Spotted this the other day, its a long distance path from Harperrig to Hawick. Thought it might be a good option for some a bit of camping and some fairly gentle off roading. My plan is to set off after the kids go to bed ~1900 and ride out to little vantage and over the thieves road and bivvy for the night somewhere over the other side and head for gala in the morning. I'm undecided how biked up I'd need to be. Cross bike with hybrid tyres, MTB with more off road bias hybrid tyres or full on trail centre 2.5" tyres.
I've never ridden the first section over the pentlands before whats that like?
The next section West Linton to Peebles looks to be fairly hard packed trail should be easy enough on a cross bike.
From Peebles there are two options, the back road round to Innerleithen, road would be preferable for a cross bike. Or an off road trail round the back to Inners which adds about 15km and 500m and I suspect would require a mtb.
Form Inners you can continue over the tops on the Southern Upland way, I've ridden (and fallen off here) a mtb is definitely required, or continue on the road to Tweedbank for home.
Looking at the routes, the full off road road would probably be a bit much at the moment, 105km largely off road and 2.3km climbing with a lot of likely tiring technical descents. https://ridewithgps.com/routes/12723507
The easier option would be made somewhat more civilised if I could get away with the cross bike for the start.
https://ridewithgps.com/routes/12723609
http://www.southofscotlandcountrysidetrails.co.uk/where-to-ride/cross-borders-drove-road/