DH inner tubes - do we really need them?

[Nautonier]

I took the tires of my new DH bike for the first time today and discovered that I am packing 1kg worth of rubber in the form of the heaviest weight DH tubes. I thought the bike was kinda heavier than it should be...

Question is, with a double wall DH tire (2.5 minion), is it really necessary to run full DH tubes front and back? I was thinking of putting a standard weight in the front and a mid weight (FR) in the back to save about 400g, what do other people run and will a FR tube in the back pinch-flat with a DH tire?

 

[nicknopants]

I run 1.9 kenda tubes in my 2.5 minions. Maybe its just me, but I get no more flats than I do if I run bigger DH tubes.

 

[tim_d]

I guess it depends how smooth you are, how rocky/rough the tracks you ride are, how low pressure you run your tyres etc.
Give the lighter tubes a go, if you start pinch flatting/getting punctures regularly, put the DH tubes back in. They're made for a reason. That's all there is to it

 

[scuba05]

Im running a 2.5 Minion F on the front, and a 2.5 highroller on the back, with standard 2.35 tubes. I think in the entire time iv had my bike(18mths), i may have had a max of 3 flats. I'm not the smoothest, or hack rider, but have never seemed to get pinch flats.
I do think running DH tubes are a bit excessive. Its A LOT of extra rotating mass, which makes the bike harder to change directions.
The advantage of using DH tubes, which are usually 2.5/2.7 is you can run much lower PSI.

Give it a go with normal 2.35 tubes. DON'T get something like 1.9/2.1 or something, as you will pinch flat like you wouldn't believe.

 

[thecat]

Throw a tubeless kit in and do away with the tubes altogether

 

[Ducky Punk]

Never got tubless

run normal tubes dh tires are thicker as and as long as you dont run silly low PSI you cant really flat cos glass and sharp stuff cant really get through that

 

[TheBug]

Definitely try an FR tube in the front straight off the bat and go from there.
I cannot stand getting DH tires on and off so I put up with the heft of rear DH tubes for the sake of my sanity. The buggers are bombproof.

 

[T-Rex]

you cant really flat cos glass and sharp stuff cant really get through that

Mmmm....

Pinch flats are caused by the rim getting driven through the tube, not the terrain or any sharp stuff puncturing the tyre casing. If you have a look at a tube that has been pinch flatted, it's got two cuts on the inside, caused by the rim. Not saying external punctures don't happen in DH, they do, but no where near as often as pinch flats.

Which brings into the discussion another variable not yet mentioned, which is how soft your rim is. A soft rim will be more inclined to bend rather than just drive itself through the tube. That's why pros use soft rims such as 721s. However, the downside is that the rims don't last as long as a harder rim. A cheaper example of a soft rim is the MTX.

But if you are really hung up on rotating mass and avoiding pinch flats, take thecat's advice and go tubeless. Ghetto tubeless is not that expensive, and if you use Stans and normal tyres, saves heaps of weigh.

 

[jacko13]

Downhill tubes are over rated. i run normal 1.9/2.1 or whatever they are xc tubes, only flats ive gotten on my new bike was from thorns, no pinches.
With my old bike i got one flat, and that was when i was trying out a single ply tire (bad idea) at a place that is quite rocky.

Also, normal tubes are about 3-4 times cheaper if you do flat them

 

[S.]

Depends on how heavy you are, where you ride and how you ride. Personally I'd never bother with anything other than a DH tube (on the rear at least) simply because freeride tubes usually don't last me even one run, let alone XC tubes, but then again I'm 90kg, not very smooth, and often ride fairly rocky stuff.

Tubeless is good for preventing pinch flats and lighter weight but it has a few distinct disadvantages in the form of being a pain in the arse to fit, messy, and prone to burping when you corner hard. By the time you run sufficient pressure for it not to burp, you're well over the pressure you'd run with tubes in order to not pinchflat.

 

[October26]

Running DH tubes on dual ply tyres I have had one flat in 6 years of riding DH.
I run just under 30psi.
I am NOT SMOOTH.
Also I weight 100+kg!

I would love to drop weight but I am slow anyway so it's not going to make much difference!

 

[thecat]

Tubeless is good for preventing pinch flats and lighter weight but it has a few distinct disadvantages in the form of being a pain in the arse to fit, messy, and prone to burping when you corner hard. By the time you run sufficient pressure for it not to burp, you're well over the pressure you'd run with tubes in order to not pinchflat.

Must depend on the tyre/tube combo. I'm 95kg just now. Run a tubless kit in Syncross rims with Ardent tyres. Run them at 25psi and have never had them burp.

I'm not the fastest guy out there and I have no style but I'm not the slowest on the hill either.

 

[scuba05]

Im 85kg, riding dual ply sidewall 2.5 minion and high roller, on WTB laser rim's (i think thats what they are called, rubbish rims). I have put in an XC tube (1.9/2.1), and flatted it on the 1st run with it. Will never bother with those again.
I've used free-ride tubes. Never had a problem(no flats), but tried to skimp some weight away with the normal 2.35's, and have never looked back. And at $8 from TBSM, it's a bargain.

I swear when i changed between DH, FR & normal tubes on the same bike, i can feel the difference. The bike doesnt want to lean or change direction at all. So its a cheap(very cheap) fix, which gave me a bit of performance. Considering my bike weights 20+ still, its not that big, but it is rotating mass.

PS: I'm definatly no weight weenie either. Everything bar tyres & tubes is stock after 18mths

 

[jjperko]

I use normal tubes also. I'm a bit sceptical of tubeless as a normal race weekend would involve dinted rims. Does that allow air out?

 

[Nautonier]

Some very interesting and helpful perspectives. I'm only 75kg kitted up, but I'm new to DH so probably a rather un-smooth rider. I ride the You Yangs a lot where there are some serious rock gardens etc and do like to run low PSI, like about 20 - 25. I think I will try a 2.3 FR front and back and maybe up the PSI a little and see how I go. If I start pinch-flatting the back I will stick the DH tube back in and just deal with the weight. I'm reluctant to go tubeless as I've heard a lot of bad things about the "burping" phenomenon and really don't like having to run my tires up around 30 PSI+ as the bike just feels bony as.

 

[spinner]

When fitting your new tubes rub talcum powder all over them , don't spare the stuff either , really chuck it on there. It stops your tube and tyre "sticking" to eachother so that when you do fold the sidewall together hitting a big rock at 25psi , there's less chance your tube will get caught in the fold and pinch flat.

Try increasing the pressure as you get more riding experience too mate. You'll roll easier and get less flats.

I run Maxxis freeride tubes and 2.5 Minions at around 30 psi and get one or two flats a year. They are a good compromise between weight and reliability.

 

[Nautonier]

just tried a normal tube in the front, a freeride in the back, upped the PSI just a little and after hammering some known pinch-flat inducing rock gardens it all held up just fine. after shedding 500g i actually really noticed the performance increase as well, the bike felt heaps more chuckable and i swear it was getting more lift on the jumps.

just got to get myself some talc powder now...

 

[ben_rides_a_bike]

I run whatever the fuck big-W sells in my 2.5 Minions, Awesome.

 

[scuba05]

I run whatever the fuck big-W sells in my 2.5 Minions, Awesome.

***shudders***
The old 1.9/2.1? Or the 1.75/1.9? Those things are so shit, as you need to crank the PSI to fill the tyre.

Put it this way, are you happy putting a $5 P.O.S. into a cople of grand bike, and putting your faith in them? If you are, good for you, but i certainly aint!

But, horses for courses

 

[ben_rides_a_bike]

***shudders***
The old 1.9/2.1? Or the 1.75/1.9? Those things are so shit, as you need to crank the PSI to fill the tyre.

Put it this way, are you happy putting a $5 P.O.S. into a cople of grand bike, and putting your faith in them? If you are, good for you, but i certainly aint!

But, horses for courses

They are soo good!

Dont diss em for what the worth, never had a flat, id put my faith in them anyday.