Tracks and Chain Tensioning

Distributor Conference 2006 Workshop

Tracks and Chain Tensioning

•Background•Installation of rubber tracks

–Research–Goals–Variables–Results

•Conclusions/Recommendations

Background info:Chain Tensioners

• 1996R&D work on new tensioner• 1997Introduction of tensioner on

Bigfoot (new model Argo)• 1998Migrated up and down to all

Argo models, Vanguard through Conquest

• 2003Avenger intro. to Distributors• 2004Avenger manufacturing startup

end of January

Background info:Chain tensioner features/benefits:

   Semi-automatically adjust to new “fixed” position

   Extends chain life 2 to 3 times by taking up more “stretch” before touching the frame and also reduces shock loading

   Eliminates chain tensioner “slap” on floor pan during turns

   Eliminates vehicle lurching during turning caused by stretched out chains

Background info:Tensioners currently used on:

• Avenger EFI, Avenger, Response, Frontier, Vanguard 2, Vanguard

• All models since 1998 (’97 for Bigfoot)

Background info:Tracks:

• Since . . . early ’80s as plastic segmented track

• Rubber tracks were desired for increased wear/life/traction

• 2000 – 2002 Centaur All-Season Tracks and Winter Tracks developed and introduced

Background info:Tracks:

• 2004, Jan. – June Development of rubber tracks for Avenger

• 2004, September Introduction of track kit

• 2005, Jan. – Mar.Testing/evaluation of tire sizing and track tension

• 2005, April 4 First Hinge Kits c/w Extensions sold

Background info:Some problems (symptoms):

• Worn tensioner blocks and damaged components

• Premature bearing and flange failures

• Broken axle hubs

Background info:Definitions:

• Chain wear• Chain stretch• Chain windup

• Forward loading• Reverse loading

• Over-tensioning

Installation of Rubber Tracks

(Things your mother never told you.)

Research

• 700 lbs of iron• 223 lbs of driver• 200 meters of dry

pavement • 110 tests• 16 tires• 2 rubber tracks• 1 unfortunate

Avenger

Goals

• Eliminate reverse loading• Reduce chain tension• Avoid track walk-off• Maintain traction

Variables

• Tire size• Tire pressure• Track length• Tire direction

•Chain tension tester was constructed using a load cell

•Tester was mounted onto the frame of an Avenger

•Free-wheel hubs

•Iron weights

•Track Extensions

Test route: Drive 100 meters, turn around, and drive 100 meters back.

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Effect of small variations in tire size with a tight track:

•Blue: Front tire is virtually the same size as the rear tire

•Red: Front tire is smaller than rear tire

•Green: Rear tire is smaller than front tire

Tight tracks = Chain wind-up

Effect of small variations in tire size with a loose track:

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Test 61

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•These are the same tests as the previous slide

•The track has been lengthened by 2”

Loose tracks = Lower chain loads

Effect of adding/removing cargo (tight track):

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Test 85

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•Blue: with 700 lbs

•Red: weight removed

Tight tracks = High drive train wear

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Test 89

Test 90

Effect of adding/removing cargo (loose track):

•Blue: with 700 lbs

•Red: weight removed

Loose tracks = Happy drive train

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Loaded Machine

Unloaded Machine

Actual Circumference

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Inches

Position

Tire Circumference

Measured tire size vs. actual tire size

Red: Measured size

Blue: Actual size on Argo (unloaded)

Yellow: Actual size on Argo (loaded)

Measured size is not the same as effective size!

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Test 110

Test 108

Effect of tire tread direction on rear chain load:

•Red: Tires mounted in standard direction

•Blue: Tires mounted in reverse direction

Reversed middle tires = lower chain loads

Recommendations:

1. Inflate all tires to 5 psi.2. Measure and record all tire

circumferences.3. Install tires as shown in

chart.4. Deflate end tires and install

track.5. Inflate tires as shown in

chart.

For rubber track installation on the Argo Avenger:

Wheel #1 Wheel #2 Wheel #3 Wheel #4

Measured size Smallest Largest 2nd largest 2nd smallest

Tire Pressure 5 psi 7 psi 7 psi 6 psi

Tire Direction Standard Reversed Reversed Standard

Recommendations:

Recommendations

• Track Length: 235” total• Track Sag: 2-3” under middle

wheels

Conclusion:•Reduced chain loads

•Longer lasting chains, bearings and sprockets

•No chain over-tensioning

•No reverse loading•Greatly reduced wear on slider blocks

•Better drive efficiency

Questions?