@Canoeheadted TBH, I quite like my 24’’ for several reasons:
It could also be indicative that your riding could do with lighter pedaling. A bigger wheel is more forgiving if you’re not spinning the pedals lightly - because of the inertia of a heavier wheel+tire+diameter, combined with the lower rpm.
@pierrox Thanks for the hint, I’ll pay attention to this, even though I tought I already did and it felt quite ok.
This does not explain the problems mounting, though, right?
r4nd1nt, I totally get what you’re saying.
Those are all the same reasons I take my KH29 anywhere.
I think pierrox is bang on.
The bigger wheels allow you to stomp more and get away with it. Not so on the smaller wheels.
Especially when coming straight from a larger wheel.
Keep riding lots and this problem becomes less and less.
Of course switching between sizes will expedite this process but even with regular riding, after a while you’ll just get it “right” all the time, no matter what wheel.
You hurt my 24’s feelings when you said that!
If someone were watching the progress of a typical beginner, they might think masochism was what kept them coming back. Anyone who ever learned to unicycle in the first place was successful at delaying gratitude. It seems logical, then, that riders will want to continue learning other skills. Unless they’ve used every bit of patience learning to simply ride.
What is your definition of skills? Riding any wheel size involves learning skills. When riders on this forum refer to skills, I think they are referring to more specific things like idling, backward, one footed, wheel walking, jumping, various tricks, etc. Many of these skills can be done by some riders on larger wheels, but I wonder how many of them learned the skills on larger wheels, rather than on a smaller wheel.
For me I ride my 36" most all the time but occasionally do ride a 24" for learning something new like idling. I’m much better at mounting the 36" then the 24". The difference is so great that I now only do a jump mount on the 24" and most of the time a rolling mount on the 36". The jump is so easy to do and so different from mounting the 36" that the skills do not interfere.
I do occasionally do a jump mount on the 36" but it is very close to the same skill as on the 24", just jump a little higher.
@JimT That’s interesting since it’s the static mount that doesn’t work out anymore and I almost never static mount my 36er. I noticed that the rolling mount also works quite well on the 24 even though it kind of feels like overkill for that wheel size.
Now then I should learn to jump mount and just give up static mounting. 
I found that there is no learning curve for the jump mount. You just have to go for it. It is especially easy if you hold the brake while jumping.
What you are describing is pretty normal. Even for me on some days going from my 26" to my 19" feels weird, and I’ve literally been riding 19/20" unicycles at least once a week for most of my life. Of course, as skill and time on both unis progress, the time needed to adjust will decrease.
Jump mounts are cool, and really easy (I’d argue the easiest mount of them all, if you aren’t scared). I have no desire to do them much though, rolling/static mounts are just more chilled.
Jump mounts are fun switching wheel sizes… when you miss the pedal because you expect it to be in a different place… (please, don’t try to jump mount in the dark, as I learned the hard way)
Sorry epuebloUNIdo, my attempt at humour. 
I would guess that the majority of unicyclist can’t and won’t ever learn idling, backward, one footed, wheel walking, jumping, and various tricks.
I think there are lot of “us” one or two trick ponies that are content just to ride, maybe have a hop or two under our belt, etc… simple stuff.
Getting better at these things by knowing where to throw weight, balance, and power are all (I think) skills to be developed. These are our skills.
Easily done on a larger wheel as well.
Back on topic… I switched up my cranks from 150mm to 127mm on my 36" today.
I had several missed freemounts. 
I’ve had the cranks on 150mm for the season to go easy on my injured knee.
But man it felt good to have that next level of smoothness back.
@slamdance On my 36er I use 150mm and on the other two 145mm. So this can’t be the reason as the difference is very small and I don’t experience the same problems going from 36 to 27.5.
(And before you tell me my cranks are to long: My knees are getting older and it’s not very flat around here. I tried shorter crank lengths but somehow my knees don’t enjoy it… maybe some time when my riding got better I’ll give it another go.)
Today I took my 24’’ to a parking lot to try some idling (getting nowhere of course - I mean regarding my skill improvement. Of course I didn’t expect to literally get anywhere idling… 
). Then I remembered your post and thought I could as well give it a try - and hit the pedals the first time I tried.
So at least on my 24 you were right for me.
The difference in wheel size has an impact on the behavior (as Pierrox said) and so does the torque-to-wheelsize ratio 
Even if on paper you have the same cranks length, you are bossing over the 24 a lot more (and as mentioned before need to adjust your technique accordingly). No surprise here and mostly time will help calibrate for each setup so you no longer think about it.
I am with you on the respect-the-knees front. However, keep in mind that crank lengths can highlight some technical improvements potential (or “improvements needs” depending on how you see it).
Personally, I found a wheel diameter to crank length ratio to work well for me off-road (about 0.5) and no matter the wheel size, it feels almost identical to me to ride if this ratio is respected (I suspect that the torque produced is similar). However, in your case the equivalent to 36@150 may be on the very short side (100mm as back envelope calculation) so it won’t be drop-in magic. But if you have some 125mm cranks in you parts bin, put them on and you may be surprised (with a slick tire it makes for an interesting cruiser around the neighborhood).
You mean on the 24’'? It has dual whole cranks, so I don’t even need to check my parts bin. I don’t remember the shorter length from the top of my head, but I guess it’s close enough to 125mm.
I’m still a bit confused about how to get this number, 0.5. For example, the rough diameter of a 24’’ wheel is 600mm, your suggested crank length is 125mm, which is roughly a ratio of 0.2 which is pretty far from your suggested 0.5. By your suggested ratio I would have to use 350mm cranks on my 27.5er (~700mm diameter).
I am sorry for the confusion. I wanted to keep the previous post short and forgot to go into the details.
Personally, I am using the ratio between the crank length and the wheel radius. You can also find on the forum a huge table created by @saskatchewanian with another formula.
The concept behind the calculation is to put a number behind a setup you like in order to quickly have an idea how to get close to that with another wheelset. As you ride your 36 mostly with 150mm cranks, this was the point of reference I took to calculate that your 24 being 2/3 of a 36, the same ratio for cranks would be 100mm (but that short of cranks require getting used to otherwise the knees will complain big time).
Anyway, give it a try with the other position on you existing cranks and see if it helps you jumping from one to the other with less wobble 
if ridden on good flat roads or paths a 24 with a smoothish tire would be very ridable with 100mm cranks without much risk of knee damage. I think that only really happens when riding really hard up hills and on rough terrain etc.
The formula I used was wheel size in inches x 25.4 / 2 to get radius in mm, then divided by crank length.
There is a whole thread about it here:New concept: Total Gear Ratio
That’s the reason for riding long cranks: Around here there are very few flat roads. Often my only options are uphill, downhill or rough terrain.
The second hole turned out to be exactly 125mm. So I gave it a try and it worked! Thanks for the tipp @Siddhartha_Valmont!