flat top and bottom steering wheel
Above: Arrow’s unique steering bush with clamp for simple front end alignment
Arrow used five different prototypes during the development phase of the X2 and made between two & five modifications to each of these designs during the testing period.
The testing ran over ten months, beginning in September 2011 and ending last month. It was conducted in Victoria, New South Wales, Queensland and Western Australia at numerous circuits in each of those states.
Drew Price Engineering would like to thank the following drivers & crew for all their hard work during the development of this new kart which has already started dominating the Cadet and Rookies classes: Dylan & Mark Hollis, Nathan & Craig Williams, Sam & Greg Dicker
