I don't think I am alone in suffering some "disappointment" when the wheels from my lovely Harpo trolley first started to fall off.
The trolley IS really good and has lots of PLUS points. But the wheels falling off are a real design flaw. (This is of course a massive understatement on how annoyingly frustrating the wheels are.)
But here is how you can fix the Harpo trolley using just a cheap metal teaspoon.
The design problem is very small... it's the teeth on the metal disc which turn the wrong way round with use, meaning that rod can't go full length into the trolley.
The teeth should be pointing towards the tyre and flush with the wheel - the wheel below is ok
If it looks like this (below) then you need to fix it
Grab a metal teaspoon rather than a screwdriver as you don't want to accidentally break off any of those teeth, you just want to push the ring down and at the same time try to push the teeth so it's going inwards towards the tyre.
BE CAREFUL NOT TO BREAK THOSE TEETH - don't use a small screwdriver - use the teaspoon as it's less likely to cause breakage.
Make sure you pull the rod towards you so that it is extended to it's fullest and carefully push that ring down.
and voila! The pesky wheels go on the trolley first time without any fiddling about.
It's a 10 minute job and saves hours of cursing at your trolley when you try to get it out of the car and the trolley decides to be a pain... and the wheels keep dropping off... and you're trying to get the harp unloaded... and it's raining... and you're annoyed because you spent so much money on this expensive trolley and.....