Climbing hills with cargo
 

The secret to cargo cycling is patients and low gears.
I know of one man that built a long cargo bike with the cargo box to the rear rather than in front of the rider, he has a hard time balancing it on the turns.


I need 10 gear-inches with 390lbs on 16% grade. That’s about 2 mph with a 60 rpm crank spped.
However it is possible to climb hills in higher gear on an MTB I use 22 gear-inches as apposed to 18gi on my recumbent bike.

this is what I do with my legs:
18 front / 34 rear sprockets = 1 to .53 ratio .............
60 rpm’s at the crank x (.53) = 31.76wheel rpm's..............
62.8” circumference x 31.76 rpm's = 1994.82 ipm ..............
Divided by 12 = 166.235 fpm ..........
166.235 x 60 minutes = 9974.117 fph ............
Divided by 5280 = 1.889 mph.........

has any one else done this kind of hill climbing?

i have. used to be part of my courier job. i got muscles in places i thought not possible.

Might make a good video. Good brakes would be in order, I would think.

I've noticed when you see these pictures of 3-world bicyclists with humongous loads, half the time, they're just pushing the bike rather than riding it, and that might work on that kind of a slope.

No way you are walking 400 lbs up a 16% grade. Those Chinese would fail miserably. It maybe possible to ride loads like this up steep grades with the gearing described, but no way you will walk it, forget about it.

Brakes aren't really important for climbing, by the way.

No, I never did try to haul anywhere near that weight up a hill, you are crazy.

Been there, done that; my low gear is around 12", so it gets me gradually up just about anything, even with file cabinets or logs on the back. Mostly you just need to be determined. I look right at the hill and tell it "I'm putting you under me." Also, walking is, in fact, a more stable lower gear. Depending on the size steps you take, you can take it down as low as you need to, and you know you won't be toppling over if you just stop for a quick breather. Not that I've done that (too often).

Yippie aye yeah, buckeroo! 400lbs up a hill pushing it with your arms, Popeye, you the man!

How do you "stop for a quick breather" when you are holding 400lbs from rolling back? Chocks?

Maybe I'm crazy, but that is when I use the brakes. To, you know, keep it from rolling downhill. They work.

How is the load being measured? I wonder if everyone is talking about the same thing. Is the 390 lbs. independent of the bike and rider? Or is the 390 lbs. a gross weight that includes the bike and rider?

Walking 400 lbs up a 16% grade would involve 64 lbs of force along the direction of the grade. And yeah, I think that could be done. It wouldn't be fast, either. I think I've put a good bit more than that into pushing cars.

You are welcome to try it, but my legs are stronger than my arms and the mechanical advantage of low gearing lead me to believe it would be much harder to walk a load uphill than to pedal it. I have some experience with heavily loaded trailer...

I have been known to walk my loaded Xtracycle up a hill. That is also known as "Chinese Low Gear" according to Tom Cuthbertson in Better Bikes. The e assist helps prevent that. Like Val says, I use the brakes to take a breather when I am walking up a hill.
When I walk the load up the hill it seems easier than pedaling.

Yay Chinese Low! For me, it's not just about having an effectively lower gear, but also a chance to use a different set of muscles for a bit, giving my riding muscles a chance to recover.

Fair enough. To be honest, I haven't hauled any really big loads uphill. Washington is pretty flat. I haven't been able to get my chain on the granny recently and have been managing with a 36 small ring and a 32 big cog.

Just pushing my rig on the flat with a big load from the sidewalk to the street for instance seems tough, but what do I know?

Not me
http://i478.photobucket.com/albums/r...ith/bike/5.jpg

I'm guessing the small man in the picture has difficulty riding astride his tall bike, hence he is pushing it. It might be better if he adapted a harness just so that he can pull his trailer.

Brakes
 

I have two disc brakes on the rear and a rim brake on the front that has a pin to hold the brake on when parked.

At 60 rpm there is not too much need to stop the hill is not too long ...although I could use a lower gear..

at 2 mph people walk past me.

The question was directed at someone who thinks walking heavy loads up steep hills is a viable option.

Personally I think I can get a much bigger load up a steep hill riding than what I could push up the same hill walking my bike, but we're all different. What is your opinion on this? The fact that your low gearing allows you to spin 60rpm while moving slower than a pedestrian seems to indicate the bike is a tool that helps you get up the hill, not something you want to get off and push like a handcart (albeit a handcart with brakes to keep it from rolling backwards :rolleyes:).

Walking seems to give up all the mechanical advantage that a bicycle affords. I don't get it.

I can use chopsticks, but prefer a fork.

I've done a bit of self-supported touring with a 5,5m sea kayak on tow (on a trailer). I would estimate total weight of myself, bike, trailer, kayak and gear to be maybe 160-170kg. This is mostly flat country, >10% grades are not very common, maxing out at 20% or thereabouts. So, weight and slope were not up to this thread's specs. But the trailer frame has a bit of flex that made things more interesting.

I learned it takes some planning to spin the trailer-bike combo up even those hills. You don't want to spin too quickly, but on the other hand you don't want to lose any momentum monkeying around with gear changes and whatnot. (At 16% grade, I'd imagine you don't have anything to shift down to, so no worries there.) I also cannot spin evenly off-seat. Uneven spinning plus trailer flex proved to result to a nasty rocking effect that made the combination very difficult to ride.

I don't know which is harder - walking the combo or spinning my lugns out at 5km/h (a 700c hybrid bike). I think Val said it: walking or pushing uphill stresses different muscles as opposed to riding. On that tour, if I were fed up with pedalling, I walked the hill, particularly if the road was unpaved (loose gravel). I'd use brakes to catch some breath and in some cases park the whole contraption to a bus stop to have a drink. Whatever was needed to get me up that hill. If I had already walked a hill recently, I'd spin.

--J

I imagine that the bicycle makes the trailer more stable front to back and takes the weight so he doesn't have to. And, once he gets done carrying the load, its much faster to return on the bicycle than walking the trailer back.

I was carrying 200lbs of mortar mix on my Xtra up a 15% grade (I guess). I almost made it up but couldn't stand up to pedal because of the load, so I walked. I had to stop to breath 3 times while pushing. I love gearing.