My first st1300. 2010. At 18,000 miles with original Bridgestone 023 tires. Ready for tires. But their not bad at all. And even wear on both. 46 yrs of different bikes and I never experienced this. Miles nor the rear wear same as front. Is this bowling ball rubber ? Whatever it is iam gettn same tires again. Just woundering if my case was rare. Iam the only owner of this bike