Hi Andrew,

I recently purchase 2018 Marin Hawk Hill 1, I have few questions. Im a newbie and can't understand technical details for mtb. 

1. How do I upgrade the rear to 142x12mm axle? What does it mean? 

2. 140mm form wont affect geometry? 

3. Is it worth to throw another 2k usd for the upgrade? Or just buy a new bike?