I think many beginners have a tendancy to use a very low gear, particularly when climbing. Whilst I don't see many other cyclists, if I do and they're going up a hill it's not unusual for their legs to be going round like catherine wheels. I suspect the thought process is that the lowest gear must be the right one for climbing, maybe they just like spinning, I dunno
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Anyway Matt, I'd second and third the comfort recommendation, if you feel you have to bob your head back and forth like a pigeon with every pedal stroke to keep going you may want to consider dropping down a cog or two.
Try to anticipate a little too, when you hit a hill start to change down at a rate which maintains your cadence and comfort, your bike wont thank you if you try to start dropping down the gears when you've already started to strain in your current gear, change it before it gets too hard
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Mind, it was back in December you posted this, you've probably got it all sussed by now
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