Hands On: Safety Wiring

Racers use safety wire for two reasons. First, safety wire provides positive locking on fasteners, preventing them from backing out. Second, safety-wired fasteners allow mechanics-and tech inspectors-to visually ascertain that key components have been tightened. This oil drain plug is a prime example. The bolt has been drilled with multiple holes to simplify the wiring process. The wire is run through a pair of holes and twisted to the approximate length needed to reach a hole drilled in one of the case's flanges. (Note: While safety-wire pliers are not required, they make the job much easier.) Proper safety-wire technique (1a) dictates that the bolt be wired so if it starts to back out the twisted wire prevents it from doing so. Novices often forget this simple fact.

When it comes to drilling nuts and bolts to accept safety wire, two methods are commonly employed. The best approach is to invest in a drilling jig, which holds the heads at the proper angle and provides a guide hole for the drill bit. Of course, you can follow the time-honored (and broken-bit-filled) tradition of putting the bolt in a vise, center punching one of the flats and drilling the hole manually. After starting the hole perpendicular to the flat the drill needs to be progressively angled so the hole ultimately exits from the adjacent flat. Get a little too energetic with the change in angle and...snap! Trying to drill fasteners when they are on the bike is a recipe for disaster. Take the time to remove the parts. Regardless of which drilling method you employ, make sure you have plenty of 1_16-inch bits on hand. Always wear eye protection when drilling.

Many racing organizations require that any plugs or fittings with water or oil behind them be securely fastened and safety wired. Since you can't drill a hole in an oil filter, a hose clamp will provide a mounting point for the wire. Tighten the clamp to the filter then wire the screw on the clamp to an anchor on either the frame or the engine. In your zeal to secure the oil filter, don't overwind the safety wire. Seven to nine twists per inch will provide optimum performance. If you wind too tightly, it can actually weaken the wire. Once the completed wire braid is cut, be sure to bend the end back on itself or prepare to suffer the annoyance of punctured fingers.

You never know how the oil filler cap will line up, so why not drill holes in both ends? Be sure to route your safety wire to the nearest practical mounting point. The easier the location is to wire up the easier it is to make last-minute adjustments. Selecting the right length of safety wire will make the job much easier. If the wire is too long and it wraps around the pliers, it'll get tangled; cut it too short, and you'll have to start from scratch. Measuring the distance between the components you want to wire and cutting the wire at three times that length is a good rule of thumb. Next, begin the wire twist at the approximate distance between mounting points. (Note plier position above.) Avoid clamping the pliers onto crossed wires, the result will be a weak point in the wire. Also, when installing or removing safety wire, be sure to pick up all wire scraps that drop to the ground. Sticky race tires have a talent for picking up small objects, and you don't want to get a flat at speed.

Since all fasteners that come in contact with fluid should be wired, every banjo bolt-whether it is on the brake system or the engine's lubrication system-needs to be safety wired. The simplest way is to wire a banjo bolt to the line itself. In cases of oil lines on the engine, simply find a convenient place to secure the wire to the engine or frame. Oil galley plugs (5a) offer their own challenge. If they can be easily removed, mark them with a center punch so the wire will line up easily in the correct pull-to-tighten manner. Some organizations will allow an application of silicone sealant or weather-stripping in areas where wiring is not practical. Always double-check fasteners for tightness prior to wiring. Again, resist the urge to drill the bolts while they are still mounted to the motorcycle.

There are several ways to wire hose clamps, so check with your racing organization for its prescribed method before starting on your bike. The two most common methods are presented here. First, route the wire braid through the slot in the clamp screw, thus preventing it from backing out. The other method (6a), used by teams such as Yoshimura, involves looping the wire around the hose on either side of the clamp. A word of caution for those who employ the latter method: Don't overtighten the wire or the hose may be damaged.

If your racing organization requires the radiator cap to be wired, drill both sides of the cap (like you did on the oil filler cap) for ease of wiring. Since radiator caps are spring-loaded, don't allow the safety-wire braid to put any tension on the cap, which could allow the pressurized cooling system to overflow.

Most mechanics usually wire the caliper bolts and axle pinch bolts together. Find a straightforward means of linking these bolts for easy removal later because tire changes are a fact of life at the track. Use silicone sealant to secure the pinch bolts on bikes that have recessed Allen bolts.

To speed up the removal of the rear axle, use an R-clip instead of a cotter pin. To avoid losing the fancy clip, wire it to the swingarm or one of the chain adjusters with a loose loop. Slipping a piece of hose over the loop gives the assembly a trick look and protects your hands when you pull the clip out of the axle. Safety wiring the bottom of the R-clip assures that it won't slip out.

Although the springs supplied with many racing exhaust systems are usually reliable, secure both ends of the springs with safety wire. The racers following you on the track will thank you. Also, wire the pipe junctions together so a broken spring doesn't end your race by allowing exhaust components to come loose. Exhaust manifold bolts (10a), with their propensity to vibrate loose, provide their own challenges. Wire them together with the goal of preventing them from falling out. Don't worry too much if limited space keeps you from wiring them tightly. Having the bolts loosen a turn shouldn't cause too much trouble.

Once you've gotten the hang of safety wiring your bike, you'll start to notice places where a bit of wire could keep you from suffering the aggravation and inconvenience of having a part come loose at speed. A loop of wire around each end of the grips will keep them from twisting off. (But be sure to bend the sharp end of the twist into the grip material.) Wiring the shift linkage (11a) will prevent you from having to circulate the track on the white flag lap in fourth gear, after you just made the big pass for the lead. The same goes for steering damper bolts (11b). Although wiring other pieces-such as the throttle cable to the carburetor housing-may sound excessive, we have heard some strange stories.... Consider this little bit of effort to be protection from future calamities.

Some components (such as exhaust hangers) aren't worth the trouble of drilling the bolts, even though they could benefit from the security of safety wire. In situations such as this, bend tabs provide a viable option to pulling out your drill and jig. These star-shaped washers get crimped up around the bolt's flats once the bolt has been tightened into position. A bit of safety wire running from one tab to another completes the process.

Getting Tooled up

Aside from the usual assortment of mechanic's tools you already have for wrenching on your bike, safety wiring requires some extra equipment. First, do yourself a favor and buy a pair of quality safety-wire pliers. Lockhart-Phillips U.S.A. (800/221-7291) has pliers starting at $33. (Yes, you can use vise grips, but why would you want to?) Opinions are split on whether you should use .025- or .032-inch wire. The thinner gauge is more pliable; the heavier wire is sturdier. Choose whichever makes you most comfortable. Buy 1_16-inch drill bits by the gross. They break easily, particularly if you aren't using a jig to guide the drill. A spring-loaded center punch and some tapping fluid will make your job easier. And always wear goggles when you're drilling. Finally, do we need to remind you to use the factory manual and a torque wrench?