chiron47

I just switched to tubeless this season and while they have held up great for training..no flats and watched stans fill a hole after pulling out a big rusty nail - but I have had 2 flats in 3 races. Both were rock punctures in the tread that were just too big for the Stan's to fill. The terrain may have been only slightly more rocky and I may have been going only slightly faster - but 2 rock punctures? I have been mountain biking on a hard tail for 12 of the 13 years - and have had a lot of flats (tacks, thorns, nails, pinches etc)- but never rocks puncturing the tread area of a tire.

So - any ideas out there? Is it just chance that I did this (twice) for the first time on tubeless tires? maybe the Epic shock system just couldn't react fast enough to allow shock travel before a rock went through? or is there something in a tubless setup that makes this more likely?

Running Panaracer Fire XC pro (last time was panaracer smoke) on DT swiss 420 with Stan's fluid at 32 psi.

Darth_Firebolt

how much do you weigh? 32psi on tubeless? i thought the point of tubeless was so you could get stupid low PSI without the pinch flats?

Smallguy

are you using UST tires or using Stan's in regular tires ?

I've been using Maxxis ADvantage tires and absolutely love em ... i bought the UST tires and I'm still using Stan's for the extra safety.... I've been hammering rock gardens and so far so good

I'm 205 and I'm running 25-30 psi

if your not using a ust tire I'd recommend switching to one

2runco

I converted my '10 Epic to tubeless a couple of months ago, and have not had any flats or problems. Only one race, next is first week of Sep. My tires are Specialized Captain on front, and Fast Trac on back. As someone else suggested, you might try lower pressure. I currently use 25 front and 28 rear, but still experimenting with this and may lower it a bit more. Love the overall ride feel and improved climbing traction with lower pressure. The trails around here are only moderately rocky, and I'm a fairly light rider (150#), so your situation may be more severe.
Good luck.

chiron47

Thanks guys.
I weigh 175 and am running non-UST tires with Stan's.
I know a lot of people run lower pressures since you don't have to worry about pinch flats - but it doesn't mean you don't have to worry about bending wheels!...so I keep it around 30. The change in feel is still noticeable and I haven't found a need to lower them any more for more traction.

I am going to try it one more time and see how it does....