This ride starts in Innerleithen which is a good base for exploring two of the 7 Stanes of Scotland. The 7 Stanes are well-developed mountain biking trail centers worth riding in their own right. No doubt you'll enjoy the 7 Stanes but the mechanic in the local bike shop offered up this ride which offers a little more solitude in the first part of the ride. The second part of the ride incorporates most of the intermediate Red Route at Glentress which has a lot of fun switchbacks with bermed turns.
You can rent mountain bikes in the town of Innerleithen or at Glentress. Glentress is one of the 7 Stanes which are seven acclaimed mountain bike trail centers in Scotland. These centers typically have full services (bike shop offering rentals, cafe, toilets, bike showers, people showers, etc.) but they get a lot of traffic and bring some coins to pay to park in the carpark. Another of the 7 Stanes, Innerleithen, is just south of the town of Glentress.
Scotland has a very progressive Outdoor Access Code which essentially guarantees everyone the right to access most land in the country for recreational purposes so long as they act responsibly. You'll pass a few fences that you must open and close behind you or else the ubiquitous sheep will get out. (Do not let the sheep get out!)
Find parking in the center of Innerleithen and follow the Tweed Valley Railway Path
west along the River Tweed. After you pass through Cardrona, at the roundabout take the B7062 southwest. Follow the B7062 for about 1/2 mile and then turn left on Kirkburn Road. There is a small park at this intersection including a trailhead for several hiking trails in the Cardrona forest.
The path climbs steeply for several miles, but most of the climbing is on the forest road. At about the 9.5-mile mark, the road will stop at a freshly cut section (as of 2014) of forest. Continue climbing up until you intersect with a singletrack at the top of the ridge. (Having the GPX from MTB Project will be helpful for this ride or use the MTB Project mobile app
Once you reach the top of the ridge, turn right onto the singletrack. From the ridge, you'll have great views of the rolling Scottish Borders countryside to distract you from the climbing. Have no fear, you can't quite see to England on a clear day. Continue following this singletrack until the 10.9-mile mark. Then the path takes a sharp right and widens slightly. Keep the forest directly on your right.
After about a third of a mile, the wide section ends at a four-way intersection. Turn right to follow a singletrack along the fence line. Much of this fence line is formed by an ancient stone fence. From here, the climb continues for a short distance before you're rewarded with a three-mile, mostly singletrack downhill section almost all the way to the town of Peebles.
In Peebles, cross the River Tweed again and carefully follow the MTB Project mobile app
for about one mile until you reach a forest road which will take you to the Buzzard's Nest area within the Glentress bike center. Here, there is a freeride park with features that you can play on.
From the Buzzard's Nest, follow the well marked Red Route which is about 75% singletrack. The Red Route features about 1800 ft of climbing including some through a dense forest (the "Spooky Wood") until you reach an overlook at Caresman Hill where you'll enjoy an impressive view of the Scottish countryside that you just rode on the other side of the River Tweed.
Once you reach Caresman Hill, most of the climbing is finished and you can look forward to a fun downhill singletrack with bermed turns and tabletops.
Follow the Red Route past the main park facilities and carpark until it exits onto the A72 road. Turn left onto the road for a few hundred feet and then turn right onto the Tweed Valley Railway Path Glentress Spur
that will take you to the Tweed Valley Railway Path
which you can follow to Innerliethen.
Or you can stay in Glentress for a while to explore some of the other trails if you still have some legs left.