Inner Tube Weight
 

A traditional tube filled with air are lighter and more shock absorbent than the airless-foam (and thus anti flat) version.

However, I have heard that some of you received so many flats with the traditional air tube that there is an entire layer of patches around the tube.
I'm just curious: how many layers of patches does it take before the air tube weighs as much as the airless-foam tube?

Figures I've seen for the 'Airfree' foam tube inserts have been around 300g per tube as compared to about 100g for a light normal tube. So the weight penalty is about 200g. 16mm Rema patches weigh about 50g for a box of 100, so about 400 patches would need to be added to add 200g to the original tube. Some of my tubes may have 5 or 6 patches, but I doubt anyone has ever gotten up to 400 patches before opting for a new tube. [And that's an underestimate since some of the patch weight is due to the foil backing which is thrown away.]

But the main issue with the foam-filled tubes isn't the weight but that they are not as resilient as an air-filled tube. That results in both higher rolling resistance (more energy lost when compressing the tube at the contact patch) and a harsher ride. I find the weight penalty to be pretty insignificant compared to both of these drawbacks.

Thanks for the informative post. I'm a bit tired with flats despite buying protections, so I was thinking about buying the airless foam version.

I already knew that these foam tubes lack shock absorption, but I did not know that they are also energy inefficient.

Inner Tube Weight
 

What tyres are you running? I have great experience with Continental GP Four Seasons, Gatorskins and Schwalbe Marathon Plus.
The SMP's are heavy but bombproof, as can be attested by many here and in the touring forum.

Expensive these tyres are, but well worth it to avoid flats, as well as their longevity.

When I do get a flat it's usually a sign the tyre's so worn it's time to buy a new one

No one has come up with something better than the pneumatic tire after all these years. Maybe one day they will, but I'm not holding my breath.

Bike tires are necessarily very vulnerable to punctures. This is because if they were invulnerable, they wouldn't ride worth a damn. Bikes have to be light. There are breakthroughs lately where puncture resistance rises with ride quality not going down, at least not by much. The tradeoff there is cost. Schwalbe and Continental seem to be at the front of the innovation curve, by the reports. Don't cheap out on tires. They make more difference than anything else on your bike. Treat yourself.

When in Paris, I noticed all of the Velib bikes (their bike share) had Schwalbe Marathon Plus tires on them. If it's good enough for that - yeah they are on my list.

Thanks for the advices guys.

Specialized Hemisphere I believe.

Door number 3..

Thorn Resistant Inner tubes have a lot more Rubber in them, and its thicker on the Outside ,

Rode a Puncture Free 9 months on a Bike tour using a pair. 700c-40 p/v

+ they hold air Longer..

now I Have 26" in the winter Ice Bike (studded tires) , 20" in 1 bike trailer and the Bike Friday, and 12.5" in the other bike trailer. s/v

Spec'd sells four different Hemisphere tires. The Armadillo line is their puncture resistant line. If you have a regular, run-of-the-mill Hemisphere you might do well to get a different tire with a flat protection barrier.

Use the Maxxis Re-Fuse folding tires 700x25 on both our tandem and my single racing bike.
Mileage between both bikes in one year was a tad over 5,000 miles. Had 2 flats; one of them was a patch that came loose.
Your results may vary; we do live in the AZ desert with more opportunities for punctures, especially thorns/poatheads.

I was tired of flats too, before outfitting both my commuters with Marathon Plus more than a year ago. Haven't had a flat since.

I've found that every bike purchased in a store, even a high end bike, needs proper tires added to it since the ones it came with are invariably crap. The only reason these manufacturers/stores get away with it year after year is that most people only ride their bikes three or four times and then forget about them. If you ride daily, you need proper tires.

My bicycle came with Hemisphere Ex based on the label. People said that it's one of the best budget commuting tyres since it wears out more slowly than other tyres. This seems true after 2 years of regular use.

But I guess I will try the Armadillo.

This is why the marathon plus is puncture resistant on the tread:

http://4.bp.blogspot.com/-mrAmpbtvnN...thonPlus-1.jpg

What i have to wonder is how compressible that blue stuff is.

My kenda kwick trax (26x1.75) has not gotten a puncture since i put it on & i'm not really riding any differently vs my previous set on my old bike which had just had 3 flats in a year on rear and 2 in the front, and those were nimbus something or other.

- Andy

That is a lot of blue stuff in the Marathon. What is it? Colored Rubber?

I'm running a 25mm Marathon on the back of my bike. I got the first flat in the first 50 miles. I managed to pick up a piece of glass the size of my pinky fingernail. It couldn't have been in the tire too long since it was sticking out a bit when I found it, and came out in one piece. But, it cut right down through the black, blue, some cords and into the tube quickly. I've now booted the tire, but originally enough cords remained that I rode it for a while without a boot.

I do like the tire, and hope it will be good for the rest of the winter. Traction is good. But it isn't impenetrable.

As far as the foam. Go to a tire shop. They do foam forklift and offroad tires. THEY ARE HEAVY. I might consider the foam, but don't want a 10 pound bike tire.

I've been using Schwalbe Marathon Plus since they came out. I put the same mileage on my car as I do on my bike, and the Schwalbe has had fewer flats. I think "exceeds the performance of car tires" is a reasonable metric for acceptability.

I know that tire width is not really I important when it comes to efficiency, but is a 1.75 inch tire noticeably faster than a 1.95 inch version (assuming same thread)?

To prevent flats keep your tires pumped to proper pressure and check them before each ride. Expect to pump at least once a week, sometimes more, sometimes less depending on tires and other numerous factors. Inspect your tires regularly to make sure they aren't worn out and replace them if they are (Gatorskins are my favorite commuter tires, the hardshell version offers a bit more protection) Don't jump off of curbs and do your best to avoid potholes, glass, and other nasties.

When you get a flat make sure to inspect the tire inside and out, the rim, the rim strip and the tube. I tend to at the very least wipe them out but a little cleaning isn't a bad idea. If you find some rough stuff inside the rim where the tube would sit uncovered you might want to use some finer sandpaper and smooth things out.

Also make sure your brakes are properly aligned so they don't rub on the tire (if your wheel is out of true this is a more or less useless gesture so keep it trued)

Avoid any flat free tires. If they were good, shops would stock those instead of tubes and more people would use them. They give such a poor ride which many have already addressed.

Inner Tube Weight
 

As much as they have great puncture protection thanks to all that extra rubber, SMP's are heavy, sluggish and bouncy.

If not in goathead territory, I much prefer the speed and ride feel of Gatorskins and Gator Hardshells

Probably some kinda polyurethane/vinyl mix. This is the one part of car-free that still bugs me, i wish i could find and afford tires that were made from renewable/sustainable materials. But, eh, what can you do?

- Andy

Wooden wheels with iron tires were around for a long, long time.

I would love some kind of plant derived material for wheels and tires. :)

- Andy