So i'm just about to convert my hardtail over to tubeless and wondering what kind of psi to aim for.
Dont have a track pump yet so i'm not sure what i've been using with tubes so far. Up til now with tubes it's been the finger prod test and a few more psi if i pinch flat but i know tubeless will allow lower psi for more bump smoothing and grip. Tyres are going to be 2.2 UST nobby nics
For the record i'm 10 stone, 5'6 and pretty much trail riding but on the xc side rather than the am. The exmoor classic ride from here is one of my local(ish) loops
http://singletrackworld.com/magarchive/issue-69/
gentlemen your learned opinions please!
A lot less than it was with tubes.
I'm 16.5 stone. With tubes and 2.1ish tyres, I was running 40psi to avoid pinch flats.
Tubeless I'm on 20 front, 25 back. I think I could go lower too.
Take your weight in stones, double it and add two for the rear and subtract one for the front.
So for you, 22 and 19 psi.
Not far off what I use actually, although I'm a stone heavier so two more psi all round.
clubber - do you get much rim damage at those tubeless pressures?
None - I've never even felt them bottom out on the rim which is why I'm pretty sure I can go lower - and I absolutely hammered it at Afan/Cwmcarn last weekend
Andy - your formula is way off for me...
I'm exactly the same weight and height as you and never managed to stop the rear burping at lower pressures. I had to pump it up so high that it negated most of the advantages!
I was just using Ghetto tubeless mind you so that could be the issue right there...
Keen to hear how you get on though!
i've got stans stuff from bike trek in ambleside but without the black rim stuff just the yellow tape, valves and sealant on their advice.
Mavic cross ride on the front and for now an alex fd19 rim on the rear until i save up for something better/lighter.
About 14 stone (don't own any scales) and run the rear of my BFe at about 35psi.
3kg lighter than you, but I run them hard. 50,45psi rear and front respectively.
Nic front and Racing Ralph rear. Both 2.25 inches.
Depends on your pump as all guages do not give the same readings. I run tubeless on 819 rims with some conti UST tyres and was getting pinch punctures on the tyres at 35 PSI.
All depends on trail surface. I'm about to purchase a Stan's or Joe's kit and do my bran-spankin-noo 719's for my hardtail so will experiment. I'm 13 stone but 26 psi sounds really low. I'm guessing about 32 on the back and 28 front but I've never done TL so we'll see!
My Topeak pump matxhes the readings on my Topeak gauge. definitely a smart piece of kit to have!
20ish all-round (I don't think my track pump can get much more accurate). Bit lower on the front on fully rigid
EDIT: 11ish stone 2.25RR/NN 29er - comfortable and grippy. Only bottomed out once on a really square edge going through a water crossing being chased by someone on a 6" travel bike 😕
20 ish rear, a bit less front. Go low, put more in if you're feeling your rims on root hits. Don't trust gauges much.
I'm 11 stone and run 28 rear about 25ish front. For those running lower - am I missing out on much extra grip, and what's the effect on speed?
thank you thats at est given me an idea of a starting point, lets hope its as easy to set up as they imply!
35 rear and 30 front for me. I'm about 12 stone but if I run them much lower they start squirming when pushed in the corners.
The correct pressure depends on many factors: personal preference, tyre volume, tyre construction, rim width, trail conditions ... blah blah blah.
Start off with a similar amount of air as before and experiment by taking some air out, test it and repeat and see what works for you.
clubber - Member
Andy - your formula is way off for me...
I just saw it somewhere, so I can't take any credit (or otherwise) for it - seems to be close to what I use though, which is low to mid twenties. I can see that if someone is much lighter or heavier it'll be way out....
I am 10 stone 9 lbs and I run NN Tubless Ready snakeskins at 20fr 22rr as I do have some hardpack sections and a surfaced long climb to the trail head but have run them at 12fr 14rr
Grip at those really low pressures was epic but they were a little squirmy (snakes skin sidewalls help to offset it as will your UST ones)
My Mountain Unicycle with a Hans Dampf with all my weight on one wheel lives at 18psi (tubed) and lots of twisting and side loading and has never had an issue.
You have no tube so crank the pressure down until you don't like how they squirm about
Spesh Butcher Control Front 20 psi. Stans Flow
Maxis Ignitor 2.35 Rear over 25psi. Mavic 821.
Had a Nobby Nick on the back and had to keep it at at least 30 PSI. Still kept puncturing...
11.5 Stone, rocky, steep Spanish trails. c456.
I go as low as I can before risk of pinch flats / burping / rim roll.
The butchers are AMAZING at 20psi.
Depends on the tyres and on how recently I've checked 'em 😉
Ragley is Nevegal 2.35 on the front, Specialized Eskar on the back, both nominally at 25psi but they go up and down. I can go lower without dinging etc but the tyres get a wee bit wobbly.
Soda is Nevegal 2.5 on the front, Eskar on the back, with 20psi in the rear (it goes slower) and so little air in the front that it doesn't register on the pump (suspension!)
100kg running 28 rear and 24 front, ghetto set up of panaracer rampage 2.35 front and rear on fulcrum red metal 5, yes they were a bugger to get seated and sealed!!!
12 ish stone, 2.25 Racing Ralphs snakeskin, run tubeless, c.26 psi front & c.31 psi rear (depends if I remember to check them & adjust as they do lose a bit over time). Run down to 20 psi on the front, but gets a bit squirrely IMO.
Anywhere from 18F/20R in snow or ridiculous mud to 26F/30R in the dry. Rubber Queen 2.2 UST, 12.5 stone of me on Flow rims.
Basically as the available grip increases I have to increase the pressure to prevent squirm. When I had Bontrager XR4 2.2 on there (very similar size) I had to run them a bit harder with like for like cornering forces because the non-UST TLR sidewalls weren't as supportive.
With smaller volume tyres I have to run higher pressures. On narrower rims I have to run higher pressures. Nowadays I check the pressure before every ride - I kept noticing the handling being a bit squirmier than I liked it and every time that was the case the pressure was down. Even as little as 10% difference was noticeable - I'm a sensitive soul. 😉
13 in the front, 20 in the rear, rigid bike and I'm using tubes. I've had the rear down to 15 - but it becomes a bit draggy, I prefer a bit more air .
Pinch punctures and tubeless? How?
On the 'Pig, 30/35 F/R, maybe -5 if I'm feeling skilled. Usually 2.3/2.1 tyres.
Unless I'm way off the mark with my musings about tubeless then I'd say it depends entirely on the tyre. My Hans Dampfs are very different to any other tyre I've had, the sidewalls are far stiffer and therefore pressures can be pretty low. In my book the 'system' stiffness = tyre stiffness + air pressure stiffness. Normal sidewalls = normal pressures or thereabouts.
Run between 30psi and 35psi out back. Width / carcass size determines upper or lower. Currently got a Spec Fastrak out back at nearer 35 in a 2.0 width.
2.2 would run at 30 maybe a tad less.
I am 15st and mostly ride natural / xc type stuff. I have run them lower but flints and dodgy landings were taking their toll on tyres more often.
about 19psi on my QH.
I only weigh 10.5 stone though
Surely it doesn't mean much without rim width? I'm 70 kg riding 2.25 RR on 19mm rims. Wonder whether going to 21mm rims would make much difference. I run 25 psi