What are the climbs like? Long and steady like Yad Moss or short and sharp?
How cold might it get as you get towards Snowdonia?
Are there good places to stock up with food and drink en route between controls?
Any particular tips on training for the climbs?
Would it be a good idea to change the cassette to even lower gears on my compact? Presently running 11-32 but could go 11-36.
Hints and tips appreciated
https://ridewithgps.com/routes/17001454Climbs: Mostly long and steady (like Yad Moss coming back). There are 5 single chevron short climbs coming out of Llanidloes towards Staylittle and the abrupt double chevron climb up the road to King's YH (west of Dolgellau, at 202km and 373km) but only 200m.
Food and drink: Route goes through lots of towns besides those which are nominated as controls (see my RwGPS link). Only leg where you would not find much is Menai back to Kings (82km) which I suspect you'd be doing 9pm - 2am. But the team at Menai provide excellent fare (and some to take onwards) and you can look forward to eating at King's too.
Gearing: With your setup I wouldn't change my cassette. I used the same for both BCM 17 and LEL. Now Mille Pennines on the other hand . . . (cassette and chainwheel substitution).
Sleep: If you are a rider who needs decent sleep then consider booking somewhere between Penrhyndeudraeth and Beddgelert (A4085). Check in there on the way up (~250km, 15 minutes and a cup of tea) and collapse there after visiting Menai (efficiently, with the door code/key; 330km, midnight+). Leaves you 40 odd km to do at dawn (5am) over to Kings, have breakfast and get away by 8 at the latest (225km from Kings to do in 14 hours). I did this last year (stopping from 10pm till 5am) and there were a fair few with a similar plan (though I suspect rather less sleep). There are beds at King's but demand outstrips supply and the hours are rationed. You could alternately book somewhere in Dolgellau. I considered
https://www.facebook.com/hybbunkhousedolgellau/ earlier this year.
Ephemera: Sunset 2103 Sat, Moonrise (nearly full but very annoyingly) 0500, Sunrise 0521 (all Beddgelert), Sunset 2054 (Usk).
If you decide to get back to Kings at whatever time, I recommend you take trouble to do so in company for the dark hours.