I'm in agreement with RegretfullyMe.
It's not about the bike. Forget about the bike.
What I see from the original post is that SH's BS brushes off his desire to go riding with him. Completely understandable. SH needs to let go of that outcome and focus on himself.
But the other thing I see is that she says she's making a major financial decision, and SH has no input. This, IMO, is wrong. SH should have a say. After all, this bike is being purchased with joint funds, no?