After a recent accident on the trail that toasted both body and bike, I figured I needed to learn something from the experience. Otherwise I might repeat the same thing over again without making changes to prevent it from happening. Experiences like this offer excellent opportunities to better oneself, or in some cases, someone else.

Today I’m handing over some technical know-how to you thanks to my accident. One of the results of my crash was a pringled wheel and the only real way to fix it was to replace the rim. So here’s the quick and dirty on building (or re-building) an MTB wheel.

The first thing you need to know is whether you’re building a 24, 28, 32, or 36 hole wheel, the process is the same. The only difference is the number of spokes per stage are different: 6 for a 24 hole, 7 for a 28 hole, 8 for a 32 hole, and 9 for a 36 hole wheel (can you spot the pattern?).

So to get started there are some things that we need to do before turning a truing key. Here’s a list of tools that you’ll need:

• Truing stand such as the Park TS-2.2
• Truing keys for the spokes
• Measuring tool or Vernier caliper
• Spoke prep or a lube
• Proper length spokes (for disc wheels each side requires two different lengths)
• Spoke nipples
• Calculator (to calculate spoke length)

Now we’re ready to go. The first step to building up a wheel is to figure out the spoke lengths for both sides of each wheel. Due to the prevalence of disc brakes on mountain bikes, most wheels today have four different lengths of spokes. The following websites have formulas to help you calculate your spoke length. You can choose any site for this task:

DTSwiss.com (has access to many major branded hubs)
WheelPro.co.uk (good site with info on how to measure)
BikeSchool.com (good site with great links)
AppliedThought.com (one more site for completeness)

Wheel building is essentially the same for front and rear wheels. There are the same number of steps and you’ll drop the same number of spokes at the same time for both front and rear. Take the number of spokes for your wheel that you’re building and divide by four - that will be the number of spokes you will set in each flange at any one given time. I am building a front wheel but the hub and rim positioning holds true for a rear rim as well.

Positioning the hub and rim

Position the hub so that the disk mount side of the hub is facing up (front wheel) and drop in the first set of 7 spokes (28 hole rim). Place the rim so that the sticker on it is facing upside down (front wheel only). If you look at the valve hole you will see that the spoke hole on the left is up and the spoke hole on the right is down. When building with this method you must always have the rim situated this way. If you’re building a rear wheel you’ll have the hub with the cassette facing you and the rim sticker right side up.

Laying in the key spoke and lacing in the first set

You can take any spoke and now fit it in the rim hole to the left of the valve hole. Thread a spoke nipple on and repeat this every forth spoke hole, rotating the rim and installing the remainder of the spokes. The wheel should look like the one in the photo. Just remember from now on you are always skipping three holes when you add the next spoke.

Setting the second round of spokes

Flip the wheel and orient the rim so that the valve hole is facing away from you. You should now have the spoke on the right side of the valve hole. Drop in the next set of 7 spokes into the hub and drop them in every other hole. Before you place a spoke you should look down at the hub and notice that the holes are offset. Pick the hole that is to the right of the key spoke and drop the spokes in every other hole. Once the spokes are in it’s time to lace them to the wheel. At this point there should be one spoke on the right of the valve hole. Install the spokes loosely at this point - you should have a wheel that looks like the one below. Turn the hub clockwise while holding the rim so that the spoke are tangent to the hub.

Dropping the third set of spokes

You’re now ready to start feeding the third set of spokes. The easiest way to remember is under the first two, over the last. This holds true for 3-cross lacing. For a two-cross lacing pattern, lace under the first spoke then over the last. Either way it’s easy - just remember these sets of spokes now go in the opposite direction that the previous two sets have been going. Thus this set will fit in the spoke hole on the opposite side of the valve hole. Once you feed the entire set of spokes you should have a familiar pattern emerging. When all the spokes from the third set are in, feed the remainder of the spokes on the opposite flange doing the same thing you did on the third set. The fourth set will have the spokes entering the other side of the flange.

Flipping and dropping the fourth set of spokes

Complete the pattern by weaving the last set of spokes just like the third set (under two, over one for 3-cross). Once you’re all laced up, get your wheel on the truing stand and using the valve hole as reference start tightening the spokes until the threads just disappear under the spoke nipple (this is why getting spoke length is critical). You can also use a spoke key or screwdriver for this task. At this point you’re getting ready to breathe life into your creation by adding spoke tension.

Tips before truing a wheel

Pre-bend the spokes so that they are straight as possible, both at the nipple and the hub flange. This task may take time but in the end will give you a wheel that is stronger and stays straighter in the long run.

Make sure you use a spoke prep. It will make assembly easier and will also prevent the spoke from winding up. A piece of masking tape on each spoke will indicate when a spoke is twisting (not my idea but a good one nevertheless).

Check for tension often, clasping 4 spokes at a time (see photo). This will take out any wind-up and will set the spokes more quickly.

Place the wheel in a truing stand and take slack off the spokes evenly. If you have the spoke lengths just right you should be able to wind up all the spokes in the nipples until the there is one thread left.

True and tension the wheel

Always start at the valve hole for reference when truing and adding tension to your wheel.

Continue bringing up the spoke tension one half turn at a time until the wheel begins to firm up. Once you begin to feel a little bit of resistance, start bringing the wheel into shape. There are four things that you need to control to complete the job: lateral truing (side to side movement), vertical truing (up and down or hop), dishing (keeping the wheel centered), and tensioning (more tension = stiffer wheel).

Try to make your truing adjustments independent of one another. For lateral truing, spin the wheel in the stand and find the place on the rim that is farthest away from where most of the rim is. If the rim is off to the left, tighten spokes that go to the right flange and loosen those that go to the left flange. If you do the same amount of tightening and loosening, you can move the rim to the side without affecting the roundness of the wheel.

A word of caution: When truing and using the example below, go around the entire wheel once while trying to improve the overall wheel. Do not concentrate only on one spot. After each time around the wheel, relieve the stress by squeezing the set of four spokes as mentioned before.

As an example, if the rim is leaning to the left and the center of the bend is between two spokes, tighten the spoke that goes to the right flange a quarter turn and loosen the spoke that goes left a quarter turn. If the center of the left bend is next to a spoke that goes to the right flange, tighten that spoke a quarter turn and loosen each of the two spokes to the left 1/8 turn. If the center of the left bend is next to a spoke that goes to the left flange, loosen that spoke a quarter turn and tighten each of the two right spokes next to it 1/8 turn. After adjusting the worst bend to the left, find the worst bend to the right, and adjust it.

Keep alternating sides. Don’t try to make each bent area perfect - just make it better, then go on to the next. The wheel will gradually get truer and truer as you go.  When you’re near the end of this job you should have a wheel where the spoke tension is fairly even. When truing a wheel I often pluck each spoke and listen to the tone to find any irregularities. Keep in mind that the left and right side spoke tensions will be different - the disc side tone will be higher than the other side. On a rear wheel with disc, the tone will be almost dead even between the two sides.

Finishing up and riding!

Once you feel like you’re done, give the wheel a once over again by compressing sets of 4 spokes and double check the state of true. If all is good and you’re happy with the amount of tension, place rim tape over the spoke ends and mount up your tires. Install your discs and you’re off! Go for a good ride then re-check your tension. Your wheels should last you a good long while.

A quick note about tension: Typically as spoke tension rises, the wheel becomes more stiff which allows it to react more quickly. So for an XC rider who’s into technical events, he or she may want to consider building a tighter wheel. For someone who is into endurance events and likes a “softer” riding wheel, less tension may be the way to go. That being said, too much tension can damage a wheel. If you have a tension meter, shoot for tensions from about 70 - 90 kgf to a maximum of 130 kgf depending on your rim and spoke selection.

Once your wheel is true and set and you have ridden your bike, if you feel the wheel is reacting slowly or feeling “mushy,” place your wheel in the truing stand and add a quarter turn counter-clockwise (tightening) to each spoke (start at the valve stem). Then re-check, true, and go for a ride. Repeat ’til you’re happy.

Cheers!

Syd

Disc brakes are now found on mountain bikes of nearly every price point and they are quickly becoming the standard. Of the multitude of types and brands, disc brakes fall simply into one of two categories: hydraulic or mechanical disc brakes. Mechanical disc brakes are generally cheaper (cost-wise), but not necessarily cheaper in quality. Both systems, as wonderful as they are, do need periodic inspections much like the brakes on your car. Seeing that a fraction of riders use a computer on their bike, I personally recommend inspecting your brakes in number of rides. I propose that you thoroughly inspect your brakes every 25th ride at the very least, or if you feel a loss in braking performance.

Here I will cover adjusting and servicing mechanical disc brakes including exchanging brake pads, servicing rotors, checking and servicing cables, and ensuring the proper functionality of the braking system. Note: the following photos may not be the same as your brake set-up but they will represent most of the systems out there.

Before your get started you need to have the correct tools for the job. The list below are the typical tools required for inspecting and servicing your mechanical disc brakes.

• 3, 4, 5mm Allen sockets
• T25 socket
• Brake cable housing cutters
• 120gt sand paper
• Needle nose pliers
• Alcohol wipes to clean rotor of finger prints
• Torque wrench

Brake lever inspection

One of the first things to inspect when you are servicing your mechanical disc brakes is the function of the brake lever and the calipers actuation lever. Apply and release the brake looking at the actuation arm (what the brake cable attaches to at the caliper). Check to see that it swings freely and does not hang up, that is, the arm returns to fully released position. If the arm does hang up, look for corrosion or possible obstructions. Usually some cleaning with penetrating oil followed by a thicker lubricant will loosen the arm.  Now, check the movement of the brake lever itself. Apply and release the lever, it should be loose. Put a bit of lube on the pivot pin to ensure proper operation of the lever. Finally, torque the cable anchor bolt to 55 in-lbs +/- 5 in-lbs.

Cable routing inspection

Next, inspect the brake cable and the routing of the cable. Look for any fraying (loose strands of the cable) or kinking of the cable or housing. Consider replacing the cables and housing if there are frays or kinks found, otherwise you will risk poor braking performance on your next ride.  Or, if the current brake cables have been on your bike for 2-3 years, it’s a good idea to replace them now.  I recommend a quality sealed cable system like those available from Gore, Jagwire, or Avid.

Removal and replacement of brake cables

When replacing the brake cables, measure the lengths of the old cable and housings to determine the proper cable routing and new lengths. Err on the long side when cutting cables as the cable length should not be too short. If the cables are too short they will limit the full range of steering. Be cautious by replacing one cable at a time since the lengths of the front and rear brake cables are very different. When cutting cables use proper cable cutters that leaves a nice flush finish to the cable ends. Always use new cable ferrules (the steel ends) to finish your job, even these little steel ends wear out.

To remove the old cable, first loosen the bolt that holds the cable in place on the brake caliper, and then pull the cable out from the housing. Loosen the adjustment barrels on the brake lever and squeeze the brake lever so that the cable is exposed enough to remove it from the slotted hinge in the brake lever.

Tighten the cable adjustment barrel about two threads from all the way in and insert the new cable. Route the cable in the same way the old cable was routed. Try lubing the housing with a small amount of synthetic oil to get the cables through the housing if needed (do not add oil if you are using Gore or Avid Flak Jackets). Finally, attach the cable to the brake caliper and torque the cable anchor bolt to 55 in-lbs +/-5 in-lbs.

Removal and inspection of brake pads

Before you get started on inspecting the brake pads, remove the wheel from the bike so you can better access the pads. Then remove the brake pads from the caliper to inspect their thickness and condition.  Look for a minimum thickness of 1mm and check the condition of the pad making sure they are not galled or contaminated with grease or oil.

There are various methods of removing your brake pads and some brake pads are removed by unscrewing a pin out of the caliper allowing the pads to drop out. Other brakes may have a small clip that holds the pad to the pistons, and still others are held in place with a magnetic piston. If you are unsure how to remove the pads, check your brake manufacturer’s owners manual or website for details. Usually the device that holds the pads in place is opposite the way the pads come out of the caliper.

Brake pads that are thicker than 1mm may not need to be replaced but should be cleaned and sanded. Lay medium close coat sand paper on a flat surface, and with a circular motion lightly rub the brake pad on the sand paper for a few seconds at a time or until the pad surface is flat and uniform. Before you reinstall the pads quickly check that the thickness is still greater than 1mm. If your brake pads are less than 1mm thick, install new pads.

Remember that your brake pad may have a return spring (placed between the pads), a cotter pin or a bolt that holds the pads in place. Otherwise, your system has a retaining spring on the back of your pad. Once you have finished servicing your pads or decided to replace them, you can install them into the caliper. One at a time, slide the pad back into the caliper paying attention to the alignment clips or holes that hold the retaining pin/clips. Then put in the retaining device in place (if you have a cotter pin remember to spread it out so the pin doesn’t work its way free). Finally, give the pads a tug to make sure they do not fall out.

Rotor inspection and cleaning

The next task is to recondition the rotors by removing any glaze that may have accumulated on them. Remove the rotor if it is attached with T25 torx bolts or a Shimano centre lock. You can service the rotor while still attached to the wheel if you don’t have the tools to remove the rotor from the hub, just be careful to keep your fingers clear.

Fold medium sandpaper around a straight block to create a flat sanding surface. Rub the sand paper tangentially on both sides of the rotor’s braking surfaces. Now the rotor should look new with cross hatching marks (small scratches) at 33 degree angles from one another.

If you removed the rotor from the wheel, reinstall the rotor and torque the bolts back at 55 – 60 inch-pounds. When applying torque to the bolts, it should be done evenly and not in a circular pattern. Last, clean the rotor off with a clean cloth and alcohol to remove any oil or fine metal particles. Replace your wheel and check the operation of the brakes.

Brake pad adjustment

Ideally the brake pad position should be set so that when the brake lever is depressed half way, the wheel should lock up. There should be very little space between the brake pads and rotor; this space should be about the thickness of a business card. This spacing can be adjusted on all mechanical disc brake systems using a dial or Allen key for the outboard pad (above, left) and adjusting cable tension for the inside pad. Some manufactures like Avid (above, right) have an inboard pad adjustment as well, again adjust the pad so that you have the space of a business card between them.

Get the proper spacing on the outboard brake pad by making adjustments with the dial or Allen key. If the spacing is too wide on the inboard brake pad, use the adjustment barrel either on the caliper or the brake lever to take up the slack. A small turn of the adjustment barrel surprisingly changes the brake lever travel a lot.

Torque inspection

Once you have the pads adjusted, the rotors and pads cleaned, and your cables lubricated, check the amount of torque on your entire braking system, particularly the caliper bolts, caliper adapters, and the brake levers. Remember to always follow your specific brake manufacturer’s recommended torque settings. Use a torque wrench to make any needed adjustments.

Typical torque values:
International standard (I.S.) caliper mount bolts are 110 in-lbs +/- 10 in-lbs (M6 x 18.5mm);
Post mount caliper mount bolts  are 80 - 90 in-lbs (Avid)

I hope this guide helps you with checking your brakes. This information will be great as a guide for those who already have a decent working knowledge of their bicycle and for those who are getting into repairing your own bike. Please have your owners manual handy for specific information regarding your brakes.

I would like to thank Gino Sena the owner of Cyclepath Northyork for the use of his shop and a few of his bikes for some of the photos in this article, also the folks at Hayes for some of the products that were featured here. Check back here and in the forums for more how to articles. Next up: brake servicing tips for hydraulic MTB brakes.

Whether you’re on the trail or in your driveway, it’s no big deal to fix a flat mountain bike tire. In the ideal situation, all you need is a pump, tire levers, and a new tube.

If your tire still has some air pressure left in it, release the air by pressing in on the tire valve. Depending on the type of valve your tire has, you may need to unscrew the pressure release or use your fingernail to press the release valve.

Next, pull the tire away from the rim. You may need to use your tire lever to get the tire started, once it’s out you can trace around the rim to quickly remove one side of the tire. Repeat the process for the other side of the tire wall. Don’t forget to remove the screw locking ring if your tubes have one.

Remove the tire and tube from the rim. Check the rim to make sure there isn’t anything ganky on the rim that could have caused your flat. Pay particular attention to the rim tape covering spoke connections inside the rim and replace as necessary. Run your hand through the tire itself to check for thorns or other sharp objects. If something causes you to bleed there’s a good chance that it’ll pierce your tire as well.

Now you’re ready to start putting things back together. Inflate your new tube with just enough air to give it some shape. This will help you place it in the tire easily. Place the tube completely inside the tire like a hot dog in a bun. Find the valve hole on your wheel and place the valve stem in the hole.

Start working one side of the tire onto the rim. You should be able to use your hands for most of it, once you’ve made your way around most of the tire you may need to use your levers to pop the tire wall bead inside the rim. Repeat for the other side (note: the second side may be more difficult than the first, especially for tight fitting tires).

Before you begin inflating your tire it’s important to make sure the tube isn’t pinched between the rim and the tire (called a pinch flat). Start at a known point on the tire (I usually start at the valve) and work your way around the tire looking for pinches. When you get back to your start point, flip the tire and check the other side all the way around.

Now you’re ready for the fun part: pumping. Inflate your tire to a reasonable pressure. My pump has a gauge that’s marked for different types of bike tires. It recommends 30-60 psi for mountain bike tires but it’s really up to you. If you like a squishy ride or you like to use your tires as a poor man’s suspension, keep the pressure low. If you’re riding hardpack you may want to go for a higher pressure which will help you go faster. I personally prefer staying at the high end of the range because I’ve found that I get fewer flats on the trail at higher pressures.

This article illustrates how to remove an internal-cup ISIS bottom-bracket. With the proper tools, this job will take at the very most 10 minutes, given a bike that has been well taken care of. I say again, this is a walk-through for removal of INTERNAL BEARING BOTTOM BRACKETS.

Not illustrated is the removal of the chain. Though not completely necessary, I like to remove it as it would otherwise pull on the front derailleur cage.

The first step is to obtain the proper tools. A good beginning toolkit is one similar to this:

The three specific tools needed for this job are a hex-key,

a crank-puller,

and a bottom-bracket cup remover.

Now, remove the crank end caps with your hex-key. This will expose the threads for installing the crankarm removal tool.

Next, install the crankarm removal tool, and use a 15mm wrench or socket to tighten the puller. This will pull the crankarm off the bottom-bracket splines.

Good, your crankarms are removed from the bottom-bracket spindle. Again, this walk-through is only good for internal-cup bottom-brackets!

NOTE: This bike is equipped with a chainguide. For our purposes here, I’ll skip the removal and installation of this part.

Install the bottom-bracket cup removal tool into the splined interface.

NOTE: On the right side of the bracket shell, the threads will be reversed, so “lefty-loosey, righty-tighty” will not work here. This is to keep the bearing cups from walking out of the bottom-bracket shell under power! Keep that in mind, so if you’re trying to loosen up a bearing cup and it won’t budge, try turning it the other way. There should not be that much torque put on any of these fasteners.

There! You’re done!

When reinstalling your bottom-bracket, make sure you use a quality lock-tite compound on all the threads of any component you removed in this process. Reinstallation is the exact opposite of what is written here.

NOTE! When reinstalling the bottom-bracket cups, do not over-tighten! Pay attention to the instructions that came with your new bottom-bracket, or look online for the proper torque specs. Overtightening can cause the bearings to bind, which will lead to galling and catastrophic failure.

This article is a step-by-step procedure on replacing a mountain bike cassette & chain.

Featured parts used here are:

SRAM 8spd (11-32) cassette

SRAM 8spd Powerlink chain (top chain is old, bottom chain is new & longer)

Tools required for this job are:

Cassette lockring tool (SRAM cassettes are compatible with Shimano lockring tools)

Chain-whip tool

Adjustible Wrench (for use with Park Cassette lockring tool)

Torque Wrench (ft-lb/Newton Meters)

Chain Tool

First, either place the bike on a stand, or upside-down. Shift the rear derailleur to the highest gear (smallest cog). Remove the rear wheel from the bike. Remove the old chain utilizing a chain tool. After removing the old chain, use it to make sure the new chain has the correct number of links. If not, remove the extra links from the new chain.

Remove the quick-release skewer/axle from the rear wheel. Insert the cassette lockring tool into the splined lockring.

Now use the chain-whip tool to keep the cassette from spinning as the lockring is being loosened.

Once the lockring is removed, the first two cogs will come off separately. The cassette should then slide smoothly off the hub. If it doesnt, apply some quality degreaser into the spline area between the cassette & hub. Let it set for a while, and then try again. If it still refuses to come off; flip the wheel over and using a small hammer and 6″ wooden dowel, tap the cassette off the hub body.

Be sure to take this opportunity to clean the hub body. Apply a quality anti-seize compound to the hub splines.
Locate the indexing spline on the hub body, and then match it to the index slot on the new cassette. Usually this index spline is smaller/narrower than the others. Line up the splines and slide the new cassette onto the hub. Make sure the cassette is seated fully onto the hub body.

Then, place the two small cogs onto the hub, making sure they are seated properly against the new cassette. Finally, install the new cassette lockring, but do not tighten yet.

Take note of the torque markings on the lockring! Then use a torque wrench to tighten the lockring onto the cassette.

Spin the cassette by hand to ensure that it moves freely and does not wobble. Fit the new chain around the derailleur guide pullys and the smallest front chainring. Again using the chain tool, fasten the chain back together (if using a standard chain, SRAM Powerlink chains do not need a chain tool).
Reinstall the rear wheel back onto the bike, and the job is done!

To replace a mountain bike chain, you’ll need a chain-tool. Some chain-tools have removable bits that are different sizes for different link-pins. Most mountain bike chains have the same link-pin size, so do not be concerned if your tool only has one bit. The Park Chain-tool is a good choice, as it has a large handle and two chain-placement channels.

First, clean any excess dirt or grease off your chain. Do this by holding a rag lightly moistened with chain-degreaser around the chain, beneath the bottom-bracket. Work the chain through your degreaser rag by backpedaling, and make sure you grip the rag lightly.

After you’ve degreased & cleaned the chain, it is now easy to see the pins on your chain. Work around the chain, looking for the “Connector Pin” that some chains have. This pin will appear different than the rest, and will not have “peening” around the head. On some chains (Shimano), the pins are peened, which flares the head of the pin, adding extra strength to the chain. With Shimano chains, a pin which is pressed out will sheer off the peening, which weakens the chain. These pins with sheered-off peening must be replaced with “connector pins”.

Connector pins are long, with a tapered end & a peened end. After inserting the connector pin fully into the chain link, the tapered end is broken off.

When selecting a pin to press out, do not select either a connector pin, or the pin next to it on the same link!

On other chains (SRAM), look for a “Master” or “Quick Link”. This is a section of chain that is slotted, allowing you to separate the chain by sliding the links together. Reassembly is the reverse.

Place the chain inside the channel on your chain tool, making sure it’s fully seated inside the cradle.

Then turn the press handle clockwise, until the removal bit contacts the pin. Make sure the bit is on the center of the pin; then continue, pressing the pin fully through the link and out the other side.

Now that the chain is separated, and replacing the chain is the reverse, except for a few steps. Make sure that the chain is routed correctly through the rear derailleur pulleys, and through the front derailleur as well.
If the chain had peened pins, the “connector” pins are used at this point to rejoin the chain. Slide the connector pin into the chain, tapered end first. After the peened end is even with the other pins on the adjacent links, break off the tapered side with a pair of pliers.

On a “master” linked chain, grasp the two ends of the chain and hook them back together with the sliding links.

Run the chain through several cycles, looking for stiff links. If one is located, observe the link pins for uneven protrusion. If it is the pin which was just replaced, use the chain tool to evenly seat the pin so that it is the same as it’s neighbors. Chain link failure is often the result of protruding pins or bent plates.

We started a wiki a while back to share mountain biking “how-to’s” on everything from mountain bike handling to maintenance and repair but since then we’ve realized the wiki format isn’t really doin’ it for us. Instead, we’ll use the blog to share these articles and ask that our readers add to the articles via the comment feature at the bottom of the page.

There are a number of methods mountain bikers use to get over logs and rocks on the trail. Depending on the size of the obstacle, here are some approaches to consider:

1. Pop a wheelie: This is the easiest way to get started and it works best for small logs or rocks. As you approach the obstacle, lift up your front wheel just before you get to it. It may take some practice to get your timing right but practice makes perfect! While this method gets your front tire over the log smoothly, it does nothing to lessen the impact on your rear wheel. Watch your chain ring as well, larger logs and rocks tend to get caught here and can send you into an endo if you’re not careful.

2. The bunny hop: Clipping in to your pedals (with either toe clips or clipless pedals) make this a whole lot easier. Make sure you have lots of speed as you approach the obstacle. Just before impact, jump up, carrying your entire bike with you (front and rear wheels) to clear the obstacle. This is risky since if you jump too soon or if you don’t have enough speed you may come down on the log or rock with your rear wheel creating a nasty “taco” out of your rim.

3. The speed hoop: This takes the most skill by far but it’s far more versatile than the other methods and can get you over much larger obstacles. (See video below).