For decades, the Park Derailleur Alignment Gauge has been a fixture of bike shops all over the globe. Most recently, the DAG-2.2 was given some key updates to work with modern frames. But with arguably better tools from other tool builders out there, Park needed to head back to the drawing board to come up with something completely new. Something like the DAG-3.

Park Tool derailleur hanger tool DAG-3

Compared to the DAG-2.2, the DAG-3 brings Park’s derailleur hanger alignment tool into the 21st century with better precision and a more user-friendly design. Now made from an extruded aluminum body, the square steel design is gone in favor of a lighter, round profile.

Park Tool derailleur hanger tool DAG 3 gauge

One of the hang ups of the previous DAG tools was the inability to easily move the indicator around chain and seat stays. Tools like the Abbey HAG made this an effortless process, so the new Park Tool model had to deliver.

Park Tool derailleur hanger tool DAG-3 in use Park Tool derailleur hanger tool DAG-3 in use

To make that happen, the sliding indicator is now housed in a rotating mount that flips into place. The 16.5″ long tool is said to be compatible with 16-29″+ wheels (ISO/ETRTO rim sizes from 317 to 630+), and the low profile head is designed to work with thru axle hangers with tight clearance including Shimano Direct Mount hangers.


To keep it functioning in the long run, the M10 threaded tip is replaceable. Priced at $116.95, the DAG-3 is part of a handful of new tools that were recently launched by Park Tool.


  1. esc8engn on

    the head looks nice, but the gauge end, i dunno. this is a long standing tool that millions are familiar with. is gen 3 all there? is it ready to supersede all earlier models?

    • K-Pop is dangerous to your health on

      Wut? Looks absolutely nothing like the HAG, and they don’t even function the same. The only thing they have in common is they thread into a der hanger just like every other der alignment tool. [shoulder shrug]

  2. TP on

    I wish it swiveled the same way Abbey/Unior hanger told do, but I’m just used to their styles. Bout time they updated this.

    • JBikes on

      I haven’t used the HAG, but based on pictures, I am not sure it is more accurate or precise.

      The biggest issue I have with the DAG is the use of the o-rings to set initial position. A scale or a spring steel split ring would be much nicer. Both of those are easy to add though.

        • None Given on

          Um, I had a 997 Turbo S….just a skosh faster than the Element, I can not scientifically prove it however as I can not say I ever raced an Element.

  3. ewyounasty on

    Pretty nice that it will work with small wheel diameters if you work on trikes in additi
    on to typical road and mountain bikes. Where is it made or is that a dumb question?

  4. Truman on

    More interesting is that the caps on the ends of the handle are the same thread pitch as Schrader valve caps. The other ends black plastic cap can be replaced with your preferred bar end as well. Custom! Nothing like a HAG or a Tru-arch or genie. The direction of flip is flipping sweet.

  5. Equipe á Grumeaux on

    So Park make you buy a whole new tool that does 80% of what their old tool did? Why not just make a new head with a rotating feeler mount, and add it to a completely acceptable 2.2? Or even a 2?

  6. Jack on

    Is the part that holds the indicator, and lets it pivot out of the way made of plastic? If so, big swing and miss by Park Tool. I’m hoping for something a lot more durable.


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