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Inner tube size

Old 06-10-21, 09:32 AM
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bikersworld
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Inner tube size

HI All

My new trek domane SL5 has 700Cx32 21mm Presta valve inner tube, it is flat now and I want to replace but not finding anything in amazon of similar size (21mm), is there a suggestion on what alternate tube I could use? This is the first time I am changing innertubes so is little confused.

Thanks.
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Old 06-10-21, 09:35 AM
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Are you wondering about the presta valve size or tube size?

any tube 700X28 or 700X32 range will work fine with no issues. The presta valve size doesn't matter at all as long as it long enough to go through the rim to add are. So you can probably get always with anything from 20mm-anysize.
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Old 06-10-21, 09:36 AM
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Thanks
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Old 06-10-21, 09:40 AM
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Get a patch kit-
https://www.amazon.com/Rema-Standard...84978276&psc=1
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Old 06-10-21, 09:49 AM
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Originally Posted by bikersworld View Post
HI All

My new trek domane SL5 has 700Cx32 21mm Presta valve inner tube, it is flat now and I want to replace but not finding anything in amazon of similar size (21mm), is there a suggestion on what alternate tube I could use? This is the first time I am changing innertubes so is little confused.

Thanks.
If the 21mm refers to the valve length, that seems pretty short.. 21mm = less than an inch (0.82").

Where did you get the 21mm number from?
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Old 06-10-21, 10:26 AM
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The shortest presta valve we stock is 48mm. 21 is stupid short, I've never in my life seen one that size.
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Old 06-10-21, 12:12 PM
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Go down to your local shop, they probably will have tubes. Agreed with cxwrench that is a super short valve. We have some 32s but that is about as short as I could fathom. 48 is plenty short.

Tubes will also have a range so you just need to make sure you tire size falls within that range and has the correct valve and you are OK. Your local shop can easily help with that and if you aren't feeling frisky you can have them replace it and you can go grab a nice frosty cold one or get riding faster.
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Old 06-10-21, 12:57 PM
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Tubes generally are made to fit a range of tire widths. Ideally, you want the tube to fit in the tire with no excess material to cause kinks and wrinkles which will just be wear to make a near future flat. And maybe a bumpy ride because air pressure isn't supporting the tire evenly.

On the other extreme, a tube that has to stretch and expand to fill the tire will tend to act like a balloon when punctured. So when flats happen, they'll be all at once instead of slow leaks that give you time to pick where you want to stop.
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Old 06-10-21, 01:39 PM
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Lots of excellent advice in the posts above.
Sometimes there are 'overlapping' size ranges in tubes.
For example, Continental tubes on one website are listed in 25-32 mm and 32-42 and 32-47 sizes.
For a 32 mm tire, for example, I'd pick the smaller tube option as it seems to reduce my chances of damaging the tube when I install it
Damaging a tube while I'm installing it in the basement shop isn't a big deal, but I did that once at the roadside and it was irritating.
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Old 06-10-21, 02:37 PM
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The 21 mm is the width of the rim. This number has little to do with the size of the inner tube. You'll want to choose a tube size appropriate to your tire size, i.e. in your case, 32 mm. The advice above to get a patch kit is excellent. Patching is reliable and quick; much quicker than trying to find a new tube.


From the Trek website:

Rim: Bontrager Affinity Disc, Tubeless Ready, 24-hole, 21mm width, presta valve
Tire: Bontrager R1 Hard-Case Lite, wire bead, 60 tpi, 700x32c
Max tire size 38c
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