Tyre Pressures for ...
 

[Closed] Tyre Pressures for Tubeless?

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Running Stans Flow, Stans rim Tape, Stans sealant with Maxxis High Roller SPC tyres.

What pressures would you start off with is 30 psi too low?

My riding is pretty rocky, gnarly (Dark Peak)

Any suggestions welcome!


 
Posted : 06/04/2011 10:00 am
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I've got my Minions at about 24 psi on Flow rims and I'm 18 stone. You can go really low with tubeless and they work better lower anyway


 
Posted : 06/04/2011 10:01 am
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christ as low as that? no danger of damagin your rims then?


 
Posted : 06/04/2011 10:03 am
 DezB
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I hate that roll-over feeling when cornering with low pressures, so I have mine at about 35. 30's a good place to start though.


 
Posted : 06/04/2011 10:04 am
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I did have them down to 19 but was starting to roll them off the rim. Just keep trying them lower until you do get a little rim contact then pop some more air back in.


 
Posted : 06/04/2011 10:05 am
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Depends on how heavy you are and how big your tyres are.

13.5 stone
2.35 High Roller
24/34 psi front/back

You can go very low, but you will start to feel your rims hit things. Personally I don't like that, and I worry about the tyre rolling off the rim. Experiment.


 
Posted : 06/04/2011 10:10 am
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30 ish for me, although with thin sidewalled tyres (Conti Speedking 2.3) they were not only squirmy but also rubbish traction at these pressures so I upped to 40 and it was much better. 87kg, Orange 5.


 
Posted : 06/04/2011 10:31 am
 GW
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I've got my Minions at about 24 psi on Flow rims and I'm 18 stone. You can go really low with tubeless and they work better lower anyway
No you can't! corner hard and the sidewalls'll fold..
at 14st I can't run a front Dual Ply Minion tubeless (on 823) at any less than about 30psi on my DH bike on a hardpack track without it folding/burping.. the rear would need to be closer to 40psi.

Depends on how heavy you are and how big your tyres are.[b]AND HOW YOU RIDE[/b]


 
Posted : 06/04/2011 10:37 am
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I ride the Peaks. I'm 15 stone. On my Hardtail I use ADvantage UST tyres. 25psi front and 30 rear. No roll when cornering hard and no rim damage.


 
Posted : 06/04/2011 10:39 am
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GW, you must be so awesome. Crikey.


 
Posted : 06/04/2011 10:41 am
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And it also depends on rim width. I've got 2.35 Bonty XR4s on Bonty Race Disc rims. The rims are narrow (17mm maybe) and the tyres recommend a 28mm rim. If I run low pressure the tyres flop about a bit. Too high and the back bounces. So I set them just right. No idea of the number of psi but my thumb can tell.


 
Posted : 06/04/2011 10:42 am
 GW
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Not awesome, just not afraid to lean, drift or get a bike sideways.


 
Posted : 06/04/2011 10:48 am
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Nor am I but you seem to be telling me that I am wrong. You must be a lot more awesome than me.

I'm humbled


 
Posted : 06/04/2011 10:49 am
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I run about 25 on the HT and 30ish on the DH.

There's an awesome set of stairs near me I use for dialling in suspension and trying out tyre pressures. It's about 200 metres long and varies between short steep flights which you can jump 2 at a time and individual steps as long as the bike. Really wide too.

Once the rear shock is dialled in, I drop the pressure to about 20psi and then gradually pump it up until i can't feel the thud of the rim. The stairs are about as brutal as i'm going to find, so if it's OK on them, it's generally OK on the trails (unless you get a massive square edged hit, but that's just poor line choice rather than the tyres fault!)


 
Posted : 06/04/2011 11:01 am
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25-30psi in Maxxis 2.35 High Rollers.


 
Posted : 06/04/2011 11:05 am
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10.5 stone, 2.1" various tyres, 25-30psi for me!


 
Posted : 06/04/2011 11:07 am
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GW - Member
Not awesome, just not afraid to lean, drift or get a bike sideways.

Posted 17 minutes ago # Report-Post

*swoons*

only kidding, i know where you are coming from. Ive learned the hard way that 20-25 psi feels wicked until you start pushing the limits. i think its a bit like suspension; the faster you are, the harder you need to run it. up to a point of course.


 
Posted : 06/04/2011 11:09 am
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I run SPC/DPC tyres and find that anything under 30psi has a tendancy to come off the rim. That's with 2.5/2.35 minions or HR's on 819 up front and the same, or Advantage 2.25 out back, wire bead. With the real UST tyres you can get a lot lower if you want to, whether you'd want to or not is up to you.

I'm not as heavy or fast as GW so that makes a big difference. Also that's on my AM bike, my DH bike has tubes. I ride a lot of rocky stuff and it works fine, never had it come off at those pressures, although i have ran out of latex, had the pressure drop a bit and then had a front rip off. Now I check my pressures regularly.


 
Posted : 06/04/2011 11:19 am
 DezB
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that makes me the HARDEST ride[b]r[/b] here! Yeah! 😈

(Edit: er, yes to the below! 🙂 )


 
Posted : 06/04/2011 11:20 am
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Dezb, I think (hope) that you meant rider?

Edit: and even that sounds wrong 🙂


 
Posted : 06/04/2011 11:25 am
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gonna start off with low 30's maybe a couple more PSI in the rear.


 
Posted : 06/04/2011 11:29 am
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Ran minion tubeless front and could not get comfortable with it. At a nice lowish pressure for most things it would get very dodgy for fast weighted corners. Got bored of trying to find the very narrow sweet spot for pressure and put a tube back in.

Everyone saying they fold etc are spot on and it can make to very nervous as I almost had a few big offs where I would never have expected it going rather fast.


 
Posted : 06/04/2011 12:23 pm
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Nor am I but you seem to be telling me that I am wrong. You must be a lot more awesome than me.

I'm humbled


Maybe your pressure gauge need recalibrating?

Im with GW here. At 11.5 stone tubeless squirm all over the place at any less than a little under 30. Clearly i'm also pretty awesome 😉


 
Posted : 06/04/2011 1:31 pm
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It's really odd - going from tubes (35-50psi depending on tyre size) to tubeless (25-30psi) the wheels don't seem noticeably slower or more squirmy - I started off at my normal tubed pressures and they felt awful.

I actually finished a ride with skinny 2.0 Mud Xs at under 20psi without any problems - no obvious squirm either strangely which I really hated on tubes at anything under 35psi.


 
Posted : 06/04/2011 1:39 pm
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the wheels don't seem noticeably slower

That's right. Tubeless lowers rolling resistance, so you can either keep the same pressure and go faster, or lower pressure for more grip and comfort and go the same speed.

I tend to go for a bit of both.


 
Posted : 06/04/2011 1:47 pm
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Ah, the joys of wide rims - on Flows with the rim strips I can get away with 20psi on the front and 25 on the back - Big Bettie front and Rubber Queen back. You can't run these pressures on 823's as they are too narrow. I get some wallow/squirm... but I don't find it a big problem.

FWIW - start at 30... in a months time they will be down at 25 and you won't have noticed 😆


 
Posted : 06/04/2011 2:43 pm
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I run stans flows...still squirm!


 
Posted : 06/04/2011 2:59 pm
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That's right. Tubeless lowers rolling resistance

I understand that, what I really meant was that significantly lower pressures seem possible without slowing it down though the same pressure as with tubes isn't noticeably faster if that makes sense.


 
Posted : 06/04/2011 3:03 pm
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I run flows, squirm equals big problem on high speed corners.


 
Posted : 06/04/2011 3:05 pm
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I run 819s and 2.3ish tyres at 30psi, and Im a 15st Fully Awesome Rider of Substantial Repute.


 
Posted : 06/04/2011 3:35 pm
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Sorry to bring this thread back to life 🙂

I have been experimenting recently with a ust 2.5 minion on flow. I'm around 12st kitted up and this setup is on my alpine which I use for bigger hills rather than pootleing around local tracks.

Tried it at first with around 30psi, squeeze test = quite hard. Rode first hour or so of a peaks route like this, didn't get on with it, first time using minions so thought I'd wasted my money. Dropped pressure slightly and didn't feel too much better.

I was then advised to drop pressure 🙂 next ride was in peaks again with around 24psi in front, much better.

This weekend been up in Scotland, rode both inners DH and red and then Glentress and the bike felt awsome. So much more confident. I appreciate that I'm adapting to the minion and the dusty dry trails but I felt like I could allow bike to two wheel drift knowing I wouldn't loose it. It also feels so much more stable on the fast rocky descents. When I tested pressure = 20psi, I'm going to follow this trend going forward and by the time I'm in the alps this year I'll be down to around 10psi!!

I appreciate that if your a heavier rider then you may need more pressure but I know guys on here who are way 🙂 heavier than me and get away with 23/24 psi easily. So unless you are running a skinny rim like a 819 then I think low pressures work really well, especially with 2.5"s


 
Posted : 20/04/2011 10:02 pm
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73kg run Ardent at 20psi and Crossmax on rear 23psi.

I think you need to experiment to see what suits your riding style and where you ride. I think the tyre makes a difference as well. Maxxis seem to be a very good UST tyre. I dont run any other make now.


 
Posted : 20/04/2011 10:17 pm
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Tyre pressures will be different for every rider depending on weight, terrain, tyre size, casing, rim width, riding style etc etc.
Tubeless tyres dont have less rolling resistance per se than tubed tyres (assuming the same tread) it all depends on the pressures you put in them.
You will just need to experiment to find what suits you. Too low a pressure and the tyre will start to squirm which will slow your cornering down, too high a pressure and you will start to increase rolling resistance which again will obviously slow you down.


 
Posted : 21/04/2011 7:31 am