Tire pressure for muni

When I first started riding, I ran everything at maximum pressure. On my 27.5 I actually ran it at 35psi or 5 psi over the maximum. It just seemed to roll easier and turn more easily. Now as I’ve been doing more challenging muni and hopping more and doing drops of 8" or so I’ve been experimenting with lower pressures. I currently weigh in at 230 lbs or 105 kg. Tire is a Maxxis High Roller II, 27.5x3.

The lowest I’ve run was 15 psi. At that pressure I found it was difficult to turn and that the unicycle really wanted to roll in a straight line. This was obviously too low for someone of my size and riding ability.

I spent about 2 days riding at 22 psi. I lowered it to this pressure for hopping and found that it bounced well and I didn’t have the steering issues with it. What I did find however was that it no longer climbed as well as it did with a higher pressure and that idling was more difficult. There were climbs on some of the trails I was riding that I had done in the past and simply couldn’t do with less pressure or that took more tries to succeed on.

Currently I’m riding with the pressure at 27 psi. It doesn’t bounce quite as well, but its more agile and I think the agility is what holds me back at the lower pressures. I’m planning on riding it at this for a few days and then trying it at 25 psi.

I actually haven’t found that lower pressure has been much of a benefit in rolling over obstacles.

Anyway, I’m just wondering what others opinions on this are.

For offroad I think you want to run as low as you can get away with - you don’t want the tire to be bottoming out on the rim when you hit something, or fold over when you land a little sideways or on a camber. I do think that lower pressure helps a lot with rolling over smaller bumps, absorbing bigger ones, and adding traction.

I’m 165 lbs and running about 17 psi in my 26x3.0 Dirt Wizard and 16 in my 27.5x3.0 WTB Bridger. So I would expect to run somewhat higher if I were 230 lbs… but not drastically higher.

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Lower pressure does help when rolling over small bumps (like small roots sticking out), on bigger bumps, it doesn’t help much, or might even be a hinderance if it is too bouncy. The lowest pressure that doesn’t give me any issues, whether that is a floaty feeling tire or hitting the rim is my rough guide - but I don’t really care about getting low rolling resistance.

I find it so much of a compromise between different terrain, my speed and my riding style that I don’t even see a point in measuring my tire pressure - I just adjust it to feel for whatever I’m doing on a given day. On any given ride there will pretty much always be a point where I’d want more or less. Even on the same trail, one day I might feel great and go fast (which tends to require more pressure), then on another day I may be tired and ride slow (where a bit softer of a tire is nice).

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Pretty much the same with me. I’ve never measured and always go based on feel of the ride. I’d usually have the tire deflated a bit (for the roots/rocks), however there was a point when I forgot to deflate after doing some road riding and I found the extra air did help maintain my speed through the trail and made free mounting easier.

Free mounting is one area where I didn’t notice tire pressure made a difference.

A heavy, thick sidewall tire will have a larger range of acceptable pressure. A thinner, lighter tire is more likely to have a pressure “sweet spot”.

My rides are mixed, so tire pressure for me reflects what works best in a variety of situations. I pump up my tire before my ride, then I don’t fiddle with it any more.

My pump has a pressure gauge, and I use it. I pump my 2.1" Schwalbe Smart Sam to 38 psi. It is a lighter tire with a “sweet spot”. It’s harder to gauge pressure “by feel”, IMO, when the pressure is higher, so I’m sticking with the pressure gauge.

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I have always run my tyre pressures quite high: 40 psi or more. I tend to roll rather than bounce, and I pick my route between obstacles, doing very few "hops and drops’. I have tried lower pressures but always found the steering sensation unpleasant. Then again, at 58 years old and with a heavy old KH24, there’s a limit to how much effort I can put into trying to hop over things.

I’m wondering how much of the camber and steering issues I’ve noticed at lower pressure are due to that. I don’t notice it as much on my 36er or trials uni, but then again on the 36er its a narrower higher pressure tire and turning is kind of sluggish just due to what it is and the trials uni should have a smaller contact patch due to the curvature of the tire.

When it comes to optimum tire pressure, the answer is not a number. That is, it’s not an interchangeable number. It depends on rider weight, tire volume (width), terrain and rider’s level of aggressiveness. At the low end, if you ever feel your rim hitting things, you’re definitely too low. If your tire rides like a rock (on rough terrain) it’s probably too much. It will take some practice to find that “sweet spot”.

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Normally wirh mountainbiking people tend to go as low as possible. Somewhere between 17-23psi is common. For your weight you’d probably be closer to the 23 psi unless using a tire insert.
The speed on an mtb lies higher and most of the times your weight is divided (not equally) between the two tires, and the tires are usually less heavy.
Also the way you hop onto things is different, as well as the forces on the tire during regular riding.

I’ve found that the Maxxis High Roller II (27.5x3.0) performs pretty well throughout the whole accepted range (I weigh around 200lbs), but doing a local xc trail here (lots of loose sand) I’m running it at 20psi.
If I ride it on the road with lots of hops and sharp edges, I run it at 30psi.

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Here’s something for you to play around with – the “Schwalbe MTB Pressure Prof”:

https://www.schwalbe.com/pressureprof/

There you can see what tyre pressure an experienced tyre manufacturer recommends considering a large number of variables such as tyre type, tube or not, riding style etc.

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But it is based on 2 wheel riders…

Greetings!
I started unicycling two months ago and after few weeks I bought second hand KH24. I have been training muni on flat trails and some basics of trial riding. My weight is 90kg/200lbs and I have found 1bar/15psi great for general riding (Duro Wildlife Leopard tyre). Even less, like 12psi is great on how it swallows roots and rocks, but it gets too bouncy on bigger obstacles. My longest road ride has been 17km and I did that too on 1bar pressure. Last few days I have been trying to learn jumping/dropping stuff, and I have found out that 1bar is probably far too little for any bigger jumps. Or at least it will eventually kill the inner tube. On my mountain bike/fatbike I have been running tubeless for years, so I have been considering setting up tubeless for my KH24 too. I’m pretty sure I’ll have to rise tire pressures as well at some point, but for meantime setting up tubeless could give some peace of mind for riding out there without spare tube or tools with me :smiley:

I’m liking around 25psi~1.7bar these days for general riding. A little less makes it bouncier and nicer for hopping, but also seems to make it less agile and harder to steer. I actually haven’t noticed lower pressure making it easier to roll over things. What I’ve found is that to roll over things my weight has to be on the pedals rather than on the saddle and that if I do that it doesn’t matter whether I have 1 or 2 bar in the tire.

I agree 100% . When people ask me: what pressure do you ride? I respond: whatever feels right.

Experiment with different pressures by feel. Once you find what works for you and your tire/wheel/tube/terrain combo, only THEN measure the pressure with an air gauge or pump. Once you have that number it becomes easy to re-inflate after the tube loses air or you get a flat. Gotta use the same gauge/pump though as there can be slight variations.