Well, I would like the resolution as good as possible, but 4 lines for text would be enough.
This is the information I would like to display:
24,5 km/h
100 rpm
48.1V
20:30
2.15 Ah
20.3A
23.30km
67:23
32.1Wh
250 W
5.2Wh/km
43.2°C
17.3°C
The speed and power may be a little larger in the middle than the other values, but the rest can be in 3 rows around the speed value.
So, I'm guessing 240x128 would be enough