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Old 2018-05-10, 02:53 PM   #1
Unitoddo
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Tire Pressure Suggestions

I've read some suggestions that tire pressure should be relatively low. I'm also noticing low tire pressures on some of the videos I've been watching. I'm currently running my tire at 30 psi. I'm wondering if that's too high. I realize that there are several factors that would go into finding the right tire pressure but is there a rule of thumb to go by?
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Old 2018-05-10, 03:32 PM   #2
Strokin99
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I don’t think there is a right answer. Depends on your weight, tire and size, and the terrain. I’m a a big boy ( 230, 5’10) and time ride with 24 lbs in my surly 26x3 tire on single track trails. When I ride the road I go up to about 28lbs I believe you just need to figure it out
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Old 2018-05-10, 03:34 PM   #3
LanceB
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The general rule of thumb is higher pressure for road riding, lower pressure for muni.
Higher pressure has less rolling resistance on hard surfaces, but will dig in (tend to drag) more on dirt. Lower pressure will tend to "float" more on loose surfaces, but be difficult to control on pavement.
Higher pressure off road will also tend to bounce you out of the saddle, whereas lower pressure has less rebound, and it's easier to stay in control over bumpy conditions.
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Old 2018-05-10, 05:35 PM   #4
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I'm 75 kg body weight and run my Monty Pro Race tyre at 38 PSI on my trials bike, that gives me bounce and prevents bashing the rim when landing on sharp edges. My reference here is "the lowest pressure that prevents rim damage when landing on sharp edges". In trials tyres are usually under-inflated compared with road bikes.

For non-trials bikes, my rule of thumb is to check the pressure rating written on the side of the tyre, and inflate the tyre to that value minus a couple PSI, then gradually release air incrementally, testing in between releases, until the vibrations from the road no longer feel uncomfortable. In this case the reference is "the highest pressure that that feels comfortable". You don't want to release too much air because an under-inflated tyres wear faster and require more energy ride. If you are riding indoors on super-smooth floors you probably can get away with higher; on the road you'll probably want a lower value.
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Old 2018-05-14, 04:48 AM   #5
johnfoss
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Quote:
Originally Posted by Scoox View Post
My reference here is "the lowest pressure that prevents rim damage when landing on sharp edges".
The new guy has nailed it. That is the starting point for the "correct" tire pressure. This is not a number, except as applies specifically to you. It is dependent on:
  • Rider weight
  • Tire size and volume (fatness)
  • Type of riding; Road, easy Muni, technical Muni, Trials, etc.
  • Your style of riding; agressive, light, etc.
  • Phase of the Moon
Okay, you can ignore that last one unless you believe in stuff like that. But the above rule, which I usually phrase as "Enough to keep your rim off the ground on drops/bumps" is only the full story if you're doing certain types of riding, generally involving obstacles or bumps. If you want to go faster, or make lots of turns, you're going to want more pressure than that. Racers generally want lots of pressure. For general Road riding, you might want a little more comfort so not so much, etc.

Again, it's not a number you can use for others, unless they are your identical twin and ride the same way you do.
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Old 2018-05-17, 07:40 AM   #6
aracer
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Quote:
Originally Posted by johnfoss View Post
"Enough to keep your rim off the ground on drops/bumps"
I just discovered that's a bit more than I'd thought - have started hopping steps on my muni and found I was grounding on the bigger hops, ending up with a pinch puncture. I have to admit I'm thinking of going tubeless instead of simply adding more pressure, as my previous criteria was enough pressure to prevent the tyre being all floppy and make the handling OK - I don't ground on normal bumps and like having the pressure as low as possible to absorb them, it feels a rather hard now I've added a few psi.

I guess going tubeless is a whole separate topic - though I've been running my MTB tyres tubeless for about 15 years! Did always think I'd switch if I started getting punctures - but after 6 years this is my first one on the muni (strangely I've had a couple on the giraffe).
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Old 2018-05-21, 01:13 AM   #7
Scoox
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To add to my earlier reply, the key to all this is to find your ideal tyre pressure and remember it, this way you don't need to waste time figuring it out all over again each time you change a tyre or repair a flat. For this you will need a pump with a pressure gauge.

The value will be different for different machines (e.g. road vs muni), and the value may change over time as your skills evolve (e.g. bigger drops may require higher pressure). By memorising your ideal value for each of your machines you basically save a lot of time and ensure a consistent feel.

PS: Embarrassingly incorrect sentences in my previous reply—that's what happens when you type on a phone, late at night.

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Old 2018-05-21, 03:23 AM   #8
YooNeeNoob
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hm...tire pressure...yeah, so this weekend, I'm 20 miles into a fun ride on my new KH36 when I notice--subtly at first, then progressively becoming more obvious--this 'thunk, thunk, thunk' coming from the frame. I get off, roll the wheel, and notice that at a particular spot, the outside tread of the tire is actually making contact with the frame (gasp!). It's like the tire had developed a bulge in one spot, big enough to just barely (but annoyingly) touch the frame. I remember adding air that morning and being surprised that it took so much to bring it up to pressure--the previous tire seemed to hold 60 psi really well, requiring only a weekly pump or two. Long story short, I think I had over-inflated the stock tire, because after I manually released some air, the tire/frame interference was gone and I sailed home to finish a fun 32-miler. I've always run the Nightrider at 60 psi, but on this occasion, it might have been inflated to a few psi more that 60. Plus, the outside temp increased over the day, which might explain why I didn't notice the problem till 20 miles into the ride. So, I guess I learned:

* all tires, even the same make/model, aren't necessarily exactly the same.
* the stock KH36 tires (Nightrider?) are sensitive to over-inflation, and prone to bulging.
* 55 psi might be my new set pressure.

..anyone experience this before?
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Old 2018-05-21, 07:55 AM   #9
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Originally Posted by YooNeeNoob View Post
* the stock KH36 tires (Nightrider?) are sensitive to over-inflation, and prone to bulging.
Would this be the new Nightrider that came out late last year and weighs about 1350 grams? Or the original Nightrider which has stiffer side walls and is about 500 gram s heavier?
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Old 2018-05-21, 11:42 PM   #10
YooNeeNoob
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Would this be the new Nightrider that came out late last year and weighs about 1350 grams? Or the original Nightrider which has stiffer side walls and is about 500 gram s heavier?
aha! yeah, well...I just ordered this unicycle a couple of weeks ago, so I'm assuming it's the new, improved, weaker tire. hahahaha

Yeah, I guess I'll really have to watch the pressure in this new baloon. Thanks
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Old 2018-05-22, 03:06 AM   #11
OneTrackMind
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Now it begs the questions.

Did you do anything that might have compromised the integrity? Tyre pressures are normally cold pressures so the warming day should not matter.

Is you pressure gauge accurate?

If these turn up negative then we must ask:

Is it a manufacturing fault in your tyre or is the maximum rated pressure too high for the new construction?

Either way I recon Rogeratunicycledotcom would be very interested.

You should add your experience and observations to this thread:
http://www.unicyclist.com/forums/sho...d.php?t=120922
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Old 2018-05-22, 03:59 AM   #12
JimT
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Quote:
Originally Posted by YooNeeNoob View Post
aha! yeah, well...I just ordered this unicycle a couple of weeks ago, so I'm assuming it's the new, improved, weaker tire. hahahaha

Yeah, I guess I'll really have to watch the pressure in this new baloon. Thanks
Based on the UDC site the tire on the KH36 is the standard Nightrider tire and not the new lite Nightrider tire.

In this case since the exact over pressure is not known it may be safe to assume that the pressure was just too much over the rated pressure of 65psi. If the standard Nightrider had a problem with pressures below the rated pressure it would have likely shown in the past.
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Old 2018-05-22, 04:17 AM   #13
YooNeeNoob
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Quote:
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Based on the UDC site the tire on the KH36 is the standard Nightrider tire and not the new lite Nightrider tire.
...sounds right. I certainly didn't immediately notice any difference between this new tire and the previous three I'd gone through. For now, I'm just gonna keep the pressure down @ between 50-55 and see how she rolls over the next month or so. I only got four years out of the first KH36, and I'm hoping this one holds up a little better. The fatal issues in the past were: frame failure and a cracked bearing that destroyed the interior surface of the hub. I'm not too disgruntleed though; I know this isn't a bike, and I'm not small at 6', 190lbs. Plus, I can buy half a dozen KH36s for the price of my road bicycle. Still, if I have more issues with this make, I might start shopping around for an alternative. I put about 70-100 road miles / week on the thing, so maybe I'm exceeding some design threshold or other...dunno. When she's rolling nice, I really LOVE my yoonee!
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Old 2018-06-03, 07:05 AM   #14
rrurban
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I keep my 27.5 x 3s at 22-24 psi, which is that special zone where you can feel the tire spring you back up when hopping without jarring your teeth but not so low and springy that the rim gets close to hitting the ground.
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