Crock has a bit of a reputation for being a nightmare of a hill to climb, entirely due to the forestry planting around the summit. Particularly bad where storm damage has been left to naturally rot away, and right on the path you’d want to take if doing the pair of summits. On here and Walk Highlands there are plenty of photos of people scrambling through branches, logs and undergrowth.
Now it was my turn. Being a commercial forest operation it makes sense that trees come and go over time and so the route up can change over the decades, and so I poured over the latest satellite imagery seeing where might be best. Gerald, @G4OIG, did them last year and gave me his route, which confirmed my thoughts on the way up Crock.
I wanted to do both hills, but time was tight, so I investigated cycle options, and ended up with this route:
It's a decent track/road, although wet when I went, and so a mix of quicksand and harder materials, meaning you're pedalling when going downhill. It's a bit of an uphill at the start but you soon come to the gap in the trees to start the ascent.
A bit damp and drizzly on the top, so wasn’t hanging around long. A few convenient little trees to prop a mast against though. A quick run on 40m, 20m and 10m before packing up and looking for the path between the trees to get back to my bike.
I did debate about going back to the car park and around the hill to the south - given I knew it would be downhill, even though the total distance would be longer to Hare Cairn. In the end I stuck to my plan and went up and around Crock and Craigie Law. The track was pretty muddy now, but downhill to the junction to Hare Cairn.
It was a pretty steep climb up the track before the final walk to the summit, but I wanted to bring the bike up for the very quick descent afterwards! It’s all freshly hardcored at the top, although trickier to find a path onto the heather as it’s a steep, loose slope. Once on the heather, there’s no path just a stomp across until a fence line and trig appeared in the distance.
After a quick run on 40m, I do an estimation of whether or not I have time to do Meall Mor, GM/ES-058, for another 5 points and one on Fraser's @MM0EFI complete list (although he didn't know it was an option ahead of time...)
And so a rapid bike ride back to the car 
It’s only 10 minutes drive to the start, and then about 20 minutes to this handy fence within the AZ.
Another quick activation, as I had to be home for the joint birthday teas at Pizza Express, with Fraser then messaging me as I’m half way back to the car…
maybe next time..
Is it a better route of Crock and Hare Cairn? Depends what you like - scrambling through dead forest, or uphill slogs on the bike. 
Two more GM/ES to go!