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Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

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

#111

Post by pandaman »

bennyelv wrote: post #105
pandaman wrote: post #97

Earlier quoted context omitted.

I think you might be transposing the cause and effect. Mechanical rim brakes had been limiting the wheel width because of physics of leverage, disc brakes opened demand for wheels of any width and users naturally migrated to the wider wheels.

It can't work like that in the world of mass produced equipment. You can only buy what the manufacturers are making, and as far as I'm aware there haven't been any wheels that are offered in different widths that the consumer can choose from. It's always: this is the latest model, it has these features, thanks.

I don't think this is a realistic world picture: if this was true then the wheel manufacturers would just keep making rim brake wheels, which a apparently more profitable in your view. In real world a wheel supplier will make wheels for the specs their customers, bike manufacturers and bike shops, order. And those order what their customers, cyclists, demand.

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

#112

Post by bennyelv »

pandaman wrote: post #111
bennyelv wrote: post #105

Earlier quoted context omitted.

It can't work like that in the world of mass produced equipment. You can only buy what the manufacturers are making, and as far as I'm aware there haven't been any wheels that are offered in different widths that the consumer can choose from. It's always: this is the latest model, it has these features, thanks.

I don't think this is a realistic world picture: if this was true then the wheel manufacturers would just keep making rim brake wheels, which a apparently more profitable in your view. In real world a wheel supplier will make wheels for the specs their customers, bike manufacturers and bike shops, order. And those order what their customers, cyclists, demand.

I hear what you're saying and that would normally make sense, but there are reasons why I don't think its true in the bike industry. It comes down to the same arguments that you often see on HN about whether or not a free market works.

Shimano can decide to stop manufacturing rim brake groupsets and spares for existing rim brake groupsets unilaterally. It doesn't matter if the customer wants it or not. The rest of the bike industry supply side won't object to it, because it pushes people towards replacing whole bicycles which benefits all of them.

Other component manufacturers can play the same games in the areas that they can control. Wheel manufacturers can start pushing to wider rims, and then increasing profitability with hookless. Benefits the frame manufacturer (oh no, you need a frame with more clearance!), the tyre manufacturer, doesn't negatively affect any other the other players who aren't directly affected, spin a marketing story about how great this new thing is based on dubious test results and claims, and off it goes.

Repeat that cycle a few times in a few different areas and you have the situation we are now currently in:

The price of a mid/high end bike has doubled in the last 5 years. The bikes have got heavier and more complicated and harder to maintain. The consumers are all pissed off with it and start leaving the sport. Sales suddenly fall off a cliff.

I'm not saying this as a conspiracy theory nut, but rather that there are a set of dynamics at play in this industry that mean that this kind of thing can happen.

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

#113

Post by tpm »

bennyelv wrote: post #107
303uru wrote: post #67

Earlier quoted context omitted.

You're kidding yourself if you think Pogacar would run 30mm tires at 55 PSI at the detriment of speed to please his sponsors. Cyclists are notorious for re-badging stuff they don't want to use and being super finicky with their gear. You're talking about guys that hardly celebrate a win with a $250k purse because they want to make sure they stopped their ride right on the finish line on their headunit.

I don't share your optimism about the strength of the scientific method in pro-cycling :) It's not too long ago (admittedly in the pre-disc brake era) that climbers would have their bike built up to sub 6.8kg and then add weight to it to bring it up to the limit rather than use deeper wheels. If you look at TT equipment all team members use the same helmet regardless of the fact that helmet performance varies massive…

> Why is nobody wearing a TT Helmet and visor on a normal road stage?

Because it doesn't work as much alone as in combination with specific aero body position. But you can't be in that position in a normal road stage because the aero handlebar extensions are forbidden in mass start stages.

Also there are less aero benefits to be had when you ride in the peloton behind other riders.

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

#114

Post by pmontra »

wiredfool wrote: post #82
pmontra wrote: post #52

Earlier quoted context omitted.

28 mm tires used to be huge tires. Pros didn't ride anything wider than 23 mm in the 90s. 25 mm would be for special occasions. 21 mm on tracks, sometimes even 19 mm. I think than Valverde used a 28 mm in a Roubaix and at the end of the race said that it was too much and not worth of the extra weight and front section. Every pro is riding on 30 or 32 mm now. Of course the rims are totally different and wrap those tir…

I bet if you ran the same tires in 42 and 28, you'd be basically at the same speed, at least on smooth roads.

The 28 wheel feels immediately faster. It's lighter, so it accelerates faster than the 42 one and there are a lot of accelerations from low speed in a ride, especially for slow riders like me. On the other side the 42 wheel should be better at keeping the speed because of the higher mass and inertia. Unfortunately that's wasted each time I use the brakes or I slow down.

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

#115

Post by seadan83 »

bennyelv wrote: post #53
pmontra wrote: post #52

Earlier quoted context omitted.

28 mm tires used to be huge tires. Pros didn't ride anything wider than 23 mm in the 90s. 25 mm would be for special occasions. 21 mm on tracks, sometimes even 19 mm. I think than Valverde used a 28 mm in a Roubaix and at the end of the race said that it was too much and not worth of the extra weight and front section. Every pro is riding on 30 or 32 mm now. Of course the rims are totally different and wrap those tir…

Unfortunately you cannot discount the “sponsor effect” here. Wheel manufacturers have been pushing wider rims because it helps them sell another set of wheels to everyone. In the days of rim brakes a wheel had a finite life (the length of time it took to wear down the braking surface). Then shimano and the frame builders pushed everyone to disc brakes, so the wheels now last for ever. What do you know, 2 years later…

As for evidence, here you go: https://www.renehersecycles.com/why-wider-tires-are-not-slow...

The aero drag of wider tire is not a lot. It is more the wider tires are not slower. Wider tires allow: more air volume in tire, lower PSI. In turn those help ride quality.

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

#116

Post by seadan83 »

bennyelv wrote: post #112
pandaman wrote: post #111

Earlier quoted context omitted.

I don't think this is a realistic world picture: if this was true then the wheel manufacturers would just keep making rim brake wheels, which a apparently more profitable in your view. In real world a wheel supplier will make wheels for the specs their customers, bike manufacturers and bike shops, order. And those order what their customers, cyclists, demand.

I hear what you're saying and that would normally make sense, but there are reasons why I don't think its true in the bike industry. It comes down to the same arguments that you often see on HN about whether or not a free market works. Shimano can decide to stop manufacturing rim brake groupsets and spares for existing rim brake groupsets unilaterally. It doesn't matter if the customer wants it or not. The rest of th…

If shimano stopped making rim brakes, no tour de France athlete would use shimano groupsets. Rim brakes are lighter, that is why.

Would shimano ever give that up? No. All these companies pride themselves for being what the elites run. Dura ace would become a joke if no elites used it. The dura ace groupo upgrade is thousands of dollars (2k to be exact, it's the most expensive 100g you can pay for), & dura ace is high profi. So mo, too much brand risk. I mean, why haven't they stopped selling rim brakes already? It makes zero sense for shimano to do that.

Further, there are plenty of bike tire manufacturers making a variety of rim sizes. Some bikes can only do 25s max, makes no sense to only have a 28mm rim.

What's more, there's millions, probably hundreds of millions of older bikes that all need new rims every few years. For what you're saying to be accurate, no company would seize that demand and instead some sort of duopoly would instead opt for forced obsolescence. I don't see that as being the case (it is for thing like iPhones/cell phones, but the bike industry is very different)

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

#117

Post by seadan83 »

bennyelv wrote: post #107
303uru wrote: post #67

Earlier quoted context omitted.

You're kidding yourself if you think Pogacar would run 30mm tires at 55 PSI at the detriment of speed to please his sponsors. Cyclists are notorious for re-badging stuff they don't want to use and being super finicky with their gear. You're talking about guys that hardly celebrate a win with a $250k purse because they want to make sure they stopped their ride right on the finish line on their headunit.

I don't share your optimism about the strength of the scientific method in pro-cycling :) It's not too long ago (admittedly in the pre-disc brake era) that climbers would have their bike built up to sub 6.8kg and then add weight to it to bring it up to the limit rather than use deeper wheels. If you look at TT equipment all team members use the same helmet regardless of the fact that helmet performance varies massive…

> Why is nobody wearing a TT Helmet and visor on a normal road stage?

(1) weight is not always worth it, notably when there are lots of climbs

(2) riding with others, need to be able to turn your head. Further, you can't get as super low when in a big group. It also doesn't help as much because the group dynamic is more important than crouching extra low and/or helmet drag

(3) out of the saddle sprints.

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

#118

Post by seadan83 »

tpm wrote: post #113
bennyelv wrote: post #107

Earlier quoted context omitted.

I don't share your optimism about the strength of the scientific method in pro-cycling :) It's not too long ago (admittedly in the pre-disc brake era) that climbers would have their bike built up to sub 6.8kg and then add weight to it to bring it up to the limit rather than use deeper wheels. If you look at TT equipment all team members use the same helmet regardless of the fact that helmet performance varies massive…

> Why is nobody wearing a TT Helmet and visor on a normal road stage? Because it doesn't work as much alone as in combination with specific aero body position. But you can't be in that position in a normal road stage because the aero handlebar extensions are forbidden in mass start stages. Also there are less aero benefits to be had when you ride in the peloton behind other riders.

You don't need aero bars to have you arms forward and narrow. It's not particularly safe, but doable for a while.

The aero bar question (whether to have them or not) comes down to how long you will spend drafting and climbing. It's a more interesting decisions in Olympics and triathlons than most road bike racing (the latter it makes no sense because people are drafting as much as possible).

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

#119

Post by seadan83 »

pmontra wrote: post #114
wiredfool wrote: post #82

Earlier quoted context omitted.

I bet if you ran the same tires in 42 and 28, you'd be basically at the same speed, at least on smooth roads.

The 28 wheel feels immediately faster. It's lighter, so it accelerates faster than the 42 one and there are a lot of accelerations from low speed in a ride, especially for slow riders like me. On the other side the 42 wheel should be better at keeping the speed because of the higher mass and inertia. Unfortunately that's wasted each time I use the brakes or I slow down.

Narrow will feel faster, and lighter accelerates faster - but the perception is often over perceived.

So, the weight difference of 28 vs 42 is going to be 100g maybe. It's not a lot. Weight vs aero experiments have found conclusions like weight over 100 miles is tiny small compared to any aero gains (talking like +3 lbs having a few minute difference over hours). Which is to say, the effects you describe are pretty small when measured.

Moreover, the choice of 28 vs 42 is rare, feels like is more choosing 25, 28 or 32; or choosing something in low 30s compared to 40s. Meaning, the weight delta is even less in real world choices. What's more, you can go to 650b and have the exact same tire weights with much bigger widths.

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

#120

Post by seadan83 »

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…

Salsa cut-throat is a gravel bike, fits 2 inch tires. Personally, I find having drops to be more comfortable because you can change hand position. Look to tour divide bikes for gravel bikes optimized for comfort and fatter tires. I don't understand your prediction for an imminent transformation.
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