Had the same feeling when my Michelin Alpin went flat from a bad valve stem. First time I have had a valve stem failure. Steel valve stem, the internals went bad. Anyway the Alpin got me home and I put the OEM back on. I rode it for 3 days. Like the feel of the Alpin better. Had mine balanced when it was mounted and the tech told me it was right on, no weights needed. I did not keep track of the mileage on it because it has been on two bikes. Between the two it is over 25K now. Not at wear bars yet, starting to think about a replacement. Love the Michelin so I may just stick with it!
No weights required for my Falken 612 with KurvyGirl aluminum valve stem. BTW, if anyone is interested in the aluminum valve stems, here's the info:
https://www.kurveygirl.com/shop/prod...kqn69u1etu2r47
I absolutely love these valve stems but be advised, you do have to grind down the valve stem support for these to fit.
Ken (Hornblower)