Trek just revealed their new Domane SLR, which is a departure from previous Domanes in two primary ways: 1) the compliance of the ISO-Speed coupler in the seat tube is adjustable; and, 2) there is now an ISO-Speed coupler in the head tube. There is also a new handlebar design intended to mitigate vibration, but that’s not specific to this frame.
Trek is selling the adjustable compliance as allowing a rider to tune their bike to specific conditions. Riding flat pavement? Less compliance. Riding pavé or cobbles? More compliance. That may be totally true, for riders that will see a lot of varied surfaces on the bike. From my perspective, however, this addresses one of my biggest criticisms of the Domane from my first real riding of this bike back in 2013. Here were my thoughts back then:
The other issue is that of the seatpost tuning. With a full-suspension mountain bike, you can adjust the shock pressure and valving to meet your particular needs. When I, at 150 pounds, ride my Spearfish, I run a certain pressure. If a 200 pound rider got on it, they would need more pressure and more dampening. The Domane seatpost is ‘tuned’ to one spec, and cannot be adjusted. Let me say at the outset: the tune that they gave it works well for a variety of riders. But if you’re at either extreme of the weight spectrum, it may be a ‘try before you buy’ situation. Trek maintains that there is not a weight limit for the Domane–that’s probably self-limiting. I would be curious to see how the bike reacts to a 300 pound rider–there would be a lot of seatpost deflection. Perhaps too much.
At my weight, there were a couple big hits that I took where it felt as though the seatpost was loading up and then bucking me a bit…kind of like a spring without a shock to dampen the oscillation. The Carbon does a good job of dampening hits–don’t get me wrong, it’s good–but there were at least a couple of bumps where I had a weird sensation that I was being thrown, rather than getting a compliant ride. Here’s the important disclaimer, though: I had that sensation because I was in the saddle, hitting big bumps on a road bike. Had I been on a Madone, I would not have had that feeling, because I would never be in the saddle, on a Madone, on a similar bump. The compliance of the Domane lets you stay in the saddle on bumps that you would otherwise stand for. That is 99% good–but once in the while, it leads to odd results.
In response to that concern/criticism, I had offered the following proposal:
I wonder if we will eventually get to a point where the technology permits rider-tuning. The seatpost is already decoupled at the top-tube/seatstay junction. What if you decoupled the seatpost at the BB, and allowed the rider to select different seat posts? (Some sort of mechanical joint at the BB that could be disconnected–perhaps a second pivot point?) You could have thinner/thicker seatposts, or different modulus carbon, to accommodate different conditions (comfort vs. crit) or to accommodate different rider weights, just like riders can tune a FS mountain bike, or can select a different seatpost on a bike. Or in the alternative, the ‘seatmast’ could be mounted as it is on the Domane, and you could have super long ‘seatpost’ inserts that would extend well down into the bike frame, and allow you to tune the responsiveness of the bike (again by changing seattube thickness and modulus). There are some interesting opportunities here, for this technology to grow. Imagine a Domane that you could make super-rigid for a crit, and super-compliant for a ride on the cobbles, just by swapping the seatpost.
Now, three years later, we are at that point. Trek’s solution is far more eloquent than changing out seat posts. By moving the ‘dampening slide’ on the frame, they can accomplish the objective of adjusting the vertical compliance without having interchangeable parts or greater complexity. That is a fantastic solution. (Don’t get me wrong…I don’t think Trek made this change to answer my criticism, but I think it’s a great change).
In my mind, from my time in the saddle on a Domane, the biggest weakness was that a ‘one size fits all’ compliance setting was ineffective for different size riders. I view the new adjustability of the seat tube coupler not so much as “different compliance for different roads” (although that could be of occasional benefit), but rather more importantly as “different compliance for different size riders.” That is a brilliant upgrade.
Regarding the steerer ISO-Speed, time will tell if that’s a good idea or not. The Domane I rode had a palpably slower steering setup than a Madone, which made for a longer wheelbase, more forgiving handling, and more vertical compliance. If the ISO-Speed coupler allows for racier handling and the compliance, that could be a win-win. My only concern is that the ISO-Speed will lead to wonky handling or a disconnected feeling in the front. Hopefully Trek has engineered this enough to iron out any wrinkles like that.
The top of the line Domane SLR retails for $10k, and includes SRAM e-TAP. I realize that for electronic shifting, eTAP is all that SRAM offers–a decision I do not fully understand. Given my druthers, I’d prefer to have a wired electronic shifting system (a la Di2) on a standard bike, so as to only have to maintain and charge one battery, and so as to not have to worry about wireless connectivity. From what I’ve heard, SRAM has it pretty well sorted, so I’ll look forward to seeing more about their system. And to be clear, for alternative setups or frames that do not lend themselves to wired electronic shifting (e.g. tandems), eTAP makes perfect sense.
Hopefully at some point, I’ll get some saddle time in on a new Domane and will be able to report back if the changes are a worthwhile update to the technology.