Mountain Bike Reviews Forum banner
Cancel
Create thread New Forums

what PSI are all'ya'll's running?

Jump to Latest
1 - 20 of 27 Posts
V

VA2SLOride

· my girl rides also
Joined
·
648 Posts
Discussion starter · #1 ·
I love the Niner. But what's up with the flats?? I've gone through five or six tubes over the last couple of weeks from getting pinch-flats.

Running the tires at around 40-45 psi feels the best, but produces the most flats. Anything higher than that and I feel like I can't grip on anything. Case and point when I washed out yesterday and found out why full-faced helmets are made.

Any thoughts on this? What are you running?

Thanks....
scott
 
Save
Like Like
#3 ·
With just about any tire I use I go 36F/40R, occasionally lower depending on the trail. I weigh about 190lbs in gear. As a comparison I rode about 30F/34R on a 26" bike with single ply tires (26/26 on DH tires). On 26" bikes I would pinch flat maybe twice a year. On the 29er I pinch flat about once a month. I rid a bunch of very technical rocky and rooty trails often at high descending speeds. I seem to have the best luck with the 28" Continental tubes, in fact I’m not sure I have pinch flatted on of them yet. I have tried a variety of 29 and 26 tubes all have been regular butyl type tubes though. I have just learned to live with the increased number of flats on the 29er.
 
#4 ·
Michelin latex

peabody said:
with 26" michelin latex tubes at 30fr and 32 rr, 160 lbs expert xc.
Click to expand...
That's really interesting. I used to run Conti Latex on my 26" bikes before switching to Tubeless. Now on the Niner I haven't dared try the Stans kit I bought yet because of all the horror storys and don't-do-it posts. I was going to use my latex tubes, but somebody, Shiggy?, wrote that they are more size specific than butyl tubes. Have you had any problems? Does it make a difference? I could run lower pressures with latex on my 26ers, but with the Niner I haven't flatted yet with Salsa superlight tubes at approx 27 psi front, 30 psi rear. I'm 143 lbs and race XC over lots and lots of roots.
 
#5 ·
Huh. I've been running 30lbs w/me at about 195lbs. I dented the bejesus out of my rear american classic rim on the first ride on my one9 at that pressure, though. I think I just wasn't used to the feel of the bike yet. Didn't get my weight in the right place during a rock garden. American classic won't sell replacement rims, btw, hafta send the whole wheel back for a rebuild. Lame. Will be living with the dent for a while. However, I did the rockiest ride ever on monday w/~28lbs and felt like I could of done with even less pressure with no worries.

It's all about technique in the end. You gotta float.
 
Discussion starter · #7 ·
I guess I'm about 175-180 with all the gear on, and have been running Bonty tubes and the standard 29" WTB nanos.

How frequently are ya'll getting flats running those low psi's? And what kind of terrain are you on? I'm on the CA central coast, where things are really rocky, dry, and jagged for the most part, and I tend to ride pretty aggressively.

I'm guessing this is the downside to these bikes?
 
Save
Like Like
Discussion starter · #8 ·
I'm finding that they're a little on the thin side, sidewall-wise....anyone out there know where I can get some beefier knobs?
 
Save
Like Like
#10 ·
enough

I use just enough to keep from pinch flatting and I haven't pinch flatted yet. Motos and Exi. I'd say no more than 35 psi. Sometimes it'll feel too squishi in the climbs, so I'll pump it for the descent.

-M
 
#11 ·
i go 40 back 35 front...

230lbs and mixed eastcoast terrain.

do you ever feel your rims bottoming out? that is the key for me to knowing there is not enough air in the tire.

i would say you might also benefit from some beefier tires like the exiwolf.
 
#12 ·
I run about 38 f&R. I'm 190. I've only flatted on my 29'er (not caused by valve ripping, seam splitting, or thorns) 1x in 2-1/2 years. I've been using Kenda's, IRC Notos, and now Maxxis Ign.

With out sounding like an ass, should you maybe look at how you are riding? Could it be a technique issue?
 
Save
Like Like
#13 ·
Geez - you guys really pump those things up.

Nano rear - 25psi

Exi front - never over 25psi - usually closer to 20-22 psi

1 pinch flat ever

155lb Sport rider on a rigid KM using 29" tubes

LP
 
#15 ·
One Niner with Nano's or Exi's [used both] at about 30/30 psi. I weigh 180 and ride mostly rocky / rooty technichal type singletracks.

I tend to ride "lightly" though, i'm more of a techy type rider than a 'steamroller'.

No flats, but plenty of scrape marks on the sidewalls of the nano's, less on the Exi's.

I run 29'er Salsa tubes.

R.
 
#17 ·
Exiwolf = tough

35psi front and rear
WTB Exiwolf front and rear (WTB tubes)
rider weight - 185lbs
1 flat this season (while climbing smooth fireroad - ?!?!)
mixed terrain - smooth with some rocky sections here and there (mostly Skegg's Point/Corte de Madera Open Space near SF, CA)
Uber fast downhill
No flats at Downieville, CA smashing into "chickenheads" at high speed (friend had 3 pinch flats when he rode his full rigid single speed 26er on the 14 mile downhill run)
 
Discussion starter · #18 ·
Well, judging by what some of you are saying, I think I may have pinpointed the problem.....GoKart brings up an interesting point. Going from a freeride bike to this bike and riding it the same way.

Guess I'll just experiment, and until I find what I need, I'll live with the flats..... :D
 
Save
Like Like
#19 ·
technique

I had more pinch flats w/ my 26er. W/ the decreased angle of attack there is no reason why a 29er should pinch more except the increased speed that the bigger wheel allows. It's a smoother ride right?

I've had one pinch this season and 3 last year. Most of them involved hitting very square rocks hard where I said to myself, "ah oh" then heard the psssssssss. I try to avoid those things now if I can. BTW, it's very rocky here in the rocky mountains. Mostly I try to ride as loose as possible. Let the arms and legs do the major absorbing. It can be a real workout on a long rocky descent.

I go about 30 front and 34 back. 190lbs. Occationally I feel the rim and know it's time to be more careful.
 
1 - 20 of 27 Posts
You have insufficient privileges to reply here.
About this Discussion
26 Replies
22 Participants
Last post:
BruceBrown
Mountain Bike Reviews Forum
posts
16M
members
534K
Since
1990
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Discussion Downhill - Freeride California - Norcal Shocks and Suspension Passion