Bike wants to go left
I had a bike storage failure over the weekend. I store my mountain bike and my singlespeed on a single rack that holds two bikes by their top tubes. On Friday, the rack came out of the wall after being up for over 2 years! Both bikes fell about 5 feet onto the ground. The mountain bike landed on top of the singlespeed. There was no obvious damage to the mountain bike. The singlespeed's front tire needed some light truing. No problem, fixed that up easily enough.
Of course, it doesn't seem like that is all. When I ride the singlespeed without hands, it feels like the bike wants to go left. It is undetectable when riding with hands on the bars. But pronounced when riding without hands. What's causing this? Anyone have any ideas?