And it happened suddenly?? The chain has been on the same cog/ring the whole time? What you say seems to violate the laws of physics. You have been the same ratio but suddenly you have to have a faster cadence to maintain the same speed? No one changed your wheel diameters?

What I wonder is whether you are not describing the issue in a way that we (at least I) can understand. That something else is going on that you haven't relayed in a way that I (we) can follow. Example- pedaling faster might be having to push harder on the pedals while the actual RPM (cadence) remains the same. A flat tire (or very low air pressure) can result in this sensation. A tight bearing or rubbing brake can do the same. But using the "pedaling faster" to describe an increased effort is what I am stuck on.

I suppose that somehow your freehub/freewheel ratchet is only engaging every so often, so that you are having to spin the cranks at a faster cadence for the otherwise same speed. Do you use a cadence meter? How are you sure that your legs are rotating at a faster RPM?

I have just about used up my ability to help you long distance. Andy