horizon wrote: In fact, as we all know, the reasons why most people don't cycle are hotly disputed. The three key reasons are: effort/inconvenience, sweating and fear of punctures.
I think it depends who you ask and where you are. A middle-aged female, I've been a regular cyclist all my life, but when I encourage my friends and acquaintances to cycle, the three main reasons are: fear of traffic, hills and rain (this is Glasgow). Women are even more likely to be put off than men.
I do think a lot of people are put off by hills as they appear to require a lot of effort and make you sweaty. Places with high cycling numbers such as Denmark, the Netherlands, Berlin, etc. are all flat.