I keep thinking about getting a Trek Domane for my long rides.
We're talking about a $3,500 bike, so I would need to expect to go on a lot of rides to justify it.
I want a size 52 SL Gen 3 frame.
Domane Gen 3 is engineered with both front and rear IsoSpeed comfort tech
for taking on long miles and rough roads.
Domane Gen 4 is the ultimate ultralight endurance rig with refined rear IsoSpeed comfort tech and updated aero tube shapes.
Gen 3 (2020+has:
SL uses 500 series frame, SLR uses lighter 700 series frame.
Gen 4 has:
SL uses 500 series frame, SLR uses "lightest" 800 series frame.
"Both are very nice riding bikes, but I feel the Gen 4 bike just feels better on the road. The front IsoSpeed on the Gen 3 is nice, but I found it deadened the ride a little if you like to feel a little bit of the road. The rear IsoSpeed on the Gen 3 SLR I had was adjustable, but once I set it, I never touched it, so it was not a huge deal. The Gen 4 removed the front and the rear is non-adjustable and I just like how feel of the ride is on it better.
"I got a used gen 3 and the ride is smooth and super stable. What a descender!"
Update (June 21, 2025): I had a long conversation with Brad at the Arnold Trek store. He explained that changes to the fork geometry and maybe the head tube angle make the Gen 4 front end more compliant, which compensates for eliminating the front IsoSpeed. The front IsoSpeed also contributed weight, so eliminating it made the bike lighter. Bottom line, I no longer feel like I need to get a Gen 3 bike.
I'm looking at upgrading my primary road bike (currently my Emonda with mechanical 105) to an Ultegra Di2 drivetrain. I may want to have the same for a Domane I buy. That would be the Domane SL 7 Gen 4 ($7150).
The Domane SL 5 Gen 4 (mechanical 105) is $3700.
The Domane SL 6 Gen 4 (105 Di2) is $5150.