I keep my bikes clean and do regular maintenance on the drivetrain. I'm careful that I don't lean the bikes on the derailleur side. That being said, for some unknown reason, I've bent the derailleur hanger 3 times this year. At $30 a pop at the bike shop to straightened the hanger, it was a no-brainer to invest in this tool. The Park Tool Derailleur alignment tool is extremely easy to use. I was able to straightened the hanger in less than 10 minutes. I recommend this tool. It has paid for itself already this year.
my touring bike lives a tough life on the road, been dumped on the derailleur side 3 or 4 times. Some gears didn't shift correctly or stay in gear ... the bike shop said, well you've got 30,000 plus miles.... new cassettes, chains, and rings didn't clear the problem, didn't really look out of alignment...., bet I was 12-15 degrees off. re aligned the drop out, gee, the bike shifts better than when new, runs quiet. I'll check my other bikes, like I said, problem solved.... Velocio
Good tool. Well built and very sturdy. With thinner rear cassette spacing and lighter weight drivetrains, this is just a must have tool for anyone who does their own maintenance. Park makes good quality tools at a reasonable price.
I was struggling to adjust the rear derailleur on one of my bikes to get clean shifts across the whole range, and realized that the derailleur was not looking properly aligned. The DAG 2.2 confirmed my suspicions, and allowed me to coax the hanger back into alignment. Problem solved. I checked my other bikes, and ended up adjusting another as well.
The tool itself is functional, rather than elegant, but it gets the job done at a decent price.
I've been riding various bikes for over 50 years, but never realized how much derailleur misalignment effected shifting. Once I read online and saw the videos, I had to have this tool. What a difference it made in the shifting on my recumbent tadpole trike! It'll pay for itself quickly in saved service trips to the LBS and trying to fix problems by buying new (unneeded) drivetrain parts. Now I'm going to check derailleur alignment every so often and offer to check my friends' bikes. Wonderful, well made tool! Typical Parks high quality, and they have many good videos on YouTube to walk you through doing your own repairs.
Was having shifting problems and could not get them corrected. After being told about hanger alignment i purchased the DAG 2.2. I found the hanger out of alignment. Aligned my hanger and readjusted the derailleur then my shifting problems went away.
The differences between this and the original DAG that I've owned for decades are not huge. In fact. I made an extension for the old tool that duplicates most of the functionality of the new one. The DAG-2.2 does seem a bit tighter and I'm happy with it, but the difference is subtle. If I hadn't needed a second tool, I would have been perfectly happy with the modified DAG.