Col de l'Iséran from Lanslebourg

Difficulty points	1055
Length	20 mi
Average gradient	4.5%
Steepest segment	10.6%
Total ascent	4760 ft

Reviews (31)

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PAVallee

8 Mo 5.0 via the Climbfinder app

This is an automatic translation, the original language is: French. Show original

One of my favourite passes in the French Alps. The first 20km are fairly easy, with a 2-3km climb and then a long, flat uphill section. From Bonneval-sur-Arc onwards, things get serious, but the scenery gets more beautiful as you climb. You'll love the views. Take some warm clothes to the summit, it's not hot up there, and stop off at Bonneval-sur-Arc, the magnificent village at the foot of the pass.

Piach

8 Mo 5.0 via the Climbfinder app

This is an automatic translation, the original language is: Italian. Show original

Up to -13km is an approach with long stretches of false flatness, then the real climb begins. It climbs in steps and there are rest sections where the gradients drop to 3-4％, the last 2.5-3km are the most difficult at 9-10％. Beautiful climb with beautiful views. I did it on a Sunday in September and there was very little traffic. It deserves

fpic12 ^premium

8 Mo 5.0

This is an automatic translation, the original language is: Italian. Show original

Wonderful climb... one of the most beautiful I have ever done. From Lanslebourg there are immediately 2km of quite hard climbing to arrive on a plateau of about 15km... it is beautiful, a green plain that leaves you open-mouthed. Towards the end you pass through the villages of Bessens and Bonneval... both very beautiful, Bonneval, all in stone, a little gem...from there begins the final hardest part that leads to the summit and you enter into a paradise...green valleys with streams, waterfalls and glaciers in the background...then towards the end the road wedges between the rocks, the last 3-4 km are very hard. asphalt always in good condition, less traffic than the galibier and narrower

WernerVanSteen

8 Mo 5.0

This is an automatic translation, the original language is: Dutch. Show original

Ridden 9 September 2025
Long climb from Lanslebourg (32km). Although the real climb only starts in Bonneval-sur-Arc, the approach from Lanslebourg is not to be underestimated, on the one hand because of the 20km but also bits that tip the 11％. Furthermore, you also have to cross the Col de la Madeleine (obviously not the Col de la Madeleine) after which the road descends again and you lose some of the altimeters you gained.
Just before Bonneval-sur-Arc you see the flank on the left where you have to go up and there is a fountain with drinkable water. Definitely fill your water bottles because after that I didn't come across an open café ! The valley you climb through is quite impressive, especially under the threatening clouds that were on hand today. The percentages are about the same during the 12km climb though, with the last 2km stretches around 10％. A strong wind was blowing on the col and a warm jacket and windstopper were no luxury. The descent to Bonneval-sur-Arc is super ; almost flat tarmac and good visibility. Sometimes the road is less wide which does make it more watchful of traffic in the summer season. Keep some energy left to return to Lanslebourg as there are a few more uphill stretches. Highly recommended, if only to realise you have just cycled up the highest asphalted mountain pass in France.

christine ^premium

9 Mo 5.0 via the Climbfinder app

a dramatic landscape. spectacular scenery from Lanslebourg. initially up wide picturesque road to col de la madeleine, then a false flat but still magnificent valley road at 1700m between bessans (a preety village) and bonnevale. lucky ko traffic so the tranquility was wonderful. the real climbing starts with stupendous views the whole way. like ithers have said, that penultimate km is a shocker! a must do climb in its entirety!

Cromagnon ^premium

9 Mo 5.0

This is an automatic translation, the original language is: French. Show original

I've never seen so many bikes on a mountain pass!
It's a real pleasure! The pros, the galley slaves, the young and the old. Cyclists in bike packing mode, climbing harder than guys in the latest Pinarello.
Up there, you had to queue for the photo. Not to mention the hordes of motorcyclists and car drivers who also wanted to celebrate their achievement of having polluted up to 2800 metres.
As far as the pass is concerned, everything has been said and written. The scenery is splendid and powerful.
The profile of this pass is atypical: 19km of beautiful, peaceful riding with the exception of this passage at 10％ which wakes you up.
We pass a Col de La Madeleine that has strayed here. Families photograph each other in front of the sign, convinced that this is the famous Tour de France pass.
The going gets tougher from Bonneval sur Arc onwards.
In fact, the climb really begins after 19 kilometres of warm-up.
Long preliminaries.
There are 13km to go, broken down into 3 short, fairly solid 4km climbs interspersed with rest areas.
The penultimate kilometre at 10％ hurts.
The Vanoise glaciers accompany us and it's so much easier to pedal in this majestic setting.
It's the Post Office calendar of my childhood! I'll be back for the snowy version.
Of course, the Iseran is one of the must-do passes.

Herve2023 ^premium

9 Mo 5.0

This is an automatic translation, the original language is: French. Show original

Aesthetically, this slope is the most beautiful: one of the most beautiful landscapes in the French Alps for a cyclist.
The route begins with a 5km climb over a pass known as the Col de la Madeleine. This is followed by a dozen or so relatively flat kilometres in a very pleasant, pastoral setting. After Bonneval, the overall climb is 8％, surrounded by the high glacial peaks of the Vanoise and the Alpes Grées.
The ascent via Lanslebourg is generally less strenuous than the 50km on the north side.
You can come back down to Val d'Isère and climb back up again, to do the whole tour...

DenisB34

9 Mo 5.0 via the Climbfinder app

This is an automatic translation, the original language is: French. Show original

excellent day... at least the afternoon shower... Departure from Bessans. VAE for our joints... LOL. but a great pleasure...

gaugau7

9 Mo 5.0 via the Climbfinder app

This is an automatic translation, the original language is: French. Show original

* It can be cold, so make sure you have a windbreaker in your bag for the descent!

gaugau7

9 Mo 1.0 via the Climbfinder app

This is an automatic translation, the original language is: French. Show original

This is clearly the most beautiful ascent I've ever made, and also one of the most difficult! The whole approach to the valley is difficult, especially when the wind is head-on. The first part from Bonneval consists of two sections on the mountainside separated by a hairpin bend. Then comes the most beautiful part of the climb, in the middle of a torrent and a waterfall. Then you move on to a very rocky environment, with the last two kilometres being terrible, especially if the wind is blowing. You can really feel the effects of the altitude! The view from the summit is superb, but it's a bit tricky.

Dirk-Jan

9 Mo 2.0 via the Climbfinder app

This is an automatic translation, the original language is: Dutch. Show original

Done from Val-Cenis. The tarmac is wretched. If that had only been the case at the climb: so be it. But the whole route from Val Cenis to the foot of the climb (and all the way to the top) is just bad. That goes nowhere with such a departmental road. The climb itself is fine, not too busy with traffic (mainly motorcyclists). However, the devil for me was in the last km: you see the ski station and think you're almost there but then suddenly there's another fireside chat and the road bends back and you see that you still have a long way to go. Cold wind up there, bring a vest or jacket for the descent

marijnS ^premium

9 Mo 5.0

This is an automatic translation, the original language is: Dutch. Show original

Did the climb from Lanslebourg Mont-Cenis today. The scenery is beautiful, but the long straight road after the col de la Madeleine is not very inspiring. And quietly looking around is not possible, as it is a busy 80 road.

But then. As you approach Bonneval, you see the road running against the mountainside. In two long pulls, you drive up to a plateau, where you enter a fairytale world. After that it is sometimes gruelling (especially the second to last kilometre), but always there is also time for recovery in some flatter kilometres.

In short: a must-do for anyone who loves climbing.
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Can't there be a segment from Bonneval? Firstly, I don't really see the part up to Bonneval as part of the Iseran. An additional advantage is that it would make the profile and percentages of the climb clearer, since at a length of 13 kilometres the scale can be given in kilometres instead of 2 kilometres.

Strokes08 ^premium

10 Mo 5.0

This is an automatic translation, the original language is: French. Show original

Col done in both directions yesterday, it's beautiful on both sides, a must do, via Bonneval sur Arc, it's hard with high percentages and a few welcome respites. 32kms from lenslebourg with 2 small passes at the start then from the valley

dominiqueb85

1 y 5.0 via the Climbfinder app

This is an automatic translation, the original language is: French. Show original

A magnificent pass on this side, a pleasure every time.

GB44

1 y 5.0

This is an automatic translation, the original language is: French. Show original

One of the most beautiful passes I've ever done, the scenery is breathtakingly superb, with the last 12 kilometres quite difficult.

hillonearth ^premium

1 y 5.0

After Bonneval the climb proper begins and the scenery on a clear day becomes breathtaking, with extensive snow to see on nearby peaks even in July. Wild feel, with few buildings. An absolute holiday highlight and the only place we saw real marmots lolloping about and making their high-pitched calls. The gradients are never too hard. For us the traffic was not too bad. Quiet at times.

pierre81

1 y 5.0

This is an automatic translation, the original language is: French. Show original

Watch out for the average percentage, which is very misleading! From Lanslebourg, you first have to negotiate the Col de la Madeleine (~3.5km at 7.3％). This is followed by a long false flat climb towards Bonneval-sur-Arc before tackling the ascent.
The pass is divided into three sections, separated by two flat areas. The first 3 km are an appetiser, before the most difficult part after the first plateau. Don't forget to wrap up warm as it can get very chilly at the top. The road is good (I was expecting worse), but beware of the traffic with lots of cars and especially motorbikes (some of which pass very close by...). And beware of the marmots that can cross in front of you!

Da_Caveman ^premium

1 y 5.0

This is an automatic translation, the original language is: Italian. Show original

A marvellous climb in a landscape that is sometimes fairytale-like. Today (15/6/2024) in Bonneval-sur-Arc the road was closed...but not for bicycles! Climbing the Iseran almost solo is a rare experience and today the huge walls of snow made it unforgettable!

jcvd25

2 y 5.0

This is an automatic translation, the original language is: French. Show original

An incredible experience! Spectacular scenery, a demanding climb and breathtaking views at the summit. A must for cycling fans!

RobiRini66

3 y 5.0 02:01:16 (9.9 mph)

This is an automatic translation, the original language is: Italian. Show original

Col du Mont Cenis from Susa and then Iseran for an epic day. Highly recommended.
Beware of the altitude, it can cut your legs, if you have already acclimatised a little it is better
Perfect road or many possibilities for a stop-off with refreshments

ankertiel

3 y 5.0 02:00:00 (10 mph)

This is an automatic translation, the original language is: Dutch. Show original

From Bourg d'Oisans, from where we warmed up after coffee, we flew up d'Huez without luggage, first on the 42/23 but soon on to the 20 because it looked like we were pedalling in thin air after 1500km of hard work from The Hague with 20kg on the back.
Around 45 minutes we reached the top, earlier or later I don't know because we didn't have any gauges, not even a speedometer, we just counted our revolutions (42÷17) ×2.1×omw...we didn't have anything else to hand.
From the campsite along the reservoir towards la Grave where the real climbing started but the serious work only started from the Lautaret. Almost at the top the light went out completely although I should already have tasted it on my shoulders which were completely salt-free. And just like Snip and Snappie hup there I was.
Koos took his chance as eternal 2nd and stood at the top with a big smile between the snow walls.
A tablespoon of salt, water and a Gini brought me back to war strength followed by a super descent where even an A-310 had to go...Telegraphe was just a pimple and from there to a wonderfully quiet camp site de commune with a beautiful church in the village that knew the first and last quarter by heart under the light of the full moon...insane....
After breakfast we headed for d'Iseran where we steamed up in 2 hours between the wonderfully refreshing snow walls under a burning sun, 5.5％ is quite distorted by the way and the descent to the authentic Val d'Isère was also a relief where we indulged in beer, coffee and crêpes, then on to Bourg St Maurice after which we continued the Roselend and Saissies to Sallanches the other day. 3000km in three weeks and legs like beech trees and jeans to Salvation Army....

Ejprins

4 y 5.0

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Magnificent! Done a few climbs in the maurienne valley but this one is in a different category in terms of beauty. I drove a lot by car to do this climb from lanslebourg. The plateau is really beautiful. Above the tree line it is magical and finally some dirty steep climbing. Unfortunately I had some fog on top that day so very cold and few views. The stone mini village in bonneval-sur-arc is not to be missed. You cycle right past it but it is worth a look!

Kevin ^premium

4 y 5.0

This is an automatic translation, the original language is: Dutch. Show original

In 2018 we rode up the Iseran from Bessans. The last kilometers climbing through the snow walls were unforgettable. In terms of environment and panorama's this climb is extremely enjoyable!

achatelet

4 y 5.0

This is an automatic translation, the original language is: French. Show original

The climb is more about the last 13 km which is the most difficult part of this pass. The landscape is incredible and it is the highest cycling pass in France.

bwestland ^premium

4 y 5.0

This is an automatic translation, the original language is: Dutch. Show original

Done the double top... After descending from the summit to Bonneval, a quiet medieval village, we turned around and started on the difficult side. After climbing steadily through the beautiful wide green valley, you get slowly to the rough top where the last kms hurt, especially with the climb to the top from Val d' Isere already in the legs. Beautiful views and snow are the bonus.

keniske

5 y 5.0

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very heavy Col if you start from Modane, from here it is just 56km up to the top but once you've reached the top you feel a real kick ;)

patrickbaert ^premium

5 y 5.0

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Cycled on 28/08/2020
Long quiet approach with in the beginning as a surprise some tough climbing kilometers just outside Lanslevillard
To "not the real" Col de la Madeleine. Real start after first hairpin turn in Bonneval sur Arc where afterwards nothing but natural beauty follows, especially after you entered the heart of the National Park de la Vanoise.
Dream scenery: snowy peaks, glaciers, rocks, hardly any traffic, no buildings, no ski lifts, no crash barriers, few people, beautiful waterfalls, stray animals ....
In the top 10 of my most beautiful climbs.

Practical: From Bonneval known white-yellow bicycle poles every kilometre (height/％ next km./distance to top.

MonsieurJaspere

5 y 5.0

This is an automatic translation, the original language is: Dutch. Show original

Most beautiful climb I've done for a while! I cycled it the day before the Tour riders, Bernal laid the foundation for his final victory there (stage cancelled) ... Beautiful Nature all around and not super hard!

Thimo Petri

6 y

This is an automatic translation, the original language is: Dutch. Show original

Beautiful climb where you really enjoy all the views!
It is easy to do, even the length is still ok! Only the last few km you have to go deeper!
21% harder than Alpe d'Huez? Perhaps by the length then, because it goes up a few percent at most.

GuuSjah

8 y

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I did this last summer, amazingly beautiful climb where the whole first part 'lives' to the final climb to 2770m altitude. Totally agree with Jan, cycling in the Alps as it should be.

Jan

9 y

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Fantastic climb from the south side. Beautiful views and certainly on the high altitudes around the top, a very 'rough' experience. It is highly recommended to climb firstly the Col du Mont Cenis from Susa, and from there on to the Iseran. As cycling fun in the Alps should be!

Climbing times

5 mph	04:01:48
7 mph	02:51:11
9 mph	02:13:24
12 mph	01:40:13

Road surface condition

41% 55% 5%

Based on 22 votes

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Traffic

29% 62% 10%

Based on 21 votes

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Frequently Asked Questions

Col de l'Iséran can be cycled from 3 sides. Col de l'Iséran from Bourg Saint Maurice is the most popular side, but the summit can also be reached via Col de l'Iséran from Lanslebourg & Col de l'Iséran from Val-d'Isère.

You don't need special gearing for Col de l'Iséran from Lanslebourg. The slope isn't long or steep enough to require much shifting down. You can conquer this climb on power alone. However, a compact gearing system with a smallest front chainring of 34 and largest rear sprocket of 28 or 30 is always nice if you enjoy cycling uphill. This helps maintain a smooth cadence.

Col de l'Iséran from Lanslebourg belongs to the Hors Catégorie, the top category. These are legendary and very tough climbs. A solid cycling condition, experience, and a good climbing gear ratio are essential to maintain a smooth cadence and complete the climb comfortably.

Col de l'Iséran from Lanslebourg is 20 mi long.

The average gradient of Col de l'Iséran from Lanslebourg is 4.5%.

Col de l'Iséran from Lanslebourg has a steepest segment with an average gradient of 10.6%.

The summit of Col de l'Iséran from Lanslebourg is at 9088 ft.

At a slow pace of 5 mph, it takes about 04:01:48 to climb Col de l'Iséran from Lanslebourg. At 7 mph the time is 02:51:11, and at 9 mph 02:13:24. For the fastest cyclists, 01:40:13 is an achievable time.

Col de l'Iséran from Lanslebourg is located in the region Savoie in France.

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Photos (95)

Reviews (31)

Climbing times

Road surface condition

Traffic

Frequently Asked Questions

Col de l'Iséran from Lanslebourg

Statistics

Short recap

Photos (95)

Reviews (31)

Climbing times

Road surface condition

Traffic

Frequently Asked Questions

Which sides of the Col de l'Iséran can be cycled up?

What gearing is needed for Col de l'Iséran from Lanslebourg?

How difficult is the Col de l'Iséran from Lanslebourg?

How long is the climb up Col de l'Iséran from Lanslebourg?

What is the gradient of Col de l'Iséran from Lanslebourg?

What is the steepest part of Col de l'Iséran from Lanslebourg?

How high is Col de l'Iséran from Lanslebourg?

How long does it take to cycle up Col de l'Iséran from Lanslebourg?

Where is Col de l'Iséran from Lanslebourg located?