A FAR smaller proportion of Australians are riding bikes compared with the 1980s, according to new Sydney University study.
While the total number of cyclists has risen, so has the nation's population, meaning that on a per capita basis bike riding has dropped 37.5 per cent between 1986 and 2011.
''It was unexpected in a sense, but it's important to be clear that the total number of cyclists has increased, it is just that the population has increased faster,'' said Sydney University's Professor Chris Rissel, who co-wrote the study with the independent researcher Chris Gillham.
''You do see more people on bikes these days, and they still need more bike paths to support them.''
The study, published in the journal World Transport Policy and Practice, found that there were about 21 per cent more people riding bikes in Australia in 2011 than there were in the 1980s, when the first systematic research was conducted on the topic.
Overall, the number of daily bike trips undertaken by people over age nine rose from 1,645,900 in 1986 to 1,989,562 in 2011, with the figures arrived at by statistical analysis of surveys and five-yearly census data.
Separate studies have found that new bikes have outsold cars in Australia since 1999, leading to the notion that the country was undergoing a cycling boom.
''The two major things we identified that are unique to the Australian context is mandatory helmet requirements, and also low investment in infrastructure and planning to support cyclists,'' Professor Rissel said.
''In general, the urban planning process has been very heavily skewed towards cars.''
Bike helmet laws became mandatory in 1992. Research produced by Professor Rissel last year found that one in five adults surveyed in Sydney would ride bikes more if they were not required to wear a helmet.
The number of bike-borne Australians dropped sharply when the helmet laws came into force, and did not recover until about 2006, the study said.
A 2011 Australian cycling participation survey showed that about 33 per cent of 10- to 17-year-olds had ridden a bike in the preceding week, equating to 768,000 young people.
About 13.4 per cent of people aged 18-39 had cycled in the previous week, according to the 2011 survey, and about 8.5 per cent of people over 40.