I’d park at Glenmore, ride up to Corrie Cas, hike-a-bike up Fiacaill Corrie Cas, ride over to MacDhui and down to Loch Etchachan. Dump the bike and hike up Mheadachoin. Return to bike and bike out via Lairig an Laoigh and Ryvoan. I’d probably stop for a pint at Glenmore Lodge after all that…
A big day out that is hard work physically, mentally and mechanically. I’ve done it a few times and it is always less ridable through Lairig an Laoigh than I recall. I “think” 90%/10%, but it is probably closer to 60%/40%. Once my cassette was rattled loose. Rough stuff.