Bicycle Tires

[Chuckanut]

I have had my new bike for about four weeks ago. I am assuming the bike shop properly inflated the tires when I bought it back then. I did not check it myself.

The tires say to inflate them to 85 PSI.

Before going out on a ride today, I attached my pump to the tires and noticed that it was reading only about 45 pounds.

Is losing 40 pounds in a month normal?

How often do you check and add air to your bicycle tires?

[Ronstar]

I check about once a month and may need to add 5 pounds or so occasionally. Maybe 20-30 lbs before the first spring ride.

Losing 40 pounds does not sound right.The bike shop probably didn't inflate to 85 lbs.

[ronin]

Unless you have a goathead or two this is not normal. I agree they weren't properly inflated to begin with, assuming 85# is the right amount. Guessing these are road bike tires with tubes. I'd check them before every ride. But that is just me. I lose 10# pretty quickly but that is on mountain bike tires, tubeless.

[Chuckanut]

I am wondering if the gauge on my bike pump is accurate.
Just checked it using the gauge for my car. the pump is in the ball park. So, either the tires were not to maximum inflation when they left the store or they are losing a lot of air.

I'll watch them.

Thanks for the info. These tires operate at a much higher pressure than my old bike which was 40-65 psi depending on the terrain (lower of rough roads, higher for good smooth pavement). The new tire simply says 85 pounds max.

[Major Tom]

Yes, agree that losing 40 pounds of pressure in a month is not normal, so they were probably not pumped up to anywhere near the theoretical maximum to begin with. My tires are rated from 40 - 65 PSI, and I keep them at around 40 - 45. I could go higher, but only use it for relatively short trips around town, so the slightly cushier ride works for me.

Like Ronstar, I check my tires about once a month and also usually end up adding about 5 pounds (sometimes a few more).

[zinger1457]

I check and adjust my road bike tire pressure before every ride, my road tires require 110 psi, not unusual to see a 10 psi change between rides.

[Ronstar]

If your tires feel rock hard, then they are probably close to 85. At 45 lbs, you'd be able to push down with your hand and see the tire move. You might want to get a tire gauge - probably around $10 - just as a check

[REattempt]

Hey, for what it is worth, I ride 5000-10,000 miles a year and set a UMCA world record.

It is absolutely normal for tires, such as you have, to lose 40lbs in a month.

Pump your tires up every time before you ride. They will likely lose 10-20lbs within a week.

If you want to optimize rolling resistance for your weight and tire size go to this link...using it added 1/2 mile per hour on my WR: http://www.dorkypantsr.us/bike-tire-...alculator.html

My .02.

[savory]

Glad you are getting out on the bike. You may have received more advice than anyone in America

When you attach a hand pump to a tire, it is not rare for the PSI to show much lower. I do not know why but it happens nearly every time, if not every time, I fill my tires.

You have a couple of choices. You may have a slow leak but I will guess not. I would simply fill the tires to the pressure suggested on the tire (perhaps a few pounds less) and go for a ride near the house or arrange to have someone pick you up, unless you want to change the tube on the road. See how the tire behaves and check it again next time you ride or before. Per the suggestions made below, check with a tire pressure gauge or your thumb. If you lose 40#, your thumb will work just fine.

The other is to remove the tube, refill with air and test it in a bucket of water. If the air bubbles appear, you have a leak. I know a patch kit was suggested or buy a new tube. Don't forget to check the inside of the tire as a sharp object might still be embedded in the tire. If you do not remove it, you'll get another flat.

I check my tires before each ride but usually just pressing it with my thumb. In time, you will know how that should feel. Even if you have 75 pounds in 85 pound tires, you will be OK.

[nash031]

Presta valve tires can lose quite a bit of air pressure over time, and depending on temperature changes and where you store your bike, no, over the course of a month a 40psi drop from 85psi wouldn't be unusual to me or anything I'd be worried about.

I typically ride at 100-110psi, and inflate before every ride. They're usually down about 90-95psi over two days between heating and cooling cycles, so not sure why people would think 40psi in a month is unusual.

Not checking tire pressure and re-inflating before every ride is unusual to me...

[donheff]

I ride almost daily. I will go two days without pumping, sometimes even three. Never more. It is hard to judge how much the tires actually lose since attaching the hose head usually releases some pressure but I would not be surprised that a high pressure tire could lose 40 pounds in a month. If you have a fat, lower pressure tire I would doubt you lost that much but you are still taking a chance - riding with low pressure invites pinch flats when you go over bumps. Get a decent pump and top up your tires frequently.

[Badger]

I would tend to believe that the store did not inflate to the rated pressure. Softer tire tends to give softer ride. Seems reasonable. However, it may also lead to a pinched tube if you hit a pot hole or curb. That being said your tires will still lose pressure although 40# is a bit much. After more than 50 years of riding I have never had pressure loss to that extreme unless one of my bikes had not been ridden for a few months. I would suggest a couple of handy tools. One is a pressure gauge in the range of your tire pressures. The other is a bicycle tire valve stem tool to make sure the core of the tire stem is properly seated and tight to prevent leaking. Both are inexpensive and can be purchased for about $15 total. Of course a bicycle pump will come in handy too.

Cheers!

[Chuckanut]

I will be watching the pressure over the next few days and weeks. Not having a starting point I can confirm makes it all guess work, but thanks to all this good advice I will get a handle on it.

Anyone care to recommend a bike tire pressure gauge they have found to be reliable and accurate?

[braumeister]

I like this one and use it regularly.
SKS Airchecker Digital Presta and Schrader Pressure Gauge

[Major Tom]

Regarding my previous post, I now realize I wasn't taking into account that the OP is riding on high pressure tires - a fact which, of course, is obvious, but I chose to ignore it. Apologies for inadvertently helping to create a mild "fog of misinformation", and thank you to those who have actual experience with high pressure tires for replying.

[Chuckanut]

Quote:

Originally Posted by Major Tom Regarding my previous post, I now realize I wasn't taking into account that the OP is riding on high pressure tires - a fact which, of course, is obvious, but I chose to ignore it. Apologies for inadvertently helping to create a mild "fog of misinformation", and thank you to those who have actual experience with high pressure tires for replying.

No problem and I appreciate your thoughts. I have since learned that my high pressure smaller tires are much more vulnerable to small losses of air than the bigger one on my old cruiser. I will just have to be more vigilant when riding.

Oh for the days when I just grabbed by 3 speed Schwinn and went all over the neighborhood without giving a thought to tire pressure, weight, gearing, brakes, bike computers, gloves, padded shorts, etc. etc. etc.....

[LOL!]

Get a floor pump with a gauge and learn to use it properly. That might sound like "Duh!", but I have seen reviewer comments on a great pump and it was clear they didn't use the pump properly.

I have a cheap $20 Blackburn pump and it is fine. I pump whenever tires have not been pumped in 2 days or if weather is cooler than the day before.

Some things to look for in a floor pump:

Diameter of barrel not too large. Large diam makes achieving high pressure hard.

Hand grip smooth where your palms go. No logos there or you will have pain and imprints.

Easy lock hose end that fits both types of valves.

Gauge large and easily seen while standing. An adjustable indicator is nice.

Hose wraps across Handle for storage.

[Texas Proud]

Quote:

Originally Posted by Chuckanut No problem and I appreciate your thoughts. I have since learned that my high pressure smaller tires are much more vulnerable to small losses of air than the bigger one on my old cruiser. I will just have to be more vigilant when riding. Oh for the days when I just grabbed by 3 speed Schwinn and went all over the neighborhood without giving a thought to tire pressure, weight, gearing, brakes, bike computers, gloves, padded shorts, etc. etc. etc.....

Just a point... and most with more knowledge than I have commented about the pressure...

But remember that a small thin tire has very little volume of air in it.... so even losing a little bit of air make a big % change in them... those old fat tires on a cruiser have a much larger volume....

So, if air is lost at the same rate (and I would think higher pressure also means a faster loss rate) then you can easily have a skinny tire down quickly...

[nuke_diver]

As others have said 40psi is a lot in a month but not inconceivable. Note also that when you hook up a pump there will be some pressure lost in doing so. I check my tires before every ride but the pressure even after 1 day is almost always 10psi lower than it was after inflation. The pump hose etc will be responsible for some of that loss.

Also checking every day means you are unlikely to be surprised by a slow leak.

And you don't need all that gear to go riding. Just go ride don't worry about looking the part of a TdF racer

[Rustic23]

After reading all the articles on how we have not saved enough it is refreshing to see this is one of our primary concerns! Oh, I forgot, there are the rules of golf also. Now I can sleep tonight.