UKH

So I'm looking at Sgurr nan Gillean walk approaching SW (not pinnacle ridge).

What I want to know is is that the 20m abseil off Sgurr nan Gillean Climbable so you can reach the summit then abseil off the top as described in the Scotlands Mountain Rdges Guide book.

Depends how confident you are, but yes. It's not at the top so the abseil is lower. You can downclimb too..

If you’re heading up the West Ridge, there is a chimney (just before where you’d abseil too) which is the common way up. You take this chimney then head across some brilliant exposed pinnacles (which lead to the tat for the abseil), this is graded Mod. You can either come down the same way and abseil or head down the SE ridge if you want a circular route (Grade 3). 
 

This is described very well in the Skye Cuillin guidebook by Cicerone, worth getting!

Let me know if you want any more info.

Jack

Are you suggesting scrambling up Nicolson’s Chimney?

Nicolson's Chimney (D)

It’s certainly not hard climbing. I used a rope when I climbed it as part of the traverse but that was mostly down to factoring in how fatigued I was and at first sight the climb looked a little awkward without positive holds. I probably needed have bothered using the rope as the climbing didn’t feel as insecure as it had looked.

As always, it’s important to bear in mind one man’s walk in the park is another’s Dawn Wall.

Here’s someone’s video… youtube.com/watch?v=YLFq7VfHnms&