Most misleading gradient sign

[roubaixtuesday]

At the base of the climb from Llangollen to Glyn Ceriog is a 13% sign.

The road promptly rears up, averaging 25% for a stretch over 500m long according to strava.

The entire 1.75 kilometre climb averages over 13%.

https://www.strava.com/segments/1836553?hl=en-GB

And it was infested with swarms of flies. Bastards.

Any competition out there?

 

[fossyant]

The signs are an 'average' - don't forget strava isn't that accurate. Worry when it says 25% or 33%

 

[roubaixtuesday]

The signs are an 'average'

I don't think so. They generally refer to the maximum part I think.

Certainly, just to pick a famous example, the Hardknott does NOT average 33%!

 

[Dogtrousers]

To be honest I've never taken them at their word. Time was they were expressed as a ratio, and I never understood what that meant. So I just got into the habit of seeing an up wedge or a down wedge.

 

[Mr Celine]

Don't believe Strava. I'm on my phone so can't link to it but there is a segment called Roman Rd Climb to the West of Hownam in the Scottish Borders. The Strava profile includes a vertical pitch of several hundred feet. Presumably this is why they rate it as cat 2.
I've never needed a rope but a triple does help.

 

[roubaixtuesday]

To be honest I've never taken them at their word

Me neither. But I've never experienced one where the gradient is fully double the advertised, for a very long stretch.

 

[Dogtrousers]

Don't believe Strava.

It's right in this instance. I just took a squint at the OS map. Just so I know what roads to avoid if I ever find myself in Llangollen.

 

[roubaixtuesday]

Don't believe Strava

I only looked on Strava because of the feeling in my legs! And I didn't take the instantaneous reported number on Strava, but the average over a significant distance.

Anyway, here's the OS. It's around a 25% average from the 150 to 275 contour.

Just for comparison, here's a later climb on same ride advertised at 17% (1:6)

The (very short) steepest part of this climb is far less severe that what the top one averages for half a kilometre!

 

[dodgy]

I'm familiar with those roads. They are steep whatever the gradients happen to be.

 

[Beebo]

A sign on M25 at junction 8 says 10%.
It is steep for a motorway but it isn’t anywhere near 10% but I will never ride it on my bike.

 

[steverob]

I guess it does depend on who installs the sign (or rather who signs off on the work order for the sign to be installed by someone else) as to what they are actually measuring.

There are two hills local to me about a mile from each other and both have a 10% sign at the bottom despite being very different climbs. On one the climb averages 10% (steepest part is maybe 15%), while the other it reaches about 10% at its steepest point (average is around 6%). Both fall under the same council's jurisdiction, so if they can't make up their minds as to what the sign is supposed to mean, I don't think any of us stand a chance either!

 

[a.twiddler]

All those crowded contour lines ought to give a clue! It's a long time since I lived in Wales but even by choosing the least hilly routes I ended up battling some unexpectedly steep climbs. I live in Cheshire now and the terrain is nothing like Wales but there are some unexpected climbs to be found (or maybe I am just getting more feak and weeble in my old age).

A few months ago I ventured into Staffordshire en route for Newcastle following the map. There was nothing unusual marked on the map but following the B5367 I found myself coming to a halt on the hill through Alsagers Bank. There were no chevrons, the contour lines were not unusually close and there were no gradient signs by the roadside. There are houses either side of the road with cars parked in front of them. It's just a street, not a sheep-lonely windy mountainside. I knew there was a hill there but nothing I couldn't climb (I thought). It's Staffordshire after all, there are hills all over the place. I ended up walking about 100 yards, which is something I haven't done for a long time. It was a lot of fun on the way back though.

Now fitted a lower bottom gear. At some time, I'll be baaack for another go.

 

[T4tomo]

at the bottom

from the top

I've ridden up and down, as long as you realise there are a couple of very sharp bends so take it slowly, I see no reason to dismount

 

[tyred]

They should simplify the signs by just saying Flat, a bit hilly, steep or bloody steep.

 

[MartinQ]

At the base of the climb from Llangollen to Glyn Ceriog is a 13% sign.

The road promptly rears up, averaging 25% for a stretch over 500m long according to strava.

The entire 1.75 kilometre climb averages over 13%.

https://www.strava.com/segments/1836553?hl=en-GB

And it was infested with swarms of flies. Bastards.

Any competition out there?

Colin Edge did it in 3 minutes, so about 20mph at 1.1kW ...
What are you complaining about