I realized the importance of inflating the tires on my bike when I went out to get it ready for a ride. I noticed that the tires were a bit low, so I grabbed the tire pump and pumped them up. I then rode my e-bike to my appointment and it wasn't until later when I got home that I realized how much better my bike performed with properly inflated tires.
Properly inflating tires
- Thread starter kev1940
- Start date
1. Both tires are equipped with tire sealant, which made me question if there are any slow leaks in them when I noticed the back tire and the front tire were low. This also reminded me of someone mentioning that sealant can dry up, so I believe it's necessary to inspect my tires for any punctures.
mrgold35
Well-Known Member
Seems like my fat tire ebikes and the wife's 2.3" plus size tires ebikes drop 1-3 psi per week. I have Stan's tire sealant, Mr. Tuffy liners, or Tannus Amour on all of them. I'm sometimes surprised how low my wife's psi can drop +20 and still feel and ride A-OK (she is 4'11" and 125lbs).
Might be worth getting a Li-On battery inflater. I purchased a Fanttik X8 150psi rechargeable air pump at the end of summer (Amazon, $50 on sale). It is small enough to toss in my rack bag. I got in the habit of checking once a week or right before a ride if we haven't taken them out for a few weeks. It is powerful enough to use on my cars.
Might be worth getting a Li-On battery inflater. I purchased a Fanttik X8 150psi rechargeable air pump at the end of summer (Amazon, $50 on sale). It is small enough to toss in my rack bag. I got in the habit of checking once a week or right before a ride if we haven't taken them out for a few weeks. It is powerful enough to use on my cars.
Yup, fat tires seem to loose a tad bit more of pressure compared to regular size tires it seems. If unsure check that the valve core is tight/seated, sometimes they arrive on the loose end. You can buy low air loss inner tubes (I never knew such a thing existed) as well. As the weather drops to colder temps you'll notice a bit more air loss. I fully agree with mrgold35 on buying a small air pump. I have a compressor in my garage and I make it a habit to check tire pressure (Subaru owner) on a regular basis.
Does this pump work with Presta valves?
mrgold35
Well-Known Member
The Fanttik X8 pump comes with a brass Presta valve adapter (the one below the air pump needle in the picture above).
spokewrench
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I remember a time when if a butyl tube was low, you knew you had a puncture. I replaced the tubes in my Radrunner and my Radmission because I was tired of having low tires catch me by surprise. The replacement tubes seem to be better, but they still seep.
I decided to document how fast. On my compressor hose I have an inflator/bleeder with a digital gage and a ball chuck with a clip. At intervals of about a week I'd close the drain valve in the compressor, turn it on, and check the sidewall temperature of the four tires, in the garage. I'd note the pressure I found in each tire and the pressure reading after I'd added air.
I set up a spreadsheet. For each entry, it would temperature-adjust the previous PSI by adding 459.67 to both temperatures and multiplying the old PSI by the ratio. I'd divide the change in pressure by the elapsed days and multiply by 7 to present a weekly change.
The changes for a tube were not consistent. One is especially odd, gaining pressure in 4 out of 8 checks. I use a ball chuck with a clip because I can normally apply and remove it without a hiss or even a pop of escaping air. If I lost a little air, that would show up as a decrease, not an increase. If my gauge were flaky, registered increases would show up on all four tires.
One cause of pressure loss in big-rig tubeless tires is the absorption of oxygen in oxidizing stuff on the interior of the tire; that's why a new tire looses pressure faster than one a year old. I guess it could work the other way around, where oxidation causes off-gassing, and one O2 molecule could produce two gas molecules from oxidation. I wonder why the tube that sometimes gains pressure is different from the other one I bought at the same time for that bike, and why of loses as often as it gains.
I decided to document how fast. On my compressor hose I have an inflator/bleeder with a digital gage and a ball chuck with a clip. At intervals of about a week I'd close the drain valve in the compressor, turn it on, and check the sidewall temperature of the four tires, in the garage. I'd note the pressure I found in each tire and the pressure reading after I'd added air.
I set up a spreadsheet. For each entry, it would temperature-adjust the previous PSI by adding 459.67 to both temperatures and multiplying the old PSI by the ratio. I'd divide the change in pressure by the elapsed days and multiply by 7 to present a weekly change.
The changes for a tube were not consistent. One is especially odd, gaining pressure in 4 out of 8 checks. I use a ball chuck with a clip because I can normally apply and remove it without a hiss or even a pop of escaping air. If I lost a little air, that would show up as a decrease, not an increase. If my gauge were flaky, registered increases would show up on all four tires.
One cause of pressure loss in big-rig tubeless tires is the absorption of oxygen in oxidizing stuff on the interior of the tire; that's why a new tire looses pressure faster than one a year old. I guess it could work the other way around, where oxidation causes off-gassing, and one O2 molecule could produce two gas molecules from oxidation. I wonder why the tube that sometimes gains pressure is different from the other one I bought at the same time for that bike, and why of loses as often as it gains.
spokewrench
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I read about a Consumer Reports test, maybe in 2011. They took 30 pairs of new tubeless automobile tires, inflating one of each kind with air and its identical mate with nitrogen. They put them in storage and checked the pressure a year later. The nitrogen tires lost less, but, as the air tires averaged about 2 psi a year, the magazine said nitrogen was just a costly dealer option.
I don't see how O2 molecules could seep through rubber faster than N2. A car tire at 30 psi might have 40 grams of oxygen. I think absorption of some of this oxygen in oxidation of the tire, caused the difference in pressure. That's why nitrogen may be cost effective in commercial tires, which are so expensive that they are recapped as many times as possible. Without oxygen, the cords in the carcass stay strong longer. If using nitrogen gets you an extra recap, it may be worth the cost.
Car racers went to nitrogen because the pressure rose less as a tire got hot in a race. Suppose you wanted 10 psi at 140 F. At 77 F before the race, you'd set them at 9 psi. If the driver reported poor handling on a test lap, they might find the pressure had risen to 12.5, not 10. That didn't happen with nitrogen.
I think they were barking up the wrong tree. I can't explain the difference unless there was water in the tire at room temperature, probably part of a lubricant used in mounting the tire. Raising the tire temperature from 77 to 140 would increase the vapor pressure about 2.5 psi. When they put nitrogen in a tire, they inflate and deflate it several times to purge air that was in it. That would dry up any water left from mounting. You could purge a tire just as well with air from a compressor tank, which at 10 psi is dry like desert air.
I don't see how O2 molecules could seep through rubber faster than N2. A car tire at 30 psi might have 40 grams of oxygen. I think absorption of some of this oxygen in oxidation of the tire, caused the difference in pressure. That's why nitrogen may be cost effective in commercial tires, which are so expensive that they are recapped as many times as possible. Without oxygen, the cords in the carcass stay strong longer. If using nitrogen gets you an extra recap, it may be worth the cost.
Car racers went to nitrogen because the pressure rose less as a tire got hot in a race. Suppose you wanted 10 psi at 140 F. At 77 F before the race, you'd set them at 9 psi. If the driver reported poor handling on a test lap, they might find the pressure had risen to 12.5, not 10. That didn't happen with nitrogen.
I think they were barking up the wrong tree. I can't explain the difference unless there was water in the tire at room temperature, probably part of a lubricant used in mounting the tire. Raising the tire temperature from 77 to 140 would increase the vapor pressure about 2.5 psi. When they put nitrogen in a tire, they inflate and deflate it several times to purge air that was in it. That would dry up any water left from mounting. You could purge a tire just as well with air from a compressor tank, which at 10 psi is dry like desert air.
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circuitsmith
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It's been my observation that (car and bicycle) tires lose air faster when they're being used than when sitting still.
So the slower diffusion of nitrogen might be more noticeable in actual use.
I commuted to work by bike for 31 years and drove the car only once or twice a week.
Going on a road trip vacation and leaving the bike at home made the difference obvious.
When bike commuting I'd add air to the bike tires every week or two.
Now retired and riding little in the winter (mainly a 2 mile jaunt to the grocery store a couple times a week) I only need to check the bike tires once a month.
I'm riding on 26"x2" Schwalbe Marathons and Michelin Air-Stop tubes.
spokewrench
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At first, both my Radrunner tires lost air fast. Now I wish I'd kept a log of the dates I checked and how much they'd lost.
Before long, the front was holding pressure much better, which was a mystery to me. The back still lost air pretty fast. Then it got erratic. It might hold pressure several days and go flat overnight. I took the tube out, put air in it, and patiently held it under water, section by section. Not a bubble. I replaced the valve core. I finally found the leak by holding the tube under water after pumping it up larger than the tire. It was a hole so small that it leaked only sometimes. I thought it was a manufacturing flaw. I patched it.
Soon there was another leak. It, too, was on the centerline. Apparently there was something in the tire, but I couldn't see or feel it. When I got a third puncture, I marked the sidewall at the valve. When I found the leak, I matched the tube to the tire to find the spot in the tire. It was a hair-thin wire 1/4 inch long, right through a knob on the tread. I couldn't believe something that thin could penetrate 1/4 inch of tire rubber without bending or breaking, instead.
There were no more punctures, but the rear tire continued to need air pretty frequently, as if the tube were porous. There you have it: two tubes of the same kind and age, ridden every day, but one holds air like yours in the garage.
I'd ridden on butyl rubber tubes from 1954 to 1972. They didn't lose air unless there was a leak. Bicycle tubes are normally butyl because it's cheaper. I think I've figured it out. In the 1950s and 1960s, halobutyl rubber was developed. It would cure faster than the old butyl and could be mixed with natural rubber or styrene-butadiene rubber (which makes tough tread rubber).
One advantage to butyl rubber is that it doesn't oxidize; loudspeaker manufacturers are changing from foam surrounds, which rot, to butyl, which doesn't. A disadvantage is that even a nail-sized puncture can cause it to deflate like a gunshot. That was no problem on a traditional English bike, but on a "road bike," the tire could come off the rim, causing a bad crash. I think bike tube manufacturers began adding a little natural rubber for less rolling resistance, to reduce the chance of a blowout from friction and heating, and to make punctures a little slower and safer.
Some manufacturers make tubes that are less porous than others, but there's still oxidation. If I inflate a tire to 30 psi above atmospheric pressure, its absolute pressure is about 45, and oxygen accounts for about 9 psi. If there is rottable rubber in the tube, I could eventually see the pressure drop to 21 with no seepage at all. During the first year, the front tire was never deflated. Not long after I got the bike, I had to remove the rear tire and tube to replace spokes. When I mounted and inflated the tire, it probably had more oxygen than the front had. That could mean a faster pressure loss due to faster oxidation of the natural rubber in the tube. The oxygen content stayed high as I kept replacing air lost through the undetected leak, then as I pumped it up after patching it three times.
I imagine that when you commuted by bike, your tires were deflated by punctures or for service more often than when you ride 4 miles a week. Maybe a higher oxygen content meant a faster loss to oxidation.
Before long, the front was holding pressure much better, which was a mystery to me. The back still lost air pretty fast. Then it got erratic. It might hold pressure several days and go flat overnight. I took the tube out, put air in it, and patiently held it under water, section by section. Not a bubble. I replaced the valve core. I finally found the leak by holding the tube under water after pumping it up larger than the tire. It was a hole so small that it leaked only sometimes. I thought it was a manufacturing flaw. I patched it.
Soon there was another leak. It, too, was on the centerline. Apparently there was something in the tire, but I couldn't see or feel it. When I got a third puncture, I marked the sidewall at the valve. When I found the leak, I matched the tube to the tire to find the spot in the tire. It was a hair-thin wire 1/4 inch long, right through a knob on the tread. I couldn't believe something that thin could penetrate 1/4 inch of tire rubber without bending or breaking, instead.
There were no more punctures, but the rear tire continued to need air pretty frequently, as if the tube were porous. There you have it: two tubes of the same kind and age, ridden every day, but one holds air like yours in the garage.
I'd ridden on butyl rubber tubes from 1954 to 1972. They didn't lose air unless there was a leak. Bicycle tubes are normally butyl because it's cheaper. I think I've figured it out. In the 1950s and 1960s, halobutyl rubber was developed. It would cure faster than the old butyl and could be mixed with natural rubber or styrene-butadiene rubber (which makes tough tread rubber).
One advantage to butyl rubber is that it doesn't oxidize; loudspeaker manufacturers are changing from foam surrounds, which rot, to butyl, which doesn't. A disadvantage is that even a nail-sized puncture can cause it to deflate like a gunshot. That was no problem on a traditional English bike, but on a "road bike," the tire could come off the rim, causing a bad crash. I think bike tube manufacturers began adding a little natural rubber for less rolling resistance, to reduce the chance of a blowout from friction and heating, and to make punctures a little slower and safer.
Some manufacturers make tubes that are less porous than others, but there's still oxidation. If I inflate a tire to 30 psi above atmospheric pressure, its absolute pressure is about 45, and oxygen accounts for about 9 psi. If there is rottable rubber in the tube, I could eventually see the pressure drop to 21 with no seepage at all. During the first year, the front tire was never deflated. Not long after I got the bike, I had to remove the rear tire and tube to replace spokes. When I mounted and inflated the tire, it probably had more oxygen than the front had. That could mean a faster pressure loss due to faster oxidation of the natural rubber in the tube. The oxygen content stayed high as I kept replacing air lost through the undetected leak, then as I pumped it up after patching it three times.
I imagine that when you commuted by bike, your tires were deflated by punctures or for service more often than when you ride 4 miles a week. Maybe a higher oxygen content meant a faster loss to oxidation.
I bought a milwaukee cordless tire inflator. Pretty sweet.
www.milwaukeetool.com
M18™ 18V Cordless Tire Inflator | Milwaukee Tool
MILWAUKEE® Fastest 18V Cordless Tire Inflator delivers fast, accurate, easy inflation with the portability to take anywhere. Optimized for passenger, light truck, and other medium duty tires
www.milwaukeetool.com
spokewrench
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Wow... $140 to $160 for the pump, and I'd need a $66 battery. Then I'd wonder when I'd need a new battery.I bought a milwaukee cordless tire inflator. Pretty sweet.
M18™ 18V Cordless Tire Inflator | Milwaukee Tool
MILWAUKEE® Fastest 18V Cordless Tire Inflator delivers fast, accurate, easy inflation with the portability to take anywhere. Optimized for passenger, light truck, and other medium duty tires
A hand pump that clipped to the frame was once enough for bicycles and motorcycles. At the farm in the 80s and 90s we used something like this.
3.7 CFM @ 90 PSI Belt Drive Air Compressor | Belt Driven Compressors | Air Compressors & Vacuum Pumps | Air & Pneumatics | www.surpluscenter.com
3.7 CFM @ 90 PSI Belt Drive Air Compressor, Belt Driven Compressors, 3.7 CFM COMPRESSOR New, cast iron single cylinder single stage belt drive
www.surpluscenter.com
That tank had a ball chuck. So did my dial gauge. It was pretty quick to take the tank around, checking car, truck, motorcycle, tractor, bailer, and other tires. In town, with just a car and a mower, I'd use a hand pump. The hassle was repeatedly getting down to disconnect the pump and check with a gauge. For $10 I took a chance on an old Black and Decker compressor that was much smaller than the one at the farm but may have been just as fast, and it had a reasonably accurate dial gauge. To use it, though, I had run extension cords.
For $30 I bought a 12 volt programmable pump with a digital display. It plugged into a lighter socket. For $10 I bought an extender to clip to battery terminals. I considered that more reliable, and I could reach all the tires on the car. I could't unscrew the chuck without having a significant and unpredictable amount of air escape from the tire; so I spent $10 on a better chuck.
That's what I used when I got an ebike. The problem was that the bike needed air every time I turned around, it seemed, when I was about to ride. Unpacking 25 feet of wire, hooking it to a battery, and repacking afterwards were a hassle for a bike that frequently needed air. So I bought a 6-gallon pancake compressor, a 25-foot hose, and a digital inflator. The compressors I'd used had been left charged for convenience, but now I learned that this was hazardous. Under pressure, a tank would rust 10 times faster, then explode. To avoid that danger, I needed to switch it on and let it make noise for several minutes and park the bike where I could reach the side away from the brake disks with the hose. When I finished, I'd switch it off, pull the release valve (which made a very loud hiss), and as it hissed, reach down and unscrew the drain valve.
The clip-on chuck on the inflator was axial and too long to fit between the rear hub and valve. It was too long for the bowl hubs on my mower, too. So spent $10 on a brass ball chuck. A chuck like that was very convenient to give a shot of air to a tire on a vehicle that weighed a ton or more. A bicycle wheel, though, was likely to move when I pressed the chuck to seal against the valve. With the inflator, I'd have to maintain the seal with one hand while I used the other to hold the inflator for a reading, add or release air, and take another reading. Eventually, I replaced the ball chuck with one that had a clip. Now when it seals it stays sealed until I release the clip.
It saves effort to check all three ebikes together. I've been collecting data so I can fit it into a schedule instead of when the need becomes evident, just before a ride. I have been considering a cordless compressor small enough to carry in a coat pocket. No filling the compressor tank and fooling with the hose, and a pocket model might get me home in the event of a puncture. I bought a small manual pump, but I have trouble getting the chuck to seal.
Catalyzt
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I just went tubeless on the Marin Team-1 kit bike (finally got around to fixing that flat.) I asked about getting 2.1s for it, but the guy at the LBS said, "tubeless isn't popular now, we don't have a lot of stock. But if you find something that works, we'll help you find a good rim for it."
"But... tubeless has less rolling resistance, fewer punctures..."
"Yeah, I know. But that's the trend now."
Arggh! We're all supposed to want the same thing, I guess, like huge phones or infotainment or whatever. Yecch.
spokewrench
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Until 1972 I didn't know how the wrong pressure would affect the performance of a bicycle or a motorcycle. I kept the recommended pressure, and those tubes didn't lose air. That year, I got a motorcycle with natural rubber tubes. I didn't have to check with a gage because I'd know by the handling within 100 feet if either tire was 3 pounds low and which tire. I'd correct it on the spot. The wheel would stay still, and the pump fitting and gauge would go on and off without losing air. I could often tell if a car or truck tire was a little low by the way it handled.
My Radmission and Abound tires aren't like those car and motorcycle tires. If I find them 10 or 20 percent low, I don't notice a difference after inflating them to normal pressure. If I find my Radrunner tires low, pumping them up will reduce rolling resistance, reduce noise, and improve handling. As these tires lose pressure, the problems sneak up on me. I don't realize there's a problem unless I check with a gauge.
spokewrench
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Thanks. That's the sort I've been looking at, maybe 2 years, and it has that kind of chuck I can get on and off with almost no air loss, and get it in with little clearance. I just found one of the same brand also with 6000 mah and a lever chuck, but it looks smaller and it's a lot cheaper. It weighs only 470 grams. Sold!
PCeBiker
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The quick release chuck on mine turned out to be a piece of junk, (it wouldn't stay on) so I had to replace it,..
I had another problem where I went to use it and the battery was dead.
I must have hit the button by accident and turned the light on when I strapped it down in my tool bag.
I happened to find a plate washer (the bottom of a hanging lamp) that fit perfectly over the buttons so I can't hit the buttons by accident.
spokewrench
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I see you used a compact clamp on your new quick release. I got a couple of dandy quick release chucks, but they came with worm gear clamps. There was no way to use one where the screw wouldn't be in the way.
Maybe I should have read customer reviews for the model I ordered. Some have noted that the sensor reads about 3 psi high. I guess I could work with that.
Maybe I should have read customer reviews for the model I ordered. Some have noted that the sensor reads about 3 psi high. I guess I could work with that.
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