Just bought my first E-bike :-)

[richtea]

Do you happen to know how to adjust the tension in the rear disk brake? I can't see any barrel adjusters at the bar or calliper end

On the pre-2021 models, there are adjusters 10-15cm after the cables leave the bars (see the thick part of the cable below the steerer):

However, you've got the new-fangled inner cabling!
I'd look either under the bars, or maybe just above the disc where the cables come back out of the frame.
They can't be in the frame, surely? Eeek.

I looked at the manuals for the 2021 Gains (BLUE PAPER GAIN HYDRO 2021 EN-ES is yours), and although it shows the routing on page 51, I couldn't see the adjusters in the diagram. Maybe worth doubling checking though.

Failing that, email Orbea - they will reply, but after 48-72 hours or so.

 

[Alba Zeus]

On the pre-2021 models, there are adjusters 10-15cm after the cables leave the bars (see the thick part of the cable below the steerer):

However, you've got the new-fangled inner cabling!
I'd look either under the bars, or maybe just above the disc where the cables come back out of the frame.
They can't be in the frame, surely? Eeek.

I have emailed Orbea for clarification but 100% can't see any adjusters in or round the brake set up

 

[Alba Zeus]

I should probably point out it’s the brake lever travel I want to adjust. When I pull the rear brake lever it touches the drop

 

[youngoldbloke]

This manual might be helpful. Can't you adjust the cable at the fixing point on the calliper?