Numerous experiments were carried out to determine the possible role of bicycles and cycling within military establishments until in 1894 a turning point occurred due to improved resilience of pneumatics and the shorter sturdier construction of the frame. To some extent, bicyclists took over the functions of dragoons, especially as messengers and scouts, substituting for horses in warfare. Bicycle units or detachments were formed at the end of the 19th century by all European armies and the US armed forces.
The United Kingdom employed bicycle troops in militia or territorial units, but not in regular units. In France, several experimental units were created, starting in 1886. They early on tried to adopt folding bicycles. In the United States, the most extensive experimentation on bicycle units was carried out by a 1st Lieutenant Moss, of the 25th United States Infantry (Colored) (an African American infantry regiment with white officers). Using a variety of cycle models, Lt. Moss and his troops carried out extensive bicycle journeys covering between 500 and 1,000 miles (800 to 1,600 km). Late in the 19th century, the United States Army tested the bicycle's suitability for cross-country troop transport. Buffalo Soldiers stationed in Montana rode bicycles across roadless landscapes for hundreds of miles at high speed.
The first known use of the bicycle in combat occurred during the Jameson Raid, in which cyclists carried messages. In the Second Boer War, military cyclists were used primarily as scouts and messengers. One unit patrolled railroad lines on specially constructed tandem bicycles that were fixed to the rails. Several raids were conducted by cycle-mounted infantry on both sides; however, the most famous unit was the Theron se Verkenningskorps (Theron Reconnaissance Corps) or TVK, a Boer unit lead by the scout Daniel Theron, whom British commander Lord Roberts described as "the hardest thorn in the flesh of the British advance." Roberts placed a reward of £1,000 on Theron's head - dead or alive - and dispatched 4,000 soldiers to find and eliminate the TVK.
During World War I, cycle-mounted infantry, scouts, messengers and ambulance carriers were extensively used by all combatants. Italy used bicycles with the Bersaglieri (light infantry units) until the end of the war. German Army Jäger (light infantry) battalions each had a bicycle company (Radfahr-Kompanie) at the outbreak of the war, and additional companies were raised during the war bringing the total to 80 companies, a number of which were formed into eight Radfahr-Bataillonen (bicycle battalions). In its aftermath, the German Army conducted a study on the use of the cycle and published its findings in a report entitled Die Radfahrertruppe.
In its 1937 invasion of China, Japan employed some 50,000 bicycle troops. Early in World War II their southern campaign through Malaya en route to capturing Singapore in 1941 was largely dependent on bicycle-riding soldiers. In both efforts bicycles allowed quiet and flexible transport of thousands of troops who were then able to surprise and confuse the defenders. Bicycles also made few demands on the Japanese war machine, needing neither trucks, nor ships to transport them, nor precious petroleum. Using bicycles, the Japanese troops were able to move faster than the withdrawing Allied Forces, often successfully cutting off their retreat. The speed of Japanese advance have also caught Allied Forces defending the main roads by surprise while attacking them from the rear.
The Finnish Army utilized bicycles extensively during the Continuation War and Lapland War. Bicycles were used as a means of transportation in Jaeger Battalions, divisional Light Detachments and regimental organic Jaeger Companies. Bicycle units spearheaded the advances of 1941 against Soviet Union. Especially successful was the 1st Jaeger Brigade which was reinforced with a tank battalion and an anti-tank battalion, providing rapid movement through limited road network. During winter time these units, like the rest of the infantry, switched to skis.
Within 1942-1944 bicycles were also added to regimental equipment pools. During Summer 1944 battles against Soviet Union bicycles provided quick mobility for reserves and counter-attacks. Finally, in Autumn 1944 bicycle troops of Jaeger Brigade spearheaded Finnish advance through Lapland against Germans, this time tanks had to be left behind due to German destruction of road network.
The hastily assembled German Volksgrenadier divisions had a battalion of bicycle infantry, to have some moble reserve.
Allied use of the bicycle in World War II was limited, but included supplying folding bicycles to paratroopers and to messengers behind friendly lines. The successful British raid on a German radar installation at Ste. Bruneval, France in 1942 was conducted by airborne cycle-commandos with the aid of such folding bikes.
Although seeing heavy use in World War I, bicycles were largely superseded by motorized transport in more modern armies. In the past few decades, however, they have taken on a new life as a "weapon of the people" in guerrilla conflicts and unconventional warfare, where the cycle's ability to carry large, about , loads of supplies at the speed of a pedestrian make it vastly useful for lightly-equipped forces. For extended periods of time, the Viet Cong and North Vietnamese Army used bicycles to ferry supplies down the "Ho Chi Minh Trail", avoiding the repeated attacks of United States and Allied bombing raids. Heavily loaded with supplies such as sacks of rice, these bicycles were seldom rideable. Instead a tender would walk alongside, pushing the bike like a wheelbarrow. With especially bulky cargo, tenders sometimes attached bamboo poles to the bike for tiller-like steering (this method can still be seen practiced in China today). Vietnamese "cargo bikes" were rebuilt in jungle workshops with reinforced frames to carry the heavy loads in all terrain.
There are some reports of the use of mountain bicycles in parachute bike jump tests by the 1st Tactical Studies Group (Airborne) using folding models, as well as combat use by U.S. Special Forces as a scouting vehicle in the War in Afghanistan (2001–present) and in subsequent battles against the Taliban. The LTTE Tamil Tigers make use of bicycle mobility in the fighting in Sri Lanka.
By beginning of WWII, the Swedish army operated six bicycle infantry regiments. They were equipped with domestically produced Swedish military bicycles. Most common was the m/42, an upright, one-speed roadster produced by several large Swedish bicycle manufacturers. These regiments were decommissioned between 1948 and 1952, and the bicycles remained for general use in the Army, or transferred to the Home Guard. Beginning in the 1970s, the Army began to sell these as military surplus. They became very popular as cheap and low-maintenance transportation, especially among students. Responding to its popularity and limited supply, an unrelated company, Kronan, began to produce a modernized version of the m/42 in 1997.