Bicycle Tire Data
A short summary on available tire data including some from Chet Kyle.
Tire modeling plays and important role in ground based vehicle modeling and this is most likely true for the bicycle too. Motorcycle modelers have spent a good deal of energy developing tire models and testing tires but little has been done for bicycle tires. The most complex models I have seen include side slip forces, tire relaxation, and toroidal tire shapes. There are only two sets of tire data for bicycle tires that I have come across. The first is tire tests done by the group at Cornell Aeronautical Laboratory:
I also recently met Chet Kyle and it turned out that he had been involved in tire testing. He has studied rolling resistance and even full dynamic forces using a tire testing machine at General Motors. Here is some of the data and reports that he provided us with:
- 1987 GM tire test report on 17" Moulton tires. [pdf] [citation]
- 1996 GM tire test reports on rolling resistance of tubular racing tires. [pdf] [citation]
- 1996 GM test of tire characteristics on flat track slow speed (2mph) steel band. [pdf] [citation]
- Coast down tests in a University Hallway using an instrumented and weighted tricycle. [pdf] [citation]
- A set of notes on a lecture Chet gave at Cal Tech on tire performance. [pdf] [citation]
There are some xls files that Chet provide too and this was his explanation:
The attached files were from my USOC correspondence to the Cycling coaches. In the Flat Track Tests (700C, there is one table for camber data that has not been plotted, so you may find the data useful. The tables give lateral force in Newtons versus tire down load and steering angle or camber angle. The flat track ran at only 3.5 mph. They have included some fore aft force data from the 1987 tests for the Sunraycer on 17 inch wheels with 1-1/4 inch Moulton tires, but the rest is for 700C tires with Continental 19mm sew up tires. The tire coast down was to discover what the rotating friction of the GM wheel mount was so you could correct the measured rolling resistance on the high speed drum (zero steer angle and zero camber). Uncorrected gave values for Crr (rolling drag per unit down force on the tire) of about .0060, while corrected values were on the order of .0025 after subtracting the drag due to bearing friction.
Chet also gave a wonderful talk about all the bicycle related projects he has been involved with over the years.
The papers provided here are copyrighted by Chester R. Kyle (2010) and are shared here under the Creative Commons Attribution 3.0 Unported license. You may share and reuse as long as the work is attributed.