Footwear Traction Tool

Choose Property

Brand	Shoe	Traction Type	Peak Friction Force (lb)

Babolat	Propulse Fury	Forward	668 (lb)
Prince	T22 Lite	Forward	688 (lb)
Yonex	Eclipsion	Forward	699 (lb)
Asics	Gel-Game 5	Forward	668 (lb)
KSwiss	Knitshot	Forward	685 (lb)
Diadora	Speed Blushield AG	Forward	689 (lb)
Nike	Zoom Cage 2	Forward	687 (lb)
Head	Nitro Pro	Forward	686 (lb)
Asics	Gel Resollution 7	Forward	704 (lb)
KSwiss	Hypercourt Express	Forward	665 (lb)
Adidas	Adizero Ubersonic 2	Forward	659 (lb)
Wilson	Glide Comp	Forward	672 (lb)
Nike	Air Zoom Ultra React	Forward	686 (lb)
Wilson	Amplifeel	Forward	694 (lb)
Wilson	Rush Pro 2.5	Forward	690 (lb)
Head	Revolt Pro 2	Forward	665 (lb)
Nike	Zoom Vapor 9.5 Tour	Forward	632 (lb)
Adidas	Barricade 17	Forward	692 (lb)
Prince	Warrior	Forward	646 (lb)
Lotto	Stratosphere	Forward	699 (lb)
New Balance	996	Forward	634 (lb)
Adidas	Barricade 2016	Forward	646 (lb)
Asics	Gel Court FF	Forward	709 (lb)
Asics	Gel-SolutionSpeed	Forward	676 (lb)
Babolat	Jet AC	Forward	706 (lb)
Babolat	Jet All Court	Forward	662 (lb)
Asics	Gel-Resolution 6	Forward	624 (lb)

Key

All linear and rotational comparative data are accumulated from tests using a normal force of 150 lb and a horizontal shear energy of 16 J.

Static Coefficient of Friction: Peak traction force (just prior to relative motion between court and shoe) divided by normal force (force pushing court and shoe together). This is the number most often used to compare maximum traction between surfaces. Dynamic traction is measured after the shoe begins sliding and is the force necessary to sustain sliding divided by the normal force. Dynamic traction is not reported here.
Peak Traction Force: Peak horizontal reaction force achieved between the shoe and the court when 16 J of energy is applied to the court. Peak traction is a maximum at the instant before relative motion begins between surfaces. The traction force resists relative motion.
Load Rate: Peak traction force divided by time to peak force. Very high loading rates are associated with high impact shock to the joints.
Shear Deformation: The distance the top and bottom of the shoe move (stretch) relative to each other prior to relative motion between court and shoe.
Shear Stiffness: Peak traction force divided by shear deformation. This will influence the comfort of the stopping/sliding motion.
Slide Distance: The distance the court and shoe moved relative to each other.
Peak Torque: For rotational traction: Peak eccentric force times distance from heel to axis of rotation in middle of forefoot.
Rotation Angle: Angle court and shoe rotate relative to each other during application of force.
Normal force: Force pushing shoe and court together — 150 lbs (667 N).
Horizontal impact energy: Energy of the pendulum head as it hits the court parallel to the shoe-court contact surface — 16 J.

For more detailed information:
- Tennis Shoe Traction
See also:
- TOOL: Footwear Cushioning Tool
- EXPERIMENT: Tennis Shoe Cushioning

Explanation

Linear Traction. A 4.25-inch forefoot portion of a tennis shoe is attached to a stationary mount. The mounting structure presses the shoe and court together with forces from 0 to over 2200 N (500 lb). A Decoturf (California Sports Surfaces) surface is securely mounted on a 3/8-inch thick aluminum plate. This court surface is free to move linearly in one direction, gliding on a bed of low friction ball bearings. The aluminum plate containing the court surface is impacted by a weighted pendulum head with an effective mass of 3.1 kg and dropped from a height to achieve impact energy of 16 J. The resulting impact force between the pendulum head and the court plate is measured by a force gauge on the pendulum head. The linear distance travelled by the court under the shoe is measured by a linear variable differential transducer (LVDT) attached to the court. Figure 1 shows a schematic of this arrangement. (For more details: Tennis Shoe Traction.)

Figure 1 — Simplified view of the translational traction setup.

Rotational Traction. The setup for the rotational traction tests is exactly the same except that the pendulum hits the court eccentrically so that the court rotates under the shoe. The axis of rotation is located directly under the forefoot section of the shoe. Figure 2 shows a schematic of the apparatus. (For more details: Tennis Shoe Traction.)

Figure 2 — Schematic of the rotational traction setup.