Danger Zone, pt. 1:  Bike Parts

For all you Top Guns out there, I want to pass along several mechanic's tips that can keep you out of the Danger Zone when it comes to part failures. Use this checklist to inspect your bicicletta:

• Handlebar.  If you've crashed it and it's carbon, replace it. Now! You cannot see the damage a fall has caused because it's inside the bar. You'll notice most pros don't use carbon bars because they can't rely on them to stay in one piece after a fall. An alloy bar will generally bend before it breaks, and you can usually finish a ride safely.
   
• Rims.  Look for small cracks around the holes where the spokes enter the rim. They won't usually result in a catastrophic failure, but they'll grow over time and your wheels will not stay true or round.
   
• Hubs.  If a hub develops looseness for no apparent reason, the axle may be broken. It's rare for a front hub but not uncommon for a rear, due to the offset for the cassette. The quick-release skewer will hold the whole shebang together, so don't pull it out during a ride to investigate why the hub is wobbling, unless you have a lift home. Realize, though, that riding on a broken axle will ruin the hub's innards.
   
• Saddle.  If your seat has titanium or aluminum rails and they are bent at all, they will fail sooner rather than later. Damaged carbon rails simply break without warning. Some failures are no big deal; others are gonna hurt like hell and it may be impossible to ride home (or have kids). Also check the underside of the saddle's shell. I've seen many a fractured saddle held together only by its cover and padding. A seat in this condition will be swayback, it might creak, and it should feel awful.
   
• Seatpost.  Inspect the clamp at the top of the post. This is the most likely place for a failure. In most cases this top section is welded or bonded to the post. It's subject to heavy stress, especially if there is lots of setback and you're a big rider. Failure means the top of the post, with your seat, falls off. I can't paint a pretty picture of what comes next. "Wrecked him? Nearly killed him!"

If you have a carbon seatpost and have distorted/crimped it by using too much clamp force where it enters the frame, replace the post ASAP. A break here is about as nasty as the clamp breaking off.

• Crankarms.  If your shoe rubs either arm to the point where it's removing material from the crankarm, whether aluminum or carbon, replace the arm(s) without delay. Crankarms don't break in the garage, they break when you're putting lots of watts into them, as when climbing or sprinting. It happens without warning and usually results in a spectacular tumble when your foot, wearing the pedal and a piece of the crankarm, slams into the pavement.

Look at it this way: You live to ride (and I hope you love your bike as well). If you pay attention to the condition of each part on your machine and replace anything that's questionable, you minimize some of cycling's risk. It's a small price to pay for having the confidence that your bike is in tip-top shape.

Danger Zone, pt. 2:  Fork Failure

As cyclists we're responsible for knowing the state of our equipment. Periodic bike inspection is an absolute must. A crash demands an immediate exam -- especially when there's been an impact involving the front end.

The fork is probably the strongest single element of a bike. It takes a lot to damage one, but you must be absolutely sure all is well. After all, not much in life is scarier than a fork failure, and you don't want that on your mind -- like at descending speed.

Let's look at two main ways forks get broken.

• Front Wheel Impacts.  This includes riding into a curb, into a nasty pothole, or into any other immovable object. You don't need to be going fast or even crash to ruin a fork. If you suspect it was damaged by a hard hit, get on the cell phone and call for a ride. Yours is over.

With a carbon fork, the damage may be internal and unseen. The fork must be pulled from the frame to check for injury to the steerer tube, the fork legs or the crown. A simple look while it's still in the frame is not enough. Take it out and put it under a bright light.

You're looking for cracks, dents, dings and bent or loose dropouts. Gouges, discoloration, peeling, delamination -- all spell impending disaster. So do buzzing sounds from inside the legs during riding. And then there's the tell-tale sensation that the bike doesn't steer or behave like it used to. If you lack the experience to do this kind of inspection, take your bike to the most experienced mechanic at your LBS. He/she might just save your life.

With a steel fork, a big frontal impact will generally bend the fork (or more likely the frame). I have seen steel forks bent to ridiculous angles, but I've never seen one fail catastrophically under a rider. That's a testimony to steel's ultimate strength and forgiveness.

If you're riding on an aluminum fork you should have replaced it eons ago. Aluminum forks become mushy and flexible over time. I've never thought aluminum is a good choice for a fork. The only time I had a bike with one, I worried so much that I got rid of that rig after only two months. The fork was way light and it was good on rough pavement, but it seemed like an accident waiting to happen.

• Garage Calamities.  I hope this has never happened to you, but it's happened to plenty of tired riders driving home with the bike on top. One push of the garage door's remote button and in a nano-second . . . disaster! After calming down, you need to take the bike (and what remains of the roof rack) to the LBS. It's going to take time to check everything that could be damaged. If it's only the fork you were lucky in the extreme. Make your next stop at the auto body shop, then drop by the local construction contractor to arrange for a repair estimate. Don't forget to mention that the garage door no longer works.

Never, ever take a chance on fork failure. Sure, a good bike's fork is expensive to replace. But that pales in comparison to the pain of a crash and cost of an ER visit.

It's like the lady told me when I was looking at a Rhodesian Ridgeback puppy for $400: "If you can't afford to buy the puppy, you can't afford to own the dog." She was right. Over the lifespan of that dog, 400 bucks was nothing.

With our bikes it's the same. We must maintain our equipment and spend what it takes to replace anything that's questionable. Especially the fork.

Danger Zone, pt. 3:  Frame Fractures

Don't kid yourself. Your frame can break. Every frame can break. Doesn't matter whether it's made of "gonna last forever" titanium, ornately lugged steel, exotic carbon or ultra-light aluminum. I've seen each of these materials fail.

But take heart -- very few frames do break, considering how many are on the road and being ridden hard. And even fewer come apart when you're JRA ("just riding along").

That's because bicycle frames are an amazingly strong conglomeration of small tubes joined by the mastery of the builder. The fact that so few break is testimony to the strength of a design that has been around since the late 1800s. We may be building bike frames out of different materials these days, but the tried-and-true basics remain unchanged.

That said, you don't want to be part of even a small sad statistic. It's important to know how to check your frame for fractures that could lead to tube separation and possible injury on the road. Let's see how.

• The first step is to have a clean bike and keep it that way. Most frame failures begin as a hairline crack. How would you expect to find one under a layer of crud?
   
• Remove the rear wheel to examine the dropouts and the tubes ("stays") they're joined to. This is one of the most likely places a crack will occur. Look closely at both sides of each dropout. Use a bright light and an eyepiece (loop) so you can really see if that scratch is only a scratch.
   
• Follow the chainstays forward to where they join the bottom bracket shell. Check the chainstay bridge, the small tube that joins the chainstays behind the BB. Some frames may not have this reinforcing tube; on others it's a place cracks can develop.
   
• Follow the seatstays up to the bridge for the rear brake. This is a very high stress area, but is also over-built for that reason. Go up to the seat cluster. The top tube, seat tube and seatstays all join here. It's a complicated joint and requires extra care in building. Check it carefully. Other than an accident, the main reason for damage here is using a seatpost that doesn't extend far enough below the cluster.
   
• Move to the front of the bike and examine the joints around the head tube. This is another area subjected to a variety of forces. If the bike has had a frontal impact (curb, dog, garage on a roof rack), look closely under the head tube end of the down tube. If it's bulged, cracked or discolored, go bike shopping.

Now, most of this so far pertains to metal frames. It can be harder to spot a problem in a carbon frame. Carbon is unique in its amazing strength, but its natural color can mask signs of damage that do occur.

• One sign of carbon tube failure is a rag getting snagged when you're wiping down the frame. Gouges, deep scratches or displaced paint need a serious look.
   
• As with any frame material, if your bike starts handling strangely or develops mysterious creaking, cracking or popping noises, stop riding it and run the above checks for tube failure.

I don't want you to be paranoid about your bike. The point of this column and the two that came before it is simple: Be diligent. Keep your bike clean. Inspect the frame, fork and other parts once a month or after any kind if mishap. By doing so you'll be safe, sound and out of the Danger Zone of hassles and injuries related to equipment failure.