Originally Posted by
tjspiel
You don't need a cyclocomputer with cadence sensor to figure out your cadence but having one makes life easier...If you're used to 50 to 60 then 80 to 90 might seem really fast and really tiring. Don't get discouraged if it takes awhile before that feels comfortable. Note: Although 80 to 90 is often recommended, for some people that may be unnecessarily high....
Great advice, OP, I'd get your local LBS to install a nice cadence computer like the Cateye RD-200, then work on getting your cadence above 70rpm working to your optimal range (whatever that turns out to be), it'll help your speed greatly.