Originally Posted by
2 wheeler
After you drive the pin into place, grab the chain on either side of the pin you just drove in and flex the chain in the direction of the plates ie 90* from the way it normally rolls. Flex it first one way then the other till the tight link loosens up. It takes some muscle to achieve the desired results, you'll know when you've got it right. This flexing motion puts some "slack" into the plates and rollers that just got squished too tight when you used the chain tool.
This is a recipe for chain failure. For Shimano and Campy chains, using their specific installation or replacement pins and following their directions, the joint will be as smooth and free as any other. For SRAM or Wippermann chains with their master link, none of this abuse is needed.