Quick - Maybe Question on changing gears Not looking for a overly technical answer here just a very simplistic one I quess.. When switching gears is it best to try and keep both front and rear gears either high or low (Depending) I mean we wouldn't want say front low and rear high or other way around would we ? 

Thanks
On most bikes you typically just need to avoid the two most extreme cross-chaining scenarios: (A) the largest front chainring and the largest rear cog and (B) the smallest front chainring and the smallest rear cog.