Crank installation

Installing your crank:


Begin with unpacking and looking at the included components. Note there are three identical thickness plastic spacers. These get placed on either side of the bottom bracket tube to shift the crank left or right depending on the frame setup.IMG_0759

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Note there are two adapters. The righthand side adapter is the longer one shown below. It has counter-clockwise threads. The lefthand side adapter has clockwise threads.

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Test fit each adapter into the frame to confirm they thread in. Just a few threads is sufficient. If you have difficulty starting the thread, use the Dremel tool with a wire wheel and clean up any residual paint that may be interfering with the threads.

Note the orange stuff on the threads is a thread locker to prevent accidental loosening of the adapters.

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As for tools and materials, you will need a wrench for the adapters. I use the Parktool BBT-9 because it’s two tools in one. The large end is for the adapters and the other side is for the “tightening cap” that goes into the hollow shaft to secure the crank arm.

Buy some good grease. Sounds “corny”, but you’ll end up using it everywhere on the bike. Check with your local bike shop as to what they recommend. I prefer Parktool PolyLube. Get use to the smell, cause you’ll have it everywhere while building and maintaining you bike.

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IMG_0764Confirm the two threaded holes at the bottom of the bottom bracket tube are clear of paint. If not, run a M5 x 0.8 tap through the holes and clean up any shaving or debris from the inside of the tube.

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Apply a liberal amount of grease to the entire interior surface of the bottom bracket tube. After final assembly, wipe any excess grease off.

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Install two plastic washer on the right hand side adapter and thread the adapter a few turns into the righthand side of the frame tube. Remember it’s counter-clockwise.

Install the remaining plastic washer on the left hand side adapter and thread the adapter a few turns (clockwise).

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Use BBT-9 tool to tighten each side. The torque is 30-50Nm, however we do not have a torque wrench for this. Instead tighten the adapter good and tight without distorting the plastic washers. As you tighten, you will feel that orange thread lock engaging and making each turn feel sticky.

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Install the crank on the righthand side. At first it will seem like it’s stuck, but as you push and wiggle, it will “pop” right through.

Once inserted, use a non-marring mallet and confirm it is fully inserted by tapping lightly.

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Confirm the “stopper plate” (sheet metal tab on crank arm between two bolts) is retracted as shown in photo below.

Note: This tab will be pushed in after final installation of the tightening cap.

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Install the left crank arm onto the shaft end. Note that each have a wide spline that is used to index them together. Align the splines and press each side of the crank assembly together with the palms of your hands until fully seated.

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Thread the “tightening cap” into the end of the shaft. The torque on this cap is really low (0.7-1.5 Nm).

We will tighten it with the other end of the BBT-9 tool. Note it has a small knurled disc used for turning the tool with your fingers. This is to avoid excessive tightening of the cap.

Tighten the cap finder tight and confirm the crank turns smoothly.

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Engage the stopper plate (little sheet metal tab between crank bolts) by pushing it inwards towards the crank bolts. You should feel it “click” into position.

Tighten the two crank arm bolts. The torque is 12-14 Nm if you have a torque wrench. If not, it should feel considerably tight.

Note: Tighten the crank arm bolts equally as you approach the final tightness. I use 1/4 turns for each side until I get to the final tightness.

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Congrats! Your crank is installed! (go celebrate!)

Proceed to Front and rear derailleur installation

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