David Brookes

CURE-E Course: Mechanics (PHYS 204A), first introduced with CURE-E in Fall 2021

Project Title: Investigating the effects of bicycle tire pressure on rolling resistance

It is an interesting challenge to come up with an authentic research project in physics that is appropriate to the level of introductory mechanics. One of the most fruitful areas for authentic investigation is friction. Students in my physics class will investigate the claim made by road cyclists that they can reduce rolling resistance by lowering tire pressure. On the surface, this seems to fly in the face of our (physics) understanding of rolling resistance that is; rolling resistance is primarily due to rubber hysteresis. However, there may be multiple mechanisms at play in rolling resistance and there may be a regime in which one mechanism dominates over another. There are a number of open questions there for students to explore: 

1. Does the claim (lower tire pressure reduces rolling resistance) have any validity? 
2. Are there particular regimes (types of surface) where lower tire pressure reduces rolling resistance? 
3. If we are able to characterize under what circumstances lower tire pressure reduces rolling resistance, can students create a model or models that explain the process? 
4. Can students use that model to predict what tire pressure is most appropriate in what conditions?