# Using 2.1 tubes for 2.5 tires.



## Combatcm (Nov 15, 2005)

I'm not worried about weight, i've used 2.1 tubes as spares and they've worked fine, i just wanted to get some input on the this idea.

Does a DH tube really have more pinch flat resistance than a regular tube? If the tire hits hard and it pinch flats i don't think it would really matter the thickness of the tube it would flat anyway. As long as you keep the 2.1 tube pumped up enough to not pinch flat you shouldn't have a problem.

Anyone have any input or have run regular tubes with no problem?


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## jawdrop on hardtail (Dec 6, 2007)

I run regular tubes in my 2.5's, no problems and minimal flats. Beats the old 2.7 DH tubes that weighed a pound each that I previously ran.


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## XSL_WiLL (Nov 2, 2004)

I used DH tubes before. I thought they were stupid heavy. And they didn't do anything to prevent flatting.


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## cactuscorn (Feb 5, 2004)

same here. back in the olden days we used tr tubes. almost as bad as the dh stuff.

as long as the tire casing will hold form ad the psi is sufficiant, the tube will work. however, a way thin 2.1 xc tube streached to the max in a 2.5 tire will indeed be thinner so on paper, it will pinch with less force than a fitted xc or dh tube. ill run 2.25's in my light wheelset with my trusty nev/bg tire combo and kenda extremes in the burly set with 2 ply dhf/hr's. the extremes are somewhere between a 2.5 xc tube and a dh tube. did this on several reccomendations but ive yet to test em out.


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## essenmeinstuff (Sep 4, 2007)

I run "regular" tubes with no problems... 

Tubes are rated at 1.9-2.1 and I run them in 2.5's, mostly cos I'm cheap, they cost like $2 each, I carry spares and only had to use them once so far...


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## kenbentit (Jan 2, 2003)

I've tried "DH" tubes as well as oversized "Normal" tubes and got plenty of pinch flats with both. The normal tubes are less weight and less $$ so they make sense to me (also makes tubeless more appealing)....


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## kntr (Jan 25, 2004)

No problems here either. I run them in 2.7 Maxxis with no problems. I think talc helps more to prevent flats than bid old DH tubes.


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## William42 (Oct 29, 2006)

I run 1.5-1.75 tubes in 2.5 dual ply tires. Run proper pressure and pinch flats aren't nearly as much of a risk.


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## one incredible donkey (Jul 19, 2007)

I'm running DH tubes now and I'll be ditching them next time I have a chance to buy some normal tubes. They're overkill for the riding I do.


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## nolson (Aug 3, 2006)

don't kid yourself, dh tubes and dh tires are the ultimate in pinch flat protection. If you ride real dh trails that are steep and nasty, when pedaling isn't an issue, it's the way to go. you can mow through rocks and roots better and the heavy rotating weight makes the bike much more stable at high speed. having said that, 2.1 xc tubes work fine, and I prefer them when pedaling is a major factor.


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## sq225917 (Dec 28, 2008)

I run 1.5 latex tubes in 2.3's no issue, light, flexible and snake bite proof to all intents and purposes.


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## cactuscorn (Feb 5, 2004)

no shyt? ill need some kinda proof and a few pics of yer hot neighbor sunbathing to believe that.


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## nenja (Jul 8, 2007)

I run Conti's MTB tubes for my 2.5 tirers, no pinch flats for a while even though i run low preassure. I'm lightweight though.


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## CharacterZero (May 19, 2004)

*Pinch vs. Puncture*

I will say that a 2.1 tube in a 2.5 tire is more prone to PUNCTURE flats, due to how thin the walls become and the stress that is placed on them.

I know it wasn't what the OP asked, but it was the main reason that I found another solution for my tire inflation needs.


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## sq225917 (Dec 28, 2008)

cactus, would i lie to you? 

Latex tubes unlike butyl are highly elastic, they have way better elongation at tear, something like 800% vs butyls 200%. So they are much much harder to puncture and pinchflat.

I've used latex tubes in my road bike for nearly 20 years and in all that time i've had maybe a handful of punctures, and i use the thinnest lowest rolling rubber i can find, no puncture proof belts for me.

Same in my MTB's, i never flat when i'm running latex. First day out on my Demo, pop, psssssssst, butyl tube gone.... never punctured since.

I replace them every 12 months or so just to be safe..


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## cactuscorn (Feb 5, 2004)

ive been scared of latex from the start. they always seemed to split at the seams, literally. maybe its better now. yer 1 of the 1st who ive heard still uses them other than the occasional racer boy xc weight weenie. still, its hard to trust ya without those pics. get to it!


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