First Timer Bottom Bracket Install on a Boston 8

We took out a square taper bottom bracket last time, and now we’re installing something of completely different style.  An integrated bottom bracket and crank set situation.

These are SRAM Omnium cranks which integrate into a GXP bottom bracket.  First you get all of your directions lined up, provided in multiple languages.

BB and crank set

SRAM crank and bottom bracket set with directions

 

GXP BB

GXP Bottom Bracket

These are the pieces of the bottom bracket when separated out of the packaging.

First, grease those threads!  I used Phil Woods grease, it’s green, just like the tube – there are many kinds of grease out there of course, but this is considered some of the best by many enthusiasts.

BB

Greased threads on one end of the bottom bracket

First you place in your center piece, it is kind enough to have a label as to how to orient toward the drive side.

BB center

It has a little arrow and says “Drive Side”

Then you screw in the cups, these are also labeled for drive side or non-drive side.  This bottom bracket shell is threaded reverse on the drive side and normal on the non-drive side.  The cups even have little arrows which tell you which way to turn them and labels for how tight (these are the Newton-meter measurements).

BB cup before grease

One end of the bottom bracket before grease, it says “Drive Side”

 

installing BB

Bottom bracket cups partially screwed in – note the green grease

Screw those in, then it’s time for the crank set. Grease again!

crank grease

Grease for the crank

Drive side goes through first.

drive side install

Drive side (the crank with the chainring) goes in first.

Then the non-drive side crank arm.  It’s important to orient this 180 degrees from the other crank arm, or else pedaling will feel alien and be rather dangerous.

 non-drive side crank

The other crank has the nut that tightens everything.

This is where the bolt that tightens the crank set lives.  So elegantly simple.  Tighten down the cranks until there is no side to side movement, and you’re ready to go on to the next step.

My newbie mistakes: Too much grease.  Spindle length that is going to make for a very tight chain line.

Observations?  Recommendations?

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