Toughest Climb in the UK

As the saying goes, we ‘..descend into the bowels of hell’. Today, ironically, was an ascent into said bowels. For me, after the third time of climbing it, I can confidently say I climbed the hardest climb in the UK.

The Cowlyd

I hear your sharp in-take of breath and sense a raised eyebrow. I probably haven’t ridden your local killer climb or even some of the more famous ascents in this country. True. But I still stand by my claim and I challenge anyone to find me a tougher tarmac road to ride up.

I’m not alone in my assertion either. Simon Warren, author of the 100 Climbs series of books confirmed it too. He mentions comparisons to the Angliru in Spain, Government health warnings and 11/10 for difficulty in his short description of the climb. If anyone has any experience of the steepest and toughest climbs in the UK, he arguably has the most. Here is an extract from his book (note the spelling mistake in the name and I do own a copy!)


the tarmac really is that good on the hairpins!

The Cowlyd is a service road that serves the Llyn Cowlyd reservoir on top of the mountain. Its a dead end. The highpoint isn’t the end of the road though. You can go over the top and plunge into the wilderness if you want until you hit the gate that ends the road. You will see and hear nothing. Pure escapism. I first climbed it a couple of years ago. My parents live in Glan Conwy, further up the valley and I often trawl OS maps looking for new roads and climbs when I’m up there visiting. I found The Cowlyd by chance really, drawn to it by the arrows on the map and a lack of Streetview past half way. After that first attempt I was 50/50 whether it was the hardest hill I had ever ridden up. Up until then the Bwlch-y-Groes was top of my list. A 2nd attempt late last year finally confirmed it was clearly the hardest hill climb I had ever done. That day, in poor weather, my Garmin packed up and I had no record of the climb. Todays ride was about getting a ride up it logged and to get some pics on the descent so I can share this beast with you all.

The climb nestles on the western side of the Conwy Valley in North Wales and climbs out of the village of Trefriw. Probably most famous for its woollen mills. The climb starts immediately from the B5106 which dissects the village. A coffee shop sits on the corner at the foot of the climb ready for your pre-climb brew or post-climb recovery.

it don’t look too bad on an OS map

Before attempting this climb. Two important things to think about.

  • Gearing
    You will need a VERY, VERY LOW GEAR. You’ve got 2 miles of 20%+ climbing to do. Go as low as you can. You will need it. You will use it. I’m 65kg, fit and 34×28 is a real struggle but then again any gear will be.
  • Brakes
    Hmmmmm. Its a bit counter-intuitive to think about brakes for a climb but trust me the descent is seriously steep. Its essential you have brakes that are probably above average.

    The first time I descended this hill I wasn’t properly prepared and I had to stop and cool my rims down in a stream.

    I ride a cross bike. I have cantis. Not great but I have upgraded them to the best brake pads I can get and I specifically check and adjust them just for this ride. Disc brakes are best. But whatever you have, ensure the calipers, cables and pads (and rims if applicable) are tip top. You crash up there and no one will find you.

So onto the ride itself. The plan was to leave around 10.30am and be back for lunch. A simple route. Out to the climb, up ‘n’ over to the reservoir, descend, take some pics and back home via Llanrwst. 2 hrs. Easy.

I left just before 10.30am. The A470 south was busy and the climb for the first mile is narrow and twisty. Frustrated drivers rev their engines and overtake hard. I hate it but as soon as you get over that first lump you drop down to the estuary, the vista opens up in front of you and the road widens, traffic is no longer and issue. I crossed the River Conwy at Tal-y-Cafn and climbed up to Tyn-y-Groes. Snow capped peaks in the distance. Two decent ascents in my legs already and the sensations were good. Dropping down to Tal-y-bont and riding on past Surf Snowdonia in Dolgarrog I had that much clothing on I couldn’t feel the bitterly cold wind but riding felt like I had my brakes on and my face was frozen. It was really hard. Next stop was Trefriw. The gates of hell where I stopped briefly to take a pic of the start of the climb. I rode on to get my 1st gear ready, turned round, left turn by the coffee shop and boom. I’m on the climb.

Coffee to start or finish? The climb starts here

I’ve already engaged my 34×28. I won’t change gear now for the next 25 mins. Its straight up out of the saddle between the houses. It gets steeper just up the road. Left at a T- Junction then right onto the climb proper. 20% at least up past some houses until they filter out but the gradient doesn’t relent.

Somewhere to take a nap on the way back down

The next half a mile is a leg breaker. The road bears round to the right gradually and just gets gently steeper and steeper until you reach a 1 in 3 left hand hairpin that makes you ride around the outside of it on the right. Its an absolutely disgusting section of road. My Garmin stopped I was riding that slowly. I doubt anyone could ride the inside. For about 30 meters after the bend the road ramps up steeper. Sat down I can pull wheelies on my 23lb cross bike. It takes every sinew in your body to haul yourself over this bit. Its the steepest section of road I have ever ridden.

33% hairpin anyone? It gets harder around the corner

Only after this ramp do you get a tiny bit of rest. A 20 metre flatter section which ends with a cattle grid and begins what I can only describe as a ladder of hairpin bends, tightly stacked on top of each other. The height gain is ridiculous. The pain in your arms and back from hauling yourself round each one is ridiculous too.

If you are not broken enough by the length of the climb so far, the relentless gradient, your aching arms, its not over by a long shot. Out of the hairpins and the trees, the road now grinds up much straighter and longer up over the mountain. Twice you’ll see a false summit which will kill off any sense of achievment you may have been considering at that point and will only serve to extend the pain. At this stage, you have no concept of time. It feels like an eternity and you can’t wait for it to to stop. You just keep grinding on and on until you know its the top because you can see down the other side.

The views are amazing if you can take your mind off the pain and have a look around.

Another cattle grid and thats it. Done. Top of the World.

As Strava told me when I got back. The climb took me 26 minutes. I hauled my 23lb cross bike with 30c tyres up, for me, the toughest climb in the UK. It don’t matter how quick I did it in (7.0km/h for me lol) but I may consider a visit again on my lightweight road bike later in the year just to compare.

nothing to shout about here other than I probably had the heaviest bike
spot the climb

Its pretty wild up there. The views on a day like today are amazing. Ironically I saw a few cars this time. Farmers mainly and one walker who warned me of ice as I dropped over the top to ride down to the reservoir. Unfortunately a massive section of ice stopped me. I couldn’t be arsed to walk round it in the mud so I just tuned round and rode back up to the summit.

Ice stopped play. Check out those snow-capped peaks in the distance!

I descended into a biting wind, stopping to take all these photos. Gloves off, photo, back on, off to the next spot. Despite been so cold it was good because it broke up what is otherwise a pretty treachrous descent. My brakes operated very well this time despite being cantis.

At the foot of the climb I had no time to stop. I had to make tracks and get back as I was going out for lunch. I continued onto Llanwrst. My jaw froze it was that cold. Finally after crossing the river again a left through the town and I was enjoying a nice (but still bloody cold) tailwind back up the A470 to home. I briefly popped onto the cycle path that runs parallel to the main road just for a change. Its decent but not long enough. Back on the main road I got my head down now and upped the pace on the relatively flat valley road before the last climb of the day back up and over past Bodnant Gardens which at the end of any ride is a slog.

A quick drop down the other side and I was home. 2hrs in the bag, legs in a box.

The Colwyd is a bucket list climb. I highly recommend you try and do it. I advise you prepare properly though. Consider the time of year. It was icy in places today. Its a mountain so the weather can be way worse up top than in the valley. Dress appropriately. Tell people where you are going. And finally, you and your bike have to be in good nick and make sure your brakes are better than average. Check and double check them. Its a dangerous descent.

There are similar climbs around here which no doubt I’ll talk about in future posts but anyway, thanks for reading.


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