The speed of recreational cyclists along paths and roadways is greatly influenced by the presence of vertical slopes. That conclusion can be drawn from the testing that is being performed by Gorski Consulting a several locations in London, Ontario. This article will present the latest results from testing and observations taken on the northward approach to the old Meadlowlily bridge in the south-eastern part of the City of London, Ontario.
The Meadowlily site is a historical roadway that became closed to motor vehicle traffic when its old bridge crossing the south branch of the Thames River was refurbished. Re-surfacing of the road south of the bridge was completed in 2017. Commencing northward from about 100 metres south of Commissioners Road Meadowlily Road begins a descent that exists for about 900 metres to the location of its bridge. The steepness of the descent varies but its maximum is about 7.3 %. The portion of the site chosen for the bicycle testing was located over a distance of 400 metres near the top of the slope close to Commissioners Road.
The location of a brown telephone junction box was a useful reference for the “Zero” marker painted on the pavement as shown in the photo below.
The photo below shows a northward view of the site and the “100 metre” marker can be seen painted on the pavement in the middle of the view. It can be seen that the gradual down-slope begins to be steeper in the background.
The photo below shows the site on approach to the “200 metre” marker is is halfway along the testing area. The road begins a slight bend to the right just before reaching the “400 metre” marker in the distant background.
The photo below looks north from about 325 metres along the test site. The end of the test site, at 400 metres, is located just past the black and yellow hazard marker visible on the right side of the road. The road carries on further in the background to the Meadowlily bridge which is located about 500 metres further into the background.
In the view below the camera is rotated 180 degrees to look back up the slope from the 400 marker.
Measurements were taken of the slope of the test site as shown in the table below.
Initial tests were conducted using a hybrid Trek bicycle. From a stopped position at the “Zero Marker” the cycle was allowed to coast, without pedalling, under several scenarios as shown in the chart below.
The “Upright” and “Leaning” refers to the body of the cyclist who remained upright or brought his upper torso down close to the handlebars to demonstrate the difference in effect of the aerodynamic drag. Tests were also conducted with the rider equipped with a knapsack loaded with 32 pounds of ballast. Overall the results indicated speeds between 40 and 45 km/h. Additional testing was conducted after a repair was made to the rear wheel which resulted in a increase in speed by a couple of km/h.
Following the coasting tests video cameras were brought to the site and set up a strategic locations to document the travel of independent cyclists who were unaware of the testing. These documentations occurred on August 31st and September 15th, 2018.
The table below shows the results obtained from these observations.
The data from the coasting tests can be compared to those of the observations of unsuspecting cyclists riding along the same test area. It can be seen that the average speed of observed cyclists is essentially the same as what would be obtained if a cyclist simply coasted from the top of the slope from an initial stopped position without pedalling. This demonstrates the relationship between the speed of recreational cyclists and the slope of a road or bike path. In general recreational cyclists coast down slopes and their speed is governed by the steepness of the slope. The steeper the slope the higher the speed.
This relationship applies for the range of speed achieved in the testing and observations. It is conceivable that, as speeds increase beyond 45 km/h, recreational cyclists may begin to apply braking to control the speed of their descent in apprehension of the potential dangers that might be generated. This may not be so with more advanced cyclists who feel more confident of their abilities.
Gorski Consulting is continuing to conduct cycling tests and observations on the slopes of other sites and this data will be reported in future articles.