Bike Forums > How to rationally determine the cost of a pound?
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12-26-13, 07:43 AM   #126
Walter S
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 Originally Posted by Machka 2) Are you suggesting that the situation is simply this ... If the bicycle weighs 20 lbs ... and you can cycle 20 km/h ... Then if the bicycle weighs 120 lbs ... you should be able to slow down to compensate for that weight? And if the bicycle weighs 20 lbs ... and you can cycle up a 6% grade hill at 8 km/h ... Then if the bicycle weighs 120 lbs ... you should be able to slow down to compensate for that weight? If that is what you're suggesting, I'd question how slow you're prepared to go.
I would agree that there are practical limits to slowing down. As I pointed out in another part of this thread, I can't go slower than about 3.5 mph. I'd really up that to 4 mph for really appreciable distances. And when I'm climbing and hit first gear, there's no place to go but to slow down or push harder or walk. That changes everything.

But as I also mentioned on the original post, my weight vs. speed questions that started this thread are not meant to address the boundary conditions. There's a lot of room to go when increasing a load beyond 20 pounds, before you reach the 120 pound mark (as an example of a load that pushes practical limits on certain terrain). It is this domain that has been my focus.

I recently took a three week trip loaded with 80 lbs. of gear. I had a few long 7% grade climbs where I found first gear and I hugged the lower limit of my speed (3.5 mph). There were some steeper but shorter climbs where I walked. I got by with about 300 yards of walking during 1200 miles of touring. I probably could have avoided walking at all if my load had been half as much. But the trip was very practical to me - I don't mind walking that short distance to have the benefit I received from covering contingencies and/or personally enjoyable items.

12-26-13, 08:06 AM   #127
Machka
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 Originally Posted by Walter S I recently took a three week trip loaded with 80 lbs. of gear. I had a few long 7% grade climbs where I found first gear and I hugged the lower limit of my speed (3.5 mph). There were some steeper but shorter climbs where I walked. I got by with about 300 yards of walking during 1200 miles of touring. I probably could have avoided walking at all if my load had been half as much. But the trip was very practical to me - I don't mind walking that short distance to have the benefit I received from covering contingencies and/or personally enjoyable items.
And that works for you ... and obviously you've come up with a way to justify carrying all the things you do.

But for me, if I rode with 120 lbs (bicycle + gear), I could hardly move the bicycle on any surface more than about 0.5% grade.

A few other things ...

What about gears? How do they factor into the formulas? I've finally got a gear setup that allows me to get what little I bring up small hills. But with some of my earlier gearing combinations, I've been off and walking while others are happily spinning away?

Also, what about fitness? When I was at the peak of my fitness, I could tackle some fairly decent hills. But now, I can barely tackle a gradual incline with my lightest bicycles.

And on the topic of fitness and strength ... Rowan is a much better hill climber than I am. If you were to load the two of us up with the same load, he would arrive at the top of a hill long before I would.

Do the mathematical calculations take all that into consideration?

Incidentally, one of the "formulas" I've read in the past is that a cycletourist should be able to lift their bicycle, complete with gear, and walk 20 or 30 metres carrying it. I believe the idea was that if a cycletourist could carry their bicycle (and gear) a short distance, they could handle pushing it up hills, lifting it over things if necessary, and also hauling it through airports and train stations.

That piece of advice helped me settle on the half my body weight limitation. I can lift and carry half my body weight over a short distance ... more than that is difficult for me.

But for me, there's a whole lot more that goes into my packing decisions than just a mathematical calculation indicating whether or not I should be able to ride with a load of a particular weight.

Last edited by Machka; 12-26-13 at 08:27 AM.

12-26-13, 08:50 AM   #128
Walter S
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 Originally Posted by Machka What about gears? How do they factor into the formulas? I've finally got a gear setup that allows me to get what little I bring up small hills. But with some of my earlier gearing combinations, I've been off and walking while others are happily spinning away?
Our bodies are less efficient when the cadence is outside a certain range, a range that varies some depending on the individual. I think that factor is only loosely based on weight. The added resistance that motivates one to find an easier gear is based on both weight and incline and wind. The calculators, I think, assume an individual that has picked the "right" gear for the conditions.

Quote:
 Originally Posted by Machka Also, what about fitness? When I was at the peak of my fitness, I could tackle some fairly decent hills. But now, I can barely tackle a gradual incline with my lightest bicycles.
Your fitness affects the wattage you can maintain. If you're more fit then obviously you're capable of higher output. I think the calculators effectively take that into account and reasonably predict the speed you can maintain at a given wattage, weight, incline, wind.

Quote:
 Originally Posted by Machka And on the topic of fitness and strength ... Rowan is a much better hill climber than I am. If you were to load the two of us up with the same load, he would arrive at the top of a hill long before I would. Do the mathematical calculations take all that into consideration?
Traveling with a companion (which I've yet to do) introduces only one variable that can affect your willingness to slow down. Other factors such as the need to catch a train or plane the next day or be back at the office do the same. The calculator indicates about how much you will have to slow down to maintain the same energy output at a higher weight. If you're not willing to actually slow down, then you simply will not reap the benefit the calculation offers.

Any sensible plan will not include predicting a speed that's slower than you're actually willing to go. My focus with this thread has been to evaluate how much one needs to slow down based on a given weight, with the assumption that my intuition about that might be wrong. For example, when accelerating I can very much feel the impact of adding weight. That can send a signal from my legs to my brain that makes me feel like "man, this thing is a beast! how will I go 1000 miles like this!". But by realizing that acceleration is impacted more than the resistance at speed, I can put that at bay some and give the real impact a chance to surface by knowing that acceleration is a small part of the journey.

Quote:
 Originally Posted by Machka Incidentally, one of the "formulas" I've read in the past is that a cycletourist should be able to lift their bicycle, complete with gear, and walk 20 or 30 metres carrying it. I believe the idea was that if a cycletourist could carry their bicycle (and gear) a short distance, they could handle pushing it up hills, and also hauling it through airports and train stations.
I agree that practical weights limit your ability to maneuver the bicycle and if you push the limits you might find that impact more difficult than the impact on riding. If the ride is on level ground and you calculate you can go 15 mph and find that acceptable, that still doesn't mean you're well prepared to get the bicycle up a flight of stairs. On my recent tour I stayed in motels a few times and was always specifically interested in a ground floor room for that reason. I also found some camping opportunities to be challenging if for example I needed to ride across a ditch next to the road or something. Luckily some experience and wheeling the cycle around in your living room makes that factor reasonably easy to evaluate without investing many miles on the road.

12-26-13, 10:14 AM   #129
Walter S
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 Originally Posted by Machka Rowan is a much better hill climber than I am. If you were to load the two of us up with the same load, he would arrive at the top of a hill long before I would.
Tell him he's a slacker and should help more. Or sneak some of your stuff into his pack!

12-26-13, 05:47 PM   #130
Machka
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 Originally Posted by Walter S Tell him he's a slacker and should help more. Or sneak some of your stuff into his pack!
I just said "if" we were to carry the same load ... in reality, he carries a bit more (the tent, the cookware).

 12-26-13, 11:24 PM #131 pataspen Senior Member   Join Date: Jan 2013 Bikes: Posts: 93 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 4 Post(s) I don't go "ultralight", but I have certainly tried to go lighter. On my first cross country ride in 1986 my bike probably weighed close to 100 pounds (I wish I weighed it before I left). On my 2012 Alaska Highway ride my total weight, including the bike, all the camping gear, all my clothes, (everything from the ground up) was 48 pounds. Food and water added to this total. It might be psychological, but I definitely notice the difference on climbs. Flats not so much and downhills are the same. One big difference is that I can lift the loaded bike over a fence or easily carry it on my shoulder when I have to hoof it into the woods at night. After every tour I analyze my stuff and see if I can use something lighter or get rid of an item completely. On the Alaska trip there really wasn't anything that I didn't bring that I wished I had.
 12-26-13, 11:29 PM #132 pataspen Senior Member   Join Date: Jan 2013 Bikes: Posts: 93 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 4 Post(s) One other thought on cost... if going lighter means you can increase your speed from 12 to 15 mph (as in your example) that theoretically means you could do a 1500 mile tour in the same time it would take you to do a 1200 mile tour. What cool things might you see in those extra 300 miles? What's the cost of missing those extra 300 miles with no increase in effort? I know that's only theoretical and probably wouldn't work out exactly that way in the real world, but if cutting your gear means you can ride easier, faster, smoother, etc., it's worth considering.
12-27-13, 07:52 AM   #133
andrewclaus
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 Originally Posted by pataspen One other thought on cost... if going lighter means you can increase your speed from 12 to 15 mph (as in your example) that theoretically means you could do a 1500 mile tour in the same time it would take you to do a 1200 mile tour. What cool things might you see in those extra 300 miles? What's the cost of missing those extra 300 miles with no increase in effort? I know that's only theoretical and probably wouldn't work out exactly that way in the real world, but if cutting your gear means you can ride easier, faster, smoother, etc., it's worth considering.
Well said, and my feelings exactly.

I had a similar trajectory in weight loss as you described in your earlier post, and my load weighed nearly the same as yours on my last tour, a 4500 mile coast-to-coaster. I had tried that ride in my younger days with a much heavier load and couldn't make it in one season, and it hurt. Over the decades I dropped the pack weight, made the ride and had fun every day, including the difficult North Cascades Hwy in WA state. You can't put a price on those pounds.

Also that ride lasted several weeks less than I had estimated based on my earlier touring mileage. That saved quite a bit of money--the tour came in way under budget. Yet another cost to consider for a heavier and slower ride, if it hasn't been already in this long thread. Good one, though.

12-27-13, 04:35 PM   #134
Rowan
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 Originally Posted by pataspen One other thought on cost... if going lighter means you can increase your speed from 12 to 15 mph (as in your example) that theoretically means you could do a 1500 mile tour in the same time it would take you to do a 1200 mile tour. What cool things might you see in those extra 300 miles? What's the cost of missing those extra 300 miles with no increase in effort? I know that's only theoretical and probably wouldn't work out exactly that way in the real world, but if cutting your gear means you can ride easier, faster, smoother, etc., it's worth considering.
The alternative outlook is to ask how much could you do on the 1200-mile tour? Linger longer to see the sights in a national park? Make new friends and spend more time with them rather than dashing off? Kicking back and relaxing by a river, or even canoeing around a lake for a day? Get up later, arrive earlier, or splurge on lunch?

Yes, it does depend on what you are touring for... the journey, the destination, or what's in between.