Monday, April 30, 2012

Press in BBs are hot, but are they worth it?

Most readers of this blog know about the many new types of BBs used today.  We offer virtually every type of BB used today in ceramic versions.  We do this because the industry has changed from one of very simple BB styles, to one where almost every frame maker has to design their own BB style, just to compete and market their new frame.  We are happy to offer all of these different styles as we try to offer want our customers want.  But if we had our way, it would be different....

So let's first look back at how it used to be.  It used to be that most frames came with an English threaded BB shell.  Exotic Italian frames used an Italian threaded BB shell.  Either way was fine as all you had to do was buy the appropriately threaded BB that matched your crank.  These older BBs used smaller bearings that were housed inside the frame (for better durability) and smaller spindles.  In theory, the smaller bearings weren't as durable and able to withstand load, compared to today's bearings, but in practice this was never really true.  You hear stories of old Campy or Shimano BBs lasting 10 years, even 15 years with no maintenance.

Then one day the bike makers said, "hey we can design our own BB style and market it explaining why it is better".  First the industry went to outboard bearings, which were larger and stronger.  This was a nice progression for BBs, while they did have more drag, the larger bearings were stronger and offered better longevity.  Then they went further and said "let's do away with the cups all together and press the bearings directly into the frame!!"

Sounds great but sometimes a step forward might not be truly forward in all aspects.  For this article, we'll focus on the two most popular press-in BBs, BB30 and BB90  There are many more, but these two are the most popular (plus BB30 has quite a few siblings).  First BB30- large bearings pressed right into your frame.  Then BB90- smaller than BB30 but still large bearings, pressed right into the frame.  In a perfect world they would be great.  But we live in an imperfect world where manufacturer tolerances vary and a press fit bearing that needs an exact fit in order to not creak and click and drive the rider insane, makes said idea not great.

The common complaint with BB30 and BB90 is that they click and creak.  This is almost always due to the bearing moving ever so slightly under load because it is not pressed into a perfectly matched space.  The tolerance varies on frames, even high end frames, and this is bad for bearings.  So the industry tried to fix this by offering Press Fit BB30 and BB86.  These are basically the same as BB30 and BB90 (forgetting for a moment that BB90 only appears on Trek frames) but rather than pressing the bearing directly into the frame, the bearing is housed in a plastic cup and then pressed into the frame.  This allows the plastic cup to take up any tolerance issues with the frame.  It could have fixed the issues, but still you hear reports of clicks and creaks because the tolerance in the frames is still not good enough and now the plastic cup moves slightly.

When you pedal your bike, everything is transmitted to the BB.  So any possible way the BB can dissipate that force, it will.  So if something can flex or move, it will and this will cause you creaks and clicks.

How do you go back to the old days?  You don't, unfortunately.  The pros will always want the best parts, and they should.  They don't care about noises because they view their bikes as tools more than we do.  We view our bikes as friends, partners, an extension of ourselves, so that we can enjoy the world at a slower speed than allowed by cars.  We like our bikes to be quiet so that while we are riding them, enjoying the world around us, we don't have to listen to them.  The pros don't care as much as they are going from point A to point B as fast as possible.  If they have an annoying click, they mention it to their mechanic at the end of the race and let him deal with it.

So, how do we deal with press in BBs and their inherent flaws?  Trial and error.  Fixes can include obscene amounts of grease, Loctite, proper torque and lots of patience.  These new BB types are superior technological wise, but at the same time suffer from some drawbacks.  But don't fret, anything that creaks can be fixed, you just have to identify the source and decide how to fix it.

Saturday, April 28, 2012

My ever decreasing tire pressure

When I first starting racing, I would pump my tires to the maximum PSI on the label.  I often would be at 150 PSI.  Then on one long hilly road race, my rear tire exploded.  I kind of new it was because of the high PSI combined with heat, that made things go BOOM!

I pumped up my tires so high because I thought it made me faster.  Heck, I even cut my chain too short once thinking that it would make for less drag on the rear derailleur, but let's not get into that.    Back to the PSI, when pumped very high, you tend to feel fast because you feel all of the road buzz.  Feels fast, but it's slow.

So, after the big BOOM, I started pumping my tires to about 120 PSI.  This seemed fine for years.  Then a few years ago I dropped down to around 105-110 PSI.  Things felt better but I wasn't sure, perhaps I was losing speed?

Then last year I dropped down to 100 PSI and finally realized, I wasn't going slower, if anything I was moving faster and with more comfort.

This year, I've been on a sharp drop in PSI.  First I went to 85 PSI, then 80 PSI and now 75 PSI.  I don't worry about pinch flats since I use thorn resistant tubes.  While possible, the probability of a pinch flat is low.

I ride a lot of bumpy, chip seal roads.  The low PSI makes me more comfortable and also faster.  The reason is the tire deflects and absorbs the bad surface, rather than bouncing over the bad surface.

I also now ride 700x25c tires.  My next tire will most likely be a 700x27c (Challenge parigi-roubaix) and I expect to run those at about 70 PSI based on some conversations I've had with others using them.

So, although counter-intuitive, if you want to ride fast, try dropping the PSI down, way way down.

Friday, April 27, 2012

Why not full ceramic?

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!

Tuesday, April 24, 2012

What's that creaking?

We all ride lots of miles and a silent bike is much more enjoyable to ride than a noisy bike.  But we've all experienced it... that clicking and creaking that pops up out of the blue.  Most people will look to the BB first and point the finger there as it seems to make the most sense.  But is the noise really coming from the BB?

First it is important to understand that the source of noises on bikes are very hard to pinpoint.  Almost all noises sound like they could be coming from the BB.  Hence the reason the BB gets blamed.  So you install a new BB only to find the noise persists.  What now?  Here are some common places to check before you decide the BB is at fault.

Clicks are usually caused by a small movement between two parts, usually metal.  Creaks are more involved and can be caused by numerous things.

This list is not in any particular order, so you should try each one individually and test ride before moving on to the next possible source.

  • Loose chainring bolts.  Make sure to grease and then torque each bolt.
  • Loose pedals.  Grease the pedal threads and re-install making sure to torque them properly.
  • Loose, dirty or worn cleats.  Check cleat bolts and replace cleats if worn.
  • Loose derailleur hanger.  Try some Loctite on the bolts that hold the hanger in place.
  • Dirty quick releases.  Clean and grease them.
  • Dirty dropout.  Wipe both front and rear dropouts so they are completely clean. Then apply some grease to all sides of the dropout so that when you clamp down the quick release, the grease is spread in between the dropout and hub.
  • Hubs that need to be serviced.  Whether just grease or news bearings, hubs should be maintained.
  • Chain issues.  A stiff link, maybe a dry chain?  Clean and grease your chain.
  • Seatpost/saddle issues.  These are often times easier to identify as they go away when you stand up and pedal, but you should still check for tightness in all bolts and maybe even clean and grease the saddle rails.
  • Is your crankarm touching the front derailleur cable?  This one gets overlooked all the time.
  • It could be your headset.  Take it apart and apply lots of grease to all touching parts.  Then re-install the headset and stem and torque the bolts to spec.
  • Handlebars are known to click and creak due to loose stem bolts.  Take the faceplate off, clean it and re-install torqueing the bolts to spec.  Most clicks here are due to too low of torque on the stem bolts.  Make sure you've got them tight enough.
  • Loose cable guide under the BB shell.  Make sure to tighten the bolt holding the cable guide on.  It is a good idea to use some Loctite on the threads of the bolt as road vibration can cause it to loosen.
  • Cable housing rubbing against each other.  This is more common with older external shift cable Shimano setups and once drove me insane until I realized what it was.  This is harder to fix since the housing will always tend to rub each other.  An easy fix is to wrap some electrical tape around each piece of housing where they rub each other.
  • Cable ferrules.  They often times will click because of a slight movement between the ferrule and the metal ferrule holder attached to the frame.  An easy fix is to wrap the ferrule with electrical tape (or switch to plastic ferrules, BUT this degrades performance slightly).
  • Headset spacers.  Many riders use several spacers (two 10mm spacers to make 20mm or a 20mm and a 5mm to make 25mm, etc.) and these can move ever so slightly under load.  The fix is to use a one piece spacer cut to the correct height.  These are hard to find in anything other than the standard 5mm, 10mm and 20mm heights BUT, fear not as we make carbon headset spacers in 5mm - 50mm in 5mm increments.
  • Spokes and nipples!  There are several places here to apply some lubricant.  The first is the spoke head.  It can rub and/or move slightly against the hub causing a click.  I like to put a drop of oil or chain lube on each spoke head so that it lubricates this area.  The next spot is where the nipple exits the rim.  If you look closely, you can see a small gap that could click under load.  Again, a drop of oil or chain lube on each nipple so that it drips down into the rim.  The third spot is any crossing spokes that touch each other.  I like to flex the spokes so they aren't touching, clean them with a shop towel and then add a dab of grease so that when they touch again, they are lubricated and won't make any noises.
  • This was sent in by Facebook Fan Gregory R:  "I once had a click that came from an over-tightened bottle cage bolt on the seat tube. When I would be out of the saddle powering up a climb or sprint, I (guess I would) cause a slight bit of flex in the seat tube and that in turn would make the cage bolt creak. Weird but true."
  • Seat post length.  This is a weird one but common.  If you are using a longer seat post, one that extends fairly far into the frame, it can flex when riding.  This flexing motion can cause a noise as it contacts the inside of the seat tube.  The solution for this is to cut the seatpost shorter or change to a shorter seat post.  If cutting, make sure to leave enough post in the frame to follow the manufacturer's minimum insertion length.
  • Here is a recent one that just happened to me.  My bike had been silent for months and all of a sudden, not 5 minutes into a ride it would click once (and then twice) every pedal stroke, but only when standing.  Before getting to crazy thinking it was something in depth, I asked myself "what has changed since the last ride?".  The answer was nothing, other than putting on my front wheel.  So, I tightened the front quick release a bit and BAM... noise gone and I can ride in peace and quiet again!!
  • Another strange one here.  I was having a clicking when climbing.  I pulled the BB, greased the threads and bearings and re-installed the crank.  The noise went away but came back a few weeks later.  So I once again pulled the BB, greased it and the noise went away again... only to come back a few weeks later.  So this time when I pulled the BB I looked inside the BB shell on the frame.  I noticed some clear coat overspray.  I removed that, re-installed the BB and crank and now the bike has been silent for a year.
  • Another new one!  Check your cassette.  I had a clicking, almost pinging noise.  Checked the usual places which didn't help, even switched the BB even though I know it's almost never the BB causing the clicking, still didn't help.  Finally I changed cassettes and the clicking went away.  This was a Shimano cassette.  Shimano cassettes have been known to click recently, so if you have clicking and ride Shimano, check your cassette!
We'll update this list as time goes along.  Please email us your stories of clicks and creaks and how you were able to fix them.  Send your emails to