Trails and Hills

I went out to the Arlington-Bedford Minuteman bike trail this morning. I did the 17 mile return trip at a 14.4mph moving average - not bad given the stops and starts at the road crossings. It was my first time back this year. I had forgotten that even 2% grades on rail trails are tough when they are a mile long. Talking of hills, Hue Rhodes sent out another training tip on hills (see the first one here). Here it is:

Why are hills so hard? One word. And it's a bad word: Weight.

When you ride on the flats, you work to overcome wind resistance. There is also friction in your wheels, friction between the road and your tires, and friction in your gears. But most of your effort goes into fighting wind. And the wind pushes back on you in proportion to your height, off the ground. Recumbent bikes face less wind resistance, because they are lower. Taller people face more wind resistance. But most people find the wind manageable, and enjoy riding on the flats.

On a hill, you have all the same forces working against you, PLUS a percentage of your weight (you plus the bike) pulling you back down. Specifically, your weight (mass x gravity) times the sine of the hill's angle. The sine of the angle increases the steeper the hill gets. So the steeper the hill, the MORE force acting to pull you back.

Example. I'll use myself. I weigh 215 pounds (I carry it well, though). My bike weighs another 20 pounds. Together we weigh 235 pounds. Let's say I am climbing a hill that is 7 degrees.

Weight = 235 pounds
Hill = 7 degrees (a 7 foot rise for every 100 feet I go horizontally.)
Sin(7 degrees) = 0.12235 x 235 = 28.6 pounds!

I have almost 30 pounds pulling me right back down the hill! As a result, I slow down. A lot. You may not weigh 235 pounds. But you might have less muscle than I do. Even if you weigh 150 pounds, you still have 18.3 pounds pulling you back down the hill. As a rider who struggles with hills, what can I do?

1. I can spend money to get a lighter bike. If I ride a mountain bike, a road bike will probably knock off 5 or so pounds. If I have a road bike and feel like spending $5000, I can probably knock off another 5 pounds for a tricked out composite bike.
2. I can weigh less. Me, personally, I could lose a few pounds. Which means that how I eat when I'm not riding (i.e. during the week) has a bigger impact on my hill climbing than anything else I do. Riding helps with cardio health, circulation, muscle strength and over-all fitness. But weight loss comes through diet control, off the bike. Sorry, but it does.
3. I can get a granny gear. If my bike doesn't have a super-light gear, I will struggle to maintain my balance as my bike slows down. Lighter gears let me spin up the hill easier, because when I'm on a hill, I can't do anything about my weight at that
4. I can accept that hills are slower, and enjoy the ride. This is probably the smartest thing to do. Riding is fun. And when I'm on a hill, I should congratulate myself for being on my bike in the first place.

I can promise myself that I'll use skim milk in my cereal next week, but in the meantime I should enjoy the scenery.
See you on the hills!

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