"401km cycling event starting from Chepstow. Controls at Hay-on-Wye, Llandovery, Tregaron, New Quay, Llandovery and Llangattock, plus 2 information controls.
"Clasic Welsh 400, traversing Wales West then East. Good commercial controls used as far as 296km. Rest/sleep control at 341km."
NB info controls reinstated (cf absence last year) and if late night stop is Llangattock again (as in 2016) then the distance is 352k (cf 2017 at Bwlch (341k)).
https://ridewithgps.com/routes/13068909 (but NB Mark's note above about disruption around Chepstow).