Anyone that has been riding mountain bikes even a little while knows that they are cursed on the trail in one specific area. My special singletrack hex seems to be the uncanny but regular occurrence of breaking my derailleur at the furthest apex of my ride.
When I was a new rider I managed to accomplish this feat three times in my first six weeks of riding. At first I thought I was just riding like an idiot, mowing over the perfect size stick that would ruin my bike ride. But I later found out that it was more than poor bike handling; the trail had it out for me in this specific area.
If you ride long enough, though, you’ll find yourself in a position when you will no longer have the ability to shift, and that’s pretty much the worst-case scenario on the trail. When a derailleur snaps, the resulting miles need to be more about damage control to be able to limp back to the trailhead (unless you’re the one rider in the universe that carries a spare derailleur on the trail).
So here’s what to do if your derailleur breaks on the trail.
Step 1 – Survey the damage to see if the derailleur is just bent or truly snapped in half.
If it’s bent you may be able to slowly move the pulley back into position to allow a smooth chain flow. More than likely, you’re going to want to take the derailleur off since it’s already dangling in several pieces. Hopefully you brought your multi-tool with one that has a handy chain break as one of the gadgets. My recommendation is the Crank Brothers M19 since it already has all the hex wrenches and screwdrivers you need anyway (it even has 4 sizes of spoke wrenches!)
Step 2 – Break your chain
After breaking your chain, you’ll want to gently thread it off the rest of your drive chain. You can then remove the rear derailleur cleanly, making sure to pocket all the hardware. Congrats! You’ve now got a scooter that resembles a mountain bike but can at least go downhills faster than you can walk.
Step 3 – Turn your bike into a single speed (Extra challenge)
If you’re up for an extra challenge and have your chain size’s master link (Powerlock if you are using SRAM), you can try to size your chain to a specific gear combo that will more or less turn your bike into a single speed. You’ll need to break your chain again to resize it to make a new single speed loop around the front chainring and rear cassette.
You’ll need to break your chain again to resize it to make a new single speed loop around the front chainring and rear cassette.
Keep in mind that there will probably be some looseness in your chain because it was your derailleur’s job to hold chain tension. Also keep in mind that this homemade single speed should have a chain position as straight as possible, so make sure to keep the chain in the middle of your rear cassette. Connect your chain using your master link and test the tension. If it’s too loose move it up one gear in the rear cassette, making sure it’s not too tight to drop it back down as you pedal.
Voila! You now have a single speed that can get you back to the trailhead in a pedaling position.
Keep in mind that you don’t want to attempt any steep climbs or technical terrain with your jerry-rigged single speed. Keep the pedaling smooth and steady since you don’t want to deal with another broken chain. This quick fix may not save you money on new components, but at least it will keep you from turning your epic ride into a hike-a-bike marathon.
Matt Chisholm is a data analyst and freelance writer who studies the environmental history of the Southern Smoky Mountain region of North Carolina. He was a contributor to Lost in Transition: Removing, Resettling, and Renewing Appalachia and the 2016 edition of the Journal of East Tennessee History, for which he won the 2017 McClung Award. When not writing, Matt enjoys road and mountain biking, hiking, trail running, and drinking beer around Concord, NC where he lives with his wife, daughter, and twin boys.
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