What exactly is a bike tune-up?

Tuning a bicycle is less like fixing a household appliance, and more like tuning a musical instrument. It requires the mechanic to have certain concrete technical skills, but also a good ear, a judicious touch and not a small amount of finesse.

Although the term "tune-up" is ubiquitously used in bicycle shops across the country, there is no standardization for what such service should entail. A $20 air-and-oil "tune-up" at one Chicago-area bike shop may be a "free courtesy service" at another.

Since tune-ups and fees associated with them vary from shop to shop, make sure you ask about not only the price, but what is included. The quality of service, workmanship and labor guarantees are also important.

At Cosmic Bikes, we have four tune-up levels: Basic Tune, Full Tune, Deluxe Tune and Complete Overhaul. The level of tune-up we recommend for your bike has to do with the condition of the bike when you bring it in, the degree to which different parts are worn, and how you plan to use the bike.

For most heavily used urban bikes, or bikes that have not been serviced in a long time, we recommend the Deluxe Tune-Up. Your bicycle will get the mechanic's undivided attention for 2-3 hours. After going over the bike with you, recommending replacement parts, and writing up the cost of the repair, the mechanic will take your bike through the following procedure:

Drivetrain. People who use their bikes heavily find that parts of the drivetrain need to be replaced periodically. If the chain is worn, no amount of lubrication will restore it to it's original functionality. Sometimes a worn chain contributes to excessive wear on the rear cassette, and, in extreme cases, front chainrings. Any worn parts will be removed at this point. The labor for servicing and replacing these parts is included in the Deluxe Tune-Up.

Cleaning and degreasing. Your bike will be cleaned from top to bottom. The chain, chainrings, freewheel, derailleurs, brakes and rims will be thoroughly degreased and dried, or replaced with new parts as needed after the bike is clean. The chain and other key parts of the drivetrain will be treated with a high-quality lubricant.

Wheels. After your bike has been cleaned, we will move on to the wheels. We'll adjust the external tension on the bearings of both wheels, and dish the wheels, which involves aligning the rims perfectly in relation to the axle. Finally, we true the wheel by precisely tensioning the spokes to make sure the rims are straight and will stay that way. A typical wheel truing operation may require a few hundred minuscule turns with a truing key.

Headset and bottom bracket. Next, we adjust the external tension on the bearings inside the headset (between the handlebar and the fork of your bike) and the bottom bracket (inside the shell between the crank arms). These bearings, along with the wheels, take a real beating even during normal riding, and the correct tension on these bearings will maximize their lifespan. Even newer sealed bearing systems require servicing, including making sure that they are properly and securely retained, and some have a degree of adjustability.

Gears and Brakes. Along with wheel-truing, this is the most "touchy-feely" part of the tune-up. The mechanic will spend considerable time coaxing these parts into perfect adjustment. If necessary, cables, housing and brake pads will be replaced. The brakes will be aligned with the rims, and "toed" to prevent squeaking. The mechanic will adjust the cable tension and the position of the brake arms to make your rear brake quicker and stiffer, and your front brake a little softer, so you don't go flying over the handlebars when you brake.

The mechanic will also replace and/or lubricate the derailleur cables, set the cable tension and adjust positioning of derailleurs for accurate shifting, and set the limit  screws on the derailleurs, to make sure the chain doesn't skip off the cogs.

Safety Check. The mechanic will fill up the tires to recommended pressure, and check the safety and secure attachment of all the parts and accessories on you bike, making sure that nothing is worn or loose, or could contribute to an accident or fall.

Test Ride & Re-Check. Finally, the mechanic will test ride your bike to check if all that work paid off. Any problems will be corrected, and then a bike will be double-checked by a second technician.

Guarantee. This tune-up includes a 90-day labor guarantee, during which time we will perform all covered corrections or adjustments free of charge.