A crash course in bike maintenance

Justin Carter, an Ace Wheelworks mechanic, tunes up a customer's bicycle. "In that first month of riding, it's almost expected that little things will go wrong," Carter said of new bicycles. (ETHAN GILSDORF FOR THE BOSTON GLOBE)

Anyone who knows me understands that I'm no mechanical genius. I have as much trouble patching an inner tube as I have patching my broken heart.

Therefore, praise be to the bicycling gods for Boston's many independent corner bike shops. Mine is Ace Wheelworks in Somerville. (I bought my bike at their sister store in Newton.) Whenever my trusty steed needs some attention, I bring it on down.

But lately, I've been nagging myself to get some basic bike maintenance skills under my belt. So, last month, I spent an afternoon hanging out with Ace's expert bike mechanics, hoping to glean a few tips and not get too much in the way.

"I think people are more aware of servicing their bikes than they used to be," said John Allis, who has owned the shop since the 1970s. But as with cars, he said, over the years bike technology has become more complex. "Repair issues are not as simple as they used to be."

And in New England, given the potholes and volume of salt dumped on roadways, bikes get beat up quickly. Though it would seem counterproductive for a bike shop owner, Allis wants his clients to be able to do basic repairs. "We encourage people to take care of their bikes on a fundamental level," he said.

Allis walked me through some of these fundamentals.

First stop, stocking a tool box. Above all, he recommends bike owners purchase a standard multitool or a set of metric Allen wrenches. "That will do most of the service work," he said. Also essential are a couple of tire levers (allowing you to pry the tire off the wheel), a spare inner tube and patch kit for flats, and a floor-model tire pump with a pressure gauge.

For chains, cables, and pivot points, lubrication - either "dry" paraffin-based (which doesn't attract dirt) or lightweight oil-based - is a must. So is a lightweight grease to apply to nuts and bolts.

For more advanced servicing, Allis suggested buying a cable cutter (which prevents frayed ends), a spoke wrench, and a chain whip and cassette-removing tool (which are used together to remove your cassette, or rear cluster of gears).

A stand is useful "if you're working a lot on your bike," Allis said. It holds it in place and allows you to spin the wheels as you work.

A no-brainer to some, but news to me: the importance of tire pressure. Allis told me a high-pressure road-bike tire will lose 10 pounds per week (fatter mountain bike or cruiser tires will lose less). Low pressure leads to pinch flats, also known as "snake bites," the result of compression of the tube between your rim and a hard surface. Proper tire pressure also prevents rim damage, and overall improves the performance of your bike.

"You get an idea of how much air they're losing a week," Allis said, "and you know how often to pump them up." Allis ought to know: The local bicycling legend coaches the Harvard team and competed in the Olympics, in 1964, 1968, and 1972.

I then spent some time with Justin Carter, 29, a five-year veteran mechanic from Arlington, who patiently showed me the ropes of Aces' $59 "T&T," or "tune and true" check-up, using my mountain bike as a guinea pig on the bike stand.

I learned that even new bikes need a little facelift as parts settle in. "In that first month of riding, it's almost expected that little things will go wrong," Carter said.

First off, he checked the major bearings at the headset (where the handlebars rotate) and the wheels. Do they rock back and forth? He also confirmed there wasn't too much play in the bottom bracket, which contains the spindle and crankset, to which the chain rings (or sprocket) and pedals are attached.

He made sure the derailleurs and brakes moved freely, and that the derailleur shifted gears smoothly. Carter then inspected my brake pads. "It's getting to be time on the rear and well past time on the front," he said.

Next, he looked for wear on the drive-train - the chain and gears - and with a special tool measured how much the chain had stretched. Too much stretch, the chain skips teeth or entire gears, making for tricky shifting; a new chain may be required.

He also showed me how to remove the plastic housing on my brake and derailleur cables (which can conceal grime and corrosion), wipe them clean and lube them. Surprisingly easy, even for me. "You could definitely benefit from a new cable," he advised.

Spinning the wheels, he checked their "trueness."

"As the rim wears it begins to bend," he said. Adjusting the spoke tension can counteract the warping, but only for so long. The spokes eventually fail, and it's time for a new rim.

Finally, Carter wiped clean my bike frame where the gunk was thickest, to inspect for rust, cracks, and other damage.

Carter's diagnosis? "You definitely need a tune-up."

In general you should get a tune-up at least once a year, more often if you ride a lot. My two-year-old bike is still new-ish. So I was happy to pick up some tips to improve its lifespan. But the behind-the-scenes visit reminded me that cyclists need to be willing to spend money for upkeep (probably $50 to $150 a year), and to do some of the basics themselves.

They also need to know when it's time to give up the ghost.

"It's the same with cars. There can be emotional attachments to bikes," said Allis. Sometimes "you're putting more money into it than it's worth." And then it's time to let go.

News and events
The MBTA is touting two new bike-friendly initiatives, both thanks to pressure from MassBike and other bike advocates: