Fragile Speedster / Real Life

• Admiral Sir John Fisher is famous for saying "speed is armor," and was a proponent of battlecruisers, which were warships as heavily armed as a battleship, but with armor no more than that of a cruiser. The resultant trade-off in armor made them faster than the battleships of their day, but in turn made them vulnerable to just about anything better-armed than a cruiser.
  • The most fragile of all were the Courageous-class battlecruisers, also known rather aptly as "large light cruisers". Even faster than most battlecruisers with a top speed of 32 knots, their armor was almost nonexistent (while most battlecruisers had protection on par with an armored cruiser, the Courageous-class were armored like the smaller light cruisers). Having proved to be quite useless in World War I, all three were converted into aircraft carriers.
  • The final nail in the coffin of the battlecruiser was the newer battleship designs that had equivalent (or better) speed, thus rendering the entire concept pointless.
  • Italian World War II warships were designed in a similar way, sacrificing armor for increased speed. As they had seen what had happened to the British battlecruisers, they were designed for a completely different use: cruisers would engage the immediately smaller class of enemy warship of the French fleet, matching their speed to chase them down while using their superior firepower to sink them, while destroyers would use their superior speed to either make hit-and-run attacks on convoys in spite of the escorts or try and torpedo enemy battleships while dodging their counterfire that would have quickly crippled or killed a conventionally armored destroyer anyway (battleships, on the other hand, were well armored, as their main job was still engaging enemy battleships). While theoretically good enough to deal with the French fleet, the more aggressive, versatile and carried-supported Royal Navy was something the Italian Navy could not face.
• Destroyers, up until the end of WWII. Generally the fastest ships utilized in fleet roles, the massive engines needed to propel the ships to such speeds meant modest armament, short range, and absolutely no armor whatsoever. But while high-explosive shells of any caliber would rapidly shred them, destroyers were so fast and maneuvered so wildly that fire control systems of the era simply couldn't cope. The only solution was to blanket the general area in shells and hope something hit. And since destroyers carried torpedoes, they could hurt much larger ships — assuming they survived long enough.
• Cruiser tanks. The "cruiser tank" was a British inter-war innovation: an armored fighting vehicle which would perform the same tasks on land as cruisers at sea, namely scouting, outflanking, harassing the enemy and destroying his logistics. The British went Min-Maxing on tanks: they developed heavy, well-armored but slow infantry tanks and fast, light cruiser tanks. Cruiser tanks were light, fast and had excellent range, but they had paper-thin armor and puny QF 2 lb (40 mm) "peashooter" cannon, which on top of their small caliber lacked any high-explosive rounds at all. They were on their own element on open terrain, such as desert, where they could fully employ their mobility, but suffered horribly at close terrain. In 1943 latest the British noticed their doctrine was flawed, and both were eventually replaced by the main battle tank. The last cruiser tank, Cromwell, is often considered as the prototype for main battle tank.
• Cheetahs. They're the frailest of the big cats and they have to eat quickly because of their inability to defend their kills from other carnivores, but they're the fastest land animal alive. In fact, they're so lightly built that they have difficulty pulling down a prey animal that's standing still, so they use their speed itself as a weapon: they intentionally startle antelopes into running at top speed, overtake them, and trip them.
• Thoroughbreds and Greyhounds. Both are the fastest examples of their species, reaching speeds averaging around 40 mph. Pretty outrageous for a horse or dog. However, that speed is usually accomplished in conjunction with skin like tissue paper and bones like a bird's. Just ask anyone who's owned either of these animals, and they will give you lists of examples of their porcelain-like fragility.
• Most birds tend work like this, discounting flightless species like ostriches and emus. Generally, birds can cover far more distance than any other animal in a given time frame, and many birds of prey are apex predators in their respective habitat. However, most birds have light skeletons with hollow bones to maximize stamina in the air, so they're at a disproportionately high risk for skeletal injury.
• Russian blues, and some other meek breeds of house cats who just want to get along with the world, are lightweight, relatively delicate and ill-suited for the harsh environment outside. As a result, any fight-happy street-smart tomcat would beat the stuffing out of a Russian blue with ease... if it could catch it. They're so fast that the main reason their owners are discouraged from letting them outside isn't that other cats will wallop them — it's that if they feel threatened they'll bolt so quickly they might easily find themselves in unknown territory and might not know how to come back home.
• Skirmishers. Traditionally, these were specialist foot soldiers or horsemen tasked with conducting reconnaissance and disrupting the enemy without being drawn into combat with them, which necessitated a comparatively high degree of mobility and the ability to strike enemy with minimal risk of retaliation. As such, they tended to be lightly armored at best, and operated in smaller groups than most other formations. While such troops were able to move around more freely than otherwise and presented a smaller target to the enemy, it also meant that they tended to be outnumbered and would generally lose a straight fight.
• Arab armies in the Islamic Golden Age. Instead of heavy metal armor, they mostly wore light chainmails or leather armor with aerated clothing, partly due to the harsh climate of the region and that soldiers had to buy their own armors during that period, but mostly because these armies favored a style of fighting based on speed, agility, and stealth, like the central place of cavalery, the popularity of attack-and-retreat tactics even before the Middle Age, and the use of mares instead of stallions, who neighed significantly more, can attest.
• Many super fast cars. Fast yes, but be wary if you crash. Racing cars are extremely delicate and fragile.
  • Even sturdy looking NASCAR stock cars' bodywork can be shredded by a blown out tire — except when it comes to the driver's safety zone. If the car's suspension or engine bay takes a blow, then chances are that the car will be incapacitated and need to be towed off the track. A damaged oil cooler or other subsystem can leave a car undrivable from the risk of engine failure not long after.
  • In Formula One cars the monocoque 'survival cell' is made of stabilized carbon and steel and is basically indestructible, even at ridiculous speeds. In NASCAR and other touring and rally cars the driver is encased in a solid roll cage. Unlike NASCAR where mild contact is expected, the peripheral parts, like suspension or wings, will break if they come into any kind of force acting in the wrong direction. The front wings and suspension especially can withstand huge loads pressing down on them but are so delicate in a forward facing collision that almost every driver had at least once a race ruined because they touched something they shouldn't have touched, like the back of another car. This is partly for performance reasons as lighter cars will be faster, but also for safety as the peripheral parts will dissipate the forces of the impact away from the driver.
    • This applies to just about any open-wheel series, such as IndyCar and Japan's Super Formula series which both follow Formula 1 in some aspects.
  • By contrast any road-legal car (with the exception of some really high-end supercars) going faster than about 80 mph is subject to this trope; no crumple zone or airbag could possible dissipate that amount of energy, and weight considerations (which is why trucks are safer) aren't quite as relevant when you're hitting a solid object, which is usually what happens.
  • The Classic Mini was designed as a very small car before anyone thought of crumple zones; the engineers thus stressed giving the car the best possible handling ability in order to give the driver the tools to avoid crashing under the widest possible range of circumstances.
  • The Caterham R500, it has no doors, no roof, no air bags, practically nothing in the way of any sort of safety features. That said, it has a power to weight ratio of 500 BHP per ton, can out-accelerate a Ferrari Enzo, the fastest road legal Ferrari ever made, and on a track it can beat the Bugatti Veyron, the fastest production car ever made. Because it's essentially an engine strapped to the bare minimum of parts to classify a vehicle as a car it can accelerate like mad and since it's so light a driver can wait until the last conceivable moment to start braking before a turn. Not bad for a car that's barely been changed since 1957.
  • Any racing car designed by Colin Chapman. Drivers who raced his Lotus-cars in their prime said that while they are incredibly fast and light, they are also mobile death traps. Many drivers, sadly, fell victim to his creations. He is still regarded as one of the greatest, if not the greatest, innovator in F1 design though.
  • The 2010 Red Bull cars designed by Adrian Newey. They dominated the latter half of the season but suffered many mechanical failures. Averted in 2011 when the Red Bulls rarely suffered any mechanical failures and their #1 driver Sebastian Vettel dominated the championship.
    • Seemingly returning to this with their 2022 machine; throwing away decent finishes and qualifying places for both Max Verstappen and Sergio Perez because the car's engine kept playing up.
  • Douglas Adams likened driving a Porsche in London to "bringing a Ming vase to a football game."
• Boffer LARP players usually know at least one Skinny Fast Kid. They're usually male, between the age of 16 and 25, and a new enough player that they can't deal or take much damage. Even a low level NPC could take them out, if they could just catch them. If a Skinny Fast Kid decides to play a NPC, beware. There is a story about Russian Tolkien-based yearly LARP, Hobbit Games. One year they had a rule that players without armor have 1 HP, armor with RL protection gives +1 HP, historically accurate (therefore heavy) armor gives more HP bonus. At one point one camp needed to send a messenger to allied camp a few kilometers away through enemy territory. On a hot summer day. The messenger decided to run unarmed and wearing only swimming trunks. Nobody managed to catch him.
• The American-built F-104 Starfighter was a supersonic fighter aircraft that was, among other things, slightly faster than the F-16 Fighting Falcon, cheaper than the F-5E Tiger II, and better armed than the Soviet Su-15 Flagon. It was a Mach 2 capable interceptor, and was a pants-browning terror to fly. It got the apt nickname "The Missile with a Man in it": its high speed, low cost, and moderate firepower came at the expense of protection and the ability to actually control the damned thing in any role other than as an interceptor. It was notoriously easy to damage or crash a Starfighter, even when you weren't trying. Air forces who presses the F-104 into light bomber roles found this out the hard way. Heaven help you when the enemy wanted a turn to actually try. This led to a record of safety issues (most notably, the forward edges of the wings were so thin and razor-sharp that they were actually hurting unwary ground crews) and many less-than-flattering nicknames like "The Widow Maker," "Tent Peg" (Erdnagel), or most evocatively, "The Lawn Dart."
• The MiG-25 "Foxbat" is the fastest armed aircraft ever, with a high flight ceiling and a fairly fast rate of climb as well; all of these characteristics are highly desirable for interceptor aircraft in order to quickly gain height and keep up with high-altitude reconnaissance aircraft and bombers. However, it's practically useless in a dogfight against other fighters, as it has no internal gun and can't turn very quickly. Also qualifies as fragile outside of combat because its engines had to be frequently replaced. It was typically operated no faster than Mach 2.5 — its airspeed indicator was redlined at Mach 2.85 — but it was capable of flying at Mach 3.2. The particular aircraft that was observed at this speed destroyed its engines in flight.
• The American SR-71 Blackbird is an even more extreme example. The fastest manned, air-breathing vehicle ever, but completely unarmed. It leaks fuel like a sieve when it's on the runway — which fuel, by the way, was so exotic it was used as coolant — but it has to as it heats up so much in flight due to the speed that it needs a loose fit to compensate for the expansion. It fits this trope even more once you consider its primary defense from enemy fire — it outran it. With a cruising speed of a little over Mach 3 (about as fast as a bullet and faster than most missiles at the time of its design) and with a service ceiling of roughly 25 km (80,000 feet), it relied on no armor what so ever. Instead of maneuvering or launching a volley of countermeasures to avoid enemy fire, Blackbird pilots instead responded by simply accelerating to a point that no aircraft could catch them, no shell could strike them, and no missile could go fast enough to challenge them. Having an especially low (for the time) radar cross section was just overkill. Of course, being an unarmed strategic scout that was not weighed down by weapons helped — it was built to do nothing but fly fast and take pictures^note The SR-71 was originally designed to launch drones, serving as a launch platform for early UAVs, until it was realized that the SR-71 could go higher than the drones, fly faster, and were much easier to recover., which meant it could specialize in its roles quite well. There could have been an interceptor based on the A-12 (a slightly earlier version of the SR-71). Three prototypes were built and 93 were ordered by the Air Force, unfortunately at the time the Vietnam War ate up so much money that the order was never fulfilled.
• The North American P-51 Mustang used by the American and British air forces in World War II was one of the fastest piston-engined fighters of the war and the longest-ranged with a single engine, but was very vulnerable to enemy fire. Most inline-engined aircraft were relatively frail compared to radial-engined planes (although the Il-2 Sturmovik of flight sim fame was a major exception, earning nicknames like "Concrete Plane" and "Flying Tank") due to their liquid cooling, but the Mustang's radiators and coolant lines were particularly vulnerable, making any hit forward of the cockpit a potential One-Hit Kill.
• The infamous Japanese A6M Zero; early models lacked armor or even self-sealing fuel tanks for the sake of keeping the plane as light as possible. Notably, its main strength was agility rather than top speed; it was actually quite slow by 1943 standards, able to easily outmaneuver American Hellcats and Corsairs in a dogfight, but unable to outrun them and thus very vulnerable to high-speed power dives.
  • This was the standard for Japanese combat air manufacturing up until about 1944: many of their fighters and bombers were pathetically armored even by the standards of the late 1930s when they were designed, but they were generally faster, better armed, more maneuverable, and had better operating range than most of their contemporaries. It was only when the Allies recovered a few downed Japanese aircraft and began designing planes to counter them that things began taking a turn for the worst and losses mounted up. By 1944 Japan did shift towards designing better-defended craft, and a late-war N1K1 "George" or Ki-84 "Frank" could easily match a Hellcat or Corsair in a fight, but by this time most of the Japanese best pilots had been killed and the new planes did not have much effect on the outcome of the war.
• The German Me-163 Komet was a rocket-propelled interceptor aircraft designed to kill bombers and capable of speeds close to the speed of sound. In fact, it was too fast — often zooming by the slow-moving bombers before the pilots could line up a shot. Its frame was made of wood, and its light construction made it very vulnerable to enemy fire, relying almost totally on its blistering speed for defense. There was even a risk of the plane disintegrating on landing, though it was hardly helped by the fact that its landing gear consisted of a single skid. And if by any means the 2-part rocket fuel-oxidiser came into contact it exploded immediately, a problem if it mixed anywhere but the rocket nozzle.
• The British DeHavilland Mosquito was a light bomber designed from the ground up for speed. Built with an all-wooden airframe which was both lightweight and easy to manufacture (many Mosquito parts were made by small furniture or piano manufacturers throughout the UK rather than in specialized plants that were easier targets for air raids) and maintain, it was for a while the fastest aircraft in the RAF, beating out the famous Spitfire fighter in speed trials. It also had no defensive armament whatsoever and its wooden airframe was highly vulnerable to enemy fire. The Mosquito still had lower loss rates than any other RAF bomber in the war (and one of the lowest loss rates of bombers in the entire war, period) simply because it was an extremely hard target to catch. By the time defending fighters could be vectored in to intercept, the "Mossies" would already have finished their bombing runs and be racing back for home. It also excelled at stealthy low-altitude precision raids and as a target-marking "Pathfinder" aircraft for larger bomber formations. Later variants of the Mosquito would be equipped with steadily heavier armaments, culminating in the FB Mk. XVIII model, designed for hunting submarines and light surface ships and equipped with a 57mm autoloading anti-tank cannon, effectively crossing over into another trope altogether.
• Tank destroyers (excepting the M36, which had fairly respectable forward armor), the M18 Hellcat in particular. The Hellcat clocked in at 60mph (97km/h) on road, making it the fastest armored fighting vehicle of the war, used a long-barreled version of the 76mm gun used by the Sherman... and had only 5 to 25 millimeters (0.2 to 1 inch(es)) of armor depending on location. Modern wheeled tank destroyers have the heavy gun of a MBT and superior speed (the slower has a speed of 85 kph (53 mph)), but have paper-thin armor (the Italian B1 Centauro 120 mm and B1 Centauro II, the two with the best armor, can only resist guns up to 40mm caliber, and only from the front arc).
• Motorcycles have a superior power-to-weight ratio compared to automobiles, allowing even an average bike to outclass an exotic sports car in acceleration and, in some cases, top speed. However, they are also considered one of the most unsafe modes of transportation on the road today because of the risk of being easily thrown off by one of the millions of drivers operating 2+ ton cars, trucks, and vans.
• Technicals are made of this trope. Being nothing more than simple pickup trucks with light weaponry (sometimes not even that light; some technicals are large pickups or even flatbed trucks with light tank turrets or howitzers mounted on the back) attached to the back they can't deal or take much damage compared to more heavily armed and armored vehicles. However in comparison they're much quicker and more maneuverable, capable of hitting targets and getting out of the line of fire before the enemy has time to properly respond.
• National Football League players:
  • Quarterback Robert Griffin III is famed for his ability in a "read option" offense, to make quick decisions to throw the ball to a receiver, hand it off to a running back, or run it ahead himself. Unfortunately, he seems ... uniquely prone to injury while being tackled. In 2009, he tore his ACL (a knee ligament) while still in college. In his 2012 rookie season in Washington, he tore his other ACL and his LCL. In 2014, he dislocated his ankle. In a 2015 preseason game, he suffered a concussion. The Redskins signed him because of his speed.
  • Before Robert Griffin, there was Michael Vick. Probably the greatest running quarterback in NFL history (though Lamar Jackson might now be giving him a run for his money), his speed frequently bamboozled defenders, even at age 30. He also finished a full sixteen-game season exactly once in 8 years as a full-time starter.
  • "Burners", in NFL parlance, are Wide Receivers that rely on straight-line speed to make plays, and fit this trope to a T. Players like Cliff Branch, Joey Galloway, or DeSean Jackson would routinely leave defensive backs grasping for air as they waltzed into the end zone. However, this speed tended to come with a lack of size and toughness that left them limited to deep routes, and thus specialized roles in the offense.
• In that other type of football, Liverpool striker Daniel Sturridge is fast, pacy, and great at scoring, but very injury prone.
• The prehistoric marine crocodile Metriorhynchus shows that this trope is Older Than Dirt — unlike most known crocodilians, Metriorhynchus lacked osteoderms (armored scales), having most likely lost them in its evolutionary history to make it a faster and more efficient swimmer. However, this left it more vulnerable to attack, especially seeing as it shared the oceans with 20+ foot long leviathans like Liopleurodon.
• Wayne Gretzky spent his professional career about 20 pounds (9 kg) lighter than the average NHL player. He was also physically the weakest player on the Oilers during his time with the team, only able to bench press 140 lb (63.5 kg). In spite of all that, his speed and skill made him the most accomplished hockey player of all time.
• Paratroopers are technically the fastest-deployed infantry units, jumping from aircraft and usually landing behind enemy lines. This allows them to quickly advance on select objectives. The problem is that paratroopers are only equipped with what they can carry or what they can find once they land, meaning that they have no armor units to ride along with them for protection, and the individual paratrooper is often carrying little more than a carbine, a pistol, and what few pieces of equipment he can place on his person without slowing down. This made paratroopers excellent for rapid-assault strategies such as commando operations or headhunter strikes, but also meant they were very poor at assaulting defensive positions or mustering a defense by themselves.
• Israeli artist Boris Shpeizman invoked this image when he created a motorcycle made entirely of glass (which provides the trope image). When he was young, his mother forbade him from having or riding a motorcycle for being dangerous. When he got older, he built one out of glass to represent childhood dreams, and that sometimes it better to hold a dream than try to make it real because it would not live up to expectations in real life.
• In fencing, there's the concept of the foible: the third of the blade furthest from the hilt. Because it's the furthest, small wrist movements are able to move it faster than the rest of the blade. Consequently, it has the smallest amount of leverage; if an opponent parries a blade by striking it with their own, hitting the foible will push the entire blade a greater distance than if any other part were hit.