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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

#61

Post by MrSkelter »

pandemic_region wrote: post #22

Unless you're on the ProTour, choose riding comfort over rolling resistance. Also see https://www.renehersecycles.com/12-myths-in-cycling-1-wider-... for a related myth-debunking of the impact of tire width (which contributes to rolling resistance) on speed.

You can have both. Wider tires are faster and more comfortable. It’s only at the point aero becomes a limiting factor that things change. In the real world most of what we “know” about tires is a myth (and the linked site isn’t doing real world testing)

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

#62

Post by arghwhat »

bluecalm wrote: post #38
arghwhat wrote: post #31

Earlier quoted context omitted.

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…

Going from 20W tire to 10W tires is going to be massive even more so for recreational not so fit riders. Such a rider may output 120-150W on average. Getting 20W free (there are two tires) results in a difference comparable to installing a small motor on your bike.

No: A 20W tire is a 20W tire at 18 mph. At 10 mph, it's roughly a 10W tire (rolling resistance should be mostly linear at these speeds). Going from 20W to 10W tires therefore only saves you 10W total at those speeds.

At 120W, you are idle pedalling. You do not really pedal lighter, so saving a few watts mean an increase in speed, but as both rolling resistance and aerodynamic drag goes up with speed the gain becomes small.

At normal climbs - the time where you'd wish pedalling was easier - you're either 1. spend in the area of 200-300W maintaining the same speed without increasing rolling resistance, making rolling resistance a smaller part of the load, or 2. drop to a granny gear, going very slow to maintain your 120W and thus making the rolling resistance negligible with any tire. In either case, rolling resistance matters much less in climbs.

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

#63

Post by pbhjpbhj »

scott_w wrote: post #14
pbhjpbhj wrote: post #8

Earlier quoted context omitted.

>"it costs $.79 / mo" but you pay in one payment How do you pay a single one-time payment at a per month rate? How many months do they charge for the one-time payment? Usually a 'single one-time payment' would be a payment for life. Typically for apps they're What you appear to be describing would be a pre- payment plan at 80¢/mo.

I just explained it in my message: you pay once for a year and that's it. This is not a lifetime access, it's a one-off payment that gives you access for 12 months. If you like it, you purchase again. I really don't understand how this is confusing for you.

>"If you like it, you purchase again."

This is not what I would call a one-time payment. If you wish to continue to use the website you pay again. That's just not what "one-time" means to me.

It's not confusing, it's just annoying marketing-speak in the sense that (paraphrasing) 'a simple one-time payment' is what customers like when purchasing something. Whereas the offer is not that, the term has been used in any case.

What is offered is 'a subscription without auto-renewal'.

If you really wish to understand my thinking I can elucidate you at length, but it seems we've spent way too long already discussing understanding of a particular piece of marketese.

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

#64

Post by pbhjpbhj »

reedf1 wrote: post #12
pbhjpbhj wrote: post #8

Earlier quoted context omitted.

>"it costs $.79 / mo" but you pay in one payment How do you pay a single one-time payment at a per month rate? How many months do they charge for the one-time payment? Usually a 'single one-time payment' would be a payment for life. Typically for apps they're What you appear to be describing would be a pre- payment plan at 80¢/mo.

Literally 5 seconds of investigation revealed that they offer three durations of membership, each a one off payment (the per month pricing is just a representative amortisation). This is actually so easy to discover, and so easy to understand, that I'm guessing you're just reflexively enraged.

Continuing membership requires recurring payment not "one-time payment".

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

#65

Post by ActorNightly »

nl wrote: post #54
ActorNightly wrote: post #20

A super easy way to tell how efficient a tire is going to roll is weight. If you are comparing tires for the same diameter/width/tread pattern, in most cases, the lighter tire is going to roll better. Tire rolling resistance comes from effectively the rebound damping on the tread. As the tire rolls, the tread on the backside of the contact patch takes some time to rebound, so the tire is effectively always rolling ov…

This isn't right. The difference in weight of a tire in the same class is insignificant (~400g) compared to the bike (~7kg) and the rider. Indeed based on your explanation the stiffness of the tread is going to be as much of a cause as anything.

Its a very rough rule, and has exceptions, but its generally works out.

Compare continental gatorskins in 28c vs continental gp5000 in 28c. Gatorskins have more casing to prevent puncture, so they are heavier, but that casing also takes away from the rolling efficiency.

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

#66

Post by 303uru »

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 skinny, highly inflated tires. But in the real world, everyone is finding fatter, less inflated tires are faster, because in the real world compliance (smoothly rolling over every road variation, rock or pebble) is faster.

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

#67

Post by 303uru »

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…

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.

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

#68

Post by ActorNightly »

scott_w wrote: post #60
ActorNightly wrote: post #23

Earlier quoted context omitted.

> something softer can absorb more of the little bumps (and also perhaps not fatigue the rider as much from a bumpy ride). Not quite. You can air down narrower road tires for this. The difference is that a wider tire (i.e a tire with more volume) is going to be more efficient at lower psi, because of a wider contact patch that ends up spreading the load out more and deflecting the tread less. This effect definitely i…

> a narrower tire is going to usually be better, because you gain the aerodynamic advantage Testing has shown this to not be true. Width is less important than overall shape of the tyre/wheel/bicycle interface when it comes to aerodynamics.

Then everyone in the peloton for races like Paris Roubaix would be on 38c gravel tires. The reason they run 28c is because while it sucks for cobblestone, there sre flatter sections where the aero advantage is worth it.

Per 10mm tire width increase, you are getting 10 watts more aero drag at 25 mph.

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

#69

Post by alephxyz »

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…

> Wheel manufacturers have been pushing wider rims because it helps them sell another set of wheels to everyone.

I think the push to wider tires and lower pressures on road setups is actually because hookless carbon rims are much easier to manufacture than clinchers, and hookless tires can't handle 80+ psi.

Clincher carbon wheels are basically considered a niche product by big manufacturers

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

#70

Post by ActorNightly »

bluecalm wrote: post #41
ActorNightly wrote: post #23

Earlier quoted context omitted.

> something softer can absorb more of the little bumps (and also perhaps not fatigue the rider as much from a bumpy ride). Not quite. You can air down narrower road tires for this. The difference is that a wider tire (i.e a tire with more volume) is going to be more efficient at lower psi, because of a wider contact patch that ends up spreading the load out more and deflecting the tread less. This effect definitely i…

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.

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