Thursday, December 13, 2012

Building our bearings by hand


As many of you know, we don't sell pre-built, machine made bearings.  A lot of our competitors are sourcing bearings from the far east, buying them as completed bearings and marketing them as a high quality ceramic bearing.  On the other hand, our ceramic bearings are Made in the USA, in our own facility.  Please note, our cups and components are made in Taiwan and China, to our specs.

In this post we thought showing you how we build each bearing by hand might shed some light on why our bearings are highly regarded and have a good track record of longevity.

Below we are building our Ceramic BB for Shimano 10/11 speed cranks.  The process is the same for all of our bearings, but this will show more in depth what we do to a full BB, rather than just wheel bearings.

Step one is to select the parts.  For this build we need an inner and outer race, a retainer, two seals (shown a few steps down) and a bunch of our shiny perfect ceramic balls.


Next we take the ceramic balls and place them into the outer race, making sure they are all on the bottom half:


Now we install the inner race being careful not to drop any of the ceramic balls.  Right now there is nothing holding them in place.


Now we have to spread all the balls evenly so that the retainer will snap into place.  Once we have spread the balls around, they hold the two races together well enough that we no longer have to worry that the balls might fall out.


Now that the balls are spread out, we snap the retainer into place.  The retainer has little plastic "arms" that hold each ball.  Here you see the back of the retainer and a seal next to the bearing.


Now we snap the rubber seal onto the backside of the bearing (the backside is the retainer side) and also the side we laser our logo onto (look at the inner race).


Now we are ready to press the bearing into the cup.  Here is the bearing next to the cup.  We will flip the bearing and press the laser logo side in first, so that the ceramic balls will face outward (making it easier for you to grease them in the future):


Here are both cups with the bearings pressed in.  You can see the retainer and how each ceramic ball is evenly spread by the retainer.  The retainer will hold the balls in place so they rotate easily:


Next we add some grease.  We differ from every other maker of ceramic bearings in that we apply as much grease as we can into the bearing.  A lot of companies will go really light on the grease knowing that the first thing you will do when you get the bearing is spin it in your hand.  So they use a low grease fill to make you think the bearing is really fast since it turns so easily.  We think that is a marketing gimmick and also a sure fire way to have early bearing failure.  So we load up on the grease, knowing that it's the ceramic balls that are what makes a ceramic bearing so fast.  The grease will break in over the first few hundred miles of riding and our bearings will loosen up quite a bit.


Now we snap the outer seal in place.  If chosen, we would've installed our orange cyclocross seals in this step but this customer chose regular seals.


Now, we apply some grease to the outside of the seal.  This will help protect the bearing from contamination and also keep the dustcap quiet since it won't rub.


Now we are getting close to a finished BB.  We then install our dustcaps.  Note the dry ID of the dustcap.


Now we apply some grease to the ID of the dustcap.  This is to help eliminate spindle wear on your crank and also to keep things quiet.  Note the grease on the ID of the dustcap.


Now we flip the bearing over so we can access the inside.  You can see the backside seal here, the one we installed before we pressed the bearing into the cup.


And then we add more grease, this time over the backside seal so that no water enters the bearing from inside your frame.



That is pretty much how we build our bearings.  We left out a few secret things we do, but in a nutshell, this is the correct way to build a bearing and ensure it not only is fast, but also lasts.

Remember that grease is the best thing for a bearing, so it is very important you follow our maintenance guide and grease your bearings periodically.

Thanks for reading!

Wednesday, September 5, 2012

What are our cyclocross seals and what do they do?

We get this question quite a bit.  I thought a blog post would clear it up.  First, our cyclocross seals are not just for cyclocross.  They are for anyone who rides in bad weather, races a lot or just wants to protect their bearings a little better.

Our cyclocross seal is a unique seal that while initially more "draggy" will break in and perform the same as our regular seals, while maintaining better sealing performance.  When chosen, we install these on the outside of the bearing so that they protect against the elements.  For some extreme cases, we'll also install them on the inside seal as well, but most of the time our normal seal is fine there.

They are really a great seal and we find more and more customers choosing this option.  The key is to ignore how the BB performs at first, because there will be a lot of drag.  After riding it for a few hundred miles, things get really good and the performance starts to shine.

These are only available for our BBs.

Wednesday, May 30, 2012

The infamous "Spin Test"



In the over 8 years we've been making ceramic BBs, there has never been as much interest in how long our BBs spin as there has been recently.  Apparently some companies have drilled it into people's minds that the longer a crank spins, the better the BB is.  This is not true.

We've blogged about grease and seals and break-in time before, so read those posts for more info on that.  Apparently the thinking on the interwebs is that if a crank spins for 30 rotations versus a crank that spins for 20, for example, the BB that spun 30 times is better.

Typically with some good riding and adequate break-in, our BBs will spin for about 15-20 rotations (see more on this below).  This is fairly normal.  The reason you don't want it to spin much more than that is that is a sign of not enough grease and possibly too light of a seal.  As you ride a BB (any BB) the grease is constantly being spread and used up while being pushed away from the rotating balls.  The grease will eventually get used up and if checking how long the crank spins at this point, it might spin a good 25+ times.  Great?  No!  That is far past the time to relube your bearings.

I do a simple check with my ceramic BB.  Every week or two I take the chain off and give the bike a good cleaning.  A this time I will spin the crank and see how it is spinning.  If it spins too freely or for too long, that's when I know to pull the cranks and lube the bearings.

It is very important to keep enough grease inside the bearings so they are lubed properly, which enhances performance and longevity.

I understand it makes complete sense that "if it spins longer, it must be better" but that is not always true.  You want the crank to spin nice and smooth, with no binding, but you don't want it to spin too long.  Can I give you an exact number as to how many times the crank should spin?  No, there are too many variables here as heavier pedals will make it spin more while a lighter crank would spin less, as the mass rotating has a great affect on spin times.  Also, how hard you spin the cranks will affect the time, did you lightly turn them or spin them as hard as you could?  Although, a good rule of thumb is that it should spin freely and quite smoothly.

I cringe writing this as I am sure someone will say, "my crank only spun 14 times", but if I had to give you a number, the 15-20 range is pretty normal for one of our BBs once broken in.  It could be more (and it could spin less too, don't obsess), but too much more and you need to grease the bearings as mentioned above.  If it only spins something really low, let's say, 3-4 times, the crank is probably too tight and binding the BB.  I personally use a Shimano Dura Ace crank, so my spin times are based on our Shimano 10 Ceramic BB, other cranks and systems like BB30 would spin differently, since they tension in a whole different way.

The energy required by your legs to overcome the grease and seal friction is so small that you would never notice it while riding.  It is noticeable when spinning a crank because the crank doesn't weigh very much, so any seal/grease drag will affect it's spin time.  When I relube my bearings, the crank will go from spinning close to 20 times down to about 6-8 times, simply because I added grease.  Then with riding it will slowly increase it's spinning time again over time, back to around 20 at which time I add more grease.

The reason our ceramic BBs are so fast, is the near perfect balls mated to the near perfect races.  When riding, the balls spin with almost no friction on the race ways, making the BB very fast.  So whether the BB spins 6-8 times after I grease it or closer to 20 when greasing is needed, it rides the same because of the balls and races.

In closing, do not obsess about how long your BB spins.  You should obsess about riding more and making sure you are in as good of shape as possible, so that our super fast BB will be paired with a super fast you!

While this post focuses on our BB, you could also substitute wheel bearings or pulleys every place we mention a BB and the same would be true.  With the main difference with pulleys being that they weigh so little, so their spin times by default will be very, very low.

Wednesday, May 2, 2012

Full Ceramic, yes or no?

A question we get from customers is: Why don't you offer full ceramic bearings? 

First, let's explain what a full ceramic bearing is and what a hybrid ceramic bearing is.  Both use ceramic balls, so they are the same there.  The difference is that hybrid ceramic bearings use a special hardened metal race (hardened to withstand the hardness of the ceramic ball) while a full ceramic bearing uses a ceramic race.

Ceramic races make for a slightly lighter bearing and can be used with little to no grease.  Plus they can't rust, usually don't pit nor suffer from wear.  Sounds great, right?  Yes!  But there is a huge catch, keep reading.

It makes sense to think that a full ceramic bearing would be better, I mean, if ceramic balls are so good, why not use a ceramic race too?  A lighter, faster bearing that uses less grease is a dream bearing.  But, in practice it can be a nightmare.

There are several reasons, one is the high cost, but most cyclists will pay for better performance, so cost isn't the issue.  So what is the real reason that full ceramic is not good?  Simple, they aren't designed for use in cycling where loads and impacts vary greatly over the course of the bearing's lifespan.  Or to put it simpler, ceramic is a great, strong material for the ball, but for the race, which absorbs shocks and impacts, it is too brittle.  This means that when you hit that pothole (although you should try to avoid them!) or those train tracks, the races can crack.  Any type of impact or sudden load can crack a ceramic race.  Did you bunny hop that obstacle in the road?  Uh-Oh!  Better check those ceramic races.

The companies pushing full ceramic bearings are the companies that get their bearings from large industrial bearing makers.  Why is this important?  Industrial bearings are designed to work in machines and controlled environments.  Cycling bearings are not.  So a full ceramic bearing is great for a machine that never has to withstand any impact, but not good for cycling.  There are numerous reports on the interwebs about cracked full ceramic bearings in wheels and BBs.  The customer likes to blame to bearing brand, and they should, but not because the bearings cracked but rather because the company sold them in the first place.

About the only safe place to use full ceramic bearings on a bicycle is the pulleys.  These are not subject to impact loads like wheels and bottom brackets are.  We've been testing full ceramic pulleys for a year and may release them at some point... stay tuned!

Saturday, April 28, 2012

Grease fill % and what it means for your riding

We thought we'd post some info on grease fill and how it effects a bearing.  Grease fill or commonly referred to grease fill % is how much grease is applied to the bearing.  100% would be a bearing completely stuffed full of grease, while 50% would be half as much.


The lower the grease fill % the easier the bearing will spin while not under any load.  The common thinking then is to use a very low %.  Some companies do this for one reason- to make you think their bearings are faster than they are.  They know the first thing you will do when you install your wheel bearings or BB is to spin the wheel or the crank and see how long it spins.  This is a great way to see how good the bearings are, right?  Not really.


A brand new bearing will spin mostly based on the amount of grease, the tightness of the seals and how heavy the spinning object is.  A heavy wheel/rim, tube and tire will spin longer than a lightweight wheel/rim, tube and tire.


Knowing this, most bearing companies apply a low fill % of grease and use light seals, since you will think the bearing is awesome because it spins so long.  But in reality, this is a bad practice.  You need enough grease to properly lube the bearing and help it's longevity.  You need proper seals to keep the bad stuff out (grit and water) and the good stuff in (the grease).


Plus, spinning a wheel or BB while unloaded (not being ridden) completely misses the point with how bearings work.  They work when loaded and the main reason our ceramic bearings are so well received is because of the quality ceramic balls that we use.  Our round balls spin easier than less round ceramic (lower grades) and even more less round steel balls.  A rounder ball will not produce as much heat like a lower quality ball, which means the rounder ball spins easier.  Matched with our races, the bearings spin like on a glass like surface.


We tend to use slightly heavier seals and a slightly higher grease fill %.  While it will take a little longer to break our bearings in, they do last longer and in the end, that is also why you upgrade to ceramic.  While we use a higher grease fill % than most other ceramic bearings, our grease is specially designed for our bearings.  It spreads easily while breaking in and isn't too tacky nor too watery.  It is ideal for ceramic bearings and can be applied more liberally without causing a complete slowdown in the turning of the bearing.


What happens when our bearings are going through the "break-in" process?


3 things:  First- as the bearings break in the grease gets spread around and pushed to the cage which reserves long-term continuous lubrication.  A thin oil film forms on the balls for lubrication.  The thin oil films will generate less drag on the balls.   Second, the seals will break in and loosen.  Third-  The ceramic balls continually polish the races making them slicker and faster with time.


Friday, April 27, 2012

Whoa! Where have we been?

We haven't updated this blog in.like.a.long.time...sorry!  Stay tuned for more updates!