A properly cared for drive belt can last a hundred thousand miles, and maintaining it just means checking its condition and tension about as often as you change the oil and filter. If your bike doesn’t have a belt-drive, we also have more MC Garage topics on replacing your chain and sprockets, taking care of your chain, and taking care of your motorcycle’s shaft drive. Want to know which motorcycle final drive is the best? Find out in our chain vs. shaft vs. belt drive MC Garage.
To inspect the belt, rotate the rear wheel and check the inside and outside surfaces, looking for cracks, missing teeth, tears, or holes. A few nicks in teeth or minor fraying along the edges is normal and nothing to worry about, but major damage means it’s time for a replacement. Next, take a look at the pulleys. If they’re chromed, you want to ensure that the material isn’t flaking off since that serves as a hard, durable coating. Otherwise, you’re just looking for uneven teeth, chipping, or other signs of wear.
Next up is your belt tension. Some manufacturers want the bike on the sidestand or with a rider on board when you check the tension, so make sure to reference your owner’s manual for the exact procedure and deflection specification. The Harley we worked with can be on the sidestand or held vertically, and it’s supposed to have 1/2- to 9/16-inch deflection under 10 pounds of pressure. To apply exactly 10 pounds you’re going to need a very well calibrated finger or a special tool like this belt gauge from Motion Pro. Yup, you need a special tool, but it’s inexpensive and has a universal fit, and that’s a small price to pay to only have to check your belt every 5,000 miles.
To check the deflection with the tool, slide the O-ring to the 10-pound line, put the tool perpendicular to the belt midway between the front and rear pulley, and note the measurement with zero pressure on the belt. Harley does you the favor of putting a window and 1/8th-inch graduation marks on the belt guard, but the tool has a ruler scribed on it as well. Once you’ve got your starting reference point, press on the bottom of the tool until the O-ring just touches the blue anodized based and measure the deflection. It’s a good idea to rotate the wheel and check the belt in several locations and then average the figure. That means adding fractions, but you’ll have to look up a separate how-to video for tips on how to do that.
If the tension is out of spec, loosen the axle and reposition the wheel to get the tension right. Some bikes will have a bolt with a locknut, while others will have a snail shell adjuster plate. Whichever style your bike has, make small adjustments—equal on both sides to maintain rear-wheel alignment—and recheck the tension until it’s spot-on. Then tighten the axle, check the tension one final time, and you’re good to go for another several thousand miles.
