Recumbent Glossary of Terms and Definitions

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Glossary

Long wheelbase, short wheelbase, idler, tiller, tadpole, boom... If all of those made sense to you, you can leave now.

But if any of them caused you to furrow your brow, welcome to the RBR Recumbent Glossary! You'll find all those terms and more with their definitions below. Look to the right of each definition for visual representations of most of the terms.

A-G

ASS: Above Seat Steering. Also worst abbreviation in the recumbent world. See also: OSS
Aerobelly: Term of endearment for pudge common among recumbent riders who enjoy too much nutrition at rest stops. The round shape of the abdomen allows for smoother airflow around the body. Or so we claim.
Bar-ends: Lever shifters that mount to the end of grips and often work well for the upright orientation of under seat steering.
Bent: Shortened form of "recumbent".
Body Sock: Cloth fairing used most commonly with long wheel base recumbents. Provides aerodynamic advantage as well as a layer of insulation during colder rides.
Boom: Length of frame tube that holds the bottom bracket and is nested within the main frame of a bike or trike. Often allows for adjustment of x-seam length by sliding the boom in or out of the frame tube.
CLWB: Compact Long Wheel Base. Configuration in which pedals are closer to being directly above the front wheel. Also called Medium Wheel Base.
Cross Member: The length of frame tube on a tadpole trike to which the front wheels are connected. So named because it crosses the main frame tube.
Delta: Trike configuration with two wheels in the rear and one wheel in front.
DF: Diamond Frame. Refers to the diamond shape of the frames of typical upright bikes. See also: Wedgie
Direct steer: Steering system in which the handlebar is directly connected to the steering pivot point. This also applies to trike configurations that essentially have two direct steering arms that are joined by a tie rod.
Fairing: An attachment for reducing wind resistance.
FOG: Fat Old Guy. The stereotypical recumbent demographic, derived from the thought that recumbents appeal most to older gentlemen who may have perhaps let themselves go a bit. See also: aerobelly
FWD: Front Wheel Drive. Transmission system that drives power to the front wheel of a bike, reducing the length and complexity of the chain run.
Grip Shift: Shifting system that incorporates shifters into the handlebar grips. Requires twisting the base of the grips around an axis to shift gears. Also generically called twist shift.

H-N

Hamster bars: Steering grips common on low racers that place the hands close together over the chest. Name is derived from the similarity between the hand/arm position and the image of a hamster sitting with its paws at its chest.
Heel strike: When the heel of the foot strikes the front wheel of a short wheelbase bike during tight turns.
High racer: A short wheelbase bike with 26" or greater wheels both front and back.
Hot spot: Sensation of burning, numbness, or pain in the feet that results from a number of possible factors. Common causes are too high of a bottom bracket, too tight a pair of shoes, or too much flex in the shoe sole.
HPV: Human Powered Vehicle. Any vehicle propelled by human exertion, even when assisted via electric systems.
Idler: Pulley that provides a path for chain travel and, in some configurations, provides tension.
Indirect Steer: Steering system that connects the handlebars to the steering system via a linkage of some sort.
Leg Suck: Phenomenon in which the foot and leg are pulled back under the seat unexpectedly when a rider drops a foot to the ground while the bike is still in motion. Especially common on tadpole trikes due to the low seat height.
LWB: Long Wheel Base. Bike in which the pedals are placed far behind the front wheel.
Low Racer: A short wheelbase bike that is low to the ground and places the rider in an extreme recumbent position.
Mashing: Pushing hard against the pedals and providing only a power stroke. See also: Spinning

O-U

OSS: Over Seat Steering. Steering mechanism is above seat level, though not necessarily directly over the seat.
Pedal Steer: A slight side-to-side motion caused by pedals that are placed far to the front of a bike or trike. Most commonly seen on short wheelbase bikes and tadpole trikes. Also associated with mashing.
Rubberbanding: The expansion/contraction of a recumbent riding group as they climb, crest, and descend hills.
Recumbent: Bike / trike on which the rider rests in a mostly reclined position wherein the upper to lower back is supported and the feet are placed forward.
Recumbent Butt: Pain or discomfort felt by some, usually on more upright recumbent seats, in the gluteal muscles.
Recumbrage: Strong reaction of recumbent riders to dismissive comments from those who find bents bizarre or illogical. We have to admit we made this word up. But the scenario is quite real.
Riser: Length of bar that connects the front fork to the handlebars.
RWD: Rear Wheel Drive. Most bikes and trikes follow this setup. It simply means that the chain runs to the rear wheel for power transfer.
RWS: Rear Wheel Steering. Commonly found on the Sidewinder tadpole trike, the rear wheel pivots to provide steering control while the front wheels provide power.
S&S: Coupling system that allows a bike to be broken down for transport and storage. Requires a special wrench and is incredibly handy for tandem tadpole trikes.
Sociable: Tandem bike that seats riders side by side rather than front and back.
Spinning: Applying force to the pedals throughout rotation in order to facilitate smooth pedaling and reducing the fatigue possibly caused by mashing.
Superman: Arm position reminiscent of Superman's forward arm reach while in flight. The position is driven by OSS bars that require nearly full arm extension for reach. "Superman" refers both to the reach and to the style of bars that require it.
SWB: Short Wheel Base. Bike configuration in which the pedals are placed to the front of the front wheel.
Tadpole: Tricycle/trike configuration with two wheels to the front and one wheel to the rear. Named for the head and tail shape of amphibious tadpoles.
Tandem: By strict definition, a bike or trike that allows for two riders. However, tandem is also used when discussing bikes that fit more than two passengers.; Also known as "tiller effect". Common on long wheelbase and low rider bikes, tiller is the movement of the handlebars side to side in order to steer because of their distance back from the turning axis.
Toe: The adjustment of the distance between the front wheels of a tadpole trike, measured from rim to rim at both the front and back of the tire.
Train: The coupling of multiple trikes together to form an ad-hoc tandem. Hase is famous for their 400 trike train. We've had a few of our rally attendees form a much smaller, though no less formidable, version.
Trike: Three wheeled recumbent. Also known as "tricycle".
Tweener bars: Over seat steering handlebar especially common on Bacchetta bikes that places the knees between the grips at the height of the pedal stroke.
USS: Under Seat Steering. Steering mechanism is below seat level, though not necessarily directly under the seat.

V-Z

Velomobile: An enclosed human powered vehicle made for aerodynamics and cycling in a variety of weather conditions.
Wedgie: Disparaging term for either a traditional upright bike or the person that rides one. Refers to the impact of a standard bicycle seat upon the backside of its rider.
Wedjudice: An adverse judgement or opinion formed about recumbents by a wedgie rider without knowledge of the facts
Wheel Flop: The tendency of a wheel to "flop" to one side or another as it begins to turn.
X-seam: Sitting length from the heel of the foot to the small of the back. X-seam is used to determine boom length or seat position on a recumbent to best suit the rider.