From Carhaix, the route properly joins the Nantes-Brest canal towpath and won’t really leave it until Redon. The profile becomes noticeably gentler: a canal is by nature almost perfectly flat, punctuated by regular locks that set the pace of the ride.
Gouarec, a small river village partway through, makes a pleasant stop for a waterside picnic. The mood here is very different from the coast: forests, locks, shaded paths, little traffic.
Pontivy, a fortified town with distinctive Napoleonic architecture, offers a good choice of accommodation for the night.
Distance shown is indicative for this leg.