Ended up with 2 new tires from Cat - over $2000 Canadian each; in researching was told could not update; tire dealer also said foam would not have saved tire-probably 30 year old tire. Now have used spare if needed. Next issue is track alignment -can't believe the shim procedure they use; both hard to get at and hard to do on the older ones. Have to remove track and tires, then unbolt front axle stub; reshim and try again to see if aligned. Some engineer was out of his mind when he designed that. Never thought of that issue when I bought the old Cat as Claas track alignment is so easy. Any advice on ways to cheat on aligning? I was told to try adjusting tire pressure?