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Proxes R888R

Developed for the track, NEW Proxes R888R delivers supreme dry handling.

With enhanced steering feel and response, combined with higher stabilty on the throttle, Proxes R888R allows track users to carry higher speed through corners for faster laps.

Faster cornering, longer lasting and more consistent, Proxes R888R translates power into lap times.

Outer Tread Area

Large tread block on outer area
Enhanced dry cornering
Increased lateral limit

GG compound

GG Track compound
- Fast warm up time

Wide Centre Rib

Wide centre rib
- Precise steering response

CAUTION! The rubber compounds used in these tires have unique properties that can cause them to lose some of their flexibilty when used or handled in temperatures below -9°C. This loss in flexibility can lead to potential cracking and other damage to the tire.

The example on the right illustrates the potential damage.

To minimise the chances of this happening, consumers and installers are advised to follow the instructions below:

1. Do not move or operate a vehicle fitted with these tires in temperatures below -9°C.
2. Avoid moving these tires in temperatures below -9°C
3. Before mounting or dismounting, store these tires for at least 24 hours in a temperature controlled environment of 200C or warmer and always inspect for signs of cracking before mounting. Never use tires that have cracked.
4. Remove the wheels from the vehicle and deflate the tires to half the normal air pressure during prolonged periods of inactivity or for storage.

Like its predecessor, Proxes R888R has a stiff race construction and a race tread compound. The optimum tread temperature range is between 71C and 105C measured using a probe type pyrometer, and ideally a maximum difference across the tread of 15C. The maximum hot pressure should not exceed 40psi.

Camber angles up to 5 degrees negative (normaly between 1 – 3) are permissible but the final setting will depend on tread temperatures. It is advisable to have as much positive castor as practical as castor induces a beneficial camber change during cornering.
It is recommend that the tires be put through a heat cycle before hard use, this will scrub them in and remove any mold release agent.
Initially, tire pressures should be set based on the weight of the car. The following table is a guide to intial setup. You should always begin at the higher pressure and never set a pressure below 17psi cold. Too little pressure can lead to over deflection of the tire and subsequent failure. After running in operatinal conditions, pressures can be adjusted to achieve optimum working temperature.
Initial Setup Guide
Very Light < 800kg
17 - 22 psi
22 - 29 psi
Light 800kg - 1000kg
20 - 26 psi
24 - 32 psi
Heavy 1000kg - 1400kg
23 - 27 psi
28 - 40 psi
Very Heavy > 1400kg
27 - 35 psi
37 - 40 psi
As a tire gets hotter the pressure increases, this is due to the moisture in the air. The cold pressure you set to achieve the desired hot pressure will depend on the conditions on the day i.e. ambient and track temperature, wet or dry. If the day/track is cold you will need to start with a higher cold pressure as the tire will not get as hot therefore the pressure increase will not be so great.
Hot pressures must be balanced side to side. Once the tires have cooled, normally there is a difference in pressure side to side. For example, when racing on a right hand track you, the offside pressures will usually be higher than the nearside.
Changing hot inflation pressures by small amounts can be used to fine tune the handling of the vehicle.
Desired performance change Potential Adjustments
Reduce Oversteer
Reduce rear pressures or increase front pressures
Increase Oversteer
Increase rear pressures or reduce front pressures
Reduce Understeer
Reduce front pressures or increase rear pressures
Increase Understeer
Increase front pressures or reduce rear pressures
Achieving the required tread temperatures will depend again on the conditions on the day i.e. ambient and track temperature, wet or dry.
Competitors sometimes say “My tires started to go off towards the end of the race”, this is usually due to the tread getting too hot.
The tread temperatures are constantly changing throughout a race, hotter when cornering and cooler when on the straights and cooling even more when slowing to come into the pits. Therefore the temperatures you record in the pits will be lower than the actual temperature during a race. A temperature meausurement in the pits within the range given in the initial setup table above could mean the tire temperature is too high during the race.
Increasing your tire pressures may cause your tread temperatures to increase, more pressure stiffens the tire’s casing which results in the tread having to do more work, resulting in the tread getting hotter. Lowering the pressure may cause temperature readings to decrease. However, you should be careful not to allow the tire inflation to fall below the pressure necessary to carry the weight of the vehicle. As noted above, too little pressure can lead to over deflection of the tire and subsequent failure.
Inevitably changing one setting may affect the overall balance of performance of a vehicle. The optimum set up of a race car will always be the best compromise between all of the adjustable parameters to suit the conditions on the day.

Tire Size Rim Diameter Load Speed Index
185/60 R13 13 80V
205/60 R13 13 86V
185/60 R14 14 82V
195/55 R15 15 85V
195/50 R15 15 82V
205/50 ZR15 15 86W
225/50 ZR15 15 91W
235/50 ZR15 15 94W
195/50 ZR16 16 84W
205/55 ZR16 16 94W XL
205/50 ZR16 16 87W
205/45 ZR16 16 83W
225/45 ZR16 16 89W
245/45 ZR16 16 94W
205/50 ZR17 17 89W
205/45 ZR17 17 84W
205/40 ZR17 17 84W XL
205/40 ZR17 17 80W
215/45 ZR17 17 87W
225/45 ZR17 17 94W XL
225/45 ZR17 17 91W
235/45 ZR17 17 94W
235/40 ZR17 17 90W
255/40 ZR17 17 94W
225/40 ZR18 18 92Y XL
235/40 ZR18 18 91Y
245/40 ZR18 18 93Y
255/35 ZR18 18 90Y
265/35 ZR18 18 93Y
275/35 ZR18 18 95Y
295/30 ZR18 18 98Y XL
235/35 ZR19 19 (91Y) XL
265/30 ZR19 19 89Y
295/30 ZR19 19 100Y XL
305/30 ZR19 19 (102Y) XL
285/35 ZR20 20 (100Y)
315/30 ZR20 20 (101Y)

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