), amended now – thanks for pointing it out.Trek have been playing with the scales once again, today launching their brand new Emonda SLR. Its daunting 16.12º gradient does not put off the puffing tourists, many of whom meander gently past the shops, pubs and cafes on The Strait before making their handrail-assisted ascent. First built in 2nd century by the Romans, the pass is unbelievably tough from both directions. What comes next will take your breath away. The majority of Scotland's roads stick to valleys as there's no need to cross the mountains but here they link the village of Applecross with the rest of the world by taking the route over the top of Bealach-na-Ba. And it's so steep, close to 25% at the point where the tall valley walls disappear and the radar slowly rises over the horizon to sit above you, tracking the remainder of your progress. In front of you is the Alpine-style Ski Centre, a simply awesome ride.

It climbs over 3.5km into the Aran Mountains on the edge of Snowdonia. The first 200m is also viciously steep. It's not too steep to begin with but as the road bends hard left at the base of an almighty tower of rock, then the gradient increases. It got me thinking this morning about what the steepest road in the UK is and what it's like to drive. Whatever it is, it makes the stretch of climbing ahead look terrifying. The road is, thankfully, nice and smooth but it’s next sting is that it banks slightly right on its 20% slope towards a corner.The maximum gradient is said to be 25%, or even 30%, and this is where the hill bends left and goes upwards again to where the hill evens out a bit.But that’s not the end, because there is a final kick up with just 50m to go to the top. What’s shown is the Bealach na Ba, looking down the hill to Loch Kishorn. Anything you have read or been told about this amazing road is likely to be true. After all that has preceded it, the finale – a set of four hairpin bends – may be all too much, but fear not.

Leave the head of Loch Kishorn, turn left and you're on your way, soon passing the large sign warning of the various dangers that lie ahead. This climb isn't for the faint-hearted.

If you can ride this, you can ride anything. It never relents, never lets up until you reach the bend in the shadow of a rocky outcrop, you've still got a fair bit of climbing to reach the top, but it's not as hard now.

Other side of the country!The picture of Ffordd Penllech is actually the bottom of Vale Street in Bristol, and the Hardknott picture is Hardknott West, not Hardknott East.You’re right Richard (and Dom! Stick with it, as eventually the one-in-three does turn into a relatively gentle one-in-six, allowing you to build a little momentum to drag your bike up on to the moor. A long, long stretch of wickedly steep tarmac lies ahead, hugging the side of the mountain, with a slight levelling halfway but steeper still after that. Remote Bwlch-y-Groes, Dinas Mawddwy, in Gwynedd, claims the title as the highest tarmacked pass in Wales and is also known as Hellfire Pass.

The hardest ascent is from the west, beginning at Fell Foot Farm, where straight away you have a 20% right-hander and that's just a taste of what lies ahead. Approaching from either direction you see the radar station's "golf ball" glowing like a beacon on the top of the ridge. Leave the A470 at Dinas Mawddwy and head into the Afon Dyfi Valley. Heave yourself round this evil corner and you're through the worst of it. The surface is rough at first and steep from the outset, but improves as you pass over a cattlegrid and approach the double hairpin. Pass through the large orange gates used to close the road in winter – proof, if you hadn't twigged already, that you're heading into serious country. Leaving Rosedale Abbey, a sign warns you of the one-in-three – yes, one-in-three – gradient to come. I'd waited a long time to ride this road, initially put off by its "private" status.

The second set of switchbacks are steeper still, and these now 30% slopes will have you straining every sinew as your front wheel desperately searches for a kinder gradient and weaves all over the road fighting to stay upright.

Try it if you dare.Bwlch Penbarras (image: SimonPix @ CreativeCommons)With an average gradient of “just” 7.7% you might imagine that this 7.5km hill is simply one long slog. Through a second gate it's easy for a while then bending right once again it's leg-breakingly tough to the finish at the station, where, looking around you, you might as well be on top of the world. I was to discover that there is absolutely no objection to cyclists riding it, although few would be mad enough. From the junction with Station Road, exit the village past the first 25% sign then the road bends left at a second 25% warning – as if you need reminding, it's going to be hard. The road levels between the sharp bends giving you a chance to attack each wicked corner then gather yourself in time for the next.

You're now face to face with the vicious 25% corner which delivers you on to the cruel slopes that cling to the side of the sheer bank. The second bend here is so steep on the inside that it forces you far right, so take care.

After a few slight rises the road surface improves dramatically and stretches far into the distance, taking the shortest route over the featureless ridge.

All rights reserved. Still, that's the least of your worries as you pass a 25% sign. You'll be counting each and every pedal rev as you slowly push your way up the scree-littered road to the summit.