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Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

bicyclerollingresistance.com

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Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#71

Post by ActorNightly »

arghwhat wrote: post #31
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

On descents you can also pick up a lot of speed by getting a heavier bike and supersizing your meals at McDonalds. Speed on descents isn't really that relevant - you're descending, so unless you're racing it's practically effort-less. What matters for people biking normally (i.e., not recreational road bike racing) is assistance in the 10-15mph regime, on flat terrain or climbing. Large changes in rolling resistance…

Yes if you bike slowly, wider tires are better. However I mentioned that in my post. A lot of people who are into biking are in the fitness zone where they are going into speeds where aero starts to matter way more. This is especially true when you consider wind.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#72

Post by ActorNightly »

edmundo wrote: post #57
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

>Speeds over 30 mph on some descents All that aero is probably not working so well for you. Even on my mountain bike with grippy and wide tires I get over 40 mph. On my gravel I can hit over 50 mph, and thats with 45mm tires.

Its totally possible to hit over 40 mph on steep hills on an MTB, especially if you weigh more. I was more referring to slight grades with just pure rolling without pedaling.

Im in Austin so I frequent COTA Bike nights on Tuesdays on the track. Coming down the hill from turn 1 with other riders is a very good test of aero efficiency, because there is a slight uphill after the bend. Couple of my friends ride gravel bikes, one of them is heavier than me, and its pretty clear that that my bike is more efficient.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#73

Post by latchkey »

bluecalm wrote: post #36
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

Gravel bikes are going to transform in coming years as now they are neither very comfortable nor fast. It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. The reason is that soft casing is way more important than knobs when it comes to rolling resistance and MTB tires can be made sof…

I absolutely love my Lauf with their weird suspension front fork. Bike is super comfortable to ride. Also has plenty of width room for wider tires. I run WTB Nano 40c, which are a great mix for road/gravel.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#74

Post by ActorNightly »

bluecalm wrote: post #36
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

Gravel bikes are going to transform in coming years as now they are neither very comfortable nor fast. It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. The reason is that soft casing is way more important than knobs when it comes to rolling resistance and MTB tires can be made sof…

>It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain.

...except when you are going fast. But I do agree that honestly, full on XC MTB are better than any gravel bike for mixed terrain. Modern race XC bikes are not only lightweight, but have enough suspension travel front and rear to tackle super rough trails, which means you don't have to rely on tire pressure for compliance (although QC on the carbon frames is questionable even from the bigger brands).

That being said, when it comes to road, ultimately, aero bikes are still king for efficiency if you are least moderately fit.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#75

Post by latchkey »

ActorNightly wrote: post #70
bluecalm wrote: post #41

Earlier quoted context omitted.

I feel the same about suspension but maybe it's just very hard to design. It would need to be very light and aero to make it worth it for road bikes which are pretty great on roads as they are. For gravel there is the Lauf suspension thing and the new light/short suspension forks but I am not surprised they are not very popular as a suspension fork means regular expensive maintenance. Why not just slap 2+ inch MTB ti…

Yep, for the front you can use something like lauf, which can be made more aerodynamic with smaller travel for road application. For the rear same idea, make the seat stay and chainstay meet earlier and mount the axle mounting dropouts on carbon leaf springs in the same way. You can also add a cable tensioning system to both suspension, which can be used as a lockout to make the bike more efficient.

Lauf owner here (with the weirdo front fork). Absolutely love it!

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#76

Post by cogman10 »

303uru wrote: post #66
ano-ther wrote: post #18

I appreciate sites like this where they make an effort to systematically review products rather than just giving a superficial impression or repeating PR. https://www.notebookcheck.net/ or https://dpreview.com/ are also good examples. They are also a testament to the dazzling amount of options that mature industries seem to produce. > The Schwalbe Racing Ray is optimized for front tire use and is a bit less aggressiv…

As a cyclist, this is a situation in which I find this type of reviewing close to worthless to be honest. Throwing a tire on a metal roller is very far removed from riding unless you're on a velodrome or perfectly maintained road. This has led to a lot of push-back in the cycling community against this site and its findings. Their testing methodology, especially before they made recent changes, largely will prefer sk…

To add to this, unless you are actually competitively cycling (you probably aren't) this sort of thing makes pretty much no difference for someone that is using cycling for transport.

It's a bit like obsessing over the lightest frame possible. Yeah, we can get a 1lb frame made of space materials but at the end of the day it's basically something that will reduce a cyclist's average speed by like 0.1mph.

For anyone doing anything other than competitive cycling, comfort is far more important than anything else and fat wheel bikes with steel frames are damn comfortable to ride on.

A relatively heavy bike with giant wheels might take your average speed down .5 or even 1 mph. You almost certainly won't notice it.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#77

Post by ActorNightly »

tleb_ wrote: post #30
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

The article from renehersecycles.com does not really agree with your comment, and explains why.

28 to 32 is negligible aero wise for most people, I don't disagree. 30 mph (or slower into the headwind for an air speed of 30 mph) will start to matter a little bit though, math doesn't lie.

But saying wider tires are better as a blanket statement implies that you can run like 45c gravel tires and still have the same aero drag, which is by far not the case.

https://www.hambini.com/cycling-aerodynamics-wider-tires-and...

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#78

Post by ActorNightly »

basil-rash wrote: post #33
ActorNightly wrote: post #25

Earlier quoted context omitted.

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement r…

If your primary goal is minimizing work, you can also try an electric bike, or driving! Tongue in cheek, but isn’t fitness the point?

Same fitness on a more efficient bike = longer distance or higher speed.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#79

Post by wiredfool »

londons_explore wrote: post #34
Neil44 wrote: post #27

Earlier quoted context omitted.

Excelent point. Personally I think I would rather run a few PSI less and have confortable ride.

can't you also get a smoother ride by having slightly slacker spokes on wheels? Then the wheel rim bounces over every rock and pebble, but the axle doesn't.

No, you can't, because the elasticity of the spoke doesn't depend on the tension, only the cross section of the spoke. (and count of spokes, and to a lesser extent the lacing pattern).

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#80

Post by wiredfool »

_Wintermute wrote: post #44
londons_explore wrote: post #34

Earlier quoted context omitted.

can't you also get a smoother ride by having slightly slacker spokes on wheels? Then the wheel rim bounces over every rock and pebble, but the axle doesn't.

Not really, spokes work under tension rather than compression, you're essentially hanging from the top-most spokes on the wheel. Also if your spokes are too slack, they can move in the hub, cause wear, and are likely to snap at the elbow.

No.

Wheels are a prestressed linear superposition of overall tension and a compressive load at the bottom. Generally, you'll see ~4 spokes at the bottom of the wheel relaxing to take the vertical load. (in a properly built wheel)

This is due to rims not being completely rigid, but being a somewhat flexible beam. Rims are nowhere near rigid enough to do the "hang from the top" thing.

Spokes will break at the elbow, but generally due to fatigue, which is made much worse when there are stress reversals. Fatigue is when cyclic loads cause small imperfections to grow into cracks, and eventually failure. If you have stress reversals under rolling loads (where the stress goes from tension to compression, anywhere in the spoke elbow) you should expect to see spike failures in ~1000 miles. A stress reversal doesn't necessarily mean that a spoke is slack, because there are some interesting stress patterns in the elbow in poorly built wheels.

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