TECH INFO

BEARINGS DIMENSION GUIDE
The evolution of the bicycle bearing
Wheels Mfg Evolution Series C Ceramic bearings
Wheels Mfg Evolution series FF loose ceramic grade 5 balls
Wheels Mfg Evolution ceramic derailleur pulleys
Wheels Mfg Evolution Series 3 sealed bearings
Wheels Mfg Evolution Series RFC grade 300 loose balls
Wheels Mfg Evolution series 25 grade 25 loose balls
What does ABEC number mean?
What does loose ball "grade" mean?
Lubrication of bearings
What is a full hybrid ceramic bearing?

The evolution of the bicycle bearing
The past number of years has seen the evolution of standard ball bearings from everyday typical steel to high strength, low weight silicon nitride ceramics. Twice as hard, 70% stiffer and 75% smoother than their steel counterparts, ceramic ball bearings are created from a hot pressed combination of silicon powder and nitrogen. The resulting combination, silicon nitride (Si3N4) is formed into the extremely dense, polished balls we use as bearings. The resistance to wear, extremely low friction coefficient and high stiffness are the main characteristics that set these gems apart from regular steel bearings. As an added bonus, they weigh 60% less too. This combination of characteristics contributes to a vastly improved rolling element performance in a bearing or rolling contact fatigue (RCF). In simple terms, the greater the RCF life, the faster you will go. Translating that into mechanical drag, a component that is critical at the lower relative revolutions in cycling, any reduction in that drag is power (watts) saved. This is exactly where ceramic bearings shine as their reduction in mechanical drag can potentially gain you approximately 30m for every 1km at the same given wattage. Cheap speed? Relative to aerodynamics and biomechanics, the greatly reduced amount of friction using ceramic bearings is just that.

Wheels Mfg Evolution Series C Ceramic bearings
These sealed bearings include the following:

• Grade 5 Silicon Nitride Ceramic balls (Si3N4). Round to 5/millionths of an inch, these ceramic balls are harder and lighter than steel and completely corrosion resistance.
• High chromium bearing steel races. The races are cryogenically treated to further change the structure of the material so that the races will resist the hardness of the ceramics and get maximum wear potential.
• High quality rubber seals that won't interfere with the balls themselves. The seals simply seal out contamination without increasing any rolling resistance.
• 30% fill Kyodo Yushi Multitemp SRL grease. These bearings offer the ultimate upgrade. Low maintenance, less weight, less rolling resistance, and long life.

Wheels Mfg Evolution series FF loose ceramic grade 5 balls

Grade 5 Silicon Nitride Ceramic balls. Round to 5/millionths of an inch, these ceramic balls are harder and lighter than steel and completely corrosion resistance. Available in many sizes to fit everything from hubs to headsets.

Wheels Mfg Evolution ceramic derailleur pulleys
High quality replacement pulley for Shimano or Campy systems. These pulley systems include:

• CNC machined delrin pulleys. Specifically formulated to allow for "float" required by modern shifting systems.
• Evolution Ceramic sealed bearings.

Wheels Mfg Evolution Series 3 sealed bearings
These sealed bearings include the following:

• Grade 10 chromium steel balls. Round to within 10 millionths and twice as round as top of the line Dura Ace and Record loose balls.
• High chromium bearing steel races.
• High quality rubber seals that won't interfere with the balls themselves. The seals simply seal out contamination without increasing any rolling resistance.
• High quality lithium grease. These bearings are acceptable replacements for any OEM bearing, already on your bike. They are economical and long lasting.

Wheels Mfg Evolution Series RFC grade 300 loose balls
Grade 300 loose balls are inexpensive and an acceptable replacement for most OEM loose bearings, on low to Medium quality componentry. Sold in bottles for easy dispensing and individually packaged for consumer use.

Wheels Mfg Evolution series 25 grade 25 loose balls
Grade 25 balls are Dura Ace or Record quality. 10 times more round than grade 300. Will provide a smoother ride and last longer. Sold in individual use packages.

What does ABEC number mean?

ABEC numbers are industry standards dictating critical dimensions in sealed bearing. In general, the higher the ABEC number, the more precise the bearing. High RPM applications such as a jet turbine would require very high tolerance bearings, such as an ABEC 7 or even an ABEC 9 bearing. Low RPM applications, such as a bicycle wheel generally required lower ABEC number bearings. Most OEM bearings are either ABEC 1 or ABEC 3. Wheels Mfg provides ABEC 3 and ABEC 5 Evolution bearings in standard sealed bearings and ABEC 5 in Evolution ceramic sealed bearings. Note that ball grade is different than ABEC number.

What does loose ball "grade" mean?

The "grade" of a loose ball reflects its "roundness", measured in inches. Here is a quick guide to ball grades. Grade Roundness diameter tolerance per ball
3= 000003
5=.000005
25=.000025
300=.0003
As a quick reference, a human hair is about .003 in diameter. So even a relatively low grade ball (300) is round to within 1/100 of human hair! Standard steel Evolution bearings are grade 25 or grade 300. Evolution Ceramic bearings are grade 5.

Lubrication of bearings
The lubrication functions to:

• Minimize friction
• Prevent rust and corrosion
• Provide a barrier against the entry of foreign matter. For most cycling applications a standard lithium grease is acceptable for both loose balls and sealed bearings. For Ceramic balls, a higher grade lithium synthetic grease is suggested. Minimal "fill" will allow free rotation of ceramic balls. Too much grease will simply negate the low rolling resistance of the ceramic balls. Wheels Mfg Evolution ceramic sealed bearings come packed with Kyodo Yushi Multitemp SRL grease.

What is a full ceramic sealed bearing?
Full ceramic bearings have Ceramic races and a "non steel" retainer, to hold the ceramic balls. Testing has shown that these bearings don't perform as well as bearings with ceramic balls inside a steel race.