I think I've finally realised the importance of a good cadence...

[Seigi]

I've noticed my lower leg muscles have changed since considerably since changing my 'cycling technique', they're not bulging outwards as much but are more prominent on my inner calves. I'm assuming this is somewhat normal as I'm shifting from 'grinding' to 'spinning'?

 

[KingstonBiker]

I've done more than double 90rpm on several occasions

I guess you don't mean 90rpm with the left pedal and 90 rpm with the right

 

[gaz]

I guess you don't mean 90rpm with the left pedal and 90 rpm with the right

No.