When I say flat, the climb into Cottenham from Rampton is 5m. The land is so shapeless, it does take some getting used to. I think it was a couple of years before I finally felt at home here and I have spoken with others that felt the same. It's not like I was born in the mountains, just somewhere with rolling hills.
I do like spending time in the hills when possible so when we decided it was time for a camping holiday in Cornwall I couldn't resist squeezing a bike into the back of the car. Unfortunately, the only one I could fit was my road bike, and that has Tour-de-France gearing on it. It has a double front chain ring, with 39 teeth on the smallest cog and 25T the largest at the back. This 39/25 combination in real terms means that 10mph is the lowest speed you can comfortably go at. Once any significant hill begins, I am out of the saddle and and heaving the pedals round. Lesson learned, I shall get a triple next time.
The landscape in much of the south of England is short sharp hills that over a ride add up to a lot of ascending. Cornwall's highest point is only 420m but you'll struggle to find a flat part.
One of my rides took me via Perranporth, Saint Agnes and it's beach - Trevaunance Cove. Fabulous views and scenery, steeped in pirate history and now surfer dudes.
Surfers at Trevaunance Cove, St. Agnes, Cornwall, surrounded by cliffs. |
Trevaunance Cove slipway. Cliffs behind. |
I find myself planning a lot of rides in hilly areas. It is a difficult balance, seeing enough landscape but without inflicting an impossible amount of pain on yourself. I last did that in Normandy, cycle camping with friends. I think we are still friends at least, we had to abort a route I had planned due to too many and too steep hills.
I have learned the hard way that online tools are not always accurate when planning a ride through a hilly area. They can cope with mountains, but the when they are short and sharp, the resolution of the elevation data is not good enough and they begin to under-estimate.
Take this ride via Perranporth, then an anti clockwise loop around St Agnes:
Trevaunance Cove is the last trough in the elevation profile:
Elevation profile of GPS trace. 399m ascent, but only 208m predicted by BikeRouteToaster. |
I took a less steep descent in, and then took a steeper road out. As it turned out, the road out was an impossible climb on my double chainset. The damp road caused my smooth tyres to spin when I was out of the saddle heaving with all my might. I was unable to deliver smooth spinning power with such high gearing. The OS map has (disappointingly) only one arrow on this section of road: 14%-20% (or 1-in-5 to 1-in-7).
Google Earth is quite a good tool for getting a feel for the landscape. If you export a GPX file from your GPS or BikeRouteToaster, it can load a GPX file and plot it over the terrain in 3D. This gives a general feel for the landscape, but its resolution is limited, meaning sheer rock faces will be smoothed out. I find hills look more realistic if you set the Elevation Exaggeration value to 2.
The total ascending measured by my GPS was 399m. BikeRouteToaster estimates 208m. This is quite a typical difference in my experience. Which is right ?
Google Earth's view with Elevation Exaggeration x2 |
When we all worked from paper maps, we would calculate ascent in one of two ways:
- The difference in height from bottom to top. There are some minor descents and re-ascents of around 10m on my elevation profile. Adding up any ascents bigger than 10m, I get a total of 308m.
- The other way is to count contour lines passed. This is tricky in steep areas, but I can do this with the elevation profile above. I count 350m.
They all disagree, with BikeRouteToaster giving the lowest ascent value. To be honest, I don't know which value is right. It's a bit like calculating the length of a coastline - it really depends on the resolution you want to work at. It's what it feels like to your body that really matters. Total ascent is a nice statistic, but the steepness of your route is more likely to make or break your ride - its no fun pushing a bike uphill.
Crackin' ride and a Cream Tea well and truly earned.
Cracking effort! I too prefer hills over headwind but I can barely imagine riding around Cornwall on such a high gear.
ReplyDeleteDid you know that up until 2010 that crazy St Agnes ascent used to be a feature in a regular steam engine challenge? Evey five years steam engines climbed Engine Hill until the annual steam rally moved to Stithians Showground.
Yep, that high gear was like getting a weights workout at the gym and I would not be able to last all day like that. I think my body could 'adapt' to a double if sticking to the B roads (and I saw plenty of roadies out on them) but they were hell at the weekend with August holiday makers - it was like a permanent rush hour near the coast.
ReplyDeleteThe steam engine event up Engine Hill must have been an excellent sight. The YouTube vids are fab. Which road are the Engines climbing ? The road I gave up on was Rocky Lane leading up from Trevaunance Cove.
I am just watching a stage of the Spanish Vuelta. It's nice to compare. A 4km section of a climb is around 20% (1 in 5) with a maximum gradient of 23.5% (I guess on a hairpin bend?). Commentator is saying that standing up results in wheelspin - yep! Also, there is a rider struggling having chosen the wrong gear ratio 36/28. My calculator says at 80rpm he is doing 13km/h. They say that at some points they are down to 8km/h. I feel his pain :-)
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