The substance taking the city potholes and turning them on their heads the substance breaks over these crags amp bumps in much the way a 29er would in its royal blue finish itrsquos got a look that gets better with a little bit of dirt and grime but there is much more to the substance than just an about town commuter shimano sora drivetrain the shimano 9 speed sora groupset is well known for its performance and durability making it the perfect choice for the substance the sora sh