I can regularly out-coast me riding partners. My bike is titanium, but about the same weight as my friends' bikes. There's no explaining it except for one thing - my Ultegra rim brakes don't have any drag at all. My friends' fancy bikes all have discs. I suspect that even a small, almost undetectable disc drag might be enough to account for what is a pretty significant difference at the end of a moderate 1/2 mile downhill.
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#1006.1Editing a commentAdd increased wind resistance with disc brakes? -
Hadn't thought of that. Perhaps. What do they say about "incremental gains?" -
• At High Speeds (45–55+ km/h / ~28–34+ mph): Wind-tunnel tests (such as those by Quintana Roo) show that rim brakes can have an aerodynamic advantage of roughly 3 to 7 watts.
• At Realistic Speeds (25–35 km/h / ~16–22 mph): The difference shrinks dramatically to just 1 to 1.5 watts, which is negligible for most everyday and recreational riders.
So coasting downhill at 30 to 40 mph, rim brakes would give you an advantage. Even more at higher speeds.
https://quintanarootri.com/blogs/new...riathlon-bikes
Overall, the rider presents the biggest aerodynamic factor. How you sit on the bike can make a big difference, obviously.
My own tests of rolling distance while coasting indicate that even the slightest wind can make a significant measurable difference.Last edited by wildbears; 3 weeks ago.
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Bears, I have been busy and traveling a lot lately. We have done some more coasting tests among friends. I will talk about it when I get a chance in a few days.Comment
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IMPORTANT UPDATE
FLASHING VERSUS STEADY LIGHTING AND WHY YOU SHOULD USE BOTH!Originally posted by wildbears View Post
A flashing light is significantly worse for triggering target fixation than a steady light. BUT....
While both types of light can draw a person’s gaze, flashing or blinking lights pose a much higher risk for a few key neurological and behavioral reasons:
Why Flashing Lights Are Worse- Disrupts Depth Perception: A flashing light makes it incredibly difficult for an approaching driver or rider to accurately judge distance and closing speed. Because the visual stimulus keeps disappearing and reappearing, the brain struggles to calculate exactly how fast it is approaching the target.
- The "Moth-to-Flame" Effect: Blinking lights naturally command a higher level of involuntary visual attention. Under stress, fatigue, or intoxication, a driver's brain can experience highway hypnosis. They unconsciously lock onto the flashing hazard, and because the human body naturally steers where the eyes are looking, they drift straight toward the light.
- Longer Eye Fixation: Studies tracked by the National Surface Transportation Safety Center for Excellence have shown that flashing hazard lights cause longer durations of eye fixation. This increases the likelihood that a distracted or tired driver will inadvertently steer out of their lane and strike a roadside vehicle or cyclist.
This creates a classic safety paradox:- Flashing lights are much better at confronting a driver and getting them to notice an object from a long distance.
- Steady lights are much better at helping a driver navigate around that object safely once they know it is there.
If you are looking to optimize a specific lighting setup or manage driving risks, let me know:- Are you looking at this from the perspective of a cyclist/motorcyclist setting up your own gear?
- Is this regarding emergency/roadside vehicle safety?
- Are you trying to train yourself on how to break target fixation while driving or riding?
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80's versus Now, Steel Bike Predicted Longevity, An AI Overview
A high-quality steel bike frame still has an infinite fatigue life and can last a lifetime; what has changed is not the inherent durability of steel itself, but rather ultra-thin tube engineering, rapid component obsolescence, and the fragile nature of high-gear-count modern drivetrains.
While a well-maintained vintage 1980s steel frame was virtually indestructible, a complex mix of engineering philosophies, consumer behavior, and modern standards has changed how long a bike remains on the road.
1. The Fatigue Limit and Wall Thickness- Vintage Over-Engineering: Steel has a physical property known as a fatigue limit. If the stress applied to the material remains below a specific threshold, it can endure infinite stress cycles without failing. 1980s steel frames (using tubing like Reynolds 531) featured thick, heavy walls that stayed safely below this threshold under almost any regular riding condition. [1, 2, 3, 4, 5]
- Modern Thin-Walled Alloys: To compete with the featherweight status of carbon fiber and aluminum, modern high-end steel tubes (like Reynolds 853 or Columbus Spirit) are engineered to be incredibly thin. While these advanced alloys are incredibly strong, their ultra-thin walls get much closer to their structural fatigue limits, making them more vulnerable to dings, deep dents, and internal rust perforation if neglected
A bike frame rarely gets retired because the metal fails; it gets retired because you can no longer buy components that fit it.- 1980s Standardization: Vintage bikes relied on universal, mechanical standards that persisted for decades: threaded bottom brackets, 1-inch threaded headsets, rim brakes, and friction shifters that could pull any cable. You can still easily find parts to keep a 1985 steel touring bike functional today.
- Modern Fragmented Standards: Modern bikes are built around rapidly shifting proprietary standards: press-fit or specialized threaded bottom brackets, varying thru-axle spacings, flat-mount disc brakes, integrated internal cable routing, and electronic groupsets. A modern frame ridden for 20,000 miles over a decade may become completely unserviceable simply because a manufacturer stops producing a proprietary headset clone or electronic wiring loom.
- Beefy 5/6-Speeds vs. Ultra-Thin 12-Speeds: An 80s drivetrain featured thick, wide chains running over 5 or 6 rear cogs. These chains took a massive amount of abuse and stretched very slowly.
- High Maintenance Cycles: Modern drivetrains compress 11, 12, or 13 gears into the exact same hub space. The chains and cog teeth are razor-thin, meaning a modern chain can stretch out in as little as 1,500 to 3,000 miles. If a rider does not rigorously replace chains, the entire drivetrain quickly wears out, leading to the perception that the bike as a whole has a short shelf-life. [1, 2, 3]
- Lugs vs. TIG Welding: Many iconic 1980s frames were joined using low-temperature brass or silver brazing inside reinforcing steel sleeves called lugs. This distributed stress away from the tube ends and preserved the steel's internal grain structure.
- Most modern mass-market steel bikes are TIG-welded. While modern TIG welding is incredibly efficient and strong, it subjects the raw tube ends to intense localized heat, creating a distinct "Heat Affected Zone" (HAZ) right next to the weld joints where fractures are more likely to develop under extreme stress cycles over time.
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