replacement tube recs?

[ebiisoo]

This is my first season mountain biking, and I have been out on about 5 beginner-advanced novice rides so far. But I have already had two rear puncture (not pinch) flats. They were both slow leaks and I didn't notice anything until the next day when my rear tire was completely flat.

The first flat was in the tube that came with my new full suspension mountain bike, and the second was a Bontrager replacement tube (26 x 2.1) that I bought from my LBS.

I got the first flat after riding the Middlesex Fells and the second one after riding in Wompatuck. I checked the inside and outside of my tire and I didn't see anything, and both punctures were in different places on the tube, relative to the valve stem.

I've patched both tubes and put the original tube back on my bike. I've been riding with my rear tire inflated to about 50 psi, and my bike has knobby Kenda tires on it. I am about 5'10" and 165 pounds.

Am I doing anything wrong, or is this normal for mountain biking? Any recs on what kind of replacement tubes to buy and from where? I was looking at the Slime Lite or the Maxxis Presta DH tube (1.5mm thick) tube on the Nashbar and JensonUSA bike pages.

[Curtis Chase]

Make sure you're getting whatever it is that's giving you flats out of the tire. Most of the time whatever it is that punctured stays in the tire. I know you mentioned that the punctures were in different places relative to the valve stem, but it's possible it's the same thorn/glass/metal shard that's given you both flats. If you put a new tube in a tire with a thorn still in it, the results will be the same.

[steveeldr]

ditto what Curtis said. When you changed the tube you took the tire off and put it back on, the foreign object would most likely be in a different location relative to the tube now.

I run slime tubes after years of living with flats (sometimes 2 or 3 on a ride and always as far from the car as possible:mad: I've had the same slime tubes on my bike for a few years now, I have had flats but just pump the tire up a bit, spin it a few times then pump up the rest of the way and off I go.:)

[pulsepro]

ditto what Curtis said. When you changed the tube you took the tire off and put it back on, the foreign object would most likely be in a different location relative to the tube now.

I run slime tubes after years of living with flats (sometimes 2 or 3 on a ride and always as far from the car as possible:mad: I've had the same slime tubes on my bike for a few years now, I have had flats but just pump the tire up a bit, spin it a few times then pump up the rest of the way and off I go.:)


Be sure to check that your rim strip/tape is staying put and doing it's job. Also, don't run 50 psi. Try 30-35 psi.

[thomllama]

go to walmart and get slime tubes... unless you are a weight wennie you'll never have an issue again. last time I yanked my tires there was somewhere around 10 thorns.. tire was still full of air.

I got to say that even I think 50lbs is a bit high. it's not a road bike. I run mine around 40-45. I like to go lower for traction but under that I feel like it's wobbling. Sorta make me feel like the axle bearings are loose.

[SteveC]

ditto on the lower psi. With your weight, you should be able to run 35 no problem. You can also slime the tubes you have, by removing the valve, and squirting in 2-3 oz of the stuff. You can buy slime at any bike shop. You won't flat again unless you run too low psi and bottom out, or if you slice the tire with glass.....the stuff really works.

[heckler]

As soon as I saw your post, I guessed the Fells! The Fells is full of thorns. They go by lots of names (green briar, for one) but they are green, leafless and extremely deadly to tubes. Look very closely at the inside of your tire. They are so small it takes a while for them to puncture the new tube. But they will! Sadly the easiest way to find them is to run your fingers along the inside of the tire and wait to bleed. It will be a small bleed but... You can see usually see them from the outside but in eithr case, you need to get those out!