In this article I’m going to discuss bicycle cone adjustment and how to tighten them correctly onto the bearings and hub of your wheel.
Bicycle cone adjustment is only relevant when dealing with loose ball bearings. This is found on bikes from the ’90s and earlier. From the mid 2000s sealed cartridge bearings would be used. The main benefit of these is they barely need adjusting and are less prone to wear (they’re sealed).
The bicycle cone is threaded onto the axle and contains a bearing race: the point where the bearings roll along the cone. Adjusting the cone: moving it up and down the axle, either let it sit more or less tight on the bearings.
A cone which sits too tight onto the bearings will result into cone binding. This means that instead of the bearings rolling onto the bearing race, they grab the cone causing friction and a less than optimal wheel rotation.
Bearings are also more likely to bind the cone when they are damaged. When your bearings are damaged, it’s highly likely your cones will also show signs of wear in the form of a pitted surface. Wear on the surface of the bearings and cones make them less smooth and consequently more likely to hook into each other. Learn more by reading the article about overhauling your bicycle hub.
A cone which sits too loose onto the bearings will result into play into the axle. This means its more likely that outside elements, like water, can seep into your bicycle hub and cause damage by corroding the cone, bearings and hub. A loose axle will also increase the wear on the bearings. A really loose axle can destroy the entire hub.
Testing a correct bicycle cone adjustment
You can test the correct bicycle cone placement by holding the wheel in your hands and rotating it with the axle sitting on top of your index fingers. The axle should not rotate along with the wheel. If it does the bearings bind the cone.
If both your bearings and cones are in good condition your cones are too tight. You should loosen them until the axle stays in place with the wheel rotating.
And that’s how you easily check for the correct bicycle cone adjustment!