Gravel Cycling
Trossachs Forest Gravel Circuit
From Aberfoyle over the Duke's Pass to Loch Achray and Loch Katrine
Quick facts
- Distance
- Not published
- Ascent
- Not published
- Difficulty
- Moderate
- Route type
- Loop
- Archetype
- Forest Circuit
- Region
- Loch Lomond & The Trossachs
- Start point
- Aberfoyle
- Grid ref
- NN 519 009
- Parking
- FK8 3UX
- Midges
- High
- Dogs
- On lead only
Surface breakdown
- Forest track55%
- Tarmac single-track30%
- Double-track15%
About this route
Aberfoyle sits on the Highland Boundary Fault, and the change from lowland to Highland country north of the village is sudden. The A821 climbs north out of Aberfoyle over the Duke's Pass — a road built in 1885 that tops out at about 240 m — through Queen Elizabeth Forest Park to Loch Achray, under the crag of Ben A'an (454 m). Beyond is Loch Katrine, which has supplied Glasgow with water since 1859; the waterworks road runs along its north shore from Trossachs Pier towards Stronachlachar.
Forest roads in Queen Elizabeth Forest Park, including the area around Loch Drunkie, give alternatives to the main road. This page used to carry generated figures and several errors, so it has been reduced to what is fixed: plan and measure your own loop on OS Explorer OL46 and follow Forestry and Land Scotland signs on the forest roads.
Highlights
- The Duke's Pass road over the Highland edge north of Aberfoyle
- Loch Drunkie and the forest roads of Queen Elizabeth Forest Park
- Ben A'an above Loch Achray
- Loch Katrine and the waterworks road along its north shore
Key waypoints
- 1. Aberfoyle
- 2. Queen Elizabeth Forest Park
- 3. Duke's Pass
- 4. Loch Drunkie
- 5. Loch Achray
- 6. Trossachs Pier, Loch Katrine
Cafés & pubs on route
- · Aberfoyle has shops and cafés — check opening times out of season
Route notes
Not a traced route — no distance, ascent or timings are published. The Duke's Pass (A821) carries visitor traffic in summer. Forest roads are managed by Forestry and Land Scotland — follow any signed timber-operation diversions. Scottish access rights cover responsible cycling on the Loch Katrine shore road; give way to walkers and any authorised vehicles. The SS Sir Walter Scott sails between Trossachs Pier and Stronachlachar in season — the 2026 season ended on 25 October, so check the operator's timetable for the next one.
Seasonal conditions
Midges can be bad in the forest in still summer weather. Autumn colour on the Duke's Pass is good. Forest tracks are muddier in winter.
Key hazards
- Visitor traffic on the Duke's Pass road in summer
- Timber lorries and operations on forest roads
- Midges in the forest in summer
Water sources on route
- Burns and lochs in the forest (treat before drinking)
Always filter or treat water from natural sources. Carry at least 1L reserve on remote sections.
OS map sheets
Nearest hill
Ben Lomond
973.7m · arrochar-trossachs
View hill
Nearest bothy
Rowchoish
7km walk-in · loch-lomond-trossachs
View bothy
Daylight Today
- Sunrise
- 07:22
- Sunset
- 16:40
- Civil dawn
- 06:43
- Civil dusk
- 17:20
NOAA Solar Calculator · 31 October 2026
Common questions
- When was the Duke's Pass built?
- The road over the Duke's Pass, now the A821, was built in 1885. Its high point is about 240 m.
- Where is Rob Roy's Cave?
- On the east shore of Loch Lomond, north of Inversnaid — not in the Trossachs near Aberfoyle.
- Can I combine the ride with the Loch Katrine steamer?
- The SS Sir Walter Scott sails between Trossachs Pier and Stronachlachar in season. Its 2026 season ran from 27 March to 25 October, so check the operator's timetable for next year before planning around it.
- How long is the circuit?
- This page does not publish a distance. The figures it used to carry were generated rather than measured, so plan and measure your own loop on OS Explorer OL46.
After the ride
Resupply, eat, drink — on the SCOT network.
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