thook

blunt

HTupolev

Tire designs have to make compromises between a variety of performance factors: rolling resistance, grip, weight, wear life, puncture and cut protection, and so forth. For example, adding a tough puncture protection layer can reduce a rider's risk of flats, but it generally comes with a cost in rolling resistance and a bit of weight. Or, one tread rubber compound might achieve better rolling resistance and grip than another, but suffer from considerably faster wear.

Higher-quality materials can allow a tire to compromise less. A manufacturer might have a high-end road racing tread compound which achieves less rolling resistance than their lower-end compound while making no functional compromises, but it might be more expensive to make. A casing fabric that uses a dense layup of thin fibers can be lighter and faster-rolling than a fabric that uses a coarse layup of thick fibers, while still being plenty strong, but it may be more expensive. And so forth.

That's a tricky comparison to make, because a Marathon Plus exists in a tire genre where there just aren't very many ultra-high-end options. It's an urban/touring tire focused on extremely high wear life and extremely resistance to damage of all sorts, at the cost of extremely high rolling resistance and being very heavy. It's a good tire for what it is: I'm not actually sure if there are any pneumatic bicycle tires out there with the same amount of focus on toughness as a Marathon Plus that push themselves as being fancier.

MyRedTrek

I'm not going to dispute what you say because my experience with tires, bikes and riding conditions/distances is limited. I definitely don't perceive a lot of resistance - get up some speed and coast and it rolls for a long distance. It seems counterintuitive that a Marathon Plus would have a comparatively high rolling resistance because of that dense anti-puncture inner layer that seems would make it stiffer. I would think the stiffer a tire the *less* rolling resistance - a wooden wagon wheel with an iron tread is going to have less rolling resistance than a pneumatic car tire.

HTupolev

Rolling resistance doesn't work like that. In the real world, it has two main components.

One major portion of rolling resistance in the is energy lost to deformation of the tire against the road surface.
When a section off the tire becomes the contact patch, it gets squished against the road surface, which sucks some energy out of your forward motion. When it rolls out of the contact patch, it springs back, returning some of that energy back into forward motion. The "spring" formed by tire pressure does this very efficiently, returning nearly as much energy to forward motion as was lost in the initial deformation. But tire materials tend to have lots of internal friction and rebound less enthusiastically, seeing a large loss of energy between deformation and rebound. And in use, the vast majority of a tire's stiffness comes from air pressure, not the stiffness of the uninflated tire itself. So a beefy tire like a Marathon Plus tends to see a much larger energy loss between deformation and rebound than a really flexible supple racing tire (such as a Vittoria Corsa Speed).

You can reduce this loss by inflating the tire more stiffly, at least if you stay within safe max tire pressure boundaries. But, this brings up the second major portion of rolling resistance: inadequate suspension.

The whole point of using pneumatic tires is to form a pneumatic suspension system. Roads have lots of little surface irregularities. Overly-stiff tires can bounce off of these irregularities, causing vertical motions in the wheel, frame, rider, etc. Aside from reducing comfort and traction, this also wastes energy: the energy that deflects the bike+rider upward comes out of your forward motion. And this is a relevant performance consideration even on rolled asphalt roads that "feel smooth."
Attempting to reduce rolling resistance in a beefy touring tire by overinflating it doesn't actually work, it just changes the physical mechanism by which you're being slowed down. In most cases, a slightly-underinflated tire actually rolls considerably faster than a slightly-overinflated tire. This is a good blog post on the issue.


Rigid wagon wheels roll and behave very poorly on real-world surfaces, which is why people switched to pneumatic tires once practical ones became available. We do use rigid metal wheels on trains, but these trains travel on smooth metal rails, not paved roads.

SJX426 

Try finding a 1/2 gallon of ice cream. Only place I know is Costco.

sweeks

And the weight decrease is *rotating* weight... for those concerned with ultimate performance (not me!) there is said to be a noticeable difference (improvement) in acceleration due to the reduction in rotating mass.

AlanO

You can carry a spare?

Iride01 

https://www.welovecycling.com/wide/2...grande-boucle/

Granted these are not steel bead clinchers, but lack of folding didn't keep the cyclist of days gone by from carrying a spare looped over both shoulders.

Even so a steel bead tire can be folded over itself twice to form three smaller loops that should be easy enough to attach to any paniers or large bags one might be carrying on a long bike tour.

Though for my one day rides, I've never had any desire to take a spare tire with me. Nor will I have any desire to use a wire bead tire again. Though perhaps something might happen one day to make me eat those last words.

WinterCommuter

the “folding” variety are usually lighter. I also prefer folding tires because i can easily stuff a complete tire (rather than just a boot) into my backpack while commuting.

JanMM

All else being equal, lighter is always better.
I've had no trouble mounting folding bead tires - first put them on a bike after riding with wire bead tires for at least 3 decades.