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3 popped tubes

2K views 26 replies 14 participants last post by  jakester29959 
#1 ·
ok so i was downhilling today and i popped yet another tube. I have kenda el moco 2.35 tires on them and i am running them with 40 psi in them. Is it the tire thats making it eat up tubes? I am not hitting anything wicked hard and i only bottomed out once or twice. So far i have popped my rear once and my front twice. should i get new tires?

thanks
 
#9 ·
OK, now I will be helpful. What do you mean by "pop"? There are 4 kinds of flats you can experience with tubes.

1. Puncture. Something went thru your tire and into your tube. A thorn, a nail, the sharp tip of a rock. When inspecting your tube you will see one hole and usually the culprit, ie. the remnants of the thorn, a nail, etc. Remove the remnants from your tire or it will happen again. Solution: get a tube with slime in it, run thorn strips.

2. Pinch flat. Could be many reasons, but mostly too low air pressure, too narrow of a rim, too flimsy of a tire, too thin of a tube. When inspecting the tube, you will see 2 slits that look like a snakebite. Solution: More air (40 is enough) wider rims, stronger tire, stronger tube.

3. Sliced sidewall causing tube to ooze thru. This will be quite visible as the tube will pop out thru a hole or slice in the tire. Solution: new tire or sew in a tire boot.

4. Bad valve stem. Often overlooked. Are you presta or schraeder? With either you can have a bad valve, or it could be gunked up, or have a small tear near the tube junction. Solution, clean valve or replace if broken.

So which one of these scenarios is the one you are having to deal with? It will help us better help you.

Seriously though, look into running tubeless.
 
#6 ·
Im surprised with 40psi and your popping tubes ?? I rode in thick chunky rocks with like 25psi with tubes and im a 200lb rider and never pinched or popped..

I would def inspect your rim and see if there is something inside that might be sharp edged , cuz you def shouldnt be popping that much lol ..
 
#7 ·
You may not think this is relevant, but it definitely is. Look into ghetto tubeless conversions. It is super easy to do, costs less than 4 good quality tubes, and is incredibly reliable. I haven't had a flat in two years. Definitely check your rims for problems, but it sounds like it's time for you to convert to the Stan's Side.
 
#10 ·
as the other guys have said, check the tyre for damage/foreign objects, also check the rim for damage,,, is the rim tape ok, are any of your spoke sticking through,,,
both my brother and myself used to run kenda tyres, (nevegal) we always used to get punctures with those things, as the side walls were to soft, even running them at 40+ psi, we now use maxxis tyres, col runs minions on his chromag stylus and ns soda, and advatage on his santa cruz butcher the minnions on his ns soda are dual ply dh ones, and his other 2 bikes are single ply,
on my bikes (chromag stylus, knolly dt) i run high rollers both dual ply dh, for the past 4 years on my hardtail i have run swampthings dualply dh,
we do get the occaisional puncture usually caused by hitting somthing hard like a rock or root,
when my swampthings wore out back in march, i thought i would try something differant, i got a pair of schwalbe hans damf, i had 3 punctures in 3 rides, even running them with almost 50 psi i was still flatting, as the side walls were to soft, so i binned them off and went back to maxxis,
 
#11 · (Edited)
when/if you check, use a rag or something soft so the fabric will get caught on the bur or FOD. check the tire real good too. somehow mark the tire/tube/rim. pump up the tube a lot and find the leak so you can zero in on the problem area.

i'm not a weight weenie, when i was stationed in Utah i double tube both my dh and xc bikes with the thicker thorn resistant tubes. why? them huge UT "goat-head" thorns would still sneak through the thorn resistant tubes. doubling up alleviated the issue.
 
#20 ·
I had a period there where I pinched with 40 lbs.... except I was mistaken.... a slow leak had left me with lower pressure, which I didn't check before every ride.

Now I always check before every ride (and run like 30-35) and I don't think I have pinched since. Don't rely on the thumb test-check the pressure to be sure. Even on a longer ride, a slow leak won't have much effect, but over the course of a week, it may.

If you do check pressure before rides, then never mind. Just wanted to throw that out there.
 
#16 ·
Kenda - El Moco

Do you have the wire bead el mocos, or the kevlar? The wire bead ones have cap ply protection - a thin strip to prevent the sidewall from flexing and allowing the rim to pinch your tube. If you have the kevlar, ditch them. 700g for a 2.35 tire is tempting for weight, but single-ply tires with thin sidewalls just can't hold up to heavy riding, more likely to burp if you go tubeless too.

Another thing - make sure you get a tube sized for your tire. The ones sized ~2.0-2.5 won't stretch as much as the little ones typically sized ~1.6-2.1.
 
#18 ·
i have seen a few people puncture on tubless set up is it really worth the hassle and expense if you still get punctures. not only that but the mess it leaves as well. when my mate pinched his rear tyre in whistler bikepark, he looked like an elephant had spunked its loads over his back, ha ha ha, the hole in the tyre was to big for the sealant to seal, he ended up having to throw a tube in there so he could ride down to the villeage.
 
#25 ·
+1

I suppose if you really want to use a regular (automotive) gauge, then a presta-shrader converter could be used, they are pretty cheap.

But having owned a pump with a built-in gauge for several years now, I don't know how I ever lived without it before.

It is never a surprise anymore when that tire that was at 32 last week (and still "feels" like 32 today) is actually at 25 or so.
 
#26 ·
I only use schrader valves, they are way more reliable and easy to use. I set my pressure using a large diameter gauge with bleed button made for the circle track race cars. No problem getting +/- 1/2 lb. Gauges on pumps get you within 5 lbs, ok if you run 40+ psi, but when you get down below 30, you need a better gauge.
 
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