Wheels & Tyres Anthony Davison Anthony Davison Welcome to Neath Port Talbot College! NPTC Vehicle Fitting Tyres

Tyre Type Tyres come in many sizes and tread design. The most common type of tyre today is a RADIAL tyre. Some years ago there were also tyres called cross ply.

Tyre Tread Patterns Differing Tread Patterns

Radial Tyre Design Radial Tread Patterns The plies on a Radial tyre are set at 90 degrees to the bead Plies are set at 90 degrees to the bead

Cross Ply Design Cross Ply tread plies are set at 45 degrees to the bead. Cross ply tyre are not as common today as they once were Tread plies set at 45 degrees to the bead

Asymmetric Tyre Multiple tread Pattern When cars are expected to perform at high speed the you must ensure they keep in contact with the road surface !! Asymmetric tyres have multiple tread patterns. The outer pattern has good road contact and is excellent at aiding cornering. The inner tread pattern has more grooves and excels in dispersing water from under the wheel. Together the whole tyre gives an all round better performance. You must fit the tyre in accordance with the manufacturers guidelines. The tyre will state which is the inner and outer side.

Rotational Tyre Direction of Rotation This type of tyre is designed to rotate in the forward direction . As you can see the tread pattern is angled in a manner as to cut through water very effectively. Again you must read the fitting instructions carefully. This type of tyre when fitted to the wheel can only be fitted to one side of the car If they are required to go from N/S to O/S then the tyre needs to be removed and turned around.

Differing Types of Tyre Bias Type Tyre Basically a hybrid between cross ply and radial tyres a bias belted tyre can probably best be described as a crossply tyre with some radial tyre attributes. It uses a crossply construction casing overlaid with belts set at an angle to the casing (radial belts are perpendicular to the casing). Rarely found on cars in the UK they are mainly restricted to use on some American vehicles.

Run Flat Tyre RFT The major safety benefit of Run Flat Technology or RFT is that it enables a driver to maintain control if a vehicle in motion suffers a rapid loss of tyre pressure. In addition, RFT tyres enable the driver to continue the journey within specified speed and distance limits, avoiding the need to replace the wheel on the side of the road. Sidewalls can be six times thicker than traditional tyres. As a result the manufactures say that “Runflat” tyres can be driven at speeds of 55-miles or 80-kilometers per hour for up to 200 miles or 300 kilometers in a deflated condition before being damaged. They normally have a directional tyre pattern which must be fitted in such a way that the tread rotates only in one direction. Specialized equipment is needed to fit Runflat tyres as the sidewalls are stiffer and thus not as pliable when fitting.

Space Saver or Temp Spare Wheel Space saver wheel must be used in an emergency. They must travel than faster than approx 50mph and should only travel up around 50 miles max They are used to give the driver maximum luggage space

Tyre Wall Markings 175/70 R 13 82 T 175 The tyre section width in millimetres 70 The aspect ratio in % (the height of the sidewall divided by the tyre's width) R Denotes the tyre's construction type - in this case it's a radial 13 Rim diameter in inches 82 Load Index T Speed Rating

Aspect Ratio The tyre aspect ratio is the term given where the height of the tyre wall is described as a percentage of the tyre width I.e. an aspect ration showing 60 on the tyre wall, is stating the wall height is 60 percent of the tyre width which Could be 165 for example W = 165 cm H = 60% of 165mm

Load Index & Load Index

Speed Rating Speed Rating H rating is one of the most popular Anthony Davison Speed Rating Speed Rating H rating is one of the most popular With a speed of approx 130mph. NPTC Vehicle Fitting Tyres

Legal Requirements of Tyres Minimum Tyre Tread

Legal Requirements of Tyres OFFENCES CAN RELATE TO:     TREAD DEPTH - a tyre worn below the legal minimum. MIXING - an incorrect mixture of radial and cross ply tyres. INFLATION - a tyre not inflated to make it suitable for the purpose to which the motor vehicle or trailer is being put. CUTS - certain long and deep cuts as specified in regulations. LUMPS, BULGES OR TEARS - caused by separation or partial failure of the tyre structure. EXPOSED PLY OR CORD UNSUITABILITY - regarding the use to which the motor vehicle or trailer is being put or to the types of tyres fitted to its other wheels.

Tyre Pressures Tyre pressures Tyre pressure should only be checked when the tyres are cool. Checking tyres after a long journey can give an increased reading of approx 4 psi. This is due to the heat of the tyre causing the air in side to expand. Tip Always set a spare wheel at 6 psi over inflated. It is easier to let air out than put air in at the roadside.

Removing and Refitting a Tyre Removing & Refitting a Tyre Deflate the tyre Break the bead seal Lift tyre bead and rotate wheel lifting bead of wheel for both inner and outer bead Lubricate new tyre beading to ease fitting Insert air up to approx 40 psi Ensure bead is sitting correctly, Deflate to correct pressure

Factory Fitted Tyres YouTube - Tyre Fitting Machine Anthony Davison NPTC Vehicle Fitting Tyres

Puncture Repair Plug & Patch Remove tyre from wheel Remove nail etc and inspect damage Assess if repair can be carried out and is cost effective Ream out hole to plug recommended size Buff up inner section to ensure adhesive has a key to stick to Apply adhesive Insert plug and pull through Rub down patch to ensure a good contact is made Cut of end of plug flush with tyre tread.

Wheel Balancing Balancing Wheels Set up balancer to accept wheel dimensions Ensure wheel is fitted correctly Lower guard and allow to rotate Assess weights required and fit at TDC (top dead centre) for both the inner and outer edge of the wheel

Balance Weights The weights are marked with their Balance Weights weight in grams and tap on to the wheel rim On fixing the weights the test should be carried out again to ensure the readings are now zero

Tyre Fitting Equipment Tyre Fitting Machine Tyre lever arm Wheel locking device Bead breaker

Tyre Fitting Equipment Wheel Balancer Display screen Weights storage Safety cover Wheel locating arm

Tyre Fitting Equipment Air Compressor Pressure Gauge Water drainage tap

Tyre Fitting Equipment Air Gun & Torque Wrenches Due to condensation turning to water you must oil the air gun on a regular basis to eliminate corrosion Torque wrench to ensure wheels are tightened to manufactures setting Always reset to zero when not in use

Tyre Fitting Equipment Tyre Pressure Gauges Remember to check tyre pressures when the tyre is cool !!

Disposal of Industrial Waste BS 14000 British Standard 14000 is a law regarding the disposal of Hazardous waste. All used tyre must be disposed of in line with the guidelines set out under this law. All tyres must be disposed of by an APPROVED WASTE TYRE company and the powers can ask to see records of the correct way in which you would dispose of old tyres. There can be heavy fines if this law is abused in any way.