Ok ive used the search button and that just made me more confused.
Im buying a muni (definate) but I dont know what crank size I should use.
I will be doing mainly downhill, some xc. I dont really care about uphill as much I will walk thats fine, so what size crank or what range of crank size should I go for?
Cheers.
You’ve opened a can of worms here. Used to be 165’s or even 170’s would be the standard answer. 150’s seem to be coming in vogue. I do mostly downhill and feel for that the 165’s are just right.
i tihnk your height enters into it as well. i’m a pretty tall guy and 150s always felt a little short, 165s however feel perfect.
I’m assuming you are looking into a 24" muni. Thats what I have, with 165mm cranks. I used to really like the control they gave me. When I rode other people’s munis with shorter cranks I did not like the trade off of extra speed for less control.
I used to be what I would call a technical muni rider, meaning I usually walked up the steep hills and stayed away from any trails longer than a few miles. I got most of my enjoyment from riding down or over challenging terrain. The long cranks are good for this type of riding.
Now I am turning into more of an XC rider. Most of my enjoyment comes from spending a few hours out in the woods (or such) and getting a workout (not saying I don’t love riding an impossible hill every now and then). There are times I wish I had shorter cranks.
Which do you think you will be? For technical riding you’re going to want longer cranks. For XC type riding you will want shorter cranks. Assuming you can’t compromise, try to figure out which type of riding you will do most, and buy accordingly.
I am an XC rider: my life changed when I used a 145 cranks setup.
I go faster on single tracks and even uphill is better (this is probably due to my bad spinning technique) the only thing that was worst was technical downhill
but I am learning to use my brake and I think I will overcome the loss of control.
Now I need to learn very technical things … but I do not know how to jump 
If you are buying a 24" muni, and are in decent shape, I would start with the 150mm cranks. In a few months, and depending how technical you get, you will probably want to go to a 137 or 125 crank.
If you get the new KH24, the Moment cranks are drilled for 125/150, a great muni option for a 24".
If you get a cotterless crankset (like the Nimbus), the cranksa re only around $22US a set, so it’s not too expensive to upgrade later.
Personally, I love the 125/150 combo, and just carry a small pedal wrench with me.
If you want to ride fast and seriously don’t intend to ride uphill much, 150s should be right.
If you want to ride over everything and do intend to eventually get your proper exercise and ride up the hills as well, then go with the 165s.
Each has their plusses and minuses of course. I rode my Wilder with 170s for the first few years and it was great, but a little slow. Now I have shorter cranks on there (I think 145s; whatever Profile makes). I’m much faster on the smooth, but technical downhill is definitely harder!
I think longer cranks (> 150s) are dictated by what you plan to ride down more than what you plan to ride up.
Personally, I stubbornly ride 150s, and I routinely ride up stuff that people walk. Until I meet someone that can ride up something I can’t because they have longer cranks, I refuse to use longer. I started with 165s, and they felt too long for my 31" inseam legs. I think uphill is so much more about technique than having longer cranks.
The important thing about cranks is you can change them. It is not a permanent, once and forever irrevocable decision that you are making.
KH seems to know a thing or two about unicycles, and puts 185s on the KH24. That works for me.
I ride the Holy Roller (26" muni) on 125s, and I sometimes ride fairly tricky off road stuff on a 700x with 114s.
Long cranks take the strain off long descents. Technique is more important on ascents.
Buy standard, and change when you know more about what suits you, your stlye, and your local terrain.
185? Maybe you mean 165, which used to be the standard crank length on the KH Freeride. I think Kris himself runs 150s, which is also what I prefer for most of my riding, although I put on 165s for Moab.
Just double checking the crank length for a KH 24 and UDC USA shows a max.length crank of 165 mm and not 185’s is a 185 length available elsewhere?
165- real nice and controled
150- can go a tiny bit faster, control is still good but don’t feel nice
110- super fast, bails are more often, hills are too hard
I ride 165s on my KH/Duro/DX24/Yuni Muni. I love them for total control everywhere. The speed lacks on big open trails, but is worth it when you get to the technical spots… 
-Tyler
I ride 165s on my KH/Duro/DX24/Yuni Muni. I love them for total control everywhere. The speed lacks on big open trails, but is worth it when you get to the technical spots…
-Tyler 
thats a great way to put it
I agree, but easier w/ 170ish cranks, both in technique and strength, esp. on really steep or technical trials.
I can’t seem to pedal smoothly on my 170’s when the cranks are vertical because my top leg goes too high (and I have long legs- size 34" pant inseem). Strangely just 5 mm. shorter 165’s I tried on tholub’s KH made a huge difference, no hesitation at vertical.
i’m the same as kevin. I’m 5’ 6".
corbin
I think 89mm are the ideal. I can still climb waaay steep hills, roll over anything, plenty of torque and speed. But anything shorter than that you would probably want a brake for the really steep decents.
(Haha, gotcha! 
165’s are my favs for all-around)
Dang man, you gotta quit fooling me like that. Not only did you have me fooled, but I also just placed an order for 89mm ISIS Muni cranks before I read your “gotcha” line. Dang man. Just dang.
Yeah 89’s would be too small for even a coker…at least for me. I’m not a speed demon, which is the only reason I can see for using cranks that short.