How to Calculate Motorcycle GVWR
Motorcycle Weight Ratings
The Gross Vehicle Weight Rating (GVWR) is the sum weight of motorcycle, accessories, and the maximum weight of the rider, passenger and cargo that can be safely carried.
If you own a touring motorcycle the GVWR is of special importance to you and something that needs to be calculated before that next trip because if exceeded it can affect stability and handling, which could result in serious injury.
Depending on the street bike manufacture the GVWR is shown on an information plate somewhere on the frame and in the service and owner’s manual. If you’re lucky enough to own a Honda Goldwing the calculations are in the owner’s manual; if you own a Harley-Davidson motorcycle you have to make some of the calculations.
In the following example, I used a 2002 Harley-Davidson FLHT owner’s manual to find a dry weight of 758 pounds and a GVWR of 1259 pounds. The dry weight is the weight of the motorcycle as shipped from the factory and doesn’t include the weight of fuel. Now we have to look up the total fuel capacity (5 gallons) and multiply that by the weight of a gallon of fuel (6lbs) for a total of 30lbs.
I used an average rider weight of 180lbs and a 140lb passenger for a total weight of 1,108 lbs. Let’s subtract the 1,108 from a GVWR of 1,259lbs, and we get 151lbs that can be safely loaded for that next trip.
Guess what, were not done yet because to calculate this correctly we need to weigh our helmets, leathers, chaps, gloves or any other piece of clothing or accessory we intend to wear for the trip so let’s subtract 51lbs (those Willie G biker jackets are heavy), and now we can only carry 100lbs. That’s not very much luggage.
I know few of you are running out to the garage to start unloading the saddle bags and tour pack and probably won’t go through the process of finding how much weight that can be safely carried, but if you’re involved in an accident, especially a blown tire you can be sure that the opposing council will attempt to pass the blame onto you.
Blown tires have been blamed for many motorcycle accidents, and every time you overload your motorcycle you become a test rider of sorts because you have exceeded the magical GVWR.
Engineers come up with the GVWR at the beginning of the design process and not during the final testing phase as many riders might think. Components such as brakes, suspension, and tire loads can be configured and tested to this number in the lab.
For example, if the brakes were designed to stop a motorcycle with a GVWR of 1259lbs, and you overload the same vehicle by 200lbs you have just exceeded the parameters that those brakes were designed for.
That doesn’t mean the brakes are going to fail but in a panic stop you may exceed the tested braking distance. Good council will look at skid mark measurements taken by an accident re-constructionist like myself and try to point that finger of blame at you.
Harley-Davidson does a poor job when it comes to helping customers find the GVWR of their motorcycle, and I believe an easy readable chart could be designed and installed to the inside lid of the saddlebags, but in the meantime you will just have to do the calculations yourself.