Tech Tip: Adjusting Chain Tension on an Eccentric Bottom Bracket

How To's/Tech Tips Mountain Biking

Is your loose chain bugging you?  Are you eccentric? Then read on…

Loose chain blues….

The Cure [not the band, sorry RL]:

1st: You put the lime in the coke… and make sure your eccentric bottom bracket’s [EBB] set screws are loose.

2nd:  Rotate the EBB to adjust the chain tension, a spanner wrench is ideal, a Tri-Y or Allen wrench can be used.  I like to rotate such that my EBB is at the lowest point that achieves proper chain tension.  This give you effectively a lower BB height.

3rd:  Tighten set screws, torque to manufactuer’s spec.  This steps invloves a lot of voodoo!  Some claim threadlocker (blue) is the only solution to ever loosening set screws, others chastise the thought of stuck bolts and proclaim anti-seize is the solution.  I follow the “a dab ‘ll do ya” school of thought and use a touch of grease [ I also check my bike before every ride, Mtnbikeriders makes no claim that this is the perfect 100% solution and shall not be held responsible for personal injury, embarassment, weight loss, nausea, poor gas mileage or even death resulting from use of said Tech Tip].

A quick and akward video of today’s tech tip:

3 thoughts on “Tech Tip: Adjusting Chain Tension on an Eccentric Bottom Bracket

  1. Ralei Really turned me off to EBBs, duw to this EBB, rather than the Bushnell/GF EBB, even withblue Loc-tite, I dound myself Constantly f’k’n with the skrews.

    if SS/EBBs are your thing this is a great post 🙂

  2. If you find that the bb is difficult to rotate use the crank for leverage against the hex wrench and turn with the pedal.

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