The original OEM rubbers came with too much slop, which is why many of us changed out the original cush rubbers when worn out, with the one specified for the Thunderbird Sport. The TBS fits so well, I had to lightly lube the rubber with olive oil and tap it in with a deadblow hammer. No slop equates into longer service, at least it has for me. !0,000 miles for my original, 25,000, so far, for the TBS rubber replacement and still no apparent wear.