Query regarding tension / unable to shift

Hi all,

This evening I was going for a cycle on Zwift when the bike randomly stopped functioning as normal.

I was suddenly unable to shift out of the highest gear (smallest cog) on the rear derailleur. I’ve had tried to figure out what has happened but have been unsuccessful.

I’ve included a photo which shows the current tension when on the highest gear.

Is my bike broken? or is this an easy fix?

Any help would be greatly appreciated.

Thanks in advance.

The cable is broken. Most likely at the shifter end where the threads of the cable can fray. Or at the derailleur end. Can’t tell without seeing. Either way a new cable is required. Google how to replace a shift cable for bicycles.

As above, it’ll have you’ve in the shifter. Be careful as they can be a pain to remove if it’s snapped close to the barrel.

10 speed 105 shifters are renowned for this.