Routine Bike Maintenance

June 11th, 2008

Routine maintenance is an important and unfortunate part of owning and riding a bicycle. Time spent working on the bike equals less time spent riding. A well-tuned bike, however, performs better and lasts longer. Will you be working on your own bike this year? Maybe you take it to the shop for the annual spring tune-up. Either way, how do you know how much service the bike really needs? Performing regular maintenance on your bike keeps you in touch with what needs service and when. It also makes it easier to communicate with the techs at the shop should you need their assistance.
Your bicycle service should always begin with washing the bike. Nobody likes to work on a dirty bike. First, if it’s a mountain bike, make a mental note if the suspension fork or rear shock is particularly oily and dirty. Then, degrease the chain, cassette and chainrings. Remove the wheels; wash them and the frame with soapy dishwater. Rinse everything with a light spray of the water hose.
Now that everything is clean, begin by inspecting the wheels. Quickly check the tire tread and sidewalls for cuts and other damage. Also look at the rims for any dents or cracks. Next, roll the axles gently between the fingers. They should roll smoothly and quietly. Any roughness indicates a need for adjustment or overhaul. Grasp the axle end and attempt to wiggle it sideways. If you feel movement, an adjustment may be required. Be aware, however, hubs with cartridge bearings are usually not adjustable. When worn out, cartridge bearings require replacement.
While the wheels are off, inspect the bottom bracket. Derail the chain and examine it using the same procedure as the hubs. The modern bottom bracket uses cartridge bearings. If the axle spins rough or has lateral movement it will need to be replaced for best performance. Next, inspect the chainrings. Worn chainrings have teeth that appear to have hooks. In some cases they may look like the dorsal fin of a shark. Chainrings that are worn can contribute to an occurrence called chain-suck. Also look for bent or broken teeth.
Prior to installing the wheels is the time to inspect the brake pads. Rubber brake pads that are unevenly worn (it’ll be obvious) should be replaced. Also, small stones and bits of aluminum are often embedded in the brake pad surface. These bits can be easily removed carefully with a sharp pointed tool. Disc brake pads are easily examined by looking into the brake caliper with a flashlight. The disc brake pads should be replaced when the pad material, which is bonded to a metal backing plate, is 2mm thick or less.
When these checks are done, restore the chain, wheels and brakes to their functioning position. Spin the wheels to see if they straight and round. Now inspect the chain for any twisted or damaged links. An easy way to do this is to rotate the cranks backward slowly while watching the chain closely. Also look over the cassette and chainrings for damaged or bent teeth. Keep in mind that when replacing any one component of the drivetrain (i.e. chain, cassette, chainring) there is a possible incompatibility between the new and old part. This may cause the chain to skip under hard pedal pressure.
A skipping chain may also be caused by worn or dirty derailleur cables. Dirty or worn cables do not allow the derailleur to align properly under the cassette. Cables in good condition slide smoothly inside the cable housing. They will also be free from kinks and broken strands. Remember to check the cable head inside the brake or shifter lever. Also inspect the cable housings and brake lines. These too should be free from both kinks and cracks. It is possible that these housings may be worn on the exterior from the friction of rubbing somewhere on the frame. Replace any housings or brake lines with significant exterior wear.
Before packing up all the tools, remember those dirty suspension parts? Inspect the fork legs and/or rear shock shaft for wear and scratches. When extremely worn, these parts will have aluminum color showing through. It is important to keep these parts clean and scratch free to avoid premature. Wipe the shock and forks clean before every ride.
That’s all there is to it. Including bike wash, this inspection can be performed in less than an hour. In fact, this is similar to the service that team mechanics perform to every bike, every day. Done every couple weeks, or when the bike is so dirty you can’t stand it, this routine maintenance will reduce the chance of problems on the road or trail. It will also keep you and your bike performing tiptop without spending too much time in the shop.

Author Tom Jow is a former U.S. National Team mechanic and bike guru at the Wild Rose.

To Tube, or Not to Tube?

June 11th, 2008

At the turn of the century one of the hottest new technologies was the tubeless tire system. Now, it seems to be all but forgotten. Unlike many components, there are just not that many new developments to be made to keep this performance enhancer in the limelight. In fact, many mountain bikes come equipped with tubeless compatible components and their owners don’t know it. As salespeople, sometimes we even forget to mention it. But using a tubeless tire system can increase the performance and enjoyment of our rides. There are two distinct types of tubeless systems available today.
In order to create a tubeless tire system, an airtight seal was needed in the rim bed. Mavic accomplished this by developing a method of installing the spokes from the hub side of the rim, leaving the inner rim bed completely sealed. The rim bead seat was also redesigned to provide an airtight seal and Universal System Tubeless (UST) was born. The tire companies Hutchinson and Michelin designed special tires that use a stronger bead wire to withstand the increased stress of the airtight bead seal. In addition, the UST tire has a layer of rubber inside the casing to complete the air containment.
Why go tubeless? The benefits of tubeless tires include lower rolling resistance, greater traction and less punctures. Without a tube, the rider can use lower tire pressure with less risk of pinch flats. With lower pressure, the tire contact patch is larger which provides more traction. The rolling resistance is decreased because with the lower tire pressure because the tire deforms and rolls over more objects instead of being deflected.
However, benefits do not come without cost. Upgrading to a UST wheel set with tires will cost several hundred dollars. Weight is always an issue on a bicycle, especially when it comes to wheels. A tubeless wheel set is of comparable weight, but the tubeless tire is a little heavier than its non-tubeless counterpart with tube. Installation can be frustrating if the tire does not inflate right away. Also, air pressure of approximately 60psi is needed to seat the bead completely; not an easy task without a floor pump or compressed air. Finally, the tire is still subject to punctures from sharp objects, and pinch flats can still occur if the tire pressure is too low. Instead of pinching a tube, the tire will have two punctures in it.
A lower cost alternative to UST tubeless is a tubeless conversion kit. While Bontrager manufactures a kit for its own brand, the most popular conversion kit is made by NoTubes.com. The tubeless conversion is made possible by a rim strip and valve combination that seals the rim spoke holes and provides an airtight bead seat. Therefore, any UST tire can then be used. More often though, a standard tube tire is used with a liquid sealant inside.
The benefits of a tubeless conversion kit are many. First, it provides all the performance enhancements of a tubeless tire system at a much lower cost. Second, the wheels are much lighter weight if used with sealant and a tube type tire. Finally, puncture resistance is increased with the sealant and seating the bead is often easier.
Tubeless conversion kits also have own their drawbacks. Installing or removing the sealant can be messy. Latex based sealants are prone to drying out, needing to be “refreshed every couple months or so. Similar to UST tubeless, initial inflation and sealing can sometimes be a challenge. Tire selection is reduced due to manufacturers recommendations.
Replacing tires is often a task that no one wants to do. New tires are not nearly as glamorous as a new shock. But look at the stacks of tires in any race truck and you will see how important tires are to performance. The correct tire and the benefits of tubeless could be just what you need to put a little excitement into your riding. Ten years later, what’s next? Road tubeless.

Tips for Tubeless
* Follow the manufacturers recommendations and instructions.
* Upon initial inflation, lubricate tire beads with soapy water. Use as little pressure as necessary to seat the bead and wear safety glasses.
* When using sealant, immediately after seating the beads, shake the tire horizontally to better distribute the liquid.
* Start with initial pressure 5psi less than with tubes. Decrease slowly until comfortable or you reach 30psi. Inadequate pressure leads to pinch flats and decreased control.
* When performing repairs, unlock as few tire beads as necessary. That means one.
* Inspect tire casings, treads and inflation pressure often
* Tubeless conversion for Cyclocross.