Which TW, 2003, 2008 or 2013?
I strongly prefer AGM (no liquid to spill, higher static voltage at 12.8, versus 12.6, handles vibration better than lead-acid)
I think Yuasa YTZ7-S will fit the later years.
If replacing a YB7C-A, you will need some padding, as the AGM is slightly smaller.
A clone is stocked at my local O'Reillys as an ETZ7-S