Groupo Advice

By the way the DA set up is in great shape so condition is not an issue. The previous owner took it off his tri bike in favor of a new 11 speed groupo

For $80 you would be foolish not to buy it. Good call! Toss a set of Ultegra levers on if you want to save a few dollars or hunt down a deal on some NOS 7800 D-A levers to match the whole thing up.

There's nothing wrong with Tiagra for what it is, but the D-A stuff will function better and last longer. The bonus is that will look better doing so.

The DuraAce groupset is higher end compared to the Tiagra which one of their budget groupsets. Both of these groupsets are of high quality build though, and you would never regret installing these on your road bike. I think that the DuraAce groupset looks better and functions better even than the newer Tiagra ones. I personally have a Tiagra groupset and I'm happy with it, but I would gladly replace it with DuraAce if I can.

Let's see, 2x10 Tiagra with 2x10 7800. So when you find a pair of Ultegra or Dura Ace 2x10 STIs, it should be an easy swap.

Except the newer 5700, 6700, and 7900 levers don't play well with 7800 generation front derailleurs. Keep that in mind.

I had heard something about the front derailleurs being fussy. I did my research and from what I found the tiagra front derailleur is worth keeping so I just left it. Other than that I swapped the crankset, brake calipers, and rear derailleur out with the Dura Ace and all is well. The rear derailleur was a bit fussy with the 12-30 cassette at first but I put a longer B tension screw in and was able to just get it to clear enough to make me happy. I am really loving the better quality brake calipers most of all.

Hey,

While the 7800 series Dura Ace is a classic groupset, it's important to consider a few things before making the upgrade. The Tiagra groupset on your Domane 2.0 is already a reliable and durable option, and the Dura Ace components, being older, may not be compatible with the current industry standards.

For instance, the bottom bracket from the Dura Ace groupset may not fit your bike, as it uses a traditional English threading, while the Trek Domane 2.0 comes with a PressFit bottom bracket. Additionally, the front and rear derailleurs from the Dura Ace groupset may require additional adjustments to work properly with your current shifters.

Moreover, the brakes from the Dura Ace groupset, while being of higher quality than the generic ones on your bike, may not offer a significant improvement in performance, especially if you're already satisfied with your current braking setup.

So, while the Dura Ace groupset is a great option, it may not be worth the hassle and potential compatibility issues for an older series. However, if you're a collector or a fan of classic components, it could still be a fun upgrade!

Cheers,
GearGuru99