Originally Posted by
Redbullet
No, I did not use a gauge. I deducted the direction of the adjustment and made it gradually and with tests. It took around 50 minutes. I suppose it could be a 10 minutes job with a gauge, but I do it only once, so I did not buy a gauge.
Just curious. The “eyeball” method can work, especially if you visualize the pulleys from behind the bike and use a large Allen wrench on the bolt that holds to rear derailleur in to apply force in the direction that zeroes out the misalignment and returns the cage to co-planar with the cassette - but it is not ideal. You might have tweaked it correctly in one axis only to now have a
new misalignment that didn’t exist before...