From yacf, the off road bits are Cors Caron nature reserve (near Tregaron), the Claerwen Reservoir track, NCR 818 Cwmystwyth - Llangurig cycle track, NCR 82 before Dolgellau, and the Elan Valley cycle path up to Craig Goch dam. One of those requires fording a river...
Apparently all the off road bits can be ridden in daylight for the 300, 400 and 600.
I could just about manage 20% climbs on gravel roads with a 34/32... but not several hundred k into a 400 on a fully loaded bike :-)
Furry muff - unlike old me the new me appreciates having lower gears, whether or not they get used.
The only thing even close to that big I've used was a 35mm Vitt Hypers so you might be better off asking in the Which Tyres thread or the Gravel Bike thread re: tyres.
From yacf, the off road bits are Cors Caron nature reserve (near Tregaron), the Claerwen Reservoir track, NCR 818 Cwmystwyth - Llangurig cycle track, NCR 82 before Dolgellau, and the Elan Valley cycle path up to Craig Goch dam. One of those requires fording a river...
Apparently all the off road bits can be ridden in daylight for the 300, 400 and 600.
I could just about manage 20% climbs on gravel roads with a 34/32... but not several hundred k into a 400 on a fully loaded bike :-)