When I pedal my 20" Avenir, every time the left pedal comes around and passes streight up something wobbles. I took it to my lbs and they couldn’t find anything wrong with it. Any Ideas?
I was riding down the sidewalk on my learner, a 16" CX w/ long seat post and this guy gets all excited. Turns out he had two unicyles in his garage and he says “You can have them Bro, cause I never use them!” Has anyone ever had this happen to them before? One of them is this 20", the other he says is a 1940’s uni w/ solid rubber tire, and wood pedals.:o
My lbs looked at it and said everything was tight and couldn’t find anything that would wiggle.
It was perfect timing because I was wanting a 20" and couldn’t afford one at the time.
I haven’t got the classic one yet. The 20" took 20 phone calls. Most of my calls were not returned when he said or at all. VERY frustrating getting my hopes up.
Knocking noises and feelings through the pedals, in order of likelihood:
Cranks loose. Sometimes this is detectable when riding, but not when you get off the uni and try to wiggle the crank. Strange but true.
Buy a crank extractor - it is something you will use regularly, and is worth the small investment. Remove the cranks, clean the mating surfaces, then refit the crank carefully, using a 14 mm socket. Ride for a few minutes, then tighten again.
I have never used or needed thread lock glues and that type of stuff.
Next choice: bearing clamps. Even a slight looseness can translate into a rhythmic knocking in time with your pedalling. Tip the uni upside down, and nip the nuts up a bit tighter wth a 10 mm spanner. Don’t overdo it. Make sure that the gaps between the clamps are even (i.e. the clamps are parallel).
Loose pedal. Nip up with a 15 mm spanner. remember that the left side pedal has a left handed thread. Tighten it the opposite way to almost any other thread you have ever tightened.
Pedal bearings - there’s always a bit of play. Too much can be a nuisance. Some pedals are adjustable, some aren’t.
You certainly need to identify the problem as soon as possible. The noise is something loose, moving and contacting something else. It will cause wear.
Any Ideas?
tighten it.
The 20" took 20 phone calls. Most of my calls were not returned when he said or at all. 
VERY frustrating getting my hopes up.