[Closed] Stans rim pressure warnings

Iron cross's are just 700c sized ZTR Olympics.Worst that'll happen is the tyre will blow off and taco the wheel.....actually that' isn't is pretty bad isn't it.
If the bead is fairly tight and it's closer to 50 than 60 I reckon she'll be reet.

I asked this question directly once. Tubeless may blow off, tubes will be fine.

Don't overdo the pressure. I used 26x1.5 road tyres on my hard tail mtb @ 65psi on Stan's crest. Rear bead blew off at speed on the road, just managed to keep control. If the front had gone I might not have been so lucky.

45 psi is loads for racing, which is what those rims are all about really. Run tubeless, 30psi is prob more like it.

I've run Stans rims with tires hard. I've lost the tyre of the rim more than once.

Tubless at 50psi my tyre exploded of the rim, couldn't hear for ages afterwards 😀 latex every where 😳

Ignore them at your peril..

My kitchen roof still has latex on it and I find it in random spots still.
Our ears rang for a bit too and my dog wasn't chuffed.
Before a smart arse chimes in.
Genuine tubeless tyres were used (and are mounted OK still) and I went to 60 psi with a recommendation of 45 on the rim.

Don't exceed the recommended pressures..

[quote=Onzadog ]I asked this question directly once. Tubeless may blow off, tubes will be fine.
Correct

I explosmed a dualply off a damaged Flow Ex a while back... Damn near broke my hand, repained the garage white, and shocked the wheel hard enough to knock it out of true- loose spokes everwhere. Wicked!

Why do tubeless blow off at pressures that tubed take Ok?

Je ne comprend pas

Run 28c slicks with tubes happily at 80psi here. I emailed stans beforehand and got this response-

'The Crest and the Iron Cross both do not work that well with road tires and tubes. They will not work at all with road tubeless tires. On the Crest the smallest I would run would be a 28 but the pressure might be limited by the rim to 80psi.

I would recommend the Alpha 340 as it works with road tires and cross tires.'.

So there you go

What @fozzybear said - from my experience the worst that will probably happen is you could blow the tire off. Which if happens while you are riding could mean a "you will die" experience. Or at best, leg-hairs covered in latest for the next week or so, and an unhappy spouse. In any case I don't think you'll damage the rim (directly via the overpressure), but probably not a good idea.

Little relevance to mountain bikes, but apparently a [url= http://reviews.mtbr.com/reynolds-cycling-factory-tour-wheel-torture-lab/3 ]Reynolds carbon road rim and tubular tyre give up at 370psi[/url]:

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Ask Charlie the bike mong he got it slightly wrong recently and woke up swannage with the explosion

Hmmm this worries me now. I'm looking at some hope/crest wheels and am running tubes with mountain race tyres at 65psi. Would this be a silly idea with Stans?

What's the worst that could happen is the way I normally tend to think. Imagine you didn't blow up the tyre whilst installing it but it happened whilst out on the trail and you have an accident whilst heading round a corner as a result. Next thing your in A and E with a branch protruding from your body. Is it worth your family worrying about you that much because you couldn't do what the manufacturer told you to? Accepted this is a dangerous sport but you're daft if you do this.

dknwhy - Member

Hmmm this worries me now. I'm looking at some hope/crest wheels and am running tubes with mountain race tyres at 65psi. Would this be a silly idea with Stans?

It's a pretty silly idea with anything tbh.

I got a bit over enthusiastic with a compressor and a crest when I couldn't get the tyre to seat

Put wheel aside and a few minutes later there was a weird noise and wheel resembled a pringle. Tyre stayed on though

Took it to lbs to see if they could true it. Some time later they picked themselves up off the floor, and still laugh every time they see me!

Little relevance to mountain bikes, but apparently a Reynolds carbon road rim and tubular tyre give up at 370psi:

Not a tub is it? Looks like a bead. If it was a tub I'd not expect any correlation between sudden tyre failure and rim failure.

I got a bit over enthusiastic with a compressor and a crest when I couldn't get the tyre to seat

Put wheel aside and a few minutes later there was a weird noise and wheel resembled a pringle. Tyre stayed on though

I've heard that before - splitting between the spoke holes along the length of the rim.

It's a pretty silly idea with anything tbh.

+1, 65psi in a MTB tyre is lunacy!

I put higher than recomended pressure in some (non tubeless) tyres on crests once. Made it to the end of the road before it went pop. Put the bead back on, pumped it up and carried on.

Wasn't silly pressure, just commuting on the road on the MTB pressure, so probably 45psi in a 2.2" tyre.

"igm - Member
Why do tubeless blow off at pressures that tubed take Ok?
Je ne comprend pas"

When you run tubeless, the bead of the tyre is seated right in the groove in the rim, so although the seating is sound the bead is only 2 or 3 mm from coming off. As pressure is increased, expanding the tyre, the seating is bound to get looser and there comes a point when it is too loose the keep the tyre on the rim.

When you run with a tube on a Stans rim, the bead of the tyre sits further within the rim under the tube and further away from coming off. Plus since the tube is a complete tube rather than a U shape, the pressure works in all directions - not just expanding the tyre but also crushing the beads more tightly onto the rim. So there is still a point at which a tubed tyre will blow off, but it's a higher pressure than with tubeless.

Stans rims are designed to be run tubeless anyway, and if you do run them the way they're designed there's no need for high pressures.

65 psi was for on road pressure btw on 29er wheels with race king tyres. Off road it's more like 40.
What's wrong with 65psi on road? Tyre states 65 as a max and road tyres run at 120psi.

For off road and tubeless, Stans recommends 2psi for every stone in body weight for mtb tyres, with a max of 40psi.

For road tyres, they say up to 80psi according to tyre manufacturer's recommendations. The recommendation not to use Crest rims with really skinny tyres must make sense - a 25c tyre mounted onto a rim with 21mm internal width must be stretched into a shape it was never designed for. The Alpha rim is 17mm internal width, which should be fine.

Even if you obey the pressure warnings you can still come unstuck as I have just found out. I'm new to tubeless, so tonight I was feeling mighty pleased with myself that I managed to get the tyre seated with a track pump (Ardent on a stans crest rim). I pumped it up to 25psi, then bang! My ears are still ringing and the rim is trashed before it's even been ridden. I'm beginning to wonder what the point is and whether I want to risk it again with the other wheel, as crest rims don't come cheap!

I've got 70psi in the Small Block 8s on Alex Ace 19 rims on my cross bike.
I've got 55psi in the Maxxis Larsens on Spank Stiffy rims on the tandem.
Both tubeless with either Stans tape or several layers of electrical tape.
None of them have blown off yet, although I did have a Bontrager tyre blow off a Stans rim at 45psi while riding.