Rear Hub Maintenance
The White Industries hub mechanism used in Mad Fiber wheels is made to very high tolerances, uses the finest materials, and is extremely robust. Here are some points regarding maintenance and adjustment.
This mechanism is designed to provide superior support to the cassette assembly and the frame triangle. The freehub body is made of 6/4 titanium to prevent notching common with aluminum bodies.
The axle is a 15mm diameter cro-moly steel tube with higher stiffness compared to aluminum axles. The entire quick release compressive force is borne by the axle. None of it can reach the bearings. Such stiffness also completes the rear triangle of your frame. When chainstays are rigidly joined, the rear triangle is stiffer, and the bottom bracket better stabilized. The entire drive train becomes more efficient. Many rear hubs use axles too light to assist the frame in performing up to its potential.
Seal lubrication
The o-ring between the freehub and hub body may be lightly lubricated from time to time to keep friction to an absolute minimum while maintaining the integrity of the seal and keeping dirt out of the hub mechanism.
Bearing Adjustment
The cartridge bearings (five in a row mounted to a large diameter steel shaft) are only adjusted for end play. This is achieved with a collar on the non-drive side that is secured by three small set screws that can be reached, one at a time, through a 1/8" access hole in the carbon hub shell. Insert a 2mm allen key (preferably a ball end type) rotating the axle and feeling for each screw.
When loosened, the collar can be moved left or right. For best bearing adjustment, press the collar towards the freehub while holding the drive side in place. Secure the set screws.
Bearing Service
Five large bearings support the rear hub. Three races are in the freehub assembly and not easily removed. We suggest sending your freehub to Mad Fiber if it requires service. Two bearings sit in aluminum housings bonded into our carbon hub. Remove them gently. When replacing, use a Loctite™ type of bearing mount. Under no circumstance hammer or pound the bearings in or out.
If new bearings are needed, they should be pushed into place using a bearing press that is the same diameter as the outer race of the bearing. Press until the bearings are seated but apply no more than 20 pounds of side force. The carbon structure is not delicate but we use minimum wall thicknesses and forces appropriate to aluminum hubs may cause deformation and bearing miss alignment. Do not press on the seal or the inner race of the bearing as this can damage the bearing beyond repair. When pressing the new bearing it is critical that the bearing is straight when entering and becoming seated into the bearing bore.
It is a good idea to replenish the grease of your bearings after sustained use. Use a small, sharp pen knife type instrument to remove the outer seals. Pry from the inner bore, out. If the metal washer that is co-molded into the seal becomes bent, you can straighten it by tapping with a mallet against a flat surface. When the seal is removed, the bearings are exposed. Push fresh grease into the mechanism with your finger. Replace the seal, it will snap back into place along its outer edge.
Disassembly
Loosen the three set screws of the non-drive side axle collar. They secure the collar and simultaneously hold the axle end cap in place. When the collar is loose, the end cap can be pulled out.
Once the end cap is removed, the entire mechanism can be withdrawn from the drive side.
The freehub pawls are controlled by independent leaf springs and engage a hardened steel pawl gear. Clean out the ratchet ring area in the hub shell so that it is free of grease. Replace pawls and spring as needed and coat pawl and spring pockets with light oil or a very thin, long lasting grease like SKF™ LGHP-2. Use less for low friction and more for better weather resistance.
Lightly lubricate the axle with oil or grease before reinserting it into the freehub and hub shell.
When the freehub body contacts the hub shell twist the driver counter clockwise to engage the pawls into the ratchet ring located in the hub shell. One or more of the pawls may become stuck at this point preventing the freehub from completely seating. Carefully use the end of a 2mm hex wrench to push them free and then continue to rotate the freehub as you push down on it until fully seated and the pawls engage. After that, tap the axle end with a mallet to fully seat it against the bearing.
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