Monday, June 28, 2010

Install them crank arms

ACCESSORY 35: Crank arms $27 @ Amazon

Excitement followed by disappointment. Rushing home to check my front door, I found that my package arrived!

The new crank arms came in a fairly nice box considering the cost was only $27. I picked these 155mm length ones from SBS, aka I wonder why all the websites call it SBS and make zero mention of the RPM Components name. Funny b/c SBS is a shop and doesn't manufacture them, yet they're referred to as SBS even at other retailers.

The pieces were nice. Reading the reviews on Amazon saying that they're light, I expected just that. A bit surprised that they're not superlight, but I'm glad they aren't super heavy either.

Even though I've been spending little on parts like this (which can sometimes cost up to $80), I still wanted to do this right. Park Tool recommended using a lube, so the lube I bought. With the amount I saved on choosing these cheaper set of crank arms, I figured it wouldn't hurt to buy some extras.

Comparing the crank arms, I found that they're really not that much shorter. That's the difference between 170mm and 155mm's that you're looking at. Super minimal, but they're supposed to be a night and day difference from what I've read.

The installation starts with removing the pedals using the 15mm wrench. It should take too much effort to loosen these pedals. They're typically hand tightened with only a slight bit of effort to tighten further. Removing them requires turning the bolts towards the rear of the trike. This means the left side is reverse threaded. Clockwise is to loosen for the left side only.

Now it's time to loosen those bolts using an 8mm allen wrench. The first time I did this, it took quite a bit of torque using some ingenious methods. Do whatever you can to loosen these puppies.

Screw in the crank puller from Park Tools. It screws in one direction on both sides - clockwise. Turning the blue handle, I hear a creaking sound. It freaks me out a bit, but I keep going. There's no other way.

Tada! And the crank arm pulls loose! Notice that the threads on the crankpuller are still sticking out. It should only be hand tightened.

All that only to find out that the chainring won't come off the crank arm!!! Ugh. I posted on BORL ( to seek some answers. We'll see what happens next.


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