On all my bikes I have had only one tire that would last 10,000 miles, and it was because the bike was rather light and the tire was made for heavier bikes. Otherwise I have come to regard 5000 or so to be average for a tire made to the weight of the bike. But if you've shopped around and not got any satisfaction, but the D251 is yet to be tried then by all means go for it. I do hear that the Avon Cobras have good staying power on our bikes. That will be what I go to next.