25mm to 32mm. Feels sluggish!

Just a little question, I’ve just bought a Trek Domane SL6 with 32mm tires. I have always used 25mm on my other bike but my Trek came with these on. On my 1st ride it felt kinda slower on the hills and just curious if that could be the wider tires that caused it?

Yep for sure

sure and on the flip side they should feel more sure footed on descents. Try 28s instead, or go back to 25s. My wheels are aero optimized for 25s, but for some riding in the mountains I put 28s on. Trek Domane too, but not one that supports 32 tires.

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Thanks. I was kinda worried then that because the Domane is an endurance bike that maybe it is slower than i thought so hopefully going back to 25mm it will be a bit nippier. Did you find yours generally slower than other race bikes because it is an endurance bike.

the geometry is relaxed, so its not going to ride like a race bike with more traditional geometry. However for an endurance bike the big bottom bracket makes it responsive to power. On the hills I can feel the difference with my upgraded carbon wheels, versus the heavier stock Bontrager alloy wheels. However going uphill the geometry does make it feel a little sluggish compared to a race bike, but going downhill the geometry shines and is confidence inspiring.

You may be more sensitive to the heavier tire but in general wider rolls better. https://www.bicyclerollingresistance.com/specials/conti-gp4000s-ii-23-25-28

If you are light rider then RR is less of of a penalty, but if you are more like a Clydesdale then the extra rolling resistance adds up over longer rides.

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25 to 32 is a pretty big jump. As @bbarrera mentioned, 28s are probably the sweet spot for the road.

Other factors to consider are the wheel itself. Are you using a light climbing wheel or something heavier? Tubes (latex vs standard) or tubeless?

Lots of great tires out there but Conti GP 5000’s are reviewing great. The non-tubeless version has been available for a little while now and the TL ones hopefully will be shipping soon.

I went with 28s on my Emonda SLR when I built up the bike over a year ago (I sent in a question to the TR podcast at the time asking about tire size and the consensus was go 28) and I haven’t looked back. With Conti GP 4000 II’s and latex tubes things are super smooth even on rough surfaces, the bike climbs great (I have a pretty lightweight carbon wheelset), and traction downhill is phenomenal. I was riding a Colnago with 23s prior and there is no comparison.

Yeah, wat do you mean big bottom bracket?

Skip to the “First Impressions” section of this tech details and impressions, a lot of good info:

It is about the SLR, which is the same as your SL except it also has the seat tube adjustment to make the ride more soft or more stiff.

I have the SLR 6 and recently switched to 28mm tubeless. Not sure if it was the reduced width or the lack of an inner tube but the difference can really be felt.

Originally on 25 and 28 Conti GP4KII tires, both nice tires on my Domane 2015 6.2 Disc. After converting to tubeless the ride feel is better and I don’t have to fix flats. Win win.

I’ve run tubeless in 25, 26, and 28mm widths, all good and some tradeoffs for each. Best so far has been S-Works Turbo Road Tubeless in 26mm. Waiting for price to come down on Conti 5000 TL before trying those.

Was it actually slower, or did it just feel slower? There’s been recent research that shows riders “think” a higher pressure narrow tire is faster because we’ve been conditioned to think that vibrations = fast. Whereas wider tires at lower pressure dampen those vibrations, feel slower as a result, but are actually faster.

Obviously, there’s a sweet spot on tire width for a given surface, but wider and feeling slower doesn’t always mean actually slower.

This is a worthwhile podcast to listen to on tire pressures and widths:


Agree with this. You might be adding 100 grams, but thats gonna be a pretty marginal difference in your climbs. (And you might make up for it in the descents with added confidence :sweat_smile:).

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You have 2 separate, but related matters - your bike and your tires.
[and FWIW: I ride the Specialized Roubaix (similar to Domane) with Conti GP4000SII 25mm.]

Regarding the tires: There’s the well documented tradeoff: lower rolling resistance for wider tires (at same air pressure) vs. heavier weight (at worst point - the outermost point of a wheel) and higher drag coefficient. Choice of tire really depends on road surface and type of riding you do. On two extremes are hilly Gran Fondos and criteriums (I’ve done both on my bike).

Riding GFs on rough surface leads to riding a wider tire with lower air pressure. You will stay in contact with the ground longer (i.e. avoid losses from the tires leaving the ground) and have less wear on your body late in the ride (i.e. be able to ride harder for a longer period of time). For Crits on flats, its exactly the opposite, particularly where the pavement is smooth. I don’t change my tires to ride both (25cm), but do vary tire pressure.

Bike: In addition to the relaxed geometry mentioned, your Domane has shock absorption built in both into the frame design and components (e.g. iso decoupler). In talking to one of the pro racers from Specialized, and experienced myself, this shock absorption has only a small negative impact on climbing speed, but is more more significant on flats, particularly during accelerations.

Anecdotally, I recently rode the Specialized Tarmac and Trek Edmonda and felt for myself the HUGE difference in responsiveness between endurance bikes and racing bikes.

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I bought the same bike this fall and love it! I’m pretty sure the negatives you’re feeling aren’t due to the tire width but rather the tire itself. I’ll be swapping out those stock Bontragers for Conti 5000’s once I’m ready to take off the Gravel Kings SKs that are on there now.

Regarding the bike geometry - comfort factor on the Domane was the deciding factor for me, and fit was perfect as doing a professional bike fit only required minor tweaks. Plus I do a lot of ride for 1 hour to start of group ride, then after the ride a solo ride home for an hour. So a lot of time on the bike, on crappy roads, and personally given fit/comfort the Domane is perfect for that. But its definitely not as quick into turns as a race bike, and having done multiple rides (rentals) on Tarmac and Emonda I don’t feel like acceleration is missing on Domane.

The Domane is probably the perfect bike for you.

I rode the Trek 5900 for 14 years (the Postal bike from the 2000 era). I loved it but I would always end up beaten up after long rides. I’ve had my Roubaix since Jan 2015 (I tested both the Domane and Roubaix) and have ridden it about 20k miles since then and love it! I did 4 10kft GFs last year. But my riding style is changing - shorter, faster. So I test rode the Tarmac and on a recent trip, rode the Edmonda. There are definitely tradeoffs to be made and hence why the pros ride the Roubaix/Domane on cobbles and the Tarmac/Edmondo (or Venge/Madone) on the road.

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Four years in I’d love to have a bike with race geometry for Wed night worlds, and races. As my only bike, the Domane is close to perfect. I only notice the endurance geometry as a limiter on climbs and sharp corners. Everywhere else it’s great. Before buying it I did same shop comparison rides between Domane, Emonda, Madone, and Giant Defy. And same day at a different shop for the Roubaix. The Domane and Roubaix noticeably fit best “out of the box” and was an easy decision at the time, having not ridden a road bike in 30 years.

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At similar pressure, 32mm tires will have lower rolling resistance than 25mm tires. The 32s will probably be 3W to the good vs 25s. You can review the data on rollingresistance.com to see what I’m talking about.

On the down side Bontrager Paradigm Disc Tubeless Ready rims have a 23mm outer width. So that clearly violates the 105 rule! Ha! Of course, so would the 25mm tires so it might not matter. In any event, as wind yaw angle starts to climb that can start to cost you. (105 rule means that as soon as tire width starts to exceed rim width by 105% or more there is substantial aerodynamic loss at higher yaw angles)

Of course, 32s weigh more than 25s but unless you have a hill top finish this difference is de minimus. Feels sluggish on the way up, feels super fast on the way down.

Most importantly, IMO, is the road surface you’re riding on. If it’s rough asphalt or just poorly maintained asphalt the rolling resistance advantage of the 32s makes them worth it. You can review the data from Silca’s blog regarding this but it doesn’t take much ‘roughness’ to make the 32s worth it.

This is a great point.

Going faster means more vibration, so we associate less vibration with going slower. But if you are getting smoother through running wider widths at lower pressures, this is actually faster even if it “feels” sluggish.