DETAILED BEARING INFORMATION
Except for TPS steel bearings (more on this later), ceramic bearings roll better than other manufacturers all-steel bearings. Why? Unlike an off the shelf / standard quality all-steel bearing, thick grease is not required with ceramic bearings since there is no metal-to-metal contact. Any time you have metal-to-metal contact, you get galling when pressure is applied. Since there is no galling possible with either a hybrid ceramic bearing (steel races/rings and ceramic balls) or full ceramic bearings, you can get by with using a light grease such as SBG-32 or a high quality synthetic oil as lubrication. To also help reduce rolling resistance, high quality/low friction Teflon lined seals are used in TPS bearings. When Si3N4 ceramic balls are used, they will not deform, flat-spot, crack, chip, dent, fracture or wear out.
Watts Saved – Researching Bicycle and Wheel manufacturer’s websites and their corresponding technical reports, here is a summary of their combined findings comparing watts saved using hybrid ceramic bearings vs. conventional steel bearings. Full ceramics save even more watts.
Bearings are rated in three distinct ways: GRADE, CLEARANCE, ABEC
Ball grade is a rating of the individual ceramic ball. Most don’t consider the ‘grade’ or finish of the races/rings. This is as important as ball grade. Why spend the extra money buying grade 3 balls, only to have them rolling between ‘grade 200’ races and rings. The ball grade is a measurement of the roundness of, or how perfect the ball is. The ‘grade’ of the races/rings are how perfectly polished they are. If you buy a bearing based on a single rating or spec, ball grade would be what you would be looking at, race/ring grade and clearance would be next.
Most commonly, balls are graded on a scale of 3 to 200, where the lower the number = the better quality of the ball. TPS ceramic balls and bearings use only high quality Si3N4 (Silicon Nitride) grade 5 balls. A grade 5 ball is round to 5 millionths of an inch, where most all-steel bearings use balls that are grade 25 and higher, often using balls with a grade of 100 or 200. In fact, I have seen other ceramic suppliers use grade 25 balls for their “high quality” bearings. Remember, the higher the grade number, the lower quality the ball and finish and the higher the built-in rolling resistance.
Have you ever replaced your bicycle wheel bearings only to find that the wheels don’t turn as good as they did when new, or make a grinding sound and, at the same time hard to turn, or don’t turn at all? The following is a trick some wheel manufacturers employ to get you to buy their bearings. Wheel manufacturers do take advantage of what the consumer (and the bike shop mechanics) don’t know. Most know about ABEC and GRADE, but nothing about CLEARANCE. Basically, clearance is how much room the ball has between the inner and outer races. Squeeze the balls too tight and the bearing will be hard to turn.
There are 5 designations of clearance. Most bearing manufacturers split the difference and most bearings are made to a ‘Normal’ clearance spec.
DESIGNATION MAGNITUDE OF CLEARANCE
c1 = radial clearance smaller than c2
c2 = radial clearance smaller than Normal
cn = NORMAL radial clearance
c3 = radial clearance greater than normal
c4 = radial clearance greater than c3
The trick that some wheel manufacturers employ is to under-size the hub’s bearing hole while, at the same time, over-sizing the axle. This squeezes the bearing from both directions and compresses it to the point that the wheel is either difficult to turn or won’t turn at all. In order to freely rotate, a ball bearing must have a certain amount of internal freedom of movement (Internal Clearance, or the space between the raceway and ball). Without this internal clearance, the bearing can be difficult to rotate or may even freeze-up and be impossible to rotate. On the other hand, too much internal clearance will result in an unstable bearing that may generate excessive noise or allow the shaft to wobble. The internal clearance is measured in terms of the direction of the load (Radial Internal Clearance and Axial Internal Clearance).
So, if you ever get into this situation, the manufacturer can (and should) tell you what radial clearance is required.
TPS bearings can be ordered in either Cn or C3 clearance which will satisfy virtually every manufacturers hubs and bottom bracket scenarios.
The purpose of the ABEC committee (Annular Bearing Engineers Committee) is to establish dimensions, tolerances, geometry, and noise standards for bearings in an attempt to aid industrial bearing manufacturers and users in the production, comparison and selection of bearings. The larger the ABEC number, the tighter the tolerance of the bearing. ABEC is often misunderstood and thought to be the “defining” rating in a bearing. ABEC simply refers to the overall tolerance of the bearing only. The tolerance rating is useful for industries where high RPM motors (10,000 RPMs or more) are used. The higher ABEC classes provide better precision, efficiency, and greater speed capabilities, but do not necessarily make the components spin faster. The ABEC rating does not specify many other critical factors, such as smoothness of the rolling contact surfaces, ball precision or quality, type of steel or material used. The bearing material is not specified in the ABEC grades. Bearings not conforming to at least ABEC 1 cannot be classified as precision bearings as their tolerances are too loose. High ABEC rated bearings allow optimal performance of critical applications requiring very high RPM and smooth operation.
A better ABEC rating does not impact the speed of the bearing in bicycle applications. Many cyclists request ABEC 9, incorrectly thinking their wheels will roll faster. I have seen quite a few bicycle bearing manufacturers push ABEC 7 and ABEC 9 bearings as their main selling and profit points.
- A piece of machinery spinning at 10,000+ RPMs would require a high ABEC rating, such as ABEC 9.
- For cycling, a rating of ABEC 5 is exceptional. With ABEC 7, you are definitely wasting your money.
- TPS has found ABEC 5 to be the perfect cost-effective match for cycling bearings, and we make the fastest bearing solutions for cycling.
The results: ABEC 5/7/9 were found to be identical in terms of bicycle wheel performance. ABEC 7 and especially ABEC 9 are very tight tolerances and are way beyond the requirements of cycling. TPS carries ABEC 5 rated bearings.
Which bearings do I need?
This question is asked all of the time, and, in order to assist you in your decision, The Parts Shoppe has put together a summary of what we carry as well as best-use recommendations.
Full Steel – TPS manufacturers full steel bearings. Our in-house made in the USA steel bearings actually outperform our imported Asia-made ceramic bearings. This is because our grade 5 steel balls are matched to the highest polished races and rings available. These high quality full steel bearings are assembled in house from SKF bearings precision components.
These high performance /cost effectivet bearings are our best sellers and a favorite with top racers. Many serious racers put in over 12,000 – 15,000 miles ( 20,000 – 25, 000 km ) per year training and report back that they are getting multiple seasons out of a single set of TPS steel bearings!
Full Ceramic – The races and balls are Silicon Nitride Si3N4 Ceramic. This is the ultimate go-fast bearing! These bearings are fully sealed with Teflon seals to keep the dirt and grit out and the light oil lubrication in. Teflon ball retainers are also used to keep rolling resistance to a minimum. These bearings are recommended for Track applications only.
Hybrid Ceramic – TPS hybrid ceramic bearings (a) use fully heat treated and hardened races, (b) are fully sealed, and (c) utilize a high quality steel ball retainer. All of this adds up to low friction performance, ultra smooth operation, high mileage and maintenance free operation. These bearings are recommended for use as wheel bearings, bottom bracket bearings and rear derailleur pulley wheel bearings. TPS carries Asia-made bearings as well as our own Made in the USA bearings utilizing the exact same races/rings as our steel bearings except that we use Cerbec Silicon Nitride ceramic balls instead of steel balls.
Our Asian bearings come with high-quality grade 3 silicon nitride balls and our in house made bearings come with USA made grade 5 silicon nitride balls PLUS higher polished races and rings that compliment a grade 5 ball.
Maintenance & Recommendations:
Break-in period: Right out of the box, TPS bearings start out rolling very smoothly and will only get better over time. Give the bearings at least 300 miles to break in.
Maintenance: As with any high-quality bearing, it is recommended to perform periodic maintenance. Bearings can be removed using a bearing puller and reinstalled using a wheel bearing press. Do not pound the bearings out or back in with a hammer/blunt object. The seals are easily removed and replaced by using a common push pin. WARNING – be careful not to bend, dent or damage the seals in any way or you will need new ones!
To ensure long bearing life:
- Inspect the bearings every 3-months. Spin the bearing by hand to notice if it is spinning smoothly or if there a feeling of grit inside.
- During this inspection, you will be able to ‘feel’ if the bearing is dry (i.e., the lube has dried out). If this is the case, rebuild the bearing(s) immediately and re-lube using SBG-32 grease.
- Clean and re-lube every 1-2 years, or if they are no longer running smoothly by first removing both seals and the ball retainer. Then, scrub using a soft bristled brush and a mild cleaner/degreaser. Finish off by re-lubing with SBG-32.
Lastly, if you still wish to shop around, here are some things to look out for:
- Companies advertising ‘too-good-to-be-true’ prices. Why? Because you will notice that they never mention the grade quality of the ball. Many of their low quality bearings use ceramic grade of 200 or worse.
- Companies advertising ‘we use the best, we use grade 0 balls’. Why? Grade 0 balls are actually ‘ungraded’! The ball manufacturer will take all of the reject balls that fail quality control at any grade level and throw these rejects into a big container. Then, they will make bearings utilizing these rejected balls and call them grade 0. It doesn’t get any worse than grade 0, so watch out.
- Companies advertising ‘Stainless Steel’ bearings. Why? There are many classifications and grades of stainless steel (currently, there are over 150 grades of stainless steel). The issues are that (a) you don’t know what stainless steel the manufacturer is using and, (b) you don’t know if it has been heat treated nor the hardness rating. Some stainless steels can be heat-treated/hardened and some can’t. They are all still considered to be stainless steels. The difference is in making a bearing out of the same soft, non-hardenable stainless steel that a butter knife is made out of vs. a fully through-hardened and wear-resistant stainless steel that a custom knife or a milling machine cutting tool is made out of. A company that has nothing to hide will tell you exactly what material is being used as well as the hardness rating. A company that has something to hide will just say ‘stainless steel’.