Puzzletome Crossword Puzzles

December 2017 Monthly Crossword
The Chain II

The chain is made up of the unclued entries. It's location can be determined from the initials of single superfluous words in each of seven clues (in clue order). It is best known (at least in the UK) for another activity. In relation to this activity, a corresponding part of the wordplay of five other clues is omitted.
Grid
Across
1 Eccentric fog (6)
5 Need it desperately for sure (8)
9 Write about evil demon in bill (8)
10 Unclued (6)
11 Gears up design with partners calling (12)
13 Judge pair with leader moving forward for racket sport (4)
14 Nitrogen manifesting origin and density like a gassy vessel? (8)
17 Underage child stretches around slippery areas (8)
18 Adapts to squadron leaders (4)
20Wind to appeal to Queen's musical controller? (5,7)
23 Cuts music and society listens (6)
24 Manipulate popular planning for (e.g.) evil obsession (8)
25 Wanting to reach extremes of aluminium scrap charge (8)
26 Safety monitor covers simple Word form (6)
Down
2 Glimpses of international user network comprising company image (4)
3 Unclued (9)
4 Book burrows into investigation of a family (6)
5 Service donating sisters to hospital? (8,7)
6 Dreadful cost in lies (8)
7 Unclued (5)
8 Ratio left one cream and three parts green? (10)
12 Unclued (10)
15Try Mini transmission? That's a weakness (9)
16 Plants crisis an unfortunate response (8)
19 Unclued (6)
21Kings laugh inside island's solar shade (5)
22A learner's best short range (4)