The Australian 12045 had 14.9/28 front tyres and 23.1/34 rears. Nearly all tractors in Australia over 100hp used those rear tyres, made by the Australian tyre company Olympic. Now that company has closed, the 23.1/34 is hard to find and expensive. The tyre moulds from Olympic were sold to Goodyear and I have managed to buy 2 new Goodyear 23.1/34's for $2050 each. Cheaper than Indian BKW's for $2450 or a Chinese 12 ply for $2500. The tractor has heavy cast wheel centres with Zetor cast into them. Some people save money by putting smaller wheels on the 12045, probably from the 8045. An 18.9/34 tyre can be bought for nearly half the price.