If you're using drops with a decent length stem, your saddle forwards and your bars much lower than your saddle... all these things contribute to your weight being more over the front wheel than the back.
Why is my Arkose rear wheel locking up under the slightest braking pressure? Happened about 4 times just then and nearly bailed. Feels like the cranks locked up too. Really odd feeling.
This is why I think the rear wheel slipped. Cranks don't seize up suddenly...
Not carrying any load so seems evenly distributed I guess