The mountains the Tour Auvergne-Rhône-Alpes visits in the final three days of its 2026 edition are not famous in the way the Galibier or Alpe d'Huez are famous. They carry no single iconic photograph, no Tour de France GC moment that every cycling fan can immediately name. What they carry is consistent difficulty — the kind of relentless gradient that cannot be managed by gearing alone, only by knowing your own threshold and holding precisely below it for the 40–50 minutes it takes to reach the top.
The Grand Colombier is one of France's few Hors Catégorie climbs without a mountain resort at its summit. The Plateau de Solaison has an alpage — a high mountain plateau used for summer cattle grazing — rather than a ski lift. Both climbs are better for the absence. No crowds of ski tourists. No resort infrastructure to soften the approach. Just the road, the gradient, and alpine pasture at the top.
The Climbs
Col du Grand Colombier (1,501m)
The Grand Colombier has four distinct ascent routes. The Tour Auvergne-Rhône-Alpes uses the Virieu-le-Petit approach in 2026 — the hardest variant. 8.4 kilometres at 10.2 percent average. Sustained gradients between 8 and 14 percent throughout the upper half, with the Lacets du Grand Colombier hairpin section providing the most technically demanding kilometre of the ascent.
The Lacets are not just a photographic landmark — they compress the gradient into consecutive tight switchbacks where the road rises steeply, turns sharply, and rises again before the previous turn is fully processed. Athletes who arrive at the Lacets with too much pace find the hairpins difficult to sustain through. Athletes who hold back on the approach to the Lacets and save something for the upper ramp survive better.
The summit is unremarkable as a location — a road junction, a view across the Ain valley, and a descent option in four directions. The reward for climbing via Virieu-le-Petit is not the summit itself. It is the knowledge of the specific thing you just climbed.
Other ascent routes: - From Culoz (southern approach): 7.8km at 8.6% — slightly easier average with the cleanest road surface - From Anglefort (western): a gentler option used in training and for riders building to the harder sides - From Lochieu (eastern): the least-used variant, longest but lowest average gradient
The descent from the Grand Colombier toward Anglefort on the race's 2026 route is technical — faster than it looks from the bottom, with road surface changes that warrant caution on wet days and in morning shade.
Plateau de Solaison (1,473m)
The Solaison climb begins at the village of Serraval and ends on the plateau's flat top section, where the road opens into high grassland and cattle grazing replaces road-side barriers. 11.3 kilometres at 9.1 percent average. Unlike the Grand Colombier, the Solaison has relatively uniform gradient — which means few moments of recovery and no section where a burst of gradient can be used as an excuse to ease.
The most common mistake on Solaison for first-time visitors is the kilometre around the halfway point where the gradient briefly eases to 6–7 percent. The ease is relative: at this point in an ascent of this length, 7 percent still demands sustained effort. Riders who accelerate at this false flat typically regret it on the upper three kilometres.
Access from Thônes: The main valley town, Thônes, is directly below Serraval. The road from Thônes to Serraval is well-signed; the Solaison ascent begins at Serraval's edge. Start early in the morning before recreational traffic builds, especially on weekends.
Col des Aravis (1,498m)
The Aravis connects the Megève basin to the Thônes valley and carries more regular cyclist traffic than most Haute-Savoie passes because the road quality is excellent and the gradient manageable without being dull. The standard ascent from La Giettaz is 10.6 kilometres at 6.3 percent — a recovery climb by the standards of the Colombier and Solaison, but deceptive at race pace late in stage 8 when three weeks of June racing have already loaded the legs. The summit cross and panorama toward Mont Blanc are the most photographed spot on the stage 8 route.
Combined with Solaison: Descend the Aravis toward Thônes, navigate through the valley to Serraval, begin Solaison. Two to three hours at training pace; approximately 90 minutes at race pace.
Recommended Routes
The Stage 8 Finale Replica (~85km from Annecy, ~2,400m)
Annecy → Thônes → La Giettaz → Col des Aravis → Thônes valley → Serraval → Plateau de Solaison → Serraval → Thônes → Annecy.
This loop replicates the final section of the race's queen stage. A substantial day — the Aravis and Solaison in sequence, with the valley kilometres keeping the legs honest between climbs. Total elevation approximately 2,400 metres.
The Grand Colombier Circuit (~120km from Belley, ~2,800m)
Belley → Culoz → Grand Colombier (Virieu-le-Petit ascent) → descent to Anglefort → Lagnieu → Belley.
The Grand Colombier from the race side, with the Virieu-le-Petit switchbacks included. Base in Belley — a small episcopal city at the foot of the Ain valley with adequate accommodation and notably good local dining.
The Multi-Day Dauphiné Loop (3–4 days, ~300km, ~7,000m)
Day 1: Grenoble → Vizille → Vercors plateau → Grenoble Day 2: Grenoble → Belley → Grand Colombier (Virieu-le-Petit) → Culoz → Belley Day 3: Belley → Annecy → Aravis → Solaison → Annecy Day 4: Annecy → Megève → Col de la Croix Fry → Thônes → Annecy (recovery)
The full itinerary for a cyclist who wants to experience both of the race's mountain stages in a coherent loop.
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Join ZealZagFollow us on InstagramWhen to Ride
June is the race month. Passes are open, road surfaces freshly repaired, temperatures warm enough to ride without base layers above 1,000 metres. June carries significant weekend traffic on the Aravis — plan early morning starts.
September is local cyclists' preferred month: cooler air, quieter roads, early autumn colour on larch sections above the Aravis.
Where to Base
Annecy for Solaison and Aravis access — one of France's most cycling-friendly towns, with bike hire and shops plentiful.
Thônes is the valley town directly below the Solaison access road — quieter, more practical for stage 8 climbs.
Belley for the Grand Colombier — small Ain town, quieter than the Annecy basin.
Grenoble covers the race start in Vizille and the Vercors and Chartreuse massifs.
Getting There
From Geneva airport: 45 minutes to Annecy. Aravis and Solaison 30–40 minutes further. Grand Colombier 90 minutes south toward Belley.
From Lyon airport: 90 minutes to Grenoble. Haute-Savoie (Aravis, Solaison) 2–2.5 hours from Lyon.
By train: TGV Paris → Annecy in ~3 hours. Car hire from Annecy for mountain access.
Frequently Asked
Is the Grand Colombier suitable for intermediate cyclists? The Virieu-le-Petit side is not recommended for riders unfamiliar with sustained double-digit gradients. The Culoz approach is manageable with a 32–34-tooth cassette. The Solaison is consistently difficult throughout — no easy alternative. Both climbs should be treated as advanced objectives.
Can I ride the Grand Colombier and Solaison on the same day? Technically yes but it requires a 90-minute drive between them. Experienced athletes have done both in one day. For most riders, treating each as a separate day's objective is the better plan.
What gearing do I need for Solaison? A compact crank (50/34 or 48/32) with at least a 32-tooth cassette for the 11.3km sustained average. Carry a lightweight rain layer — weather at 1,500m changes quickly.
Are there cafés on the Solaison climb? No cafés on the ascent. Thônes (~15km below) has bakeries and cafés — stock up before leaving.
For today's Dauphiné GC preview and start list analysis, see our Tour Auvergne-Rhône-Alpes 2026 preview. For Dolomite cycling from this week's Giro Donne, see the Cadore cycling route guide.
