Loch Katrine is a long, narrow loch with a tarmac road on its north shore that's closed to general traffic. It belongs to the waterworks that has sent the loch's water to Glasgow since 1859. That makes the Loch Katrine cycle route one of the best-known rides in central Scotland. Most people drive to Trossachs Pier, hire a bike, ride 21km (13 miles) along the loch to Stronachlachar, and take the steamship back. That's a fine day.
The Glasgow new waterworks at Loch Katrine, wood engraving after a photograph by Thomas Annan, 1859. Wellcome Collection, CC BY 4.0
It's also possible to do the full circular from Aberfoyle, which is more interesting and a lot more work. You earn the loch with a climb to start, ride round it, then earn it again on the way home. About 54km (34 miles) if you come back over the Duke's Pass road, 62km (38 miles) if you loop home on the quiet forest tracks (more on both ways home below). Around 840 metres of climbing on the forest version, five to seven hours depending on stops and weather. A proper day out.
If you want the loop on your phone or GPS watch before you set off, we've mapped it on Komoot, clockwise with the forest way home. Or ask in the shop and we'll send a GPX over. It sits alongside the other route guides we keep on file for hire customers.
The route
Go clockwise. The hardest climbing comes at the end whichever way you do it, so put the variety up front:
1. Aberfoyle to Stronachlachar via the Statute Labour Road. 23km (14 miles), gravel. Out the back of Aberfoyle into Loch Ard Forest, past Milton, onto the historic Statute Labour Road. Mostly fine forest gravel, gentle gradients across a long haul, never technical. We've a separate post on this stretch and the café at the top.
2. Stronachlachar to Trossachs Pier along the north shore of Loch Katrine. 21km (13 miles), smooth tarmac, almost traffic-free. Single-track waterworks tarmac, closed to general motor traffic. Mostly flat with two notable points. First, the graveyard brae, where the road kicks up past the Clan MacGregor burial ground at East Portnellan. On our own mapped route it lands about 8km out from Stronachlachar, and the steepest hundred metres of it is a shade over 8%. Second, the views across to Ben A'an and Ben Venue at the eastern end, depending on cloud.
3. Trossachs Pier back to Aberfoyle. Two ways home, and we'd point most people at the first.
The forest way (what we'd ride): NCN7 through Achray Forest. Gravel and forest road along the south side of Loch Achray and past Loch Drunkie, away from the main road (the Three Lochs Forest Drive stretch is shared with the odd slow car in season), with one last climb through the forest above Aberfoyle before you drop past the Lodge into the village. It finishes on what we reckon is one of the best gravel descents in Scotland, and you roll back to the shop with a daft grin on your face. It's the longer way home, the whole loop comes to around 62km (38 miles) this way, but it's the better one.
The road way: over Duke's Pass on the A821. About 11km (7 miles), one tough climb, the loop's nearer 54km (34 miles) this way. Shorter, and there's a glorious view from the top, but mind yourself: the A821 over Duke's Pass is a well-known motorbiking road. Bikes come through fast and cut the corners, and there's coach traffic in summer. 3.8km of 6-11% gradients up, a quick descent into the village. If your legs are gone after 44km, this is where you'll find out, and if you're not confident sharing a road with fast traffic, take the forest.
The MacGregor stop
The walled Clan MacGregor burial ground on its causeway in Loch Katrine at Portnellan
The graveyard at the foot of that pitch is worth chaining the bike to a fence for. Twelve grave-slabs sit inside a square inner enclosure, the oldest dated 1699, with a heraldic shield and the date 1781 over the entrance. Four more slabs lie just outside it.
The reason it's up on a mound is the same reason the north shore road has no cars on it. When Glasgow raised the loch for its water supply, the burial ground would have gone under. In 1922 the Corporation built a retaining wall round it, raised the ground and built a causeway out to it. It sits on made ground now, above the water it was nearly lost to.
Rob Roy MacGregor (the actual one, not Sir Walter Scott's literary version) was born at Glengyle, the clachan at the head of Loch Katrine, in 1671. We get into the Scott-versus-history business in the fairy minister post. There's a second, smaller MacGregor enclosure up at Glengyle House, for the chiefs. His people are in this graveyard. Read the carvings. The view from the top is the loch he grew up looking at.
Five minutes there. It changes the day.
When to take the boat instead
Trossachs Pier and the Sir Walter Scott, postcard by William Watt, 1900-05. Public domain, via Wikimedia Commons
If the full loop isn't your idea of a fun afternoon, take the boat back across the middle. The SS Sir Walter Scott (built 1899, restored 2023, biofuel steam) and the motor vessel Lady of the Lake both carry bikes from Stronachlachar to Trossachs Pier, subject to availability and a surcharge (£3 hire bike, £5 personal bike). That direction only runs May to October, and there's one afternoon sailing back, at 3.30pm. Pre-book the bike space as well as your seat. They fill up.
That cuts the day to:
Aberfoyle to Stronachlachar by bike (23km / 14 miles gravel)
Stronachlachar to Trossachs Pier by boat (45 minutes)
Trossachs Pier to Aberfoyle, forest way or over Duke's Pass (see above)
From Trossachs Pier you've still got the same choice home: the forest way, or the road over Duke's Pass. Or skip the loop idea entirely and ride out and back on the Statute Labour Road for lunch at the Pier Café. And if you've never ridden gravel before, start with the Faerie Loop and come back for this one.
What you need
This is a full-day mixed-surface ride with a real climb at the end:
A gravel bike or sturdy hardtail. Tyres at least 35mm. [Hire bikes from us](/bike-hire) are sized and set up for it. Not sure whether to bring your own? We've written about that.
Lower gears than you think. There's a climb at the end whichever way you go home, and it will find any gear ratio that's borderline.
Two bottles of water minimum. Café at Stronachlachar mid-ride; nothing reliable between Trossachs Pier and Aberfoyle.
Lights and a small layer for the descent. Wind chill on the last descent is significant even in June.
Cash or card for the café and the boat surcharge, if you're taking the boat.
Phone with offline maps. The Loch Katrine north-shore road has limited mobile signal.
What can go wrong
Duke's Pass weather. It's exposed at the summit. If it's raining in Aberfoyle, it'll be wetter and windier up there. A dry forecast is worth waiting for.
Boat fully booked. If you're planning to take the boat back, book ahead. Bike space on each sailing is limited.
Forestry closures on the Statute Labour Road. Loch Ard Forest is a working forest. Check the Forestry and Land Scotland page for Loch Ard if you've travelled to do this ride.
A821 in summer. Sunday afternoons in July can be busy with cars, motorbikes, and coaches over Duke's Pass. Earlier starts mean quieter roads back into Aberfoyle.
Why it's worth doing
You ride roads built by three different agents: a parish that conscripted its tenants, a city that needed water and, if you take the road home, a duke who wanted his own way over the hill to the Trossachs. You pass the burial ground of the family that gave Scotland its most famous outlaw. The loch they wrap around has been the model for Highland tourism since Sir Walter Scott published The Lady of the Lake in 1810 and turned the Trossachs into a destination overnight.
Loch Katrine, path by the loch, photochrom print, 1890-1900. Library of Congress, public domain, via Wikimedia Commons
It's a long day. It earns its lunch.
Come and ride it. Start with a proper breakfast and a coffee at ours before you head out, it's a long day, and we'll show you where to book the boat if you'd rather take it on the way back.
