16 October 1998

JOHN DEERE 6810

ONE thing soon became clear – Deeres Triple Link brings new calm. All unsprung 6010 series driven by the test team have been hard bouncers on the road. But in this 6810, even with its system switched off courtesy of a non-standard external valve, the pitching had gone. Something fundamental had changed, and our guess puts the systems long centrelink at the root of it (see diagram). Buyers who choose not to go for front suspension dont get this set-up.

Pulling the test trailer on smooth tarmac generated just a mini-nod at 35-36kph, which died completely on adding suspension. Moving to cobble and switching suspension off forced a slow-down from 40kph over the worst sections, but with Triple Link back in play it seemed a road mending gang had been busy; suddenly, comfortable full-steam travel was no problem.

Absolute comfort is still compromised by plenty of cab side-to-side shake. And on any going the 6810s steering isnt too bright; the tractor always wanders more than the opposition, and with a plough on the back things only get worse.

In the field the Deeres front suspension showed no traction or driver comfort benefit using the plough, but did with a cultivator in the ground. Unsprung, the operator can put up with 12kph work for an hour or so, if not all day. Switching in suspension doesnt so much generate a quantum comfort leap as tip the balance towards consistently speedier work, a trick it achieves by taking the sting from ridges and ruts.

The 6810s long nose plunges more than others, its suspension feels the softest of all and theres plenty of travel to keep the wheels riding the contours and gripping. Only severe provocation (like driving full tilt into a furrow wall) forced the axles rubber bump stops into play, and only hard, deep ruts had it clattering the check chains on full extension.

Deere suggests that moving the front axles point of pull back to the centre of gravity cuts front end hop when pulling hard, particularly uphill. Well, the polders arent the best place to confirm that one. But we forced a fight by dropping the cultivator deep into a dry, panned headland, making the unsprung front end really dance as the wide Michelins bit and squirmed. And the makers claim is right. Adding suspension kept the wheels in noticeably better touch with terra firma, potentially improving grip and giving both driver and tractor an easier time – a likely workrate booster in hilly areas.

&#42 Science says: Mr Good Average

Measurements show the Deere rides either a little better than average or spot-on it, with and without front springing or the plough. With Triple Link switched off the cab sees much less vertical disturbance than the Cases but rather more than the Deutz, probably as the Agrotrons cab suspension is filtering shocks out. Switching on front suspension quells nose movement to much the same extent as the Case and Deutz systems, and much better than in the Fendt.

Adding an 1800kg plough sees the unsprung story repeated. Then with springing switched on the Deere falls exactly on the four-tractor average, with its cab taking shocks that are little lower than the Case or Fendt but not as low as the suspended-cabin Deutz.

&#42 Conclusion

A stable system delivering good results in all test sections. Front axles rearward-placed pulling point a likely traction plus.

&#8226 Setup: twin rams/accumulators on solid axle, counter-pressure circuit, Panhard rod.

&#8226 100mm total travel, 11deg oscillation

&#8226 Central link under tractor moves pulling force back to tractors centre of gravity

&#8226 Price premium: £2619-£3868

&#8226 Available on: 100hp-175hp models