Utility Cycling - Max Weight??

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View Full Version : Max Weight??


TuckertonRR
05-16-08, 08:48 AM
What's the most weight that you can tow with a bike? What are the constraints, just one's ability to pedal & make the chain go round? how much tension can a chain take? the gearring?


tfahrner
05-16-08, 09:35 AM
ok i'll play.

by "bike" can it not be a trike? with bikes a constraint is that you must be able to reach a certain speed fairly quickly lest you simply can't balance. getting the load moving is the hardest part -- once it's rolling it's not so bad to keep it going. and forget hills up or down -- that's a whole nother area.

also by "tow" i assume you're thinking trailer, say 3 or more wheels so balance isn't an issue. can the trailer be on rails so the rolling resistance is minimal?

ok, cherry picking here, i'll wager that with a ridiculously low gear, like maybe 4 gear inches, on a bicycle hitched to a freight car on rails on level ground, one could get the thing rolling loaded up with, o, at least 5,000 lbs. maybe much more.

if it can be a trike doing the hauling, just gear it down further and weight the drive wheel(s) for traction and i'll haul an aircraft carrier into drydock for you -- very, very, very slowly. couple inches a day at least! think hour hand versus second hand: same energy, different gearing.

now, using an off-the-shelf bicycle and maybe an automotive trailer hitched to it, where the trailer doesn't have independent brakes and the load is balanced over the trailer axle, i figure about 1000 lbs is the max load you could handle pedaling slowly across town, assuming it's flat. no sudden braking because the trailer will just push the bike with locked-up wheels over the road.

we own a dutch delivery trike that is rated to 670lbs but can probably handle 1000. on a bicycle, it's hard to design one that can handle loads in the 500lb range gracefully.

bloompedal08
05-16-08, 09:38 AM
The amount of weight you can haul is a factor of incline, wind speed, your personal strength, smoothness of the road, etc. On a perfectly flat, well-paved road with no wind resistance, a reasonably fit 100# teenage girl should be able to pull 1000# for a long distance, given appropriate gearing on the bike. Where I live, I don't like to pull more than 300#, because of the hills, wind, crappy streets, etc.


StephenH
05-16-08, 11:45 AM
Riding around with my Worksman front-loader trike, I find that the extra weight is surprisingly noticeable on the least little hill. Flat pedaling, no problem. Minor upgrade, and all the sudden you notice every pound on that thing, even if it's not much. So yeah, you can haul 1,000 lbs on the right rig, but there aren't that many places where you would want to.

If you did have hills, downhill might give you as much trouble as uphill, unless you had exceptionally good brakes.

AllenG
05-16-08, 12:00 PM
My largest load on my Xtra-Lite was 400 lbs. of potting soil, and I weigh 150, so I my bike can handle 550 pounds for 12 miles (and I'm cheating here, it has a Panasonic electric assist motor).

Gearing is an issue, as is the robustness of the equipment. My Xtra-Lite is a hub eating machine, I've cracked a few hubs on it now.
Currently I'm running a NuVinci. Of all the hubs I've owned I believe the NuVinci to be the most robust and capable of handling grossly large loads. It just doesn't seem to care what it's pulling.

cman
05-16-08, 12:37 PM
Bikes at work has and article.

http://www.bikesatwork.com/hauling-cargo-by-bike/hpv-cargo-capacity.html

StephenH
05-16-08, 03:12 PM
Interesting link.

"The lowest gear of most mountain bikes is between 16 and 22 gear inches (see our section on gearing and gear inches (http://www.bikesatwork.com/hauling-cargo-by-bike/gearing-and-gear-inches.html) for an explanation). We've found that a bike equipped with a low gear of 18 gear inches is sufficient to allow most people to pull a trailer carrying 300 lbs up a moderate (4%) grade. While it is possible to pull a load greater than this up such a grade, it takes considerably more effort."

Note that one of the Mercurio cargo trikes I listed earlier had gearing of 1:1 or 26 gear inches. My Worksman front loader is about 39- I'll have to count teeth when I get home.

(Later)
Counted, has 36 teeth in front, gives me 45 gear-inches.

Per the chart on that website, I could haul 2101 lbs with "maximum exertion" on level ground. This sounds about right, and would be about par with pushing a car, which I can do. On a 2% slope with "significant exertion", I can move the trike, myself, and 128 lbs of cargo.

One thing I've noticed, too, in a lot of these third-world countries, when you see people moving huge loads by bike or trike, they'll just have the load on the bike while they walk beside it. I guess the moral is, once you get down to walking speeds and below, it's just as efficient to get off and push as it is to ride anything with superlow gears.

Nightshade
05-16-08, 08:19 PM
Max weight you ask? Well......Let me see now. :innocent:

"I" weight 300# (down from 380# :thumb:) My homemade trailer can haul 300#, my bike
weight 45#, so I can "haul" 645# easy!:D

My Worksman PAV trike is heavy duty machine weighing in at 105#, so with the trunk I installed,
which can haul 350#, I figure roughly 455# total trike adding 300# for my butt you get a
whopping 755# that I hual when fully loaded!:eek::eek::eek: Holy God! I'm 255# overlimit!

God! No wonder I ride that trike in low gear all the time. :cry::cry:

ken cummings
05-16-08, 08:53 PM
A while back at an IHPVA meet a two person recumbent pulled one ton of people crowded onto a 4-wheel trailer. On the flat. On a steeper hill there would be a problem with front end lift-off. Or loss of traction if you have a long enough wheel-base. I've seen a pedal-powered winch/elevator system used to lift people and equipment into and out of a deep cave. In France I believe. It took something like an hour to lift a person some 2300 feet.

StephenH
05-16-08, 10:11 PM
Seems like this weighed 3 tons (might have been 3,000 lbs, I forget):
http://www.publico.clix.pt/imagens.aspx/138766?tp=UH&db=IMAGENS

streetlightpoet
05-16-08, 10:24 PM
http://www.airstream.net/images/cyclist.jpg
a decent amount.

Novakane
05-17-08, 12:33 AM
http://www.airstream.net/images/cyclist.jpg
a decent amount.

Holy crap... Where is the derailleur? That's either a single speed or an internal hub... Either way, given the airstream no wonder he looks so darned serious!

wahoonc
05-17-08, 09:09 AM
Holy crap... Where is the derailleur? That's either a single speed or an internal hub... Either way, given the airstream no wonder he looks so darned serious!

Internal hub, 3 or 4 speed Sturmey Archer. He was also a professional racer. The trailer was a shell without the interior cabinets and fittings. But still probably weighed in close to 2,000#. (I am an Airstream owner too)

Aaron:)

invisiblehand
05-18-08, 07:39 PM
What happened when he wanted to stop?

:eek:


http://www.airstream.net/images/cyclist.jpg
a decent amount.

bloompedal08
05-18-08, 08:51 PM
What happened when he wanted to stop?

:eek:

given the controlled conditions of this experiment, i'll wager he gave himself a good 500 feet to bring it to a halt :backpedal:

surfimp
05-18-08, 09:25 PM
http://www.stevelange.net/images/steve_and_kids_sm.jpg

I can haul my Wike trailer with both boys and assorted sundries (around 90-100lbs. depending on food & toys in the trunk) on my fixed gear up mild hills. My bike is running 700x37 tires and 42x16 gearing which is about 71" gear inches IIRC. Gets the old heart rate up! :)

Steve