The ideal tire pressure for muni depends on a lot of different factors. It depends on rider weight, stiffness of the tire, what tire you’re using, how new the tire is, what tube you’re using, what rim you’re using, your riding style, the terrain on the trail, how rocky and rooty the trail is, and other factors. There is no set rule for tire pressure that will hold for everyone for every situation.
I typically ride with something between 16 psi and 22 psi. It all depends on the trail and whether I remember to check the pressure before the ride.
The basic concern is that you want enough air in the tire to keep from getting pinch flats. You also want enough air in the tire so the tire doesn’t fold over when doing side hops or when pecking up a hill.
Here’s a set of guidelines or a heuristic to help in determining ideal tire pressure. This is a list that I posted back in 2000 and has been copied to the tips section of Muniac Manor
Ride right into a root or a similar obstacle. Don’t try to hop over it, just ride right into it and try to roll over it. If the wheel bounces back instead of rolling over the root consider lowering the tire pressure. If you lose traction on the root consider lowering the tire pressure.
Side hop up a hill. If the tire folds over increase the tire pressure. Wider rims also help prevent the tire from folding over. Tires with stiffer sidewalls (like the Intense DH tires) are less likely to fold over than tires with softer sidewalls.
Hop and jump on a log or similar obstacle perpendicular to its length (the length of the log will be to your left and right). Pick a log that is about 6" or less in diameter. A parking lot divider will also work. If the tire bottoms out then increase the tire pressure.
If you get pitched off the MUni during a ride because the tire bounced backwards (or upwards) after hitting an obstacle instead of rolling over the obstacle consider lowering the tire pressure.
If you are going to be riding on fire roads or other similar “easy” trails consider increasing the tire pressure to decrease rolling resistance.
If you lose traction during a ride consider lowering the tire pressure.
If you ever get a pinch flat consider increasing the tire pressure. Also look for a thicker tube like the Intense DH tubes.
In the end it all depends on the rider, the terrain, and the style of riding. The pressure that works for me may not be the pressure that works for you.
gb4 is in iowa and does pretty freaking awesome work. gb4mfg.com i think.
also i’m 180, and i run between 15-20 psi for off road on a 24x2.6 gazz. I generally put some air in if i fold the tube or “bottom out” on a drop/obstacle. Oddly enough the pushing down right before a big jump is usually where the tire squishes the most and if i hit the rim there i know i’m a few pounds too light.
On Tue, 9 Nov 2004 19:28:06 -0600, “onetrack” wrote:
>You should write a book.
The collected wisdom stored in past rsu messages constitutes at least
one good book, probably many good books. If such book(s) were
compiled, JC would appear to be a major author of it, probably topping
Kudos to the knowledge of JC and his continued willingness to share!
Klaas Bil - Newsgroup Addict
I figure it’s pretty clear that offroad unicycling is a stupid thing to do - joemarshall
That post was quick and easy. It was just a cut and paste job from Muniac Manor.
I’m not the best one to write a book. I’d be more interested in reading a book or watching a How To video by Kris Holm than reading a book by me. Kris has so much more to offer in terms of knowledge than I do. Kris can cover everything from the history of muni and trials, to technique, maintenance, and the nitty gritty of equipment development and the evolution of equipment.
If I do anything I should consider working on a FAQ, but then I’d have to take time off from reading the group so I’d have time to do it. And I also dislike writing formal documents. It’s much easier to write a post here than to write something more formal like a FAQ.
Aside from what others have so far said, I learned this from riding and carefuly watching others ride on the rocky terrain up in Santa Barbara.
After fiddling with tire pressure for quite a while, I now try and keep the highest pressure I can and still roll over all the rocks and stick onto oblique surfaces on hops. The reason is that a real mushy tire basically turns your Mnui into a straight line rig, and dexterity and turning ability is key on some single tracks, especially those littered with rocks. When watching others, at least half the upd’s are bacause someone couldn’t pull a quick turn or weave through stuff (you can’t hop over everything) because the Muni was so unresponsive owing to a super low tire pressure.
I spent an hour on a long stair set sarting with a super high tire pressure and kept lowering it till I could ride without jaring my bones and at 210 pounds, that was about 23 lbs. A little rougher ride, but much more dexterity.
What tire(s) are people using there in Santa Barbara? The Duro tire has a different profile than the 24" Gazz. The 26" Gazz has a different tread than the 24" Gazz. All tires are different.
I’ve found the 24" Gazz to be plenty maneuverable. I’ve also got a unicycle with the 26x3 Gazz and I found that tire to be a straight line rig – It doesn’t like to turn at all. I haven’t tried the Duro tire or any other 3" wide tire to offer other comparisons. The profile of the Duro tire looks like it would be good for maneuverability even when soft and mushy, but I haven’t actually tried it so I could be wrong.
Hope you all don’t mind if I go a wee bit astray here: How do you choose best wheelsize for muni? Beside the fact that a 26" rim will roll a little longer on each revolution than a 24" and a 26" rim (perhaps) gives you a greater variety of tyres to choose from – what other factors rule when you decide which wheelsize to use? I would expect a 26" with a 3" Gazza to be pretty heavy for hopping, and also quite doughy to idle with, especially when deflated to the pressures we are talking about here. Or?
Virtually everyone in Santa Barbara runs a 24 Gaz, though Hans has a 26 inch Muni that he sometimes rides (also with a Gaz). I have never tried the Duro, nor the 24 X 2.8 “Roller” made by Specialized, so can’t coment on either of those tires.
I think this Muni tire pressure question is pretty open ended, and so full of variables that no “answer” fits all situations. My perspective is totally drawn from the rock strewn single tracks up in SB. I actually live in Venice, Ca, and drive up to SB on weekends. Local single tracks here are steep dirt, and I run super high pressure on these to remain nimble enough to dodge ruts that drop to Shanghai.