Flex in the bottom bracket when you get out of the saddle. This loosens the cable to the rear derailleur causing it to shift down.
See here: http://sheldonbrown.com/autoshift.html
@danb started
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Flex in the bottom bracket when you get out of the saddle.
This loosens the cable to the rear derailleur causing it to shift down.
See here: http://sheldonbrown.com/autoshift.html