When I was a teenager in the 60s I did a lot of cycling - everyone did in the City of York - it was a good way to get around a flat city.
http://www.york-tourism.co.uk/
http://www.york.gov.uk/cycling/
http://www.yorkminster.org/
Now I am 55 I have renewed my interest. Last year I lost 4 stone doing the Atkins Diet. Losing another stone will be harder, but I do enjoy cycling the country lanes around Reading in Berkshire where I now live. I know that will help a 500+ cals per hour! Fot those of you outside the UK I must add 1 stone = 14 pounds!
I have a 12 year old Trek 800 which I bought in Cyprus and which is in almost new condition. I have had some road tyres put on and a complete service. I will give this bike a run for its money and may invest in a lighter road bike later on.
The bike market has changed a lot since I bought my Falcon with ten speeds and drop handlebars when I was 16 - that was a big step up from my Dad's old three speed classic town bike.