Can anyone recommend serious science and engineering sources on bicycles? I've looked hard and only found a couple: * Bicycling Science by David Gordon Wilson: Book by MIT mechanical engineering professor, going back four editions to the 1970s. https://mitpress.mit.edu/books/bicycling-science-fourth-edit... * "Bicycle Technology" by SS Wilson in Scientific American (Mar 1973): Great starting point on the technology a…
I don't have a reference, but I feel it's important to find something as recent as possible. Bike geometries, MTB bike geometries in particular, have changed in the last 10 years. And full suspension became mainstream.
Cheap tires are slower. Reliable tires are slower. It's obvious from the pictures that the fatties they're testing are special, with paper thin skinwalls. I can totally see that a high performance fattie would be just as good as a high performance narrow tire. It's the inelastic deformation of the tire casing (and inner tube) that eats power. Unfortunately thin-walled high performance tires are also delicate. I've se…
The Rene Herse tires are just branding on tires he has made for him by Panaracer. They used to be called Compass Tires till he made a deal with the Rene Herse estate to use the Herse name for branding. He basically asks Panaracer to make everything thinner & lighter and delete flat protection, reduce the tread thickness, etc.. They are fast & potentially comfortable tires for their size due to being made as very racy…
This is valuable context.
Yet, some high profile riders such as Ted King (possible the top gravel racer) and Lael Wilcox (ultra endurance racing and bikepacking) use these tires with success. If someone is getting a lot of flats using the Extralight casing, they should consider the Endurance or Ultra Endurance casings and/or setting up tubeless.
But even Jan will recommend the Panaracer Gravelkings when necessary, especially off-road[0].
It's not about drag or friction, it's about weight. Wider tires are heavier. Which is a big no no in professional cycling where every milligram counts.
The article mentions this, and concludes that the weight doesn't matter as much as people seem to believe: > Wider tires are a little heavier than narrow ones. The difference is smaller than many cyclists imagine – the air inside a wide tire doesn’t add weight – but a wide tire has a little more rubber and casing. Won’t this make the wider tires harder to accelerate? The answer is “No.” > The reason is simple: Bicycl…
Ah when I mentioned professional cycling I actually was specifically thinking about mountain climbing. I don't follow cycling much except the Tour. The article didn't mention anything about the climbers, they only mention flat road physics.
That’s the first order effects, however substances deform under pressure which is just one of many complexities involved. For car tires on dry pavement you get maximum grip from racing slicks. Unfortunately they need to swap in the rain.
I might be missing something here but I believe slick tire compounds are geared toward longevity at the expense of lower grip. Unless you are referring to racing tires in general which are grippier than their street equivalents.
Slick tyres are not suitable for use on common road vehicles, which must be able to operate in all weather conditions. They are used in auto racing where competitors can choose different tyres based on the weather conditions and can often change tyres during a race. Slick tyres provide far more traction than grooved tyres on dry roads, due to their greater contact area but typically have far less traction than grooved tyres under wet conditions. Wet roads severely diminish the traction because of aquaplaning due to water trapped between the tyre contact area and the road surface. Grooved tyres are designed to remove water from the contact area through the grooves, thereby maintaining traction even in wet conditions.
That list is looking suspiciously void of brakes that would have trouble fitting a 28 mm tire. Yes, disc brakes can be very good, but the gap is much smaller than must people would expect.
Heh, I've had my fair share that would hit the limit in the 25-28mm. In particular the shimano SLR/dual action/dual lever or whatever they are called. I don't agree with the "gap is much smaller than people would expect". Have you tried a decent hydraulic brake? I raced on and off road, was a bike messenger, designed and built (from tubes) a mtb frame, and bike commuted nearly every workday of my life. Disc brakes ha…
Heh, I don't doubt that they are powerful and I sure won't bend over backwards to still get rim brakes next time I want/need a bike, but the "want" isn't exactly strengthened by the switch. And yes, even aluminium wheels aren't really a joy decelerating in the rain (and yes, I've been to that group ride where one guy could show off his nice new aero carbon toy while my nice new aero carbon toy had to stay at home because for a dozen hours of mostly rain as a rim rider your choice will definitely fall on the one with the aluminium wheels. I guess I just can't warm up to the idea of front wheels with twentysomething spokes. It's confusing enough already that carbon front wheels (for rim) almost universally come with 18 instead of 16, what's up with that?
I might be missing something here but I believe slick tire compounds are geared toward longevity at the expense of lower grip. Unless you are referring to racing tires in general which are grippier than their street equivalents.
Racing slicks are a type of flat tire designed for maximizing grip in dry conditions. https://en.wikipedia.org/wiki/Racing_slick Slick tyres are not suitable for use on common road vehicles, which must be able to operate in all weather conditions. They are used in auto racing where competitors can choose different tyres based on the weather conditions and can often change tyres during a race. Slick tyres provide far…
Ah, so that terminology refers to the absence of tread. Thanks for the link.
> Anecdotally my gravel bike is faster with 28 mm slick tires than with 42 mm sawtooth tires. Out of curiosity, do you know this to be true, or believe this to be true? I ask because the perception of speed with skinnier tires is one of the things the article touches on. I felt similarly when I put GP5000 28mm slicks on the gravel bike, but when I looked at my ride history, I couldn’t really back that feeling of spee…
My experience is the same as yours. When I rode the same regular routes on my gravel bike on slick 38s vs my road bike on slick 25s (up from 23s, as big as I could fit!), the road bike felt faster but GPS data didn't really back it up over the course of a whole ride. The road bike is a bit more nimble with twitchier handling sure, but the more jarring ride of the skinny tires gives the illusion of speed. But in the r…
You also want to measure the amount of power you're inputting.
Could be the same speed, but you need to peddle harder to maintain it
Heh, I've had my fair share that would hit the limit in the 25-28mm. In particular the shimano SLR/dual action/dual lever or whatever they are called. I don't agree with the "gap is much smaller than people would expect". Have you tried a decent hydraulic brake? I raced on and off road, was a bike messenger, designed and built (from tubes) a mtb frame, and bike commuted nearly every workday of my life. Disc brakes ha…
Heh, I don't doubt that they are powerful and I sure won't bend over backwards to still get rim brakes next time I want/need a bike, but the "want" isn't exactly strengthened by the switch. And yes, even aluminium wheels aren't really a joy decelerating in the rain (and yes, I've been to that group ride where one guy could show off his nice new aero carbon toy while my nice new aero carbon toy had to stay at home bec…
Er, not sure on the spokes. Why not use 18? Is 16 better somehow? I'm over 200 pounds and am hard on wheels, I've been pretty happy with Santa Cruz carbons, which in the road flavor are 24 spokes.
> One extra MPH means a lot when you’re doing a multiple hour ride at an average of 10-15MPH. Why spend your effort on optimizing your bike performance by 8% if you can instead simply shorten the distance by 8%?
Recreational riding is about going places. You could shorten your distance to zero by not leaving the house at all, but that's missing the point. I like to go places, and the further I can go on the same amount of energy the better.
1) You may "go places" by driving your car (that goes 50mph) closer to your target place. Then use your "unoptimized" bike to reach your target at shorter distance.
2) "shorten your distance to zero" is too extreme, because we need some physical exercise and want some enjoyable experience.
> One extra MPH means a lot when you’re doing a multiple hour ride at an average of 10-15MPH. Why spend your effort on optimizing your bike performance by 8% if you can instead simply shorten the distance by 8%?
How exactly do you shorten trails, or race courses?