Mechanical

Miscellaneous Mechanical Ramblings

The Bike Stand, Miscellaneous Mechanical Ramblings The Bike Stand, Miscellaneous Mechanical Ramblings The Bike Stand, Miscellaneous Mechanical Ramblings

Steven Willis Blog Page

Bottom Brackets I came across a good one the other day I was to change out a bottom bracket for a customer. It was a FSA ISIS bb. I took out the right hand cup with a very large breaker bar with a 1/2" drive splined tool. Everything went along fine then I was starting to pull out the bb from the left side and it came out about 1/4" of a inch before I could feel it hit something. Since I felt this before I knew what to do. The little screw that holds the bottom bracket guide onto the bottom of the shell was too long and was hitting the bb cartridge as it was coming out. No big deal I just unscrewed that little bugger a few turns and boom out came the cartridge bb. If you feel some resistance always try and know why before you push past it.

Bottom Brackets 2 are going through a lot of changes right now. When I first started in this business there was just a cup and cone inside a threaded European style bottom bracket. If it was a low end bike or a very pricey one, they were pretty much the same. Low end ones were not as smooth and probably softer steel. Sometime back in the late 80’s I started seeing sealed bearing bottom brackets come out. Very nice and smooth feeling. Now the last ten years it has gone a little crazy. First with external bottom brackets that moved the bearings out side of the frame. Then they went back inside the frame but made it bigger with the BB30, PF30 and even a BB86. All these seemed like a good idea but something was lost in doing it. The new stuff just creaked and did not last as long. I “fixed” most the creaking with a lot of grease but the short life span I see as the companies are trying to make it non adjustable. You put them in and that is it. In the old cup and cone they would last forever just take it apart and re-grease it every few years, but it had to be adjusted by a skilled mechanic and here lies the problem. Where have all the skilled mechanic gone? In the towns near me the great mechanics have become sales people because the shops make more money having kids slam the bikes together to maximize the profit to the shop. Even with all these new style BB’s most bikes sold have a cup and cone BB like this picture. What you may want to do is just shift the chain into the smaller front chain ring then just pull it away from the chain ring then lightly spin the crank. How well does it spin. Even with a very light spin it should spin for a long time and even when it stops it will spin backwards a little first. If it doesn’t spin well time to adjust the BB. There is just too many types to try and show how to do it, but I can say the adjustment is done on the side with the lock ring. That is the non-drive side. To do it properly you pull the arms off move the adjustable cup in or out then tighten the lock ring down. You check it by just feeling the axle with your fingers. When it feels real smooth you put the drive side arm back on then try and rock it in and out. If it moves time to tighten the BB up a small bit to take the play out of it. Now you may see why shops don’t do this anymore and companies started making BB that do not adjust anymore.

Bottom Bracket 3 Terms
  1. European any of the threaded shells, Mostly British but also come in French, Italian, Swiss, English(Whitworth).
  2. Eccentric An eccentric is a cylindrical plug or bearing cup that fits into an enlarged bottom bracket shell. The plug is machined to accept a typical bottom bracket, but offset from the center of the plug, so that by rotating the plug, the location of the bottom bracket (and hence the chain tension) may be adjusted (fore and aft to tension the chain, the upper or lower eccentric position for a given chain length can be chosen to fine tune bottom bracket height). Once properly adjusted the plug is then fixed in place by a pair of set screws, a clamping bottom bracket shell, an expanding wedge in the plug, or the plug may be manufactured in left and right halves that clamp against the faces of the bottom bracket shell with screws that connect the two halves.
  3. ISIS Drive "International Splined Interface Standard" 10 splines instead of a square to mount the crank arms. Available in 68, 70 or 73mm shell. (Not compatible with Shimano Octalink.)
  4. Octalink Shimano's proprietary splined interface. Uses 8 splines instead of the 10 used by ISIS. V1 version has much shallower splines than the V2.
  5. Ultra-Torque In late 2006, Campagnolo introduced an outboard bearing design called Ultra-TorqueTM, which has each crank arm permanently attached to halves of the axle (called semi-axles) which then join in the middle of the bottom bracket with a Hirth joint and a bolt.
  6. Giga-X-Pipe Truvativ External bearing system. The drive side crank arm and BB spindle are an integrated unit and the bearings are attached outside of the bottom bracket shell. The left side spline interface is not compatible with ISIS crankarms.
  7. X-Type and Hollowtech II Shimano Hollowtech II, RaceFace X-Type, FSA MegaExo External bearing system. The drive side crank arm and BB spindle are an integrated unit and the bearings are attached outside of the bottom bracket shell.
  8. BB90/95 BB90/95 utilizes a 24mm OD spindle. Exclusive to Trek bicycles, this BB interface is almost identical to the BB86/92 except there are no cups. The bearings are pressed directly into the frame.
  9. BB86/92 The BB86/92 interface refers to the shell width as opposed to BB30 which refers to the spindle diameter. BB86/92 uses press-fit cups instead of threaded and is compatible with 24mm OD spindle. BB86 is the road version and BB92 is for MTB.
  10. Pressfit 30 BB shell = 46mm I.D. / 68-73mm width. Pressfit 30 is designed for 30mm spindles and uses bearings housed in nylon cups which press into the frames bottom bracket shell. Frames will need a 46mm inner-diameter bottom bracket shell to accommodate this system.
  11. BB30 BB shell = 42mm I.D. / 68-73mm width. BB30 is the term for an open standard of oversized bottom bracket shell that uses a 30mm spindle and direct-fit, pressed-in bearings. The design eliminates the use of external cups that are threaded into the BB shell to hold the bearings, reducing both overall bike weight and the q-factor of the pedals. The larger bottom bracket shell also accommodates a 30mm spindle, instead of the more common 24mm spindle. This translates into increased drivetrain stiffness.

Brake Squealing is one of those things you need to do some thinking before you mess up your brakes. Squealing is sound. Not that hard yet, and sound is vibration. The vibration is carried through the air to your ears. Ok that is the hard part. So where does that vibration come from? That is what you need to fix.
Most shops and people I know go right to the toe it in and if it does not get better just do it more because if a little is good a lot must be great. Toeing in a brake is when you bend or on newer brakes just align the shoe so the front of the brake shoe hits the rim a second before the back of the shoe makes contact with the rim. What this does is cause the two brake arms to tighten up on the center bolt. Well that is great if that is were the squeal is coming from. But not great if that is not were the sound is starting from.
Were I start is with the brand of the brake. Yes a cheap stamped out arm brake will almost always squeal so a small amount of toe in is a good thing. If you are looking at a well made forged arm brake that is not were you want to go. Those arms are so hard I have seen people crack the arm by trying that. So before you pull out the old trusty arm bender try adjustment first.
The first thing I do for a real screamer is take it all apart and check all the parts are in there and that there is no dirt is in between the arms. A small amount of dirt will allow the arms some movement and that will allow the screeching sound. The proper adjustment point is were it will move freely but have no play with the spring not hooked up yet. After I get to that spot I will say 90% of the squealing will be gone. I then put it back in the bike and see if both pads are set parallel with the rim. Remember the pad may be worn at an angle or the center bolt may not be straight or the hole in the fork may be off all of them will cause that noise to come back. Now check the brake pads are they like a rock. Yes that will not be good either. Get some new rubber on there and now take it out for a spin. Is it all quiet yet. If not try and see if it is the front or just the rear. Then What I do is try some different pads and I also try a different wheel. All that an cause a squeal.. Good luck!

Rim Brake Pads have become a bit of a nightmare in the last few years. There used to be just two styles of pads. Yes there where lots of different brands but pretty much you could go into any bike shop and with two different pads and fit any rim brake out there. Now there is at least four different styles of pads out there. So when people come in and ask for a brake pad it takes a long time to try to figure it out and most times we can’t do it. Because not all styles of brakes use the same style of pads. Back in the day the two pads were a nutted pad and a threadless post. The nutted pad would fit all road side pulls and center pulls and the threadless post pads would fit cantilever brakes. With the advent of the linear pull brakes with its new pad style called threaded post it all got strange. Since the linear pull became the most common brake sold a lot of the other style brakes started using that style of pads. So not only do you need to know what type of brake you have you need to now what pad fits yours. I made up a picture that shows on the top row the five types of rim brakes out there and on the bottom row I show the pads that are out there. The brakes line up with the pad that most often used with that brake. But as you may have seen the U-brake is using the threaded post pad of a linear pull brake. So take a minute to look at your brake and learn what you have. Also most style of pads can be bought with a replaceable insert style pad so you can get inserts for a specific need like carbon rims or extreme weather pads. A last little bit grease the threads it makes installing the pad much easer.

Carbon Cranks Creaking sounds like a bolt needs to be tighten up or maybe pedals need a dose of grease and re tightening. So I tighten up the chainring bolts then the crank bolts then the pedals. Guess what still creaking. The customer asked for a new bottom bracket to be installed. He bought it from me so I was going to get it warranted and warrant the labor. I put his bb in and a few days later he is back with the same creak. I ride it and recommended we try and different crank. I have a similar crank and put mine on his bike. Silence at last. It seems the aluminum inserts in the carbon FSA cranks moved ever so slightly. Well the good news FSA warranted the cranks I got my cranks back. All creaks that I can remember on bikes have always been movement. Cut out the movement and you can cut out the creaks.

Cassettes are a relatively new component on bikes. They come about because as the manufactures were adding more and more cogs the axle got longer and longer until the axles were braking. Not a great thing to happen. Maillard came up with a freewheel called a Helico Matic, that the bearings were real small and went all the way through the freewheel at about the same time Shimano came up with a Cassette system that mounted the ratcheting part of the freewheel to the hub and that let the normal sized bearings to be moved out right up against the frame. Then no more broken axles. The early ones were pressed fitted onto an alloy shaft that was part of the hub. It worked but over the years this part broke off and the cassette body was being held onto the hub by the axle set. The second generation ones had a small threaded sleeve that held the cassette body onto the hub body. Much less problems now.
Here are three pictures, the first one shows the early style cogs all removed from the cassette body. picture 1 The second and third ones shows the cogs on the body both front and back but the hub broke away and is now stuck inside the body. picture 2 and picture 3
The other change that happened was on the early cassettes the outer most cog was treaded and that was what held all the splined cogs on. On the later and still used cassettes there is a flat disk that is threaded into the cassette body and that is what holds all the cogs on.
On the early cassettes you needed two chain whips, which are flat steel bars with a chain pined onto it. You would hold the inner cogs with one then spin off the outer most cog with the other one and it is standard right hand threaded. With the newer ones you need a tool that looks like an older freewheel tool called a cassette cracker. I know it sounds funny. Get the tool from a shop and they may show you how to do it. I put the tool in my vise lay the cassette down on to it then take a chain whip and put it on the largest cog and turn it counter clock ways to spin it off. Now go have fun and ride.

Disc BrakesI have recently learned something about bike “Disc Brakes” they need a break-in period. So I went out on the internet and found some articles about how to do this.

For optimal results, new disc-brake pads and rotors should be put through a break-in process known as "bed-in", "burnishing", or "burn-in". When properly done the bed-in process improves brake power, reduces brake noises, eliminates vibration, and squeal and prolongs rotor and pad life. Unfortunately, while disc-brake manufacturers all publish recommended bed-in procedures, for the sake of simplicity these procedures are, at best, loose guidelines. If mechanics follow these procedures to the letter, they may waste a great deal of time and effort, the results could fall short of accomplishing bed-in, or the results could be badly overheated brake-system components that are more likely to produce the very symptoms that bed-in should prevent.

Here are some examples of manufacturer's recommended bed-in procedures:

Shimano: Clean the rotor. On pavement, get the bike up to a good speed, then firmly and evenly apply the front brake until the bike comes to almost a complete stop. Repeat 10 times. You should notice the brake becoming more powerful with each braking cycle. Repeat for the rear brake.

Avid/SRAM: Accelerate the bike to a moderate speed (approximately 12 miles per hour), then firmly apply the brakes until you are at walking speed. Repeat approximately 20 times. Accelerate the bike to a faster speed (approximately 20 miles per hour) Then very firmly and suddenly apply the brakes until you are at walking speed. Repeat approximately 10 times. Do not lock the wheels up at any point during the bed-in procedure. Allow the brakes to cool prior to any additional riding.

Hayes: Disc brakes require a special burnish period to achieve maximum braking power. The burnish period lasts for about 30-50 hard stops. During this period some noise may occur. Brake pads are complex structures. At the simplest level, brake pads are a combination of abrasive particles or fibers (of various materials) bonded together by a phenolic resin. Complexity results from the wide variety of abrasive materials and resin compounds that are used. Additionally, variable ratios of the abrasive material to resin material exist for different pads.

The bed-in procedure, therefore, has two purposes. First, if the brake setup has not established perfect parallelism between the pad faces and the rotor faces, then the bed-in process improves this conformity. However, the amount of braking necessary to produces full conformity is a function of the initial degree of severity to which the pad and rotor faces are not parallel.

Below are some guidelines to help you (If you have a new bike you can skip to step 3):

1. Clean your rotors
One of the biggest mistakes riders make is putting new pads into a system where the rotors are dirty with oils or other contaminants. Use disc brake cleaner to remove residue from the rotor before bedding in new pads.

2. Check new pads
Ensure that you use clean and undamaged new pads, as anything else won’t bed in. Pads that have seen any use at all will have been through braking cycles. While they will work to a degree, you won’t get the full benefit.

3. Find a safe place
With your new pads fitted to your caliper, you need to find a long, gradual road descent with a smooth surface. Something that allows a 20mph roll with enough space and safety to perform some hard stops will be ideal.

4. Drag and stop
Everyone has their own method of getting new pads to bite. We build up speed, drag the brake for five or six seconds to build heat and then increase lever pressure until the bike stops. Six or seven runs will have the brakes working perfectly.

5. Ignore early pulls
Early stops will feel poor, but the response should build with each cycle. The heating of the pad causes it to transfer some of the material to the rotor, keying the pad and rotor together and giving your brakes bite and immediacy.

6. Adjust the lever
You might want to tweak your brake lever so that it adapts to the feel of the newly bedded brake pads. Some brakes adjust automatically, but those with lever bite-point adjusters can also be fettled manually.

7. Test
Now that you’ve bedded in your new pads on the road, it’s time to see whether or not they’re allowing you to hit turns harder and more deeply. And remember, it’s brakes that help racers go faster!

Flats can be a problem or if you are like me and falling off the back is a god send. But it seems so easy but I have had two this week that they were on a ride and forgot to find the reason for the flat and went through all the tubes they had. They called home got picked up and brought the wheels to me only to have me fined a thorn in one and a wire in other by rubbing my fingers in the inside of the tire. Take the time to search the tire with your finger tips and look at the out side of the tire. You can even match up the hole with the tire and see if it helps you too.

Flats 2 We recently got a problem I do not see to often. That is using the wrong size tube in a tire. It came this way from the factory and has been causing a lot of problems. The tube was too big. It was a 20x1.5 to 1.75 and needed a 20x1.3. So the tube folded over on it self and would develop these small blowouts but you could see these folds in the tube. We may never have figured it out until I got the customer to bring in the whole wheel and saw the tire was smaller then the tube. You can usually go to a thinner tube but should never go with a bigger tube.

Flats 3 One of the things that is nice, if anything is nice about flats, is the ability to "read" the flat. Almost all flats I have encountered leave very easy to "read" signs of what caused them. Which allows you to fix the cause very fast so the same thing does not happen again. But about 25% of the tubes I sell seem to be defective. I have had very few defective tubes out of the box in my many years of fixing flats and all of them were the valve. But the tubes I sell over the counter seem to have these unexplained big holes in them. If you think about the tube as a balloon how many times in your life have you blown up a balloon and found a hole in it. Never with me and my children. I will usually just warrant the tube as long as I get my say about what caused the hole. If the customer will listen they get a free lesson on tube installation and they get a new tube. But the best for everybody is they do not get that "defective" tube any more.

Frame alignment seems to be a dying art. An older woman came in the store the other day and was looking at bikes but kept complaining that they were not as good as her old bike. When I asked about her old bike she said that she hit it with her car and another shop said it could not be fixed. Being an arrogant old coot I said I could fix it just bring it in. Well I did fix it and it was a pain but not that bad and it was not that expensive to do. So if you love your bike and you should mess up the frame even if a few shops say "No way" keep looking they may be right but I feel everything can be fixed, it just has a cost. But most times it shows up as just does not feel right. Before you go out and start buying a new bike let some one that has the tools give it a look over and if you hear the word "no" look at another shop.

Freewheels are ratcheting gears that mount on the rear wheel, well at least most of the time. Most are removed with a tool called a freewheel puller. It is not a puller but just a tool that slides into the inner part of the freewheel body and lets you spin it off. I would recommend buying the tool from a shop and then ask them to show you how to do it. There are so many styles and types of tools you will need more then one for each brand of freewheel made. Hell maybe you should just let the shop pull it. These tools come in splined and notched styles. Some you need to take the axle out of the wheel to get to the freewheel body, major pain. All are right hand threaded. I always use a vise and place the tool in the vise lay the freewheel down on the tool then turn counter clock ways to take it off. A lot of times you need to support the tool so I will use the axle nuts or the QR to hold the tool against the freewheel to help take it off and not destroy the freewheel, and yes that does happen. Especially the old notched Regina freewheels.
The odd ball freewheels that I know about are the Maillard Helico Matic. It was held onto the body with a locking ring and let the bearings move way out by the drop outs. It worked but never gained much popularity and now are very hard to find. The other is Shimano’s, pain in the butt, front freewheel system where the freewheel was in the bottom bracket but, I am happy to say is gone now.

Freewheels 2 Most better modern bikes today use cassettes not freewheels. The lower end ones that use them are all made with a standard ISO thread of 1.375x24 TPI. Now to get a little confusing for you. There is this bike called a freestyle bike also know as BMX. The smallest normal freewheel that fits this tread is a 16 tooth freewheel. When the kids wanted smaller the created a smaller thread called metric it is 30x1 mm. It can take down to a 13 tooth freewheel. Now for the exception. Mega Mart made a freewheel that is 14 tooth and almost imposable to get and it fits the standard ISO threads. Don't you just love Mega Mart stores.

Front Derailleurs are one of the most misunderstood and hard to get right simple adjustments. Even on a new bike where you can be sure most of the parts are working. So much of the adjustments are things other then those two little set screws. A customer came in with a bike he had spent considerable time on the front derailleur and still could not get to work. After I spent about 1/2 hour of my time, more then it would take me to fix it, telling him what I will do to it. He left it for me to fix. Now remember this is on a new bike. I raised it up and twisted it so it would line up with the chain rings. Shortened the cable and housing and ran the cable over the pinch bolt and tab instead of under the pinch bolt tab. Then I readjusted the set screws to limit the travel. As repairs go not a big deal but how do I describe this with out doing it. I would love to show people but that would add to the time. My opinion is try it your self first but at some point find some one you trust and just let go.

Front Derailleur II When an older front derailleur stops working correctly and you know it is not the cable. I look at four things. The first one, is the outer part of the cage twisted in relationship to the chainrings. Look down from the seat to see this one. A problem that happens when your pants get caught in it. Second is the curve of the outer part of the cage bent up too high or curved down into the chain rings. It happens when something gets caught in there too. Third one is look inside the cage. Has the chain cut a grove into the cage? If you can not see try to feel it with your finger but be careful it may be sharp. The forth one has the front derailleur move straight down into the crank. Each has its own fix but it is a good place to start.

Rear Derailleur Hangers that are designed to break apart is what is on most aluminum and carbon bike frames now. They are designed to keep you from breaking the bike frame when the rear derailleur dies. Rear derailleurs most often die when we drop our bikes and the hanger bends ever so slightly inwards. Since it does not know that when you now shift into the largest cog in the back right next to the spokes of the rear wheel the spoke grab the rear derailleur and rip it away. Sorry but this happens all the time. Some kids bikes try to help by having a guard to take the hit but it too will bend in after enough hits then it will push the derailleur in too. The good part is this replaceable hanger thing works to save the frame. They seem to run between 20 and 30 dollars plus the cost of the derailleur and labor. Much cheaper then a new bike. Most all modern bikes sold at bike shops have this. The only ones I see that don’t are Mega Mart type bikes. The only complaint I have with these things is there is hundreds of different hangers. I just don’t understand that maybe ten would be good but over a hundred just is crazy and remember most all those bikes are made in the same factories in China so they could use the same hanger. Even the same brand bike will use different hangers on their bikes. Anyway here is a picture of hangers made in America by Wheels Manufacturing. See what I mean and that is not all that is out there. So go get your bike and run down to your local bike shop and have them order one for you so if yours breaks you will have one to get you back out riding.

Greasing Threads Had a fun one last night we were trying to get a splined Shimano bottom bracket out of a trashed Serotta road bike. No matter how hard we twisted with 24 inch lever it would not move and yes we were doing it the right direction. So I pulled out a 1/2" air impact tool and that cup spun right out. After every body put their eyes back in their head we spent some time talking about the damage that one of these things can do. Some big powerful tools can be great but I would be very careful with them and this would have been mush easier if the original owner or shop tried greasing the threads first.

Handle Bars A customer came in with a problem the other day. His bars would drop down every time he put pressure on them. I looked at them and measured them up and even though he was told the clamp on the bar was the same as the handle bar they were not. Very close but not the same. I always try and match the bar and stem with the same brand. What ever brand you have stick with it. This problem seems to show up most in the old 26.0 size. A lot of the 26.0 are really 25.8 or 25.9 by my micrometer.

Installing Shimano splined crank arms I have seen a lot of damage Shimano splined crank arms out there and it looks like the problem is a simple one. When people start to install a crank arm that was pulled off using the one key release system that comes on a lot of upper end Shimano cranks. People try and put it back on with out removing the one key release system and it can be hard to feel for those splines. I always remove the one key release system with the little pin tool you get with the cranks or use the tips of a set of small needle nose pliers. It take a little longer but if you do not there is a good chance that you will slice a little of the aluminum spline in the crank and then you will get a nice creak that will never go away.

Pedal Threads. Even though I have never had a pedal come out from a crank that I installed new it happens a lot around here in Scotch Plains, I will not point any fingers. But, if the threads are greased and the pedals are tightened up correctly they just do not come out. If it does come out here is really only two things you can do one is buy another crank arm and the second is tap it out over size and in stall a treaded insert. I recently met some one that tried this method of melting at low temp a alloy of aluminum and some unknown metal with a propane torch and re cut the threads and it lasted only one day. So we are back to the insert but I will also say it is expensive but I have never had one of those fail yet. Where is that piece of wood to knock on.

Rapid Rise rear derailleurs by Shimano. For years now many component companies have tried to come up with a fix for the fact that the two shift levers on a bike work opposite of each other. It is not a problem to people that have enough miles on a bike but does seem to cause some concern to new riders. Years ago a company called Suntour came up with a fix to change the action of the front derailleur. It would pull the chain from the larger chainrings to the smaller ones. It did not do it well because a spring had to push the chain back up to the larger rings and under any kind of load it just did not work well. It was popular with low end bikes and if the rider wanted the derailleur could be changed to a standard one and because the shift lever was friction it was perfect again. Now enter the modern era "INDEX". Shimano did the same idea except they did it to the rear derailleur and named it "Rapid Rise". It works well the only problem I see is the same problem as before under load the spring will not push it back up as well. But with Shimano's pick up point on the gears it is much better then the older systems. The problem is with compatibility. There is none. I have put a non Rapid Rise rear derailleur on a Rapid Rise shifter and it worked the numbers just did not run true. So if you have to replace your rear derailleur or you shift lever make sure to get one that will work on the system you have because you can not switch or change the parts to the other way.

Seatpost 1 I do not care how good your eyes are you nor any one else can tell a 27.2mm seatpost from a 27.0mm post by looking at it with out help. So if you go into your local bike store and need a new seatpost please bring your old one in or your bike frame so they can measure the old one for you. Most seatposts come in 2 tenths of a mm difference that is like the thickness of two sheets of printer paper, yes I just measured it, so trust me when I say bring it in.

Seatpost 2 must be greased. I know it goes against most logic but a dry or not greased seatpost will slip more then a greased one. The dry post will develop small rust or aluminum oxide on the surface and that will allow the post to move around in the frame. Next if you do not grease the seatpost at some point in the future it will become one with the frame. I recommend putting some tape on the post to mark the height then pull it out, clean it then re grease it at least once a year. We include that on all the tune ups we do here at The Bike Stand.

Seatpost 3 The squeegee effect. This is were your seatpost is too long. Anything over 10 cm in your frame is too long. When you do as I say and grease your seatpost before you put it in but it is too long the grease will be dragged off the seatpost in the "squeegee effect" rendering the post with no grease at the bottom. When this happens you have a post that is frozen in your frame and is even harder to get out because there is so much contact between the frame and the post. So buy the correct size or cut it down so you have 10 cm or less in your bike. It will also make it lighter.

Seatpost 4 The carbon seatpost. I know carbon is so cool and so light but you have to understand that most frames are not designed for the proper clamping of a carbon seatpost. I have seen so many really expensive carbon post ruined by the frame and clamp. I would recommend some of the really light and oh so cool aluminum alloy post and just forget about using carbon there. If you want carbon you need to use special clamps like Campagnolo that helps spread the force around the whole post and not the back. You can also turn the clamp 180 degrees away from the slit in the seat tube and that helps too.

Shifting problems with Shimano STI. A few things could be making Shimano STI shift when you did not ask it to or not down shift at all. First and most simple is cable stretch. To check that shift it in to the smallest cog and make sure to push the smaller lever in a few extra times to make sure the derailleur is let all the way out. Hold the bike off the ground and shift the right lever one click. Now pedal it a few turns it should pop right up to the next gear. If it did not then you need to tighten the cable. If it does then you need to look at the friction in the cable by shifting down, still just holding the bike up in the air, and see how fast it moves down. It should drop right down in less then one turn of the cranks. If it does not then you need to oil or change the cable and housing or oil with a very light lube, the shifter pod in the lever. When the lube dries out it will not down shift well and you may down shift three clicks and it goes down two and you will feel the third later or called ghost shifting. Similar to that is a small kink in the cable or housing that really can only be fixed with new cable or housing. The last and does not happen very often is the pod needs replacing but about 90% just gets fixed.

Spokes Breaking I know no one wants to think it is their fault but there are people out there that just seem to break more spokes then others. I do not mean just bigger people either. I have a customer that seems to have problems with braking spokes on nice higher end wheels. I brought it up the other day it may be him. I can fix the wheel but he may just put more stress on his wheels then other people. I out weigh him by 30 lbs. and I can not even remember the last spoke I broke. If you are breaking spokes it may be the wheel was made poorly, it may have defects in materials, it may be the wheel is too light and it may be you ride hard.

Spoke Sizing remineds me a little of the seat post, they come in hundreds of different sizes and a few different gauges. I love the people that come in and want to buy a spoke and say it is for a 26 inch wheel. I am sorry but I still laugh a little at that point. After I apologize for laughing I explain why. By pulling out an older Sutherland's manual I look up 26 inch wheel size and point to the part where it says number of spokes, height of the hub flange, number of crosses, and brand and model of rim. Then I get that Oh I get it now look and they bring the wheel in. life is good again.

Stem Creaking most people know to grease the threads on the binder bolts on stems but not ever body knows to grease or oil the flats parts too. It goes against the grain to fix a creak in the stem with a lubricant but it works it also stops the bars from moving in the stem. Just really clean the bar stem connection real good then grease it up and tighten it down.

Stem to Handle Bar Sizing have become a nightmare to bike shops. It has always been bad you had a few different French sizes a few different British sizes and a few American sizes too. My answer was to try and match brand to brand in stems and bars. That helps some but not all. I will try and list all that I can about different sizes of stem and bars. Remember you will need a set of very good measuring calipers to do this so if you need that go down to your favorite bicycle shop and ask for help and if they help you maybe you should buy the parts from them too. And yes I think it is getting better now.

  1. English 25.4mm/ 1", 23.8mm/ 15/16 ", 31.8mm
  2. French 25.0mm, 23.5mm, exceptions Belleri and Mavic 26.0mm
  3. Italian 25.0mm, 23.5mm, 31.8mm 26.0mm. exceptions old Cinelli 26.4mm, TTT 25.8mm, Italmanubri 25.6mm
  4. ISO 25.4mm/ 1".
  5. Japanese 25.4./ 1", 31.8mm. exception Dura-Ace 26.0 some others 26.4
  6. American 25.4mm/ 1", 26.0mm, 31.8mm
This is all that I can find there may be more. Steel stems are a little more forgiving to the wrong size but aluminum stems are not, if it is not right just don't do it.

Threaded Head sets it has come up again that the average person may not know all the fit problems associated with head sets. I will try and give some insight in to this. There is at least five different threads out there.

  1. British 1"x24tpi
  2. French 25mmx1mm
  3. Italian 25.4mmx24tpi
  4. Raleigh 1"x26tpi
  5. Austrian 26mmx1mm
and at least three different sizes of steerer tubes.
  1. 1"
  2. 1 1/8"
  3. 1 1/4"
These numbers are the size of the out side of the steerer tube and you will need to pull the fork out to get to the steerer tube. Since the stem goes inside the steerer tube it will be smaller. They are as follows.
  1. 22.2mm fits a 1" British.
  2. 21.9mm or 22.0mm fits a 1" French and Swiss steerer.
  3. .833" fits 1" American steerer.
  4. 25.4 or 1" fits 1 1/8" steerer.
  5. 28.6 or 1 1/8" fits a 1 1/4" steerer.
There may be more but that is all I ever see here. Now the next problem is the crown race. The very bottom of the steerer tube that the very bottom of the head set sits on. I found at least seven different sizes but we will cut that down to four for ease of understanding.
  1. 26.4 on high end bikes with Campagnolo head sets.
  2. 27.0 on most moderate priced bikes.
  3. 30.0 on all 1 1/8" steerers.
  4. 33.0 on all 1 1/4" steeres.
The nice thing is with the newer 1 1/8" and the 1 1/4" there is only one crown race size. But the older 1" there is a fit problem. The head tube size is broken up in to a about four different ones.
  1. 30.0 or 30.2 most modern 1" steeres.
  2. 32.7 BMX or some mountain bike 1" steeres.
  3. 34.0 on all 1 1/8" steeres.
  4. 37.0 on all 1 1/4" steerers.
The last piece of information you will need to know when dealing with your head set is the stack height. The stack height is the total amount of steerer that the head set will need to fit in your frame. If you were to take the head set completely out of your frame and fork and put the fork steerer in to the head tube the part of the steerer tube that came out the top is what you need for stack height. So when you start looking to replace your head set you will need to know all this. I would recommend what ever shop helps you figure this all out with you is the one that should get your sale.

STI Shimano shifters not going back down again. First of all do not take it apart. That is a last ditch attempt because you probably will not get it together ever again. The first thing to do is get a clear picture in your head of how it works. There is a gear that has teeth in it that the paws fit into. The gear rotates one way by you pushing it up into a larger cog or chainring and a little spring pulls it back down the range. The spring can do its job when you push the lever in, it opens a paw up and the gear moves to the next paw. Sometimes you can get to the gear and see it happen. If you can, try spraying a penetrating oil in to it while you wiggle the paws with a pin. After a while the light oil will start to get into the smallest reaches of the pod and you will see it move up and down again. All the time you are doing this I also want you to be pulling on the cable when you are trying to shift it and also shift it hard really bang on it. By banging on it the paws start to loosen up faster. The spray lube I use is Tri-Flow, or WD-40 the best I can find, but any spray lube should work.

Tools 1 A fun one the other day a customer came in with and older style freewheel they bought on Ebay. And guess what he put it on himself with no grease and road it to see if the cogs where worn or not and then thought about if he could get it off or not. I was lucky enough to have the right tool for it but I would recommend have the source for the tool either at your local bike shop or your self before you need it.

Tools 2 A customer called my attention to the mess of tools on my bench. I quickly apologized for the mess and he quickly said "no I like that you do not just have the tools you use them." Well he made my day.

Tools 3 Just as a warning. If you buy a tool at my shop and use it. it is yours. I have had people buy tools tell me it did not work and want their money back. I would ask to see the bike to see if this was the case. When they said "no it does not work" I tell them there is no refunds for tools and please leave the store. Take some time and figure out if it works first before you buy it. I will show you how it fits, how it works and then sell you the tool. So if you think you can pull this one over on local shops think again.

Valves The valves used on modern bikes come in three different styles, as least I know of three. The Schrader also called American valve, Presta valve also called French valve, and Woods valve, also called a Dunlop valve. a picture of the three valves. In my opinion no one valve is better then the other just different and maybe better in a particular situation. As you can see the Schrader is what your car has and most bikes use in this country. It lets you even fill it up at a gas station, more on that later. The second one is the Presta and as you can see it is thinner so if you have very thin wheels the smaller the hole in the rim that the valve goes through the stronger the rim would be. The last one you may never see in this country but they do show up every now and then. Most pumps sold at better bike shops will do all the valves most pumps sold at Mega Mart will only do the Schrader. To make life a bit easer for you there is also an adapter called a Presta to Schrader adapter picture, to let you use a cheap pump or gas station to fill up your tires. If you have a Woods valve and get a flat you will have to put a Schrader valve tube in there so not a real problem. The only thing to remember is to know what you have before you go buy one and now that is easy for you. As for the gas stations out there. If you ever went and looked at their compressor you would understand they are huge. I saw one about 7 feet tall and at least 5 feet in diameter. With that much volume your tire can become unseated from the rim and blow up. It is not the fault of the tire or tube. If you have to use a gas station air chuck do it is small burst so you do not lift the tire off the rim.