From Abergavenny, you head north-west up the Usk valley to the outskirts of Govilon, where the climb proper starts. The road lurches up steeply, over the Brecon and Monmouthshire canal and round a tight left-hand bend. Here I can usually smell the acrid odour of braking traffic, descending on the opposite side of the road. The first landmark, after a long, painful straight is the ‘Fiddler’s elbow’. Round this and the gradient nudges into double figures, through a conifer plantation. The road is deceiving: it doesn’t look that steep and even though I’ve been climbing the Tumble for years, I still check my GPS device at this point. This is where the inner voice harangues me – ‘give up’.

Cross the cattle grid and you’re out onto open, treeless moorland. There are fantastic views west, up the Usk Valley towards the high, twin peaks of the Brecon Beacons and back over your shoulder, north into the glacially sculpted hills and valleys of the Black Mountains. Not that I’m ever ready to savour them: the gradient eases off here but the cross wind – an eager little devil – usually hits you, heaping torment on to the pain. There are a couple of short, steep, out of the saddle ramps before the final section – a luxury at 3-4% - past the tarn and on to the top.

Stage three of the Tour of Britain finished on the summit. Mick Bennett, the race director was proved correct in his assumption that the Tumble will be a ‘significant moment in the race,’ and the ‘toughest summit finish yet’ of the Tour of Britain, revived in 2004.

If you fancy a tilt at the Tumble yourself, contact us and we'll give you all the pointers. The sportive riders will pile over the top, down to Blaenavon, across the spectacular landscape of Llangynidr moor and back along the Usk Valley to Abergavenny. It really is a great route, all on roads I know well.

I regularly climb the Tumble, and I always remember September, when I saw how it’s really done.