Does 100 feet equal one mile?

[RickH]

No, no, no; the hill that's too steep to ride down is the one where the rear wheel won't stay on the tarmac.

When it is that steep, the technique for riding is demonstrated at 3mins 45seconds on this video!



Rick.

[David_S]

Does 100 feet equal a mile?

No, not in my experience. I'm based in SW Cumbria on edge of Lake District. If I head inland my routes are undulating. By way of contrast, the Cumbrian coast, unlike that of Cornwall is flattish.

Below are two of my routes and times from recent rides, both in similar fair weather conditions, in fact recorded over the same weekend, for which I have calculated an average MPH assuming 100 feet equals one mile.

Inland Route:
Distance.......................................50.3 miles
Ascent.........................................5,413 feet (and this route deliberately designed to avoid the hills of the big passes!)
Time...........................................237 minutes
Average Speed................................12.7 mph
Distance restated 100 feet = 1 mile.......104.4 miles
Restated Average Speed Equivalent........26.4 mph

Coastal Route:
Distance.......................................27.7 miles
Ascent.........................................1,126 feet
Time...........................................92 minutes
Average Speed................................18.1 mph
Distance restated 100 feet = 1 mile.......38.8 miles
Restated Average Speed Equivalent........25.4 mph

I do not believe there is any way I could maintain an average speed of 26MPH over a 100 mile level flat route or even 25MPH over a level 40 mile route.

I do not know what speed I could maintain on a flat level course, but for the sake of speculation, if I assume it is 20MPH, then on my undulating route time of 237 minutes, I would cover a distance of 79 miles, making 188 feet worth 1 mile. On my flatter route time of 92 minutes I would cover a distance of 30.7 miles making 379 feet worth 1 mile.

A vast difference in the effect of climbing, which I put down to the nature of the routes. The undulating route is over poorer road surfaces and includes steep tricky descents with much braking, therefore fewer opportunities to gain time 'lost' on ascents. The flatter route on better roads with less sever inclines involves much less braking.

Conclusion: There is not a linear formula that links ascent to equivalent miles. But as a rule of thumb there is no way 100 feet is worth a mile it is many more feet per mile, possibly closer to 200 feet. If I could be bothered, I could do the calculation as an average on all my routes. Maybe I'll do that on a cold dark wet Sunday in winter!

[Mick F]

As I said, my calculation comes out as 1min per 100ft.
Roughly that makes 300ft per mile.

Out today and did (only) 16miles, but I did 2,100ft of total ascent.

That equates to +7miles = 23miles on the flat.

[horizon]

Yes, it looks like 100 ft is much too low a figure. But I could take 200 ft (or even 150 ft) bearing in mind:

Our relatively heavy bike (a Galaxy Twin)
The fact that we like to take stuff with us (flasks, raincoats etc)
Mrs H's less cycling experience
My own level of ability

But I think that the very steep hils around here do warrant some special allowance: it is not impossible that a steep slope will be much more physically depleting than the same ascent over a longer distance, even allowing for the extra mileage.

The other way to look at this is to speculate that hills aren't in fact that bad, no matter what we make of them at the time. Yes, they're tiring but usually they take about 10 - 15 mins maximum to climb, on or off the bike. This puts the lie to people's claims that hills make cycling impossibly arduous. On the contrary, the posts above are asserting that hills are not really making as much difference as you might think.

[Mick F]

Yep.
We live with hills. There is nowhere flat.
Some hills are long and some are short.
Some hills are steep, and some shallow.
Some are a mixture of both.

[David_S]

As well as steepness and length of ascent, it would be my contention that a significant determent of the effect of 'climbing' on time taken to cover a set distance, is the conditions of descent. If faced with a steep descent over a rough narrow road surface with s-bends and unguarded drops, you descend slowly, very slowly!

Extending my calculation above to cover my rides this summer, I calculated a figure of 196 feet per mile based on assumed level flat average speed of 20mph. This is different than Mike F's calculation, which may reflect other variables such as average ride distance, nature of terrain, steepness and length of ascents/descents, weight of rider, different bikes, different gearing, etc etc.

Whatever, hills slow you down!

[Psamathe]

I would have thought a lot must depend on weight. On flat ground, I would expect weight to have a lowish impact compared to when you start going up an incline.

And this would make is very different for different people.

Ian

[horizon]

The idea was really just to make comparisons (will this ride be harder than the last one?). Is 30 miles and 2000 ft harder than 40 miles and 1000 ft? Thanks to modern technology (aka Bike Hike) it's possible to work out quickly and accurately the distance and ascent of a ride in advance. Using a very broad a rule of thumb may not allow you to predict timings or transfer to other riders/groups but it would still make sense for one person (or two on tandem). However if the rule of thumb is wildly inaccurate, it will start to exaggerate (or minimise) the difference between rides and thus render itself less useful. However to calibrate the rule would only require a couple of rides. I think 150 ft is pretty close for us though I am sure that other riders will find that too generous. I'm going to more accurately time future rides to get the calibration as close as possible.