Load Limits and Towing Capacity

How Much Can I Tow in this Trailer? Mac & Cheese for the Local Food Bank!

Yesterday, I used my "free to me" trailer for grocery shopping - it's nice not to have to worry about fitting everything in a bag or even two, and backpacks can be a PIA. Starting out, however, cargo capacity became a question when I started out up a little slope in the parking lot to leave for home. Further on, I felt doubly privileged to shop in a place as flat as Ocean Shores, Washington.

In the motor vehicle world, load limits and towing capacity are pretty cut and dried. What's more, manufacturers publish their values, though these are not always highlighted when the numbers don't support selling vehicles to people.

Two major values include:

• Gross Vehicle Weight Rating (GVWR) - this is the maximum amount the vehicle is rated which includes the vehicle itself, fuel and oil, and all payload (passengers, pets and luggage, including any roof racks and contents thereof). Our Subaru Outback has a GVWR rating of 4,695 pounds, since its empty weight is 3,600 pounds, that means we can carry a bit less than 1,000 pounds. If there are five people in the car, that doesn't leave a whole bunch leftover for luggage.
• Maximum Towing Capacity - this is the maximum amount the vehicle can safely tow. Some so-called utility vehicles, such as the Vokswagen Allroad have no approved towing capacity at all. Our Subaru Outback has a rated towing capacity of 2,700 pounds.

There are lots of other ratings, such as "Gross Combined Weight Rating," but these are not so easy to track down. It appears that Subaru simply lets you tow 2,700 pounds whether the vehicle itself is full or empty.

How Does This Apply to Bikes?
In the bicycle world, these values are not so easy to find. It's pretty easy to find out the "empty weight" of most new bicycles, but payload - not so much. It's pretty clear some bikes have a lot more payload capacity than others - tandem bikes, for example, have uprated wheels to support the extra weight, but these values are NOT easy to find, though I have noticed that motorcycles and even electric scooters now specify a maxium payload (typically 240 pounds, and up to 400-500 for motorcycles). It gets even tougher when you start towing stuff with your bike. As in the case of cars, you can tow a lot more weight than the vehicle payload suggests. Our Subaru can tow nearly three times its payload. The Volkswagen that claims it is an Outback competitor can't tow anything. But how much is too much? Inquiring minds want to know! Does that spendy Trek Madone have a GVWR higher than the "Wallyworld Cheapie?" And what about that Dutch Cargo bike versus a Touring versus a Cyclocross bike?

I HAVE found a few items that relate. For example, here, they have a "calculator" and the site also lists weight capacities of 300 pounds for pretty heavy-duty looking trailers. Here, a site lists payload capacities for some bikes from major makers (sorry Surly owners, but no number for you!). Apparently, some manufacturers note that wheels are the weak link (Raleigh notes "All frames are tested to 550 pounds. It is the wheels that limit rider weight more than frames."), but there, the trail grows cold.

Harley Does it Different
While motorcycles are somewhere "in between," Harley Davidson uses a frame decal sticker with the GVWR on it. They also list the individual axle capacities. There's a discussion on motorcycle weight capabilities on Northwest Motorcycling Sound Rider, here. The link even has a couple of photos and discusses how difficult it was for him to find weight carrying capacity for some motorcycles.