How to Adjust Slider Drop Outs

Slider dropouts set the tension on the chains of performance bicycles. The tensioning dropout mechanism works for both single speed BMX type bike frames and for mountain bikes with gears. The dropouts provide a quick release for taking the back wheel off to replace a tube or tire. The chain tension remains the same after the wheel installs back onto the frame. The slider mechanism provides a means of chain tension adjustment. Riders adjust dropouts to correct chain tension to accommodate new chains, or incidental wheel misalignment.

Things You'll Need

  • Metric hex key wrench set
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Instructions

    • 1

      Flip the bicycle over and set it down on the seat and handlebars with the wheels up.

    • 2

      Loosen both side bolts on the slider dropouts on both sides of the axle with a fitting hex key wrench. Two to three full rotations sufficiently loosen the bolts.

    • 3

      Use a hex key wrench to tighten the long tension set screw on the chain side with clockwise turns to force the wheel farther back into the frame and increase the chain tension. Turn the set screw on the tension drop out counterclockwise to loosen the chain. Set the chain tension for a single-speed bike or the chainstay length for gears to a satisfactory setting. Tighten the two side bolts to hold your adjustment.

    • 4

      Loosen or tighten the set screw on the tension drop out on the opposite side of the axle to match the adjustment you made on the chain drive side.

    • 5

      Spin the back wheel slowly and view it from the rear of the bike to be sure it is properly aligned. Make any necessary adjustments to get the wheel spinning straight with the tension set screw on the non-drive side, then tighten the side bolts. Adjust dropouts as such any time to set chain tension or wheel alignment.