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 aggressive than the Schwalbe Rocket Ron, […] Schwalbe suggests pairing the Racing Ray with the Racing Ralph (read review), which is optimized for use on the rear wheel.
> The Racing Ray used to be only available with the Addix SpeedGrip compound, which [is] grippier than their Addix Speed compound. We just noticed Schwalbe also released a Super Race version with the Addix Speed compound somewhere in the last few years, and we're not sure about the front wheel claims for that version.
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.
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 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 road usually doesn't require less than 60 psi, and above 60 psi the rolling resistance of wider tires is about the same as narrower tires, but watt savings from aero can be significant.
I got a gravel bike to replace my old road bike because everyone was raving about it, and I absolutely hated riding it. Sure, at slow recreational speeds, it was more comfortable, but when getting places, it just didn't roll as well down hills, making me having to pedal more over extended times to get uphill.
Now I ride an aero road bike with TT bars, with 28c tires, and even when running them at 60-70 psi for rough pavement, the aero gains from the narrower wheels are significant, as I can pick up speeds over 30 mph on some descents which carry me way further uphill.
The power losses on a perfectly smooth road are aero and rolling resistance. But once you get onto bumpy surfaces, now you also need to consider the power losses of the bumps on the bike AND on the rider because the rider is the one supplying the power, even the power which does not transmit through the cranks.
Although I do agree with you partially, if you're racing, ride what ever makes you fastest. Energy efficiency isn't paramount, getting to the finish first is. But if you're not racing, then really consider if the tradeoff of comfort is worth it.
The BRR website's test protocol uses a fairly smooth metal drum for testing. This is good for testing rolling resistance but not for testing total system losses over rough roads. So although BRR is a great resource, take it with a grain of salt.
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 tires in a way that the old metallic rims could not do, hence the aerodynamic gains.
Edit: I've got a gravel bike with 42 mm tires and a 28 mm set. I use the 28 mm when going in the hills on asphalt. I'm with you on that: it's a day/night difference. On mixed mostly flat terrains the 42 mm tires are the best compromise.
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 matters here, like going from an almost 40W tire to a 20W tire. But aerodynamics have a very minimal effect here, and going below 20W tires won't really make a meaningful difference in biking effort compared to the effect on your butt and wrists.
The reason is that soft casing is way more important than knobs when it comes to rolling resistance and MTB tires can be made soft because all the additional rubber coming with width while gravel tires are usually harder and thus slower (and less grippy and less comfotable). Notable exception is Continental Terra Speed but it's still not as good as Race King and way more puncture prone.
The problem with most current gravel frames is that they don't fit wide and fast MTB tires so you are stuck with the worst of both worlds - slow, not comfortable and still not grippy/soft enough to go fast off-road unless it's a very well maintained road.
on my road bike with 28c and inner tubes, 60 psi is what i use on _good_ road surface. maybe the roads are just shit here, but even 55 psi feel rough. i usually run on around 50 psi, 40 in winter.
there was a time i lost my track pump and i just pump the tyres using a mini pump without a guage. later i discovered i was running on something as low as 30 psi.
i have never had a pinch flat. i don't think i'm particularly light. full load when doing groceries is probably 85 kg. is it just that my pressure juage is woefully inaccurate?
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.
Tongue in cheek, but isn’t fitness the point?
Edit: after browsing the site, the Marathons are the lowest rolling resistance touring tires too! Double bonus for an excellent tire, which I can now recommend without reservations.
Then look at the methodology:
> The total rolling resistance of an average rider with a total bike + rider weight of 85 kg / 188 lbs that averages 28.8 km/h / 18 mph will be double the rolling resistance you can find on our website. If you're heavier than that or average higher speeds, the total rolling resistance will increase roughly linearly with the increase in weight or speed.
All I can say is that I am a lot heavier than 85kg with my bike and that I am usually riding at 20-25 km/h.
So let's say the lower bound they mention would 2x15 and the upper bound 2x25. Let's assume 127kg with luggage, that scales linearly to 3x15 - 3x25, but the speed is only 2/3, so we can dial it back. My napkin math now says the difference between a good pair of tires and a bad one is 30 vs 50.
And I'm still not sure if that translates 1:1 to the assumed typical 100 Watts of an average rider..
I found https://www.gribble.org/cycling/power_v_speed.html though and if I plug in my numbers, the coefficient of rolling resistance is our variable, and
0.00465 -> Rolling resistance is working against you with 5.79 (N) of force, or 50.15 watts of power.
0.00273 -> Rolling resistance is working against you with 3.40 (N) of force, or 30.01 watts of power.
So the tires make about 2-3 kph, which fits what most people have posted when I was researching this.
I let both of my kids try things and choose, both choose tires with fairly low resistance. One more so than the other, but both clearly regarded high pressure as somehow comfortable: Apply pressure to pedal, feel bike move. Responsiveness.
Happily, this is also more comfortable.
There are other trade offs than rolling resistance. Like puncture resistance, grip/cornering ability, aerodynamics, weight etc. that also comes into account when choosing a tire setup.
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 is pronounced for gravel riding when you have to run pressures lower than 60 psi, and a wider tire is better. However for on road riding, even on rough roads, a narrower tire is going to usually be better, because you gain the aerodynamic advantage, even if you run at lower psi. If you can sustain above 20 mph, running a 28c tire vs a 38c will save you 20 watts, which is noticeable.
>Then bytul vs latex vs tpu tubes.
This matters extremely little for most people. Maybe like 4 watts at most. For racing, when you are optimizing everything, its worth it, but generally tubes matter way less then tire selection. That being said, there really isn't any reason not to run TPU tubes because they are a lot more pliable and puncture resistant.
Generally asking bike industry to do actual engineering is an impossible task, but for optimal design there is no reason why even road bikes should not have suspension that doesn't rely on tire compliance. You can do carbon leaf springs with very small dampers. The best we get is suspension stems and seatposts, which suck because you still have all that unsprung mass of the entire bike bouncing around.
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.
It's even more difficult with off-road tyres, as it's not really the rubber compound providing the grip.
Also on 2 wheels going fast around corners doesn't only involve grip but confidence. This is partly personal/psychological and partly based on feedback from the tire that comes on how the carcass of the tire deform while you are leaning the bike. It could be that a tire with more grip doesn't give you as much confidence as a tire with less grip on which you are closing in much closer to the limit.
Off the road the grip is so dependent on surface that it is even more difficult. There are tire for dry, mud or mixed surfaces and what you will encounter on the trail might be somewhere in between all of these.
For example if you run an MTB tyre hard it will bounce around on a rocky surface and roll less efficiently than if you run it at lower pressure that allows the tyre to deform and bounce around less.
Interesting site nonetheless and a useful data point to compare tyres in a systematic way.
The only tests which BRR does which are likely applicable to mountain bike tires mounted to mountain bikes ridden on trails are the puncture tests, as you're likely to find sharp objects even on trails. Maybe the wet grip tests matter, if you often encounter wet large rock that you ride on.
"One-time payment, no auto-renewal"
[5 lines further down]
"From $ 0.79 / month"
There's no auto-renewal, you get an email telling you your membership is expiring and asks you to pay again.
What you've posted implies they're lying and they are verifiably not.
They're not lying as such but it's at least accidentally misleading. "It's a subscription" should be up front, then go into how it's prepay and well behaved.
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 <$10 for the lifetime of the buyer (or app if that dies first; there are issues around this sort of pricing, but people are expecting a minimum of several years).
What you appear to be describing would be a pre- payment plan at 80¢/mo.
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 over a bump that is the uncompressed tread the front of the contact patch
The lighter the tire, the less sidewall and puncture material there is, which means that the rebound damping on the tire is going to be less.
Indeed based on your explanation the stiffness of the tread is going to be as much of a cause as anything.
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.
