Radial Ply
Imported tractors are normally fitted with Radial Ply tyres. These tyres are all marked with a Load Index and Speed Symbol on the sidewall. A copy of the Speed Symbol table is below.
However, these merely indicate the tyres maximum carrying capacity and speed at the maximum speed. When it comes to recommended tyre pressures, it would be advisable to either use the tyre pressures as recommended by the tractor manufacturer, or alternatively call in a tyre expert to recommend tyre pressures. This is particularly important when looking at 4 wheel drive or Front Wheel Assist tractors.
Speed Symbol | Speed km/h |
A1 | 5 |
A2 | 10 |
A3 | 15 |
A4 | 20 |
A5 | 25 |
A6 | 30 |
A7 | 35 |
A8 | 40 |
B | 50 |
C | 60 |
D | 65 |
E | 70 |
F | 80 |
G | 90 |
LI | kg | LI | kg | LI | kg | LI | kg |
96 | 710 | 119 | 1360 | 142 | 2650 | 165 | 5150 |
97 | 730 | 120 | 1400 | 143 | 2725 | 166 | 5300 |
98 | 750 | 121 | 1450 | 144 | 2800 | 167 | 5450 |
99 | 775 | 122 | 1500 | 145 | 2900 | 168 | 5600 |
100 | 800 | 123 | 1550 | 146 | 3000 | 169 | 5800 |
101 | 825 | 124 | 1600 | 147 | 3075 | 170 | 6000 |
102 | 850 | 125 | 1650 | 148 | 3150 | 171 | 6150 |
103 | 875 | 126 | 1700 | 149 | 3250 | 172 | 6300 |
104 | 900 | 127 | 1750 | 150 | 3350 | 173 | 6500 |
105 | 925 | 128 | 1800 | 151 | 3450 | 174 | 6700 |
106 | 950 | 129 | 1850 | 152 | 3550 | 175 | 6900 |
107 | 975 | 130 | 1900 | 153 | 3650 | ||
108 | 1000 | 131 | 1950 | 154 | 3750 | ||
109 | 1030 | 132 | 2000 | 155 | 3875 | ||
110 | 1060 | 133 | 2060 | 156 | 4000 | ||
111 | 1090 | 134 | 2120 | 157 | 4125 | ||
112 | 1120 | 135 | 2180 | 158 | 4250 | ||
113 | 1150 | 136 | 2240 | 159 | 4375 | ||
114 | 1180 | 137 | 2300 | 160 | 4500 | ||
115 | 1215 | 138 | 2360 | 161 | 4625 | ||
116 | 1250 | 139 | 2430 | 162 | 4759 | ||
117 | 1285 | 140 | 2500 | 163 | 4875 | ||
118 | 1320 | 141 | 2575 | 164 | 5000 |
Useful notes
Find the very useful technical (and other) information at www.satmc.co.za.
Farmers can use old tyres in a number of ways, says Eastern Cape farmer Roelof Bezuidenhout. These include the following:
- Feed troughs.
- Building walls and fences. This protects animal hides in cases where animals are pushed against fences or run into them. Arranged along the ground at the bottom of a fence, old tyres can keep out burrowing animals (and jackals or other predators which may want to follow).
- Strengthening contour lines and stabilising soil and vegetation.
- Tied together and dragged behind a vehicle, old tyres function as an implement for levelling fields or gravel roads.
Source: Farmer’s Weekly 30 May 2014. See also the article by Joseph, F. & van der Westhuizen, M. listed under the last heading.
Although advanced materials may be used that protect against tyre damage, rubber is particularly prone to absorbing oil, grease, fuel and other solvents, and is further degraded by exposure to heat and light. Therefore, tyres should be kept in a cool, clean and dark area, and away from other machinery such as motors, generators and welders as the ozone emitted by such equipment causes cracks in the rubber and, ultimately, failure of the tyre carcass. Similarly, wash any chemicals off the tyres after using the tractor in spraying operations.
For storing tyres mounted on rims, but not on machinery, reduce the pressure to ten psi and store vertically on the tread. Tyres off rims can be stacked evenly on their sidewalls, but never so high as to distort the bottom tyre.
On a machine or implement in storage for extended periods, block up the vehicle to lift the tyres off the ground. If this is not possible, increase the standard tyre pressure by 25% to reduce deflection and move the vehicle periodically.
Source: adapted from an article by Goodyear which appeared in Pula-Imvula (a magazine put out by Grain SA), January 2009.
Role players
Websites and publications
- Southern Africa Treads Liana Shaw (Editor) Visit www.satreads.com.
- TYRE & RUBBER Recycling www.tyreandrubberrecycling.com
- Each company involved – see above – has a website and manuals, which are usually beefed up versions of what is on their website.
- Other publications (usually car ones) carry tyre-related articles every now and then.
SOME ARTICLES
- Taylor M. 2023, June 21. “Big changes for South Africa’s tyre manufacturers – Here’s what they’re doing”. Top Auto. Available at https://topauto.co.za/news/79512/big-change-for-south-africas-tyre-manufacturers-heres-what-theyre-doing
- Burger S. 2023, May 3. “Tyre recycling industry body aims to support green procurement”. Engineering News. Available at https://www.engineeringnews.co.za/article/tyre-recycling-industry-body-aims-to-support-green-procurement-2023-05-03
- Burger S. 2023, February 15. “SATMC to focus on proactive steps to combat waste tyres, industry challenges”. Engineering News. Available at www.engineeringnews.co.za/article/satmc-to-focus-on-proactive-steps-to-combat-waste-tyres-industry-challenges-2023-02-15/rep_id:4136
- Burger S. 2022, July 29. “Increased import duties will help local industry compete against dumped goods – SATMC”. Engineering News. Available at www.engineeringnews.co.za/article/increased-import-duties-will-help-local-industry-compete-against-dumped-goods-satmc-2022-07-29
- Cloete S. 2020, November 24. “The many benefits of good tyre traction”. Farmer’s Weekly. Available at www.farmersweekly.co.za/agri-technology/machinery-equipment/the-many-benefits-of-good-tyre-traction/
- Venter I. 2019, November 14. “Second-hand tyre survey shows 61% are not fit for use”. Engineering News. Available at www.engineeringnews.co.za/article/second-hand-tyre-survey-shows-61-are-not-fit-for-use-2019-11-14
- Phillips L. 2019, July 27. “Technology improves efficiency of agri tyres”. Farmer’s Weekly. Available at www.farmersweekly.co.za/agri-technology/machinery-equipment/technology-improves-efficiency-of-agri-tyres/
- Frankson L. 2019, March 14. “REDISA commits to reviving operations”. Available at https://infrastructurenews.co.za/2019/03/14/redisa-commits-to-reviving-operations
- Venter, J. 2019, February 6. “Choosing the best tyres for your bakkie”. Farmer’s Weekly. Available at www.farmersweekly.co.za/agri-technology/motoring/choosing-best-tyres-bakkie/
- Joseph, F. & van der Westhuizen, M. 2019, January 13. “How old tyres can stop soil erosion in its tracks”. Farmer’s Weekly. Available at www.farmersweekly.co.za/crops/field-crops/old-tyres-can-stop-soil-erosion-tracks/