Durability is king. Although technology matters, the latest and greatest materials or construction process don’t matter if it leaves you walking off the trail. That’s not the case with SUNringlé. Our industry-leading tubeless setups are simple to use, helping riders feel confident in their wheel products. Three different methods can be used to join the rim end: pinning, sleeving and welding.
This method consists of joining the ends of the rim with a steel pin inserted into a cavity on both sides of the rim extrusion. The extrusion shape for the rim is made with the pin cavities extruded in place. The rim is then placed in a machine that constricts the diameter of the rim by means of a band around the outside of the rim and a hydraulic cylinder that pulls the ends of the band together. This force causes the rim ends to be forced over the pins, closing the joint.
This method of rim end joining is done in the same way as the pinning process, but uses an extruded aluminum insert matching the inner profile shape of the rim rather than pins. The sleeving method is usually used on rims that are lighter and considered to be of higher quality than pinned rims.
The Purpose of Eyelets
Eyelets are pressed into rim spoke holes for reinforcement as a way to obtain even spoke tensions during wheel building. Eyelets also reinforce the rim spoke face area at the nipple contact point. There are two types of eyelets: single or double. Eyelets are typically made of nickel-plated brass but can also be plated mild steel and stainless steel.
Eyelets achieve even spoke tension by reducing the friction of turning the nipple. Without an eyelet, there is a high resistance to turning the nipple against the sharp, softer edge of the aluminum spoke hole. This problem is especially evident when spoke tension is being set with nipple torque reading devices. Eyelets are usually inserted in the rim after any finishing processes.
Rim coatings are usually paint or powder coatings. Paint is obvious, but for powder coating, the rim is cleaned before the powder coating is applied with a spray gun that coats the rim with an even layer of powdered material. The rim is then heated in an oven under carefully controlled conditions to melt the powder, creating a solid coating on the rim.
The welding method is used on all levels of rims from high-volume OEM rims to high- quality aftermarket rims. The method typically uses a flash-butt process. The process is done in a large welder that grips the ends of the rim in clamps to hold and guide the rim during welding.
Anodizing is unique because it isn’t an applied coating. It is a process that uses electric current in baths that cause the top layer of the metal to convert to an oxide. The rim is first washed and then etched to clean the metal and remove surface contaminations. It is then anodized to create a protective oxide surface layer. If a color is desired, the rim can then be dipped in a color bath that is absorbed into the rim oxide. Sealing and drying operations follow to complete the process.