Hi,
A cadence sensor will just tell you stuff you should already know based on your
gears and road speed. Its not hard to be aware of pedalling fast and slow.
Mashing and spinning related to cadence are things you just do, and I work
on improving both because what you really want is to be able to when you want
to is to put a lot of torque through the pedals at high rpm = maximum power.
If your geeky its useful information, as is a power meter too. But really all
you need to do is change your mindset about being in the right gear.
At any one time you have a mashing and spinning option by changing
up or down from the gear you generally feel most comfortable in.
Generally the mistake people make is mashing too much, and they
need to work on spinning until it becomes a de facto mindset part.
Generally work on spinning more than mashing starting off, but when
you can and do generally pedal fast, you aren't going to going to get
anywhere trying to pedal really fast, unless your a sprinter.
In the longer run spinning and mashing combine, in that you work
on being able to spin higher and higher gears with more pedal torque.
In other words long term its all about averege power output.
For a 50+ person like me its more about just doing the hills easier,
not going as fast as possible all the time, peak rather than average.
rgds, sreten.