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I've now got a bike with 2.35" (or 60mm) Schwalbe Big Apple and feel a bit slow. There's no testing to prove this claim, but riding my fixie (25mm) the last couple of years just felt quicker/easier. Is that because the fixie is lighter (~10lbs) and has more efficient gearing or the thinner tires?

I am now thinking of going thinner, namely Marathon Supreme 40mm. I don't think I want to go thinner because I fell in love with the cushion. Will this make for a noticably quicker ride and will I lose much cushioning? Or should I just buy bigger legs?

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    Tires, gearing, geometry (you can't put as much power down on a dutch bike as on a race bike usually, plus a sharper steering makes a bike feel faster too), they all can have an effect on how fast a bike goes. – Batman Sep 7 '16 at 15:34
  • Marathon tires are in general fairly stiff and will not roll very fast. These tires are "utility" tires, where puncture resistance is valued over comfort and speed. – Rider_X Sep 7 '16 at 16:49
  • Regarding Marathon rolling resistance: bicyclerollingresistance.com/tour-reviews – ojs Sep 7 '16 at 17:19
  • @ojs - I would be a little careful. 1) All of the tires in those tests have similar construction, none are particularly supple. 2) the test uses a steel roller drum, which only measures hysteresis losses. On real world surfaces suspension losses / impedence can far exceed hysteresis losses. The Silca Journal article has a great example of this when they compare rolling resistence across different different surfaces. – Rider_X Sep 7 '16 at 20:38
  • @ojs - I will add, that you can game the measurement of hysteresis losses (on a roller) by using higher pressures. The problem is that as pressure increases, so do the real world suspension losses (which no one currently measures - difficult). At some point suspension losses overwhelm hysteresis losses, this was the "breakpoint" referred to in the Silca Journal article. Because few, if any, rolling resistance tire comparisons consider suspension losses they can be misleading. – Rider_X Sep 7 '16 at 20:48
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There is plenty of discussions on the internet about larger volume tires actually being faster than narrower tires. For example, a recent Cycling Tips pod cast has a good discussion. However, real world experience will likely be the opposite due to the tire construction used on the majority of tires available in the market place.

Tire construction

Unfortunately, tire construction is a confounding factor when discussing performance of large volume tires. Most larger volume tires on the market use heavier casings and thicker tread, as they intended use case is "heavy duty". Add in some puncture resistance strips (standard on most large volume tires currently in the market) and you get a very thick and stiff tire.

A stiff tire will have higher rolling resistance compared to a more supple tire due to a a process called hysteresis, where the energy required to flex the tire slows you down and higher suspension losses (which has also been termed impedance). Suspension losses vary by road surface and can be quite high on rougher surfaces. Here a stiffer tire response more slowly to road imperfection (i.e., flexes to accommodate the imperfection), which in turn vibrates the rider. The vibrating soft tissue "consumes" energy (actually it converts forward momentum into heat due to internal friction within the body). BQ showed this in an extreme context, where very rough surfaces more than doubled the amount of effort required.

All things being equal, a larger volume tire will also be heavier than a narrower tire. Add in heavy duty construction found on most high volume tires, and you end up with a much heavier tire. This results in a large weight penalty which can noticeably affect acceleration, furthering the feel of the tire being slower.

Because most high volume tires on the market have stiff heavy duty construction, these tires will typically have much higher rolling resistance than more narrow tires, which, on average, tend to be more performance focused, featuring more supple construction and lighter weights.

Light Supple High Volume Tires

An exception to this generalization is light supple high volume tires, which are currently quite hard to find. These tires will also have low hysteresis and very low suspension losses as the supple construction means the flex easily and the large volume means you can run them at a lower pressure, there by greatly reducing suspension losses. On most real world road surfaces (especially open chip seal or gravel roads), these type of tires will be faster, than a narrower tire of similar construction due to the large difference in suspension losses.

These typically will not have puncture protection, further adding to the suppleness. Lack of puncture protection is less of an issue in large volume supple tires, because the force placed on encountered objects by the tire is reduced due to the fact the tires flex easily and the tires are run at a lower pressure. This means the regular tire rubber is typically strong enough to resist the object and an extra puncture strip is not required.

Finally, a light suppler large volume tire will still be heavier than an narrower tire so there is an acceleration penalty. That said, this penalty is much smaller than with the "heavy duty" large volume tires and for most everyday riding it will be hard to notice. It is therefore a bit of a non issue relative to the gains in comfort and higher sustained speed due to reduced suspension losses.

The real problem is getting your hands on light, supple, large volume tires. Only a few brands currently exist, with pretty much all of them are being manufactured by Panaracer.

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    Compass Cycles has tires which claim to be large volume/supple casing (which are manufactured by Panaracer). – kmm Sep 7 '16 at 17:28
  • @kmm - Yes, Soma and Cannondale also have high vol supple tires manufactured by Panaracer. That is what I was referring to in my last paragraph. Given that SE isn't for product recommendations I tried to avoid mentioning brands in the answer. I think comments are more appropriate venue. That said, I have had a good experience so far with a pair of Compass Barrow Pass tyres, they on average were 2-4 kph faster than the larger vol puncture resistant tires I was using at the time. That's a massive difference. – Rider_X Sep 7 '16 at 17:32
  • It is also notable that the rolling resistance of these tires is never measured. Panaracer under its own brand is good but not best. – ojs Sep 8 '16 at 19:30
  • @ojs - I agree I think the published testing so far is subpar. Ideally, three components (hysteresis, impedance and suspension losses) could be measured and reported independently. While I implied in my answer that impedance and suspension losses are essentially the same thing, I believe they somewhat separate processes, with impedance representing the heat generated from deflecting a mass up, while suspension losses relate to heat generated from how a mass (i.e., the rider) vibrates. I am currently thinking of some approaches on how to independently measure these components. – Rider_X Sep 8 '16 at 19:44
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I don't know if the 60mm will have a higher rolling resistance than the 40mm, there are a lot of variables that can make the difference. There are tons of articles and studies on the internet that compare rolling resistance of tires. Here is one that says:

Wider tires are faster

Tire rolling resistance comes from internal friction within materials (energy loss due to hysteresis) and small bumps that lift the bike and rider.

When it comes to internal friction, wider tires have shorter contact patches and, thus, less deflection. If pressure is the same, the area of the contact patch must be the same to support the same load. (Since both load and pounds per square inch remain constant, the area in contact with the road will also be the same.) But a wider, shorter contact patch will have less vertical depth of deflection, So internal friction and hysteresis loss will be lower.

If a wider tire is constructed of the same materials in the same thicknesses as a narrower one, it will often roll faster on a rough surface, despite being heavier. This is due to both lower internal friction and the fact that the wider tire will better absorb imperfections in the road, thus lifting the bike and rider slightly less on each little impact.

I think that regardless of the higher or lower rolling resistance, you will feel the extra weight of the 60mm tire as you accelerate, or the lighter weight of the 40mm, however you look at it. There is more mass around the circumference of the wheel with a 60mm tire, and that will have to be overcome to accelerate (think turning too), which may give you the "sluggish" feel, relative to a smaller, lighter 40mm tire.

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  • The effect of tire mass on acceleration is bogus, except perhaps in track racing. And a wider tire is only equal/better than a narrow one in terms of rolling resistance if the same tire pressure is used, which is hardly ever the case, since a wider tire, at the same pressure, will be stiffer and give a harsher ride. – Daniel R Hicks Sep 7 '16 at 19:26
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    @DanielRHicks - differences in acceleration can be quite noticeable. For example, on club rides it is noticeably harder to stick with a strong surge on a larger heavier tire. You don't have to race to encounter this, spirited riding can be enough. – Rider_X Sep 7 '16 at 20:57
  • @Rider_X I agree, I can notice a difference, road bike to road bike, running 25's vs 28's, same wheel set – ebrohman Sep 7 '16 at 22:42
  • @Rider_X - I'm pretty sure what you're noticing is the difference in the rolling resistance of the tire, not its moment of inertia. The amount of actual acceleration you do in a "strong surge" is really quite small. – Daniel R Hicks Sep 8 '16 at 0:07
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    @Rider_X - The point is, that a pound on the wheel rim contributes the same amount total inertia as two pounds that are not rotating. It's not the "ten times" or whatever that is often quoted. The difference in tire weights you're talking about is mere ounces. – Daniel R Hicks Sep 8 '16 at 11:55
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I have attached a link below to a site that measures rolling resistance for tires in watts. It is the first objective test I have come across concerning this issue. There has been a lot of conjecture & opinion on how the variables of width, volume, tread, clincher/tubular, material science, pressures effect outright performance but little evidence.

For what it's worth, take a look at; http://www.bicyclerollingresistance.com/

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