This is Beinn Mheadhoin and Beinn a'Chaorainn. BM could maybe be done with Ben Macdui, as Fraser once did, but a long day.
Cycle from Linn of Dee, for around 50 minutes.
1.5 hours hike to Beinn Mheadhoin
Then hour down, beyond stream near Stob Coire, and up to Beinn a'Chaorainn
40 mins back to bike
Cycle back to car park, 30 minutes
Around 5.5 hours total including 30 min activations