l am looking to fit a pair of pirelli sand tyres to my 05 ec 250 for a up and coming beach race , the standard recomended tyre sizes are 90x90x21 for the front and 140x80x18 for the rear , bearing this in mind will a 80x100x21 for the front and 120x100x18 for the rear fit , if any one has had any bike time out on these tyres or can recomend a tyre for sand l would like to hear from them , cheers