Why tap the blades after coldset?
 

Why does Nagasawa hit the fork blades after cold setting?

http://www.youtube.com/watch?v=q7VGz...UGA&lf=channel


thanks, Brian

To relieve stress?

No, seriously. To relieve any residual stress it the fork blade after bending, not his stress of course.... :D

The interesting thing is the hammer looks to be a rubber/plastic headed one. Not too much impact from those... At first thought it was to remove the side ways bulge from the bending (on a form without too much side of tube support) but one blade is hit in line with the bending, the other blade is sideways to the bend. Andy.

sure looks like he's hitting it in the direction of un-raking to me. I have no idea why, probably something someone taught him

Looks like a large rubber mallet(also no ring when he hits it, the vid should pick it up if metal), unlikely to remove any stress with a couple of minor hits like he uses(not to mention the force needed to bend them in the first place). So....probably something someone taught him and who knows what its for, maybe a tradition he follows.

thanks, Brian

too bad they didn't ask. I would think it probably bends the blades back a little. Not gonna try it though.

I don't know why he does it but I always try to over-bend tube and un-bend it to get a perfect radius that will last. I have only raked two fork legs however and they were already in a fork. I do not strike the parts as the back wall is stretched thin.