Assuming fixed tire width, what features makes a tire more comfortable?

Question

What features should I look for in 2" tires to maximize comfort on my Cannondale Adventure 1 with 27.5 wheels? I know that higher tpi/epi is considered softer. However, would a 67 tpi/epi Schwalbe Green Marathon be significantly more comfortable than the 60 tpi/epi Kenda Kwick Drumlin? I can't find a tpi/epi spec on the stock, 2", Goodyear Transit Tour tires.

I do plan to get the widest tire possible. After some measurements and manual reading, I found I have clearance for 2" tires in the front and rear. Maybe 2.2" in the rear if I'm willing to risk only having 2.5mm of clearance instead of the 3mm minimum I found on the web.

edit: Based on the responses, I was debating between the Schwable Super Moto X and the Schwable Marathon Efficiency. I ended up getting the Marathon Efficiency because I figured the decreased rolling resistance would be important for a bike as heavy as the Cannondale Adventure. Thanks to all who answered and commented!

Answer 1

I'm afraid there's no single specs that can be used to know what can make a tire comfortable. The main criteria is suppleness (besides pressure, obviously), that allows a tire to easily deform to absorb asperities in the road (provided that the pressure is low enough to allow the derformation), but it's not a "metric" per se. By contrast, a rigid tire will deform less and transmit more energy to the wheel axle, with results in comforting.

About TPI, I understood that it can be used as a red flag, 60TPI is the minimum, less reveals a low quality tire ...but that is not per se a sufficient, as the construction of the tire also plays a role and is not always described in the spec. To give an example, the legendary stiff Schwalbe Marathon Plus has the same number of TPI than the Schwalbe G-One R, a tire that is considered to supple. Terravail also sells tires in two versions: light&supple vs durable, and same number of TPIs for both of them.

Suppleness is usually a feature that is found in performance/premium tires, as supple tires typically have lower rolling resistance. Theoretically, I have the impression there's a correlation between rolling resistance and comfort: one of the factors that causes rolling resistance the energy required to deform the tire. But rolling resistance is rarely mentioned by manufacturers, and if it is, they don't explain how it is measured. But to compare tires of the same maufacturer of the same family it can be a proxy. There is also this website: https://www.bicyclerollingresistance.com/ but it's a lab testing that may not be representative in real situations.

Features like puncture protection layers for example influence rigidity, as well as using a tube. So it's also compromise.

In the segment you mention, I have the impression there are mostly "cheap" or "puncture resistant" tires. The comfort offering exists but is very limited, but is growing. When I did this research last year for tires of this kind of size - for a commuter that should be comfortable on cobblestones, I settled up for the Schwalbe Marathon Almotion (or Efficiency if riding mostly on tarmac). Schwalbe has the "balloon tire" label for largish tires meant to be ridden at low pressure (with tubes) - Big Apple and Big Ben, that are to my knowledge, the only "non performance" supple tires. There might be other tires available in other regions and from other brands, so it's not an endorsement.

Answer 2

I'm with DoNuT in the comments. Tire pressure is more important than tire type.

Use the recommended inflation as a starting point and then experiment with tire pressure. You'll find that different pressures work better in different situations and you'll find your max / min pressure. Carry a frame pump and a gauge and experiment.

Describing the two extremes:
Smoothing out rough roads require less pressure. You are looking for the lowest pressure you can ride without bottoming out or spinning the tire. Bottoming out the tire on a hole or bump causes tire/rim/tube damage. Spinning the tire causes the tire to slip on the rim while the valve stem stays in one place and gets cut by the rim.
You'll select a test pressure, maybe 5 pounds less than recommended, ride normally a short distance and observe tire behavior and ride feel. If it still feels rough and the tire is nowhere near bottoming out or slipping take out a little more.

On totally smooth streets you might try going a little higher than the recommended pressure. The key is to find a higher pressure that is still comfortable and will not blow the tire off the rim. Finding max pressure is a little harder than finding minimum pressure. I don't like to go higher than 10 psi over recommended, other people are braver.

Most of the time people are somewhere in the middle between the roughest and the smoothest. How it feels to you is what matters and it takes some experimentation.