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Ask a Mechanic: Removing Stripped Bolts

February 17th, 2012

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I have a disc rotor bolt with a stripped head that is stuck in my hub so I can’t replace my old brake rotor. Do you know of a way to get it out without using power tools that might do more damage? From: Larry

AnswerWell Larry it looks like your rotor is in a situation everyone fears: being stuck between a rock and hard place. It is time to apply an unstoppable force (humanity’s intelligence) to this immovable object.

The first thing to do is counterintuitive. Replace the other 5 bolts into the hub that you already removed and tighten them to the maximum recommended torque. This will lessen the strain on the one bolt that is stuck. Then take your t-25 torx wrench and hammer it into the bolt head so that it can engage what is left of the splines. It is a good idea to use a cheap torx tool such as the ones that come packaged with an Avid brake so that you don’t ruin your good tool. Then, while pressing down hard on the tool, slowly and steadily add counter-clockwise torque (anti-clockwise to the decedents of those guys we beat during the revolution) until the bolt releases.*

If this fails to unseat the bolt it is time to use an extraction tool. There are many on the market. I typically use what is called an “easy out” using only hand tools. However most extraction tools are designed to work with power drills that are typically some variation of a reverse drill bit. If the bolt is really rounded out then even these won’t work.

While some of you reading this may be tempted to use a Dremel to cut a slot into the bolt head and use a screwdriver to remove the bolt, don’t do it. This rarely works, as it is difficult to apply enough torque using a screwdriver. Plus, you risk damaging the rotor and hub.

If all else fails, the head of the bolt needs to be drilled. Select a drill bit that is just barely larger than the bolt’s shaft diameter to get the job done. Once the head is removed the tension on the bolt will be released and you should be able to remove the bolt with a set of vise grips.

If what is left of the bolt is still frozen inside the hub, then just leave the little nub there. 5 steel rotor bolts is strong enough to get the job done without any worry of failure. It is not uncommon for racers to use only 4 or 3 bolts per rotor although I strongly recommend that you do not do this. 5-10 grams of weight saving is not worth the risk of a brake failure or ovalizing your rotor’s mounting points.

Don’t let that last bit scare you as this rarely happens. As you work, keep in mind that few endeavors produce the unique elation that comes from removing a stripped bolt. Should you experience this elation, share your bicycle repair derived good cheer with others.

*The procedure described in this paragraph also works for removing a stripped fork steerer clamping bolt on a stem.

img_3348-2-smDaniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , ,

Ask a Mechanic: Ultegra Di2 on CX Bikes and Hub Troubleshooting

February 6th, 2012

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: Even though ‘cross season just ended I am already dreaming up my race bike for next year. The new electronic Shimano Ultegra group looks perfect for ‘cross since it doesn’t have shifter cables to get contaminated in the dirt and mud. The problem is that I want to use a 1×10 setup. Is this possible with Ultegra Ui2 or do I need to use a front derailleur for it to work?  From: Andrew

Your electronic dreams can come true, Andrew! Unlike Dura-Ace Di2, the new electronic Ultegra group does not house the brains of the system in the front derailleur. According to Chad at Shimano American, each component has a chip built into it to guide its function independent of the other parts. This makes it possible to use a 1×10 setup with only a right shifter if you so desire. With Ultegra Ui2 coming in at a price lower than mechanical Dura-Ace, I expect to see it at a lot of ‘cross and amateur road races next year.

Shimano Ultegra Di2 6770 Shift/Brake Lever Set

Dreaming of running electronic shifting on your cross bike? Consider a 1x10 setup with Ultegra Di2.

Even though ‘cross sensation and current national champion Jeremy “J-Pow” Powers rides for SRAM which does not currently have an electronic group, I can imagine J-Pow at some time in the future spinning one of his personally made DJ tracks featuring a derailleur servo sample. I can hear the future of ‘cross shifting and it is at the core of a techno-house track.

Question: I have a pair of Mavic Kysrium SL wheels that are about 4 years old and I am having some problems with them. The front hub feels loose and has side-to-side play that I can’t seem to adjust out. Also, my rear wheel makes a weird noise at high speed, but the noise goes away when I slow down. I can’t figure it out. Any ideas?  From: Mark

Answer: Like the hands of the clock, so are the wheels of our lives. They continue to turn day after day with little thought given to them until their movements cease to smoothly advance or simply halt altogether. Mark, I am afraid the bearings in your front hub are shot. But, at least they made it four years before giving up the ghost.

With respect to your rear wheel, the noise problem you are experiencing is quite common with Mavic hubs. The bushing that the freehub body rides on is either dry, contaminated, or worn out. It is catching on the hub intermittently at high speed and generating the pulsing sound that you are experiencing.

Thankfully, the fix is simple. Remove the skewer and cassette before removing the cover/face of the non-drive side of the axle that is held in by an o-ring. Inside the axle you will find a hex broach for a 10mm allen wrench. With a 10mm allen on the non-drive and a 5mm allen on the drive side, unscrew the axle in order to liberate the freehub body from the hub. Be careful as you remove it because there are loose pawls inside that will spring loose only to di

sappear into the ether. After removing the freehub body, clean the inside with degreaser. Do the same with the pawls.

Mavic M10 FTS-L Freehub Body (Shimano/Sram)

Mavic's steel freehub bodies are tough to wear out and are cheaper to replace than an entire wheelset.

Once everything is clean, lube the bushing in the freehub body and the springs with hydraulic brake mineral oil or 5-weight suspension fork oil. Lube the rubber seal that contacts the back of the freehub body as well. I know this type of oil is an unusual lubrication recommendation but Mavic recommended this to me years ago and it really does work well. Any other lube will damage the bushing and/or cause it to catch the hub at high speed thereby creating the problem you are trying to fix. The recommendation makes sense because suspension fork bushings are lubricated using the same product.

After reassembling everything (don’t forget the washer inside the freehub body) if you are still experiencing the same problem or notice excessive play, then the bushing is worn you’ll need a new freehub body.

This will silence the specter in your rear wheel and return you to the blissful paradise from which you were wrestled; a station where time and miles pass by nearly unnoticed beneath your wheels.

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , , , , , , , , , ,

Ask a Mechanic: More on Bottom Brackets, Tire Widths

January 23rd, 2012

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: Can I use Shimano outboard bearing bottom bracket cups from a Dura-Ace road crank on my Shimano XT mountain cranks? They look like they are the same, so it should work right?  From: Carl

Answer: Looks can be deceiving Carl. Much like the lady at the local watering hole that looked great until your sobriety returned, bike parts often promise compatibility by beguiling us with their fancy labels and comely machined edges, only to disappoint us when they are fully assembled. This is one of those cases.

Shimano Dura Ace 7900 Bottom Bracket Cup Set

Looks can be deceiving - these Dura Ace BB cups won't work with mountain cranks, even though they may look compatible.

This is why calipers can be a mechanic’s best friend. When applied to the parts in question, the calipers revealed that the road cups are too narrow to work with mountain cranks. Resist the temptation to simply add spacers behind the cups to shim them to the correct width. If you do this there will not be enough threads left on the cup to safely engage the bottom bracket shell threads in your frame. Avoid the heartbreak of destroying a frame by attempting to save $30 on the correct bottom bracket.

Just because some of you readers may be wondering if a mountain bottom bracket will work with a road crank, the answer to that question is also, “No.” It is too wide and will ruin your chainline while leaving an unsafe amount of spline interface between the bottom bracket spindle and the left crank arm.

Pay no heed to the siren song of rigged compatibility between components and you will be a happy man Carl.

Question: What is the deal with tire width measurements? Many manufacturers claim to make tires that are the same width but there is a huge discrepancy in width from one brand to another. How do I know which tires are marked correctly without mounting them?  From: Brandon

Answer: Humans are prone to exaggeration. This is especially true when it comes to lengths and widths. Just ask any of our buddies at Tackle Warehouse how big the bass was they caught last weekend! Or, just ask your girlfriend what dress size she wears for a reverse of the bass example! Tires tend to follow the bass model.

However, exaggeration is only one part of the problem. Rim width, tire manufacturing variances, air pressure, tubeless vs. tubed installation, the age of the tire, and even the design of the rim’s bead hook will have an effect on tire width. For example a Continental Grand Prix 700×23c is true to size when mounted on a standard 19mm wide road rim. But put the same tire on a wide Hed Belgium rim, and the width grows to around 28! The profile increases as well, though not as dramatically. Tires that are mounted tubeless have a greater tendency to stretch after they have been installed for a month or so. Mountain tires can grow as much as 10mm due to casing stretch (tubed tires stretch too, it just takes much longer). Then there is the issue with mountain tires of whether the manufacturer is measuring the casing width or the knob width. Each manufacturer does it differently. With some tires the knobs are the widest part of the tire, and in others it is the casing.

Unfortunately, the only way to really know a tire’s width is to mount the tire on a rim and measure it. That is why we are mounting tires and taking our own measurements and posting them in the product description so that you don’t have to. We use standard width rims to best approximate what most of our customers use. Specifically, we use a WTB Laser TCS trail rim with a 21mm inner width and inflate the tires to 32 psi. If your rim is wider or narrower, take the difference between our rim width and yours and multiply it by .75 and you will get the approximate difference in tire width for your application. We also use tubes to take these measurements because it is impractical to do a tubeless mounting for every tire we carry since we would have to give away the test tire after it was coated in sealant. Plus there is the time delay issue of tire stretch that would require us to age each tire before measuring. A safe approximation is to add 5mm (~ 0.2”) to our measurement of the width of any mountain tire that you plan to mount tubeless.

Some basic generalizations that apply to tire width by manufacturer are as follows: Michelin and WTB tires run narrow. Specialized, Schwalbe, and Continental tires generally run true to size with respect to width but tend to have a tall profile. Maxxis mountain tires are now true to size after being narrow for many years. Just remember that these are all generalizations and that some tire models within these brands don’t fit the stereotype. The WTB 2.4 Mutano Raptor is a prime example, as they tend to be true to size. Oftentimes manufacturers will describe tires as being “high volume.” This tends to refer to the profile rather than the tread or casing width. High volume tires offer a cushier ride and better traction in the rough stuff. We will let you know in our description if this claim is true or not, or if the manufacturer should have claimed it but didn’t.

In the end though, it isn’t about how big your tires are; it is how you ride them that matters!

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , ,

Ask a Mechanic: Flat Tires and Dropping Weight

January 16th, 2012

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I weigh about 230lbs and wanted to “ride some weight off.” On my very first time out – new tires and all, I had a flat and have since been shy about riding because I just don’t care to change a flat every trip. Aside from carrying a repair kit – which I did – is there a reliable preventative measure I could take in the future? From: Jim

AnswerGiven your weight, you have a high likelihood of incurring pinch-flats or snakebites. The term snakebite comes from the twin holes made in an innertube when it is pinched between the road and your rim.

The Hardshell casing on the Gatorskin wraps further into the sidewall and an extra-wide PolyX Breaker covers the entire tread strip from shoulder-to-shoulder.

If the source of your flats is from a foreign object puncturing the tire then the same armored tires that I recommended for you should help to ward off this type of problem as well.

There are two ways to avoid this type of flat. One is to use high air pressure. In your case 115-120 psi would be good. The other way to prevent this type of flat is to use an armored tire. While there are a plethora of armored tires on the market, the ones you need have an armored sidewall as well as an armored tread. Examples of this type of tire include, but are not limited to, Continental Gatorskin Hardshell tires and the Schwalbe Ultremo DD HD tire. The thicker sidewall found in these tires will cushion and protect your innertube when it is pinched. Downhill mountain bike tires have used this type of protection for over a decade to prevent the same problem.

The nuclear option for flat prevention is to switch to road tubeless. The beauty of road tubeless is that they can’t pinch flat unless you nail them hard enough to destroy your rim too. Even better when you get a puncture, the foreign object seals the hole until it is removed. When it is removed, there is sealant waiting to seal the tire so you can keep rolling. Lastly, tubeless road tires handle better than all of the armored tires offering more grip and a much smoother ride.

Whichever solution you choose, ride hard and watch out for those snakes!

Question: I want to shed some weight on my mountain bike but I don’t have a lot of money to do it. The other challenge is that I don’t want to give up reliability or performance. Any suggestions?  From: Bill

Answer: You sound like a hard guy to please Bill, but that doesn’t mean I won’t try to. What can I say; sometimes a guy just wants everything. I know I do! Well, I have good news for you because your seemingly impossible desire is actually achievable. In fact, I think I can improve the performance of your bike with some of these relatively inexpensive suggestions.

Every weight weenie knows that taking weight off your wheels is the best way to improve a bike’s handling while making the climbs significantly easier (or, faster and just as hard if you are into that). This does not mean you need to drop two grand on a carbon wheelset to drop some weight, although to quote Ferris Beuller, “If you have the means, I highly recommend picking one up.”

I bet I can actually drop a half-pound off of your bike for under $20. Just switching to ultra light tubes can take around 100g off of each wheel without any sacrifice in performance. Many old school riders will tell you that ultra light tubes are unreliable but I have experienced no degradation in reliability with them. Let’s be honest with ourselves here. If a thorn gets through a 0.5mm thick tube, it will get through 1.0mm thick tube also.

Schwalbe Racing Ralph Tubeless Ready Tire 2012

A lightweight tire like the Schwalbe Racing Ralph will shed grams without sacrificing grip.

If you already have tubeless rated tires and are using tubes, you can drop between 50-100g per wheel by converting to tubeless. This typically involves just adding some sealing tape to the rim and an aftermarket tubeless valve. Check out this blog I posted a while back for tubeless compatibility issues. This weight loss solution costs less than $30 and will dramatically improve both reliability and traction.

Another option is to switch to lighter tires whether they be tubeless or tubed tires. Schwalbe makes a number of light tires that have outstanding grip for their weight. A pair of tires will run you $130. This may sound like a lot but compared to the price of a new wheelset they are a steal. When you factor in the improved grip and the fact that you can save a comparable amount of weight by switching tires rather than switching wheels and using your old tires, the choice is a no-brainer.

So there is some food for thought that will hopefully satiate your hunger for a lighter steed. Keep the rubber side down and ride in peace my friend.

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , , , , , , , , , , ,

Bottom Brackets Demystified: A Guide to Adapters

January 4th, 2012

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

I have been getting a slew of questions regarding bottom bracket standards, adaptors, and the like. To be honest, it has been a real headache for me and our customers. To help ease the pain that I suspect many of you share with me, I have a couple common questions listed below followed by a brief list of common adaptors and parts I have experience using with success.

With any luck the industry will start working together to come up with fewer standards we can all share rather than the mess of competing standards we have today. If not, we will just have to follow the example of Look and have each frame manufacturer come up with a frame specific crank. I would prefer the former to the latter, but realize the chances of the former actually happening are slim.

Remember: Even though SRAM and Shimano cranks both use 24mm spindles, they are very different. SRAM GXP spindles step down on the non-drive side. The other key difference is that SRAM GXP cranks are tightened down on the non-drive bearing only, while Shimano cranks press on the outer race of both bearings. These differences require different adaptor solutions in nearly all cases. Make sure you have the right adaptor for your application especially if it is for SRAM. Lastly, I advise home mechanics to avoid SRAM GXP crank adaptors that require installation of a sleeve to be installed on the stepped down GXP spindle to work in a bottom bracket or adaptor that is primarily made for Shimano applications. This type of adaptor is trickier to install and is not worth the headache, especially if you don’t have a lot of mechanical experience.

Question: I’m trying to mount a Shimano Dura-Ace crank on a BBRight equipped Cervelo S5. Is there an adaptor or specific bottom bracket available to make it work? From: Scott

Cervelo S5 Team Ultegra Di2 2012

Enduro (ABI) makes an adapter to mount Shimano cranks to the BBright frame design on the S5.

Answer: Enduro (ABI) makes the adaptor you need. It is a press-in reducer type that uses the existing BBRight/PF30 bottom bracket and just reduces the bearing bore down to 24mm while adding the extra width needed for a Shimano crank. Unfortunately this part is only available from Cervelo at the moment, which means you need to work with an authorized Cervelo dealer to get them (fortunately, we are an authorized dealer). Hopefully it will be available from distributors soon.

Question: I have a PressFit 30 bottom bracket on my 2012 Specialized Stumpy hardtail and I want to install SRAM X9 GXP cranks on it. I know I need some sort of SRAM specific adaptor but I can’t find anything except adaptors that are made for Shimano cranks. Is there anything out there, or do I just need to fork out for a BB30 crank? From: Jack

This adapter allows you to use a standard BSA (GXP or otherwise) BB in a PF30 frame.

Answer: The best solution I have found so far for your situation is made by SRAM. It is a SRAM PressFit 30 to English Bottom Bracket adaptor (manufacturer’s part# 00.6415.049.010). This is a neat adaptor because it works for any PressFit 30 frame that is 68mm or 73mm wide. It uses standard English outboard bearing bottom bracket cups that thread into the adaptor. Just follow the included instructions for the correct number of spacers and the location of the wave washer for your specific application.

This adaptor also works for Shimano cranks, just use the outboard bearing bottom bracket spacers you would normally use in a frame with a standard English bottom bracket width that corresponds to your PF30 bottom bracket shell width (i.e. 68 or 73mm).

Below is a list of reliable adaptors for common applications:

Adaptors for BB30 frames to use 24mm spindle cranks

Rotor BB30 to BB24 Converter Bottom Bracket - This is a Shimano specific adaptor that places the bearings outboard of a BB30 frame in order to work just like a normal English bottom bracket would with outboard bearings threaded into it. However, with this one the bearings are pressed into the adaptor so no additional bottom bracket is required for use with this adaptor. This is the stiffest adaptor solution that I am aware of for BB30 frames.

Parlee makes a similar BB30 to English adaptor but with this one the two cups do not thread together to prevent the cups from moving within the frame or coming loose in a slightly oversized frame bottom bracket bore (but this is somewhat unlikely). This is also a Shimano only solution.

Wheels Manufacturing Bottom Bracket Adaptors - These adaptors are perhaps the easiest to use. They simply press into a standard BB30 bearing and reduce the bore to 24mm while extending the overall width to meet the standard required for Shimano, Race Face, FSA, or Rotor 24mm spindle cranks designed to work with English bottom brackets. SRAM GXP specific versions are also available.

Adaptors for PressFit 30 (PF30) frames for use with 24mm spindle cranks

SRAM PressFit 30 to English Bottom Bracket Adaptor (manufacturers part# 00.6415.049.010)–This is a neat adaptor because it works for any PressFit 30 frame that is 68mm or 73mm wide. It uses standard English outboard bearing bottom bracket cups that thread into the adaptor. Just follow the included instructions for use with a 24mm SRAM GXP crank for the correct application of spacers and wave washers.

For use with a Shimano crank, just use the spacers you would normally use in a frame with a standard English bottom bracket width of either 68mm or 73mm.

With these adapters, you can use any steel 24mm or GXP crank on any BB30 or PF30 frame.

Wheels Manufacturing Bottom Bracket Adaptors - These adaptors are very easy to use but as of Dec. 2011 they are only available for Shimano cranks. They simply press into a standard PF30 bottom bracket bearing and reduce the bore to 24mm while extending the overall width to meet the standard required for Shimano, Race Face, FSA, or Rotor 24mm spindle cranks designed to work with English bottom brackets.

Adaptors for BBRight frames for use with 24mm spindle cranks

Enduro (ABI) makes an adaptor that is a press-in reducer type that uses the existing BBRight/PF30 bottom bracket and just reduces the bearing bore down to 24mm while adding the extra width needed for a Shimano crank. Unfortunately, as stated above, this part is only available from Cervelo at the moment, which means you need to work with an authorized Cervelo dealer to get them.

There are currently no adaptors available to use SRAM GXP cranks in a BBRight frame without using a sleeve-type adaptor from another vendor in conjunction with the Enduro adaptor. I do not recommend using this kind of solution.

Hopefully this post has done more to clarify the issue at hand rather than confuse. But if you are still scratching your head, please feel free to shoot me an e-mail or post a question on our Facebook wall.

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , , , , , , , , , , , , , ,

Ask a Mechanic: Internal Cable Routing

December 19th, 2011

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I have a new Cannondale SuperSix Evo 1 road bike and I want to upgrade the cable to a Gore Sealed system. This bike has internal cable routing for the rear brake. I’ve done some research on the Internet and it looks like it is really difficult to replace this cable. Any tips on how to do this? From: Jack

Answer: Internal cable routing is the bane of most mechanics’ existence. It doesn’t have to be though. Bike companies could fully line the internal routes of their frames with tubing to guide the cable through. They don’t do this because it costs more, is heavier, and engineers often lack the mechanical experience to foresee these types of issues during the design and production of a bike frame.

Gore Ride-On Professional Brake Cable Kit Black

Gore's Professional System Brake Cables uses compression-less housing for crisp, immediate brake response.

Nevertheless, there is an easy solution that can help immensely in situations like yours. Just add in the liner tubing that the thoughtless bike company did not. Take a stretch of liner tubing such as the liners included in the Gore Sealed kit, and place this over the inner wire before pulling the wire out of the frame. Even if you are not going to use a sealed cable system, you can use this trick as an installation aid. If that is the case, once you get the new inner wire through the tubing, remove the tubing from the frame.

Now some of you are probably asking yourself, “Where do I get this tubing if I am not using a sealed kit?” You actually already possess the tubing you need! Just use the plastic liner of an old section of derailleur housing. To get to it use a knife or a pair of pliers to crack the outer sheath near one end. Then use needle nose pliers to grab onto one of the housing wires and peel it back like you would a banana. Once you peel it all the way to the end it will open up just like a banana peel and you will be left with just the tubing inside.

If I wrote these instructions clearly, following them should result in thousands of fewer four-letter-words uttered in anger. My work here is done. Press on in confidence home mechanics!

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , , ,

Ask a Mechanic: Repairing Tubeless Tires

December 14th, 2011

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I have a brand new WTB Bronson TCS tire that I flatted on my first ride. It was a pinch flat that I got on a high-speed section of rocky trail. The tire was setup tubeless but the impact caused a tiny 2mm puncture right next to the bead and no matter how much sealant I put in the tire it won’t hold air. Is there a way I can save this tire? From: Kyle

Answer: Wow, you pinch flatted a tubeless tire!?! Kudos, my friend. You must have really been hauling the mail, or running far too low air pressure in your tire. Either way, you have something to be proud of, as this is a feat that is difficult to achieve.

To answer your question, there is an easy way to save your tire. Put a tube in it. There is no way to reliably patch a tire punctured near the bead. If the flat were somewhere else on the tire you would have a fighting chance at fixing it.

A GU packet can serve as a boot, just make sure it's empty.

A GU packet can serve as a boot, just make sure it's empty.

Although I know the advice I am about to offer on how to patch a tubeless tire will not help you in this instance, I offer it anyway to help the many others that have suffered punctures in more normal locations.

First you’ll need something we call a “boot.” This is not to be confused with a different word pronounced the same way (a homophone) by our northern neighbors meaning “nearby, or concerning a given subject.” No, the boot I am referring to is a small scrap of material that is used as a patch. This material could be made of any number of items. The important thing is that your chosen boot is somewhat flexible, yet does not stretch easily. Common boot materials include American paper currency, energy gel wrappers, old bicycle tire sidewall casing material, discarded bulletproof vests, etc. Keep in mind that the larger the hole, the stiffer the boot needs to be to patch it effectively.

Simply take some inner tube patch cement or tubular tire glue and apply a thin layer to the area of the tire to be booted or patched. Do the same to the boot. Let the glue glaze over and become tacky while remaining slightly viscous. Then press the two together while working out any bubbles that may have formed during application. Make sure the edge of the boot adheres to the tire around the entire circumference of the boot. If it does not, don’t fret. Just apply more glue to the edges and work them by pressing the boot down with your fingers until it fully seals. Give the whole assembly a few hours to cure and you will be back living comfortably in the modern era of tubeless tires in no time flat (pun fully intended).

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , , , , , ,

Ask a Mechanic: Drivetrain Noise and Cable Issues

December 2nd, 2011

Our weekly column is back, where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

SRAM's Red Cassette is an exceptional component, but is notoriously loud.

Question: Hello Daniel, I need some advice from you if you don’t mind. I am using a Sram Red groupset and I’m having issues with noise coming from the rear derailleur. When I start riding, its o.k.; no sound whatsoever, but after about 10km the noise starts again and lasts until I reach home. It sounds like bearings without grease. I have dismantled the rear derailleur, checked the pulleys and serviced it, but it is still there. When the noise first started I thought it was coming from the rear wheel so I changed to another wheel and the noise is still there. Do you ever have this problem? Any idea what I should do? Should I replace it, it’s only three months old. I would appreciate any help. From: Ben

Answer: Ben, it sounds like this noise might be from the cassette. Sram Red cassettes are known to be very loud. The powerdome construction tends to amplify drivetrain noise like the horn on a Victrola. You might try using a Sram powerglide or any Shimano cassette.

If this is not the problem, the only other possible causes would likely be a poorly adjusted rear derailleur, bent or loose derailleur hanger, or an inadequately lubed chain. The chain one makes sense given that the problem starts only part way into a ride. Let me know if any of these solutions work for you.

Question: I am having a problem with the rear shifting on my Cervelo S1 with a full Ultegra SL group. I took it to my LBS and the mechanic diagnosed it as cable stretch and readjusted the tension. This seemed to fix the problem for about 1 ride, but after that the shifting went bad again. I checked the cable anchor bolt and it is tight, any idea what is wrong? From: Randy

Answer: Randy, I’m “a-frayed” that your cables need to be replaced (hint: your issue is likely due to worn or frayed cables). If there is a lot of drag at the shifter (resistance to the shifter moving) then the cables are worn and should be replaced. If there is little to no drag at the shifter, your cable could be coming apart inside the shifter. As each strand of wire breaks the cable gets longer and the tension goes down causing unreliable shifting. If this is what is happening, then you need to nip it in the bud before the cable snaps entirely and the frayed head is left jammed inside the shifter rendering it a dead, rigor mortised lump of gears.

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , , ,

Ask a Mechanic: How to True a Wheel

July 7th, 2011

In this weekly column, our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I have always wanted to know how to true wheels. But the thought of wrecking a wheel has prevented me from experimenting with the process before receiving some instruction. Can you give me any tips to get me started?   From: Dave

Answer: So you want to reinvent the wheel? Don’t worry; truing wheels isn’t as hard as most people would have you believe. If you can tune a stringed instrument there is a strong probability that you can also true a wheel. But this is not a necessary prerequisite skill. The trick to truing wheels is to make small adjustments.

If you don’t want to invest in a truing stand you can use your brake caliper to do the work for you on a road bike. Simply adjust the barrel adjuster on the brake caliper so the pads are closer to the rim in order to better gauge how far off your wheel is. If you have a disc brake equipped mountain bike, you can use a zip tie wrapped around your seatstay or fork lowers for the same purpose. Just cut it short and use the tail as your gauge. As you work around the wheel you can rotate the zip tie so that the end of the tail moves closer to the rim as you progress with your wheel true. Now before truing any wheel, make sure your hub bearings are adjusted correctly. If the wheel wobbles at the axle and you try to true it, you won’t get anywhere with your wheel true.

Feedback Sports Support Truing Station

This Truing Station from Feedback Sports will make the task at hand much easier.

To adjust the spokes just turn the nipples counter clockwise in order to tighten them and pull the rim toward the side you want it to go. If you need to pull the wheel right, tighten a spoke coming from the right hub flange in the offending area, and vice versa for left. Avoid turning a single nipple more than a quarter of a turn for the first 10 wheels you attempt to true. This will help to keep you out of trouble. Also, avoid loosening spokes opposite the ones you have tightened. Loosening spokes can lead to uneven spoke tension that can weaken your wheel, make other spokes break, or cause the entire wheel to de-tension.

Always start on the area of the wheel that is furthest out of true. Don’t worry about getting this area perfect. Just get it better than the next area that is out of true. Then move on to the new worst area. Continue to do this as you work your way around the wheel until you are done. This will keep adjustments small thereby preventing you from getting into trouble. More importantly, following this procedure will help to maintain more even spoke tension around the wheel.

Remember that all of the spokes work together to hold a wheel straight, round, and true. Much like a V8 engine that can still run with one cylinder not firing, a wheel can still function with areas of wildly uneven spoke tension. But, also like the misfiring V8, the wheel won’t work very well and will likely face a serious breakdown in the near future. So keep your adjustments small, start on the biggest problems first, and don’t let the tension get too uneven.

A practice wheel is also helpful. 32 or 36 spoke wheels are the easiest to learn on.

If you do get into trouble, just go to the best mechanic in your area and he or she will be able to get everything straightened out (pun fully intended) so just give it a shot!

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , , , ,

Ask a mechanic: Wheel Noise

June 22nd, 2011

In this weekly column, our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com.

Question: I keep getting noise coming from my rear wheel. It’s a Hed 32 hole Belgium rim laced three cross to a Powertap hub. The spoke tension is nice and high and the whole combination is nearly new. I can’t figure out where the noise is coming from. Any ideas?  From: Alan

Answer: Ever heard the saying that “The squeaky wheel gets the grease?” A literal application of this metaphor is the way that most mechanics tackle this type of issue.

The first thing I would check is that your skewer is greased to prevent noise coming from the skewer and hub end caps rubbing together. It goes without saying that you want the skewer to be tight when closed on the bike. On your particular hub you have removable end caps that can move around where they interface the bearings and axle.

Next I would check the cassette. Make sure it is tight and that the freehub body is greased to help prevent noise that could come from the cogs rubbing against the body.

Phil Wood Tenacious Oil

Use Phil Wood's Tenacious Oil where the spoke nipple meets the rim and to lubricate spoke intersections where they cross or meet the hub.

Another spot to check is where the spoke nipple meets the rim. I like to place a drop of heavy oil such as Phil Wood’s tenacious oil in this location. The oil helps to protect alloy nipples from scoring while keeping noise down. It also helps to prevent the nipples from ratcheting off of the spoke as cyclical loads are placed on it during every revolution.

You can use the same oil to lubricate the spoke intersections where they cross or meet the hub. Any place that you have metal on metal contact can cause noise so you may as well cover all of your bases.

Lastly, and I have a feeling this could be source of your noise; you may need to have your wheel built with brass spoke washers. These washers are placed under the head of the spoke and take up the slack between the j-bend and hub flange for cases when the j-bend is too long, the hub flange is too thin, or both. A sloppy fit here can cause creaking issues that I have experienced on wheels of my own. Unfortunately, this fix requires rebuilding the wheel.

With any luck one of the other fixes will solve the problem. If not, there is a vast number of wonderful high tech music playing devices available on the market these days…

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Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.

Evan Ask a Mechanic , , , ,