How strong is the shifter? Towards the end of my ride today, it was really hard to get into 1st gear. When I parked back at my house, I sat and shifted from N to 1st over and over and about half the time, 1st wouldn't work. This is my first bike so I don't know which parts are more easy to break. I don't think it's my trans cuz every other gear worked fine. Not sure.....