Chamechaude seen from the Charmant Som, with Belledonne behind. Photo: Marion Frachisse / Chartreuse Tourisme
Chartreuse & Charmant Som
73 kmHalf a day~1 h 50 ridingFrom Grenoble
A step up: you climb to the Col de Porte and then to the Charmant Som pastures, one of the finest viewpoints in the massif, before dropping back via the Col du Coq. 73 km, inside the 100 km included.
🏍️ Included in the €49 discovery deal. This loop is under 100 km, so it fits inside the mileage allowance of your half-day on a Triumph — from age 20 on an A2 licence.
The loop in detailGrenoble, Col de Porte, Charmant Som, Col du Coq73 kmapprox. 1 h 50
envie2rouler shop — Grenoble (La Tronche)start
Le Sappey-en-Chartreuse+12 km
Col de Porte+6 km
Charmant Som+6 km
Col du Coq+19 km
envie2rouler shop — Grenoble+31 km
What you pass along the way
The Col de Porte (1,326 m): the start of the narrow pasture road up to the Charmant Som.
The Charmant Som pastures, above 1,660 m: one of the finest viewpoints reachable by road in the Isère, with the mountain farm at the end of the road.
The Col du Coq (1,434 m), at the foot of the Dent de Crolles, on the way back.
Photo stops not to be missed
Six stops scouted along the 73 km of the loop, including the finest road viewpoint in the Isère.
1
The Col de Porte, 1,326 mThe start of the narrow pasture road up to the Charmant Som.
2
The hairpins on the climb to the Charmant SomA narrow road, tight hairpins, pastures all around. Frame the bike against the slope, parking in a wide spot.
3
The end-of-road car park at the Charmant Som, above 1,660 mThe view drops onto the Grande Chartreuse monastery in its valley and reaches, on a clear day, as far as Mont Blanc. It is the most open viewpoint you can reach by motorcycle within an hour of Grenoble.
4
The mountain herdsFrom June to September, the cows stand on the road around the mountain farm. Slow down — and take the picture while you are at it.
5
The Col du Coq, 1,434 mThe Dent de Crolles above you, late in the day when the wall turns orange.
6
The descent into the GrésivaudanThe valley opening up with Belledonne opposite, from one of the upper bends.
What you will see along the way
The Charmant Som pasture road
From the Col de Porte (1,326 m), a narrow road climbs another six kilometres to the Charmant Som pastures, above 1,660 metres. It is one of the finest road viewpoints in the Isère: on a clear day the view reaches the Vercors, Belledonne and Mont Blanc. The climb is narrow, in tight hairpins, and ends facing the void.
From the top of the Charmant Som, 1,867 m: the cliffs of the massif and the Belledonne range beyond. The road stops a little lower, at the pasture car park. Photo: Albane Villecourt / Chartreuse Tourisme
The Col de Porte and the Col du Coq
The outward leg runs through Le Sappey-en-Chartreuse and the Col de Palaquit (1,154 m) before the Col de Porte. The way back tips over the Col du Coq (1,434 m), at the foot of the Dent de Crolles, then drops into the Grésivaudan. Three passes, one viewpoint, and only 73 kilometres.
Chamechaude, 2,082 m, above the forest: the summit that watches over the whole climb to the Col de Porte. Photo: Albane Villecourt / Chartreuse Tourisme
A step up from the other discovery loops
This is the most demanding of our three Chartreuse loops: the Charmant Som road is narrow, with no barrier in places, and asks you to be comfortable at low speed. In exchange, it is also the one with the widest panorama.
Good to know before you set off
73 km: the loop fits inside the 100 km included in the €49 discovery deal.
About 1 h 50 of actual riding, plus the time you spend at the viewpoint.
The Charmant Som road closes in winter and can stay snow-covered late into spring. Best season: June to October.
A narrow road, busy with walkers at weekends: ride up early and take a wide line through the hairpins.
Herds are up on the pastures from June to September, often on the road itself.
Frequently asked questions
Is the Charmant Som road open all year?
No. It closes in winter and reopens once it is cleared, usually in spring. The safest window runs from June to October. Check conditions before you set off.
Is this loop harder than the other discovery rides?
Yes, a step up. The climb to the Charmant Som is narrow, in tight hairpins and with no barrier in places. It remains fine on an A2 licence, but you need to be comfortable at low speed.
What can you see from the Charmant Som?
Balcony pastures above the massif and, on a clear day, a view over the Vercors, the Belledonne range and Mont Blanc. It is the most open viewpoint reachable by motorcycle within an hour of Grenoble.
What does the €49 discovery deal include?
A half-day rental with 100 km and insurance included, from Grenoble, on an A2 or a full A licence. Helmet and gloves are optional extras. The discovery deal is non-cancellable.
Ready to ride for €49?
The Triumph Trident 660 (A2) is waiting for you in Grenoble, prepared and insured. Book your discovery half-day, pick your date and your slot, and set off on this loop.
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