MTB tyre pressures
-
- Posts: 155
- Joined: Mon Mar 21, 2011 2:35 pm
MTB tyre pressures
Postby chriscole » Fri Mar 07, 2014 10:36 pm
Acquiring a MTB for the first time in over a decade, and it appears the object of my affections come off the shelf with tubes & clincher tyres. Whilst I ponder the merits of seeing the light and moving to tubeless, what are people's feelings about the lowest sensible tyre pressure (in a 2" / 2.25" width MTB tyre on a 650B wheel) to avoid fun things like rolling the tyre off the wheel when cornering, etc?
Cheers,
Chris
- HappyHumber
- Posts: 5072
- Joined: Wed Nov 14, 2007 11:48 pm
- Location: Perth, (S.o.R.) W.A.
Re: MTB tyre pressures
Postby HappyHumber » Fri Mar 07, 2014 10:39 pm
Experimentation is really your only answer. We can only really smother you with opinions here.
Hit me up via the BNA dm; I'll get an alert. If y'know, you know.
- trailgumby
- Posts: 15469
- Joined: Sat Jan 03, 2009 5:30 pm
- Location: Northern Beaches, Sydney
- Contact:
Re: MTB tyre pressures
Postby trailgumby » Fri Mar 07, 2014 11:01 pm
It's a bit trial and error. Keep going down until you can feel tyres starting to move around too much or you start getting pinchflats on the back. Front bears less weight and is your control tyre so less pressure is normal.
With tubes I'd be looking at 35-40 psi in the rear.
Hope this helps.
Sent from my android thingy using Crapatalk
-
- Posts: 46
- Joined: Wed Mar 05, 2014 8:28 pm
Re: MTB tyre pressures
Postby clint66 » Sat Mar 08, 2014 2:50 am
I run 20psi in the front and 28ish on the rear. Im in Perth though, so we have a bit of pea gravel to contend with. much more grip with the lower pressure and no pinch flats or any other issues. you still need to pump up the tyres every week or so. but you get that with a tube anyway.
-
- Posts: 588
- Joined: Mon Sep 19, 2011 1:13 am
- Location: Perth, NOR
Re: MTB tyre pressures
Postby dmwill » Sat Mar 08, 2014 1:17 pm
I always take note of my bike setup before I go riding - tyre spec and pressure, suspension setup (pressure/rebound etc). Really helps to determine what works best.
- singlespeedscott
- Posts: 5510
- Joined: Sun Jan 20, 2008 4:35 pm
- Location: Elimbah, Queensland
Re: MTB tyre pressures
Postby singlespeedscott » Sat Mar 08, 2014 4:05 pm
- Duck!
- Expert
- Posts: 9877
- Joined: Tue May 21, 2013 8:21 pm
- Location: On The Tools
Re: MTB tyre pressures
Postby Duck! » Mon Mar 10, 2014 9:27 pm
-
- Posts: 155
- Joined: Mon Mar 21, 2011 2:35 pm
Re: MTB tyre pressures
Postby chriscole » Tue Mar 11, 2014 9:19 pm
Will see how it goes at various pressures & riding conditions (I weigh 80kg with gear on).
Unsure about moving to tubeless as the "self-sealing" goodness sounds like it might be outweighed by the "glueing one's tyre to one's rim" badness. Also biased as I'm used to road-ish bikes with simple tubes and clincher tyres.
- Duck!
- Expert
- Posts: 9877
- Joined: Tue May 21, 2013 8:21 pm
- Location: On The Tools
Re: MTB tyre pressures
Postby Duck! » Wed Mar 12, 2014 9:14 am
-
- Posts: 46
- Joined: Wed Mar 05, 2014 8:28 pm
Re: MTB tyre pressures
Postby clint66 » Wed Mar 12, 2014 1:59 pm
http://www.notubes.com/help/index.aspx" onclick="window.open(this.href);return false;
- barefoot
- Posts: 1203
- Joined: Tue Jan 29, 2008 11:05 am
- Location: Ballarat
Re: MTB tyre pressures
Postby barefoot » Wed Mar 12, 2014 3:56 pm
Yeah, that's about what I run too.clint66 wrote:go tubeless you wont regret it.
I run 20psi in the front and 28ish on the rear. Im in Perth though, so we have a bit of pea gravel to contend with. much more grip with the lower pressure and no pinch flats or any other issues. you still need to pump up the tyres every week or so. but you get that with a tube anyway.
With tubes. Under ~85kg of me.
Haven't had a flat in years. Have been tormenting the puncture fairies with this fact for years and they still haven't smote me for it.
I hit the front up to nearly 30psi a few weeks ago. It was awful. Nasty squirrelly feeling like the front was about to wash out on every corner.
I don't know how anybody can ride a MTB with 40psi in the tyres...
tim
- m@
- Posts: 5112
- Joined: Tue Apr 15, 2008 12:20 pm
- Location: Wurundjeri Country
- Contact:
Re: MTB tyre pressures
Postby m@ » Wed Mar 12, 2014 4:35 pm
If the RRs are the UST/"Tubeless ready" model, all you'll need to do is swap the rim tape for Bontrager tubeless strips and valves, pour in some Stan's sealant and throw them on a compressor to seal 'em up. About six months to a year later, you might need to use a spoke tool to remove the valve core for cleaning (a 2 minute job), or unseat one side of the tyre to remove the dried-up gribbly bits and pour in some fresh sealant.chriscole wrote:LBS currently building up a Giant XTC Advanced 2 650B hardtail for me. Comes with some Racing Ralphs on it and a (presumably) heavy wheelset which is tube + clincher.
Time saved over fixing punctures = lots. Fun had by running stupidly low pressures = lots more!
- trailgumby
- Posts: 15469
- Joined: Sat Jan 03, 2009 5:30 pm
- Location: Northern Beaches, Sydney
- Contact:
Re: MTB tyre pressures
Postby trailgumby » Wed Mar 12, 2014 5:27 pm
OEM tyres are usually TLR or simple folding bead. They aren't known for their robust sidewalls.
Some guys won't stop to offer help with punctures if they see you have RaRa's. I'm not sure how that psychology is supposed to work myself, but it does show I suppose the level of irritation among riders in my area with the weakness of the sidewall on this tyre.
The SnakeSkin version is supposed to be much better. I'll be going that way next purchase after pretty much destroying the sidewall after dried sealant let me down last ride.
Sent from my android thingy using Crapatalk
- Duck!
- Expert
- Posts: 9877
- Joined: Tue May 21, 2013 8:21 pm
- Location: On The Tools
Re: MTB tyre pressures
Postby Duck! » Wed Mar 12, 2014 7:39 pm
UST & "Tubeless Ready" (TLR) are very different tyres. TLR RaRas (which will be the stock tyres) are a waste of time - the super thin sidewalls are about as airtight as a flyscreen and take weeks to seal enough to stop the sealant spraying out through them. Those things are the embodiment of the horror stories you hear from people fearful of converting to tubeless, but the good news is they are the exception and definitely not the rule.There are many, many far less troublesome tyres available (ironically including other variants of RaRas, providing they're suited to your kind of dirt).m@ wrote:If the RRs are the UST/"Tubeless ready" model, all you'll need to do is swap the rim tape for Bontrager tubeless strips and valves, pour in some Stan's sealant and throw them on a compressor to seal 'em up. About six months to a year later, you might need to use a spoke tool to remove the valve core for cleaning (a 2 minute job), or unseat one side of the tyre to remove the dried-up gribbly bits and pour in some fresh sealant.chriscole wrote:LBS currently building up a Giant XTC Advanced 2 650B hardtail for me. Comes with some Racing Ralphs on it and a (presumably) heavy wheelset which is tube + clincher.
Time saved over fixing punctures = lots. Fun had by running stupidly low pressures = lots more!
-
- Posts: 155
- Joined: Mon Mar 21, 2011 2:35 pm
Re: MTB tyre pressures
Postby chriscole » Wed Mar 12, 2014 8:49 pm
I think you've effectively convinced me to stick with tubes and normal tyres for the time being.
-
- Posts: 53
- Joined: Mon Mar 03, 2014 11:53 pm
- Location: Colac " The Lac", Victoria
Re: MTB tyre pressures
Postby magilla0_2 » Wed Mar 12, 2014 10:58 pm
In my 26" and 29er with 2.1 tyres, I ran 28 lb front and rear, and now on a 650b with 2.5 tyres I am running 23-25 lb and I tip the scales somewhere between 90-95kg
- m@
- Posts: 5112
- Joined: Tue Apr 15, 2008 12:20 pm
- Location: Wurundjeri Country
- Contact:
Re: MTB tyre pressures
Postby m@ » Thu Mar 13, 2014 10:11 am
Nice going guys!chriscole wrote:Thanks for the input guys.
I think you've effectively convinced me to stick with tubes and normal tyres for the time being.
Now, I thought the stock RRs on my Anthem were labelled UST, but apparently not - possibly I was bamboozled by Schwalbe's EVO label.
Either way though, I believe the EVO model has SnakeSkin sidewalls... I rode them quite a bit before going tubeless and they did have some pinholes but still sealed up almost instantly and didn't lose any pressure after the first 24 hours.
I've since ridden them to death and replaced with Nobby Nic/RR EVOs, which were installed tubeless from new with no noticeable loss of pressure at all. So if the OP has EVO/SnakeSkin tyres - which are supplied as stock on some Giants - from my experience he has little to lose by going tubeless.
- Bentnose
- Posts: 1327
- Joined: Sun Jan 03, 2010 9:00 am
- Location: N/E suburbs Melbourne, Victoria
Re: MTB tyre pressures
Postby Bentnose » Sat Mar 22, 2014 4:20 pm
- trailgumby
- Posts: 15469
- Joined: Sat Jan 03, 2009 5:30 pm
- Location: Northern Beaches, Sydney
- Contact:
Re: MTB tyre pressures
Postby trailgumby » Sat Mar 22, 2014 6:33 pm
Sent from my android thingy using Crapatalk
- Bentnose
- Posts: 1327
- Joined: Sun Jan 03, 2010 9:00 am
- Location: N/E suburbs Melbourne, Victoria
Re: MTB tyre pressures
Postby Bentnose » Sun Mar 23, 2014 8:03 am
-
- Posts: 53
- Joined: Mon Mar 03, 2014 11:53 pm
- Location: Colac " The Lac", Victoria
Re: MTB tyre pressures
Postby magilla0_2 » Sun Mar 23, 2014 8:16 am
- trailgumby
- Posts: 15469
- Joined: Sat Jan 03, 2009 5:30 pm
- Location: Northern Beaches, Sydney
- Contact:
Re: MTB tyre pressures
Postby trailgumby » Sun Mar 23, 2014 1:28 pm
My track pump, a Topeak Joe Blow something or other, seems to be close enough to it.
So long as your gauge is consistent, the absolute number you arrive at by trial and error doesn't matter.... but, you might just have to take it with you to each event you do, as it won't compare to what others have.
- Bentnose
- Posts: 1327
- Joined: Sun Jan 03, 2010 9:00 am
- Location: N/E suburbs Melbourne, Victoria
Re: MTB tyre pressures
Postby Bentnose » Sun Mar 23, 2014 4:42 pm
I take it with me to every event, I find tyre pressures to be quite critical on a MTB for maximum performance, particularily with tubeless when you can run them so low, too high and you have no grip, too low and you can damage your rims and they feel too squishy. If I went back to tubes it would feel like no grip all of the time.trailgumby wrote:I have one of those BBB digital gauges which shows pressures in PSI to one decimal place. I leave it in my Camelbak, since i want to have it with me out on the trail just in case, and it only weighs a few grams - outstanding value for under $30.
My track pump, a Topeak Joe Blow something or other, seems to be close enough to it.
So long as your gauge is consistent, the absolute number you arrive at by trial and error doesn't matter.... but, you might just have to take it with you to each event you do, as it won't compare to what others have.
- singlespeedscott
- Posts: 5510
- Joined: Sun Jan 20, 2008 4:35 pm
- Location: Elimbah, Queensland
Re: MTB tyre pressures
Postby singlespeedscott » Sun Mar 23, 2014 7:12 pm
I run tubes I have plenty of grip. The tiny amount of friction between the tyre and a 1/4mm thick inner tube has very little effect on tyre grip.Bentnose wrote:I take it with me to every event, I find tyre pressures to be quite critical on a MTB for maximum performance, particularily with tubeless when you can run them so low, too high and you have no grip, too low and you can damage your rims and they feel too squishy. If I went back to tubes it would feel like no grip all of the time.trailgumby wrote:I have one of those BBB digital gauges which shows pressures in PSI to one decimal place. I leave it in my Camelbak, since i want to have it with me out on the trail just in case, and it only weighs a few grams - outstanding value for under $30.
My track pump, a Topeak Joe Blow something or other, seems to be close enough to it.
So long as your gauge is consistent, the absolute number you arrive at by trial and error doesn't matter.... but, you might just have to take it with you to each event you do, as it won't compare to what others have.
- trailgumby
- Posts: 15469
- Joined: Sat Jan 03, 2009 5:30 pm
- Location: Northern Beaches, Sydney
- Contact:
Re: MTB tyre pressures
Postby trailgumby » Sun Mar 23, 2014 7:26 pm
True. But then friction isn't really the issue. It's the ability of the casing or casing/tube combo to conform to the track.singlespeedscott wrote:I run tubes I have plenty of grip. The tiny amount of friction between the tyre and a 1/4mm thick inner tube has very little effect on tyre grip.
The extra rubber in the shape of the butyl rubber tube contributes little to supporting the casing, but reduces the ability of the tread to conform to the trail surface. A possible exception would be latex tubes.
That's my theory anyway, and I believe it would be the consensus view.
The primary advantage to tubeless is the ability to run lower pressures without pinchflatting, expanding the contact patch. The lower limit is when the tyre starts squirming around too much and burping becomes a risk.
- General Australian Cycling Topics
- Info / announcements
- Buying a bike / parts
- General Cycling Discussion
- The Bike Shed
- Cycling Health
- Cycling Safety and Advocacy
- Women's Cycling
- Bike & Gear Reviews
- Cycling Trade
- Stolen Bikes
- Bicycle FAQs
- The Market Place
- Member to Member Bike and Gear Sales
- Want to Buy, Group Buy, Swap
- My Bikes or Gear Elsewhere
- Serious Biking
- Audax / Randonneuring
- Retro biking
- Commuting
- MTB
- Recumbents
- Fixed Gear/ Single Speed
- Track
- Electric Bicycles
- Cyclocross and Gravel Grinding
- Dragsters / Lowriders / Cruisers
- Children's Bikes
- Cargo Bikes and Utility Cycling
- Road Racing
- Road Biking
- Training
- Time Trial
- Triathlon
- International and National Tours and Events
- Cycle Touring
- Touring Australia
- Touring Overseas
- Touring Bikes and Equipment
- Australia
- Western Australia
- New South Wales
- Queensland
- South Australia
- Victoria
- ACT
- Tasmania
- Northern Territory
- Country & Regional
Who is online
Users browsing this forum: No registered users
- All times are UTC+10:00
- Top
- Delete cookies
About the Australian Cycling Forums
The Australian Cycling Forums is a welcoming community where you can ask questions and talk about the type of bikes and cycling topics you like.
Bicycles Network Australia
Forum Information
Connect with BNA
This website uses affiliate links to retail platforms including ebay, amazon, proviz and ribble.