Chris King Bottom Bracket Installation

The Vaytanium is well into its second year and has put down many hard miles. On its inaugural Gravel Metric, flash flooding saw it riding in water over the bottom bracket. This past winter, it was pressed into service in the rain, snow, salt, mud, slush, and everything in between. I wanted a titanium bike for corrosion resistance (among other reasons), and I’ve gotten my money’s worth out of it. And yet when it was built up, Tobie used a standard SRAM GXP bottom bracket. (It’s a standard, english threaded GXP BB).

That BB has been, shall we say…abused?

Yeah, I think abused is fair to say.

Nonetheless, it’s held up well. Notwithstanding repeated dunkings (and extended pedalling with it underwater), the forces of winter, mud, and muck, I’ve had no problems with it. I did pull it apart this spring, take the seals out, and clean and grease it…but I didn’t have a compelling need to do so (other than my bike maintenance OCD).

With the recent closure of a local bike shop, I had the opportunity to pick up a compact SRAM Force crank (50-34). I was interested in trying the compact crank to replace the cyclocross SRAM Rival crank that the Vaya was built up with originally. If I recall correctly, the original crank was 46-38. I was interested in having both a bigger and a smaller chainring, for the varied tasks that the Vaya gets pushed into. The compact crank came bundled with a SRAM Force BB. Swapping in a new crank, it simply made sense to add the new BB as well. One night, I started the process of upgrading the Vaya’s crank. Before that task was completed, the Ridley got its Quarq power cranks, and demanded use of the BB. That left the poor Vaya, with its pants down around its ankles and no BB. This simply would not stand.

Accordingly, a NCC run was made to find a suitable replacement. I couldn’t figure out what component brand/color to use.

I mean really…it was a hard choice.

And then, like a bolt from the blue (pardon the pun), it came to me. I should use a Pink Chris King BB.

Ok, not really pink. But Chris King, nonetheless.

Following the CK instructions, I thoroughly cleaned the BB, and checked the threads–they were perfect.

I then took the little plastic liner that goes between the BB cups, and applied a very light coating of grease to the o-rings, so they would seat/seal nicely in the cups.

I then applied a liberal layer of titanium friendly never-seize to the threads, and threaded in the BB cups.

(Apparently, I haven’t cleaned the camera lens since Kettle).

Note to future designers of BBs: You’ve done it wrong. In a perfect world, the BB should get tighter with forward pedalling (if adjusted at all), and the drive side crank should be standard thread. In reality, they’re set up backwards…the drive side crank is reverse thread, and tightening the BB requires turning it towards the rear of the bike (as if pedalling backwards).

To avoid marring the beautiful blue finish, I used a BB cup socket for full engagement:

According to CK, the next step is removing the plastic bushing from the BB cup. The easiest way for me to do this was to gently reach through the BB and push the bushing out from the opposite side. I used a plastic auto-body trim bar to do the pushing.

A light coating of grease was installed on the drive side spindle of the crankset, and the plastic bushing was gently pushed onto the spindle.

Fully seated:

I put a little grease on the non-drive-side bushing, and slid that into position next.

According to the directions, it should slightly protrude from the BB cup when fully seated. (Note that in this picture, the non-drive side plastic bushing has already been reinstalled).

Next is a test-fit, which went perfectly. The following step is a final assembly. The crankset is placed into position, and the non-drive side assembly continues. CK ships the crank with a plastic washer used for most installations. I was installing a 2 speed road crank, and the directions said to not use any washers…other than the spring disc washer included. I slipped it over the crank’s splines, indexed and affixed on the drive side crank…

Did some initial tightening with an 8mm allen wrench…

And then did final tightening with a torque wrench and 8mm allen socket. A little cleanup and then…

Beautiful… Pedals were greased and installed, front derailleur was tweaked, and the Vaytanium was returned to service.

NOTE: the pic of the disc spring washer above shows it on the non-drive side. That is incorrect. It should be on the drive side. I had installed incorrectly whilst decoding the Chris King spacer directions, and neglected to get an updated pic. Proper installation shown here:

20120811-133453.jpg

8 thoughts on “Chris King Bottom Bracket Installation

  1. There is a reason mechanical engineers design parts. ;) The reason the right bb and left pedal need to be reversed threaded is because of the mechanical act of “Precession. I’ll let you look it up.

    I got real world verification on precession about a decade ago when on my bmx bike i actually installed the crank arms on opposite sides of the bike(I was doing something odd, like left hand drive or something,cant remember why). I tightened down the pedals hard, but they still came loose multiple times over the course of a few hours.

  2. Dude, not sure if it’s the pics. Is the disc spring not meant to be on the Drive Side, should be the first thing on the spindle. In your pics it appears the disc spring is on the non drive side.

    • Good catch. The spring spacer is meant to be on the drive side. Pics were from early in install, before I figured that out–was preoccupied with the spacer issue.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s