Figure 4-4: Unbending a bent rear derailleur in .NET

Printing Denso QR Bar Code in .NET Figure 4-4: Unbending a bent rear derailleur

If you straightened out the rear derailleur enough to ride home, you may want to take it to your local bike shop to be properly tuned Bike mechanics use a special rear derailleur hanger alignment tool to properly position the derailleur If the rear derailleur is damaged beyond repair and won t shift or allow you to continue biking, you ll need to bypass the derailleur and turn your bike into a single speed If this happens to you, follow these steps to get back on the road:

1 Use a chain tool to separate the chain See 10 for more information on separating and reconnecting a chain 2 Decide on a gear that is appropriate for your ride home We recommend that you pick the middle chainring on triple-chainring bikes or the smallest chainring on two-chainring bikes and the middle cog in the cassette Leave the rear derailleur on the bicycle 3 Hold the chain together to determine if there is any overlap in the two ends If there is, you ll need to remove some links in order to keep enough tension on the chain 4 After removing the additional links, reconnect the chain Spin the cranks a few times to be sure that there is enough tension on the chain and that it won t come off the chainring If it doesn t, you should be good enough to finish your journey If a cable is old, worn, or frayed there is a chance one may break while you re riding If it s a cable for the derailleurs, you ll be limited in the number of gears you can use, but you ll still be able to ride home If the front derailleur cable breaks, the lack of tension will move the derailleur to the left and position the chain on the smallest chainring If you have a triple chainring and want to use the middle chainring, pull the derailleur over the middle chainring and tighten the L-limit screw (shown in Figure 4-5) to keep it in place For more details on adjusting the front derailleur, refer to 14 In the case of a rear derailleur cable break, the derailleur will move the chain to the smallest cog on the cassette If you re comfortable riding in this gear, you can finish your ride However, if you need a more appropriate gear, you ll need to adjust the rear derailleur Keep in mind that there is only a limited amount of adjustments with this method and you might only be able to use one of the three smallest cogs To make the adjustment, follow these three steps: 1 Place the chain on one of the larger cogs 2 Use your hand to push in on the rear derailleur 3 Tighten the H-limit screw (shown in Figure 4-6) to keep the derailleur in place Keep in mind that you may have to fine-tune the position of the derailleur so that the chain runs smoothly

Certain repairs probably shouldn t be attempted while you re on the road In some cases, you probably won t have the tools with you In other cases, the chance of a malfunction happening makes continued riding a dangerous proposition Here are some situations when you should put away your emergency tool kit and start walking home: When your brake cables have broken: If you break a brake cable, you ll be limited to half your brakes Not only will you have reduced braking power, but applying only the front or rear brakes could cause you to have an accident Squeeze too hard on only the front brakes and you wind up being thrown head forward over your handlebars Do the same with the rear brakes, and you could skid out When your front or rear brakes are out, your best bet is to walk your bike if possible or ride it home very slowly When your crank is loose or has fallen off: If the crank has loosened or fallen off, it may be best to call it a day The crank must be tightened with a significant amount of torque and this tightening is best done with the proper tools (including a torque wrench) and with the bike supported by a bike stand if possible When your pedals are loose: Pedals can be secured with the proper wrench, but if you don t have one available, you should walk your bike home Riding with a loose pedal will damage the crank and could lead to an accident if the threads give out When you have a problem with the bottom bracket: Working on the bottom bracket requires specialized tools that most riders wouldn t consider taking along on a ride If the bottom bracket comes loose or falls apart, don t continue to ride When your frame is damaged: A damaged frame is usually the result of an accident If you ve had an accident, you should immediately inspect the bike, paying particular attention to the frame Besides looking at the frame from different directions to determine if it s bent, you should inspect the frame close up, looking for cracks, especially in any welded sections, as well as cracks, bubbles, or ripples in the paint (See the following section for more on what to do after an accident) A damaged or bent frame undermines the integrity of the bike and increases the chance of an accident