Two cols on a Commencal

A 30lb Commencal hardtail. Not the weapon of choice for col bagging but that's all the lady at the tourist office in Bedous could offer me, and at €10 a day I wasn't really complaining: any bike is better than no bike.

Our base for our family week in the Pyrenees, the Fontaines D'Escot, is smack bang at the bottom of the Col de Marie Blanque – the steep side – and that was to be the first challenge of the day.

Incidentally, the Fontaines comes highly recommended – it's a beautiful, rambling old hotel with a long history (there's evidence of people using the thermal spring there way back into Roman times) and the current owners, Corinne and Richy, are busy turning the building that was closed as a hotel for 30 years into a great place to stay. Currently there's a posh wing and a more traditional bit, with some self catering units too. Definitely worth a look if you're bringing the bike and the family.

Anyway, to the climb. Most Pyrenean cols have a helpful sign at the bottom giving you the breakdown for the ascent, and the Marie Blanque is pretty daunting. It's not long, only 9km, but it manages 700m of climbing along the way and kilometre averages of 12 and 13 percent towards the top. It's an uncompromising climb, a bit like the steep middle section of the Ventoux, as if the road builders had to get to the summit and didn't have much tarmac left. With the tyre pumped up harder than recommended and the fork locked out the Commencal was tackling the climb with plenty of gusto and it was 5km in before I had to leave the big ring.

As soon as the gradient steepened though the pace was a bit more sedate, as much my fault (a week of determined Camembert eating) as the bike's. The road clings to a pretty vertiginous valley wall and the gradient is unrelenting, getting steeper as you go. No hairpins, save for one right at the top, and the last two km, with 250m of vertical gain, are purgatory. There's no tea rooms at the top of this one, just a sign to lean your bike against for the photo and the road pointing down, crossing the plateau before diving down into the next valley.

The valley road meanders up towards Laruns, but all the time getting closer to what looks like an impenetrable wall of mountains. By the time you reach the town it's a bit more obvious that there's two choices: dive right through a narrow cutting towards the Col du Portalet and Spain; or head left towards the ski station of Gourette and beyond it the Hors-category, 1709m Col d'Aubisque, where I was headed.

It's 16km to the top and there's the best part of 1,200m of climbing to do. Up to the the thermal station of Eaux Bonnes it's a fairly easy amble with some loose hairpins thrown in and great views of the valley floor, but after the spa town the graidents begin to ramp up as the road scrambles for a navigable route up the valley, following the river for a distance before diving across to the northern wall for a bit of serious height gain. The weather, which had been cloudy and calm, was great form climbing, but the cloud level of about 1300m meant that by the time my tired legs had dragged me up to Gourette with 4.5km still to climb, the mists were swirling and visibility was down to about 50m, less if I was wearing my fogged up specs.

All the time the road struck upwards, and by now I was hurting pretty badly, the excesses of the week and the weight of the bike (and rider) taking its toll. Kilometres seemed to be taking hours, with no visibility and no frame of reference for my progress I was starting to wane, but the dolly mixtures in the back pocket kept me going on the final stretch, and after the obligatory photo op it was time to don the arm warmers and dive back the way I'd come, before heading for home via what's surely the world's most serpentine bit of tarmac, the D918 from Arudy to Asasp-Arros: 25km of riding and not a single straight bit, it's a fantastic finish to a long day.

Cols bagged: 2. Alttitude gained: about 2,100m. Fun had: lots