@theclaud Does this look good?
Gower 100k
Is it all OK for a Road bike ?
I reckon so. There are a few rustic surfaces in some of the lanes up over Blue Anchor but it's all part of the mix. A few notes:
At the start (and finish) I'd definitely use the B4290 Jersey Marine Rd instead of the bike path by the M4, which is grotty and depressing. And at the roundabout at the end of it, the easiest thing to do is to hop across the pavement and take the road (Fford Amazon) which goes round the back of Amazon and the field hospital - this cuts out the worst of the rest of the continuing grotty bike path, which isn't too bad when you rejoin it, a few silly wiggly bits notwithstanding.
At Quay Parade at 10.9km (or earlier on the bridge at 10.2), get on the road - there's a huge development underway that wipes out the bike path. He gets to go under the horrible new beige bridge (it's supposed to be gold) that looks like the inside of a Crunchie bar. The pattern in it is supposed to be swans... I'd rejoin the bike path at 12.2km where it's just a straightforward hop up the dropped kerb. It's fine then all the way to Mumbles - there's no need for the diversion marked at 14.6.
Gower section all looks good, except I'd stay on the main road where you have the little diversion via Church Lane at 27km - it's pretty but swaps a nice swoopy fast dip for a little ford followed by a bastard climb. Fine if he really does like punishing himself with gratuitous hills tho.
The section from 82.8 is a bit of a weird no-man's land but you're going to hit some of that one way or another so no problem. Middle Rd is a good call for avoiding the horrible Carmarthen Rd. The picturesque stuff is all over by this point but that's Swansea for you. New Cut Road is ugly but you can hurtle down it fast enough not to notice...
Postscript, and nowt to do with Gower, but for someone who likes climbing he's starting at quite a good spot for a ride in the other direction - via Neath Abbey and Cimla over the Bwlch to Treorchy, up the Rhigos and then back down the Neath Valley...