The rake of a fork is a measurement of how far forward it is angled and has an effect on the handling of a bike and possibly also the clearances. Every bike frame is designed with a specific fork rake in mind. There is some amount of leeway but for best results you should stay as close to the spec'ed rake as possible. I got 45 mms from looking at the spec of the frame on the Aventon site. The aventon mataro fork on city grounds however seems to have a 35 mm rake, so I don't know. Their carbon forks have a 45 mm rake. It may be that the frame was spec'ed differently for different year models.