Added in Etape Cymru, which I found MILES harder than IM Wales, but appears initially to be comparable. So I checked the maths and I wonder where some of the data is coming from. I believe IM Wales has 1,220 metres of "up", so just 10.9m/mile. Likewise, I think last year's Outlaw had 496m of up, which makes just 4.3m/mile. If I'm right, perhaps the variance can be explained by the well known Iron-Ego Inflation Coefficient?

That said, I might be talking right out of my starfish as oft times before, so I won't change the numbers below.

Scottish coast to coast 42.99m per mile

Fred Whitton 30.89m

Aqueduct thingy - 27.9m

Chiltern 100 Biggy - 24.5m

Etape Cymru - 21.7m

Ironman Wales - 21.4m

Cheshire Cat - 20.9 m

Bike Radar - 17.4m

IMFR - 16.0m

IM Regensberg 13.39m

IMCH- 11.25m

Outlaw 11.07m

Challenge Vichy (2013 race ?) 9.6m

IMDE - 8.69 m