J Track Reference

“J’ type rubber tracks – The biggest step forward since the invention of the wheel.”

Ted Lockwood ( DTN Equipment – Queensland )

For 35 years I have worked with the problems of rubber tracks and have seen many failures associated with the overlap bonded join. This has highlighted in the more recent interchange ability of rubber and steel to some models without any recoil modification and the track being expected to absorb the impact of the steel design. Since establishing in Australia four years ago from New Zealand I have seen this problem accelerated with the high temperatures of Queensland . I saw the opposite problem in NZ with cold rubber temperatures and water corrosion of the cording to some makes.

Recently I tested recoil functions to six different models of mini machines within the 3 – 4 ton range and found many inconsistencies in operation against the rubber track manufacturers working tension parameters. This in some cases is with recoil tension operating above the track manufacturer’s recommendation by over 50% when working in some conditions. This error is where the recoil change has been overlooked in change or setting when the track change to rubber is carried out. Most machines are with softer recoil for rubber track and greater free length to allow the track to slip in sprocket drive whilst recoiler is with some travel left. In some makes the recoiler is fitted with a spacer when steel track is installed to limit the travel of the recoiler . I have found these spacers still fitted with Rubber track use.

The track failure will always occur to the weakest point which is the moulded overlap join if the tension exceeds the design. This can be compounded with manufacturer bonding conditions such as vulcanising temperature change or factory humidity levels. The other is the type of cording used and its gauge. At the join all cords are with the identical overlap and the reason is that in manufacture the track is made in same flat mould and cut with required number of links In another process the track is joined.

The J’ TRACK is without this join as the inner cords are continual stainless wire cord wound from a point one side to the other. Different size track is with different mould. This is a more expensive method of manufacture, yet with an increase of over 40% in longitudinal strength. This will allow the track to stall at traction motor relief drive setting within the design strength of the track in most cases. Many manufacturers have designed to this track and after market suppliers with overlap joined type are experiencing failure at the customers expense.

WHY THE CHANGE? Because the rubber track is being improved to allow for abuse and use beyond original intended design.