You might be referring to a wheelie or a stoppie
ell.stackexchange.com/users/26439/Peter
This trick is called a wheelie : A trick or manoeuvre whereby a bicycle or motorcycle is ridden for a short distance with the front wheel raised off the ground.
Example: A boy cavorted around on a dirt bike doing wheelies .
Here's a picture of a motorcyclist performing a wheelie: And riding on the front wheel, apart from being called a stoppie , can also be referred to as a nose wheelie .
This was suggested by the user Matt Menzenski in the comments section.
ell.stackexchange.com/users/6450/Michael Rybkin
Noun:
wheelie: the only term I use wheely: An alternate spelling according to Wiktionary wheelstand: A synonym according to Wiktionary.
mono: Listed on Wiktionary as UK and Australian slang.
For a verb or a verb phrase: pop a wheelie: the only version I use wheelie:
according to Wiktionary do a wheelie:
according to users wheelstand:
according to Wiktionary.
perform a wheelie: seen on the Wikipedia page You can also use the verb phrase in the plural if you're doing the stunt multiple times.
Wiktionary lists these nouns for a wheelie on the front wheel endo stoppie nose wheelie: I'm guessing on the meaning of this one based on an image search.
Example sentences from various parts of Wiktionary:
I learned how to let the clutch out slo-ow-ly
so my tractor wouldn't pop a wheely and go hauling over backward.
Jim fell off his bike when he was trying to do a wheelie.
Popping wheelies with your bike was really cool as a kid.
You can also feather the clutch to keep from wheelying over, as wel as using throttle control.
The other possible problem with uphill, downhill and crested roads is that bikes tend to wheelie over them.
I'd recommend reading the Wikipedia page, too, because that shows a whole vocabulary of technical distinctions that I never imagined.
Most fun you can have on your computer.
ell.stackexchange.com/users/81926/Jetpack
In addition to the various terms already given, mountain bikers refer to this as a manual (see, e.g., British Cycling , REI , Red Bull ).
"Manual" can also be used as a verb.
ell.stackexchange.com/users/4468/David Richerby
The person is doing a "Wheelie"
ell.stackexchange.com/users/81669/The_Flin
Perhaps out of date, but: Doing a mono , or Mono-
ing Mono being a prefix
meaning "one" or "single", eg monopod - a camera support having just one foot (mono=one pod=foot) - c.f. a tripod
ell.stackexchange.com/users/20194/Bohemian
In Australia you are 'doing (or pulling) a mono'.
Interestingly, the meaning of 'wheelie' now depends on whether you are on a bike or in a car.
It used to be that if you got the front end of a car in the air it was a 'wheelie' (short for wheel stand), but this required tremendous amounts of power. '
Wheelie' eventually came to mean spinning the rear wheels-
something much tamer.
On a bicycle, however, you can still do a legitimate, old-style wheelie, or mono.
ell.stackexchange.com/users/81985/Areel Xocha
When talking about the trick in BMX for example: Manual , a bicycle technique similar to a wheelie, but without the use of pedal torque . https://en.wikipedia.org/wiki/Manual
ell.stackexchange.com/users/716/Viktor Mellgren
What do we call it when someone rides a bicycle or a motorcycle and suddenly  stands on only one wheel  (usually on the back wheel) for a short period?
A word or a phrase for "riding a bicycle on only one wheel"
ell.stackexchange.com
<word-request><phrase-request>
ell.stackexchange.com/questions/179167
ell.stackexchange.com/users/48965/helen
This is known as a wheelie or a stoppie. This can be called a wheelie/wheely, but less common terms are 'wheelstand' or 'stoppie'.
This can be called a wheelie/wheely, but less common terms are 'wheelstand' or 'stoppie'.