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Pumping air into bike tires

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
I am pretty new to bikes. I just bought a road bike and a floor pump.

Is there supposed to be a lot of resistance to the pumping action beyond 30 psi? My tires need 100-120 psi, and it resists quite a bit at ~40 psi and I don't want to blow up the tire.

I don't have a pocket pressure guage. I am fearing that the guage on the floor pump might be defective, although I have never pumped tires before, so I dont' know if this is supposed to be the way it is and I just have to muscle up and just keep pumping.

Thanks guys!

PS, I unscrewed the presta valve screw all the way up prior to attaching the air pump.

Dunno if it will help, but here are some specs:
Trek 2.1, wheels have presta valve.
Bontreger floor pump with presta/schader valve head.
 
Last edited:

bobsmith1492

Diamond Member
Feb 21, 2004
3,880
2
81
How big is your floor pump? Link?

Can you feel if air is actually going into the tire? If the pump isn't all the way on the valve you can get a lot of resistance without any air getting into the tire.

Otherwise, yes it can take a lot of effort at higher pressure levels.
 

TheUnk

Golden Member
Jun 24, 2005
1,810
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71
120psi sounds way too high. I don't know about road bikes, but my mt. bike 40psi is as high as I go, usually keep it mid 30s
 

bobsmith1492

Diamond Member
Feb 21, 2004
3,880
2
81
120psi sounds way too high. I don't know about road bikes, but my mt. bike 40psi is as high as I go, usually keep it mid 30s
No, it's not; road bike tires take a lot more pressure since they are a lot thinner.
 

alkemyst

No Lifer
Feb 13, 2001
83,981
14
81
is your pump rated to go to 120psi?

It's usually going to be a bit tougher once you get past 60-80psi.
 

DAPUNISHER

Super Moderator and Elite Member
Moderator
Aug 22, 2001
21,922
2,017
136
120psi sounds way too high. I don't know about road bikes, but my mt. bike 40psi is as high as I go, usually keep it mid 30s
You must not weight a lot, and/or ride flat, groomed, trails, or street only? Because if I aired my MTB in the 30's, pinch flats and a potentially taco'd rim would be the results.

TO Op: If it is a lower end Bontrager, you just have to muscle it, as you suspected.

The more expensive TC WSD is advertised to help take the struggle out of reaching pressure. I do not know how much easier it is in reality though. http://bontrager.com/model/04525
 

bobsmith1492

Diamond Member
Feb 21, 2004
3,880
2
81
You must have skinny tires, Dapunisher... 30s is standard for 2.5" or so mtb tires. We'll do 30 if the trails are sandy but usually more like 40.
 

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
Thanks guys, I'll put more muscle into it. It is a lower end Bont. floor pump (~45$ msrp). My tires are rated 100-120psi. Pump is rated for 140psi I believe.

For some reason, it seemed to help if I "chirped" the valve to let a little air out of the tire prior to putting hooking up the pump (got to 60 psi without much muscle required).

Just to be sure, Ill buy an air gauge off amazon as an added precaution.

Thanks all!

btw, there are some pretty sweet trails around washington dc!
 

KMc

Golden Member
Jan 26, 2007
1,153
0
76
I think you were just hitting that "wall" of pressure that you need to overcome to get air past the presta valve. If you had just kept pumping, you would have felt a little pop as the valve opened and then it would have started pumping much easier. However, your solution of "chirping" or breaking the valve seal before connecting the pump is the way to go. I think you'll find your pump gauge is sufficiently accurate.
 

LongTimePCUser

Senior member
Jul 1, 2000
472
0
76
If it staes 120 psi on the tire, then it is probably a Presta valve.
I once shopped on Amazon for Presta air gauges and found that none of them were rated beter than 1 or 2 stars out of 5 by the people who bought them. They don't work.

Rely on the gauge on the floor pump.

Remember, that if it is a Presta valve, that you you have to completely unscrew it by hand before pumping and the re-screw it afterwards. If you don't unscrew it completely it will be very hard to pump air into the tire. Also, make sure the pump hose is firmly attached to the valve.
 

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
Thanks all! I went to a free workshop at my local bike shop the other night and learned how to change out the tube and stuff. It was pretty rad, learned quite a bit. I didn't know the rear tire comes off so easily, all you do is put it into the smallest cog, unlatch the quick release on the brake and wheel and the rear wheel just falls out. Also, putting baby powder on the wheel tubes helps to keep them from "melting" to the tire so that removal is made easier - never thought of that before, but makes sense.

I'll be locking up the rear wheel with the frame with a cable securing the front wheel from now on. (instead of just locking the front wheel with the frame)



I just pumped up the tires to 110 psi without much problem, got "tough" around 95psi. Hopefully the weather holds up so I can hit some trails :D
 

GoSharks

Diamond Member
Nov 29, 1999
3,057
0
76
Also, putting baby powder on the wheel tubes helps to keep them from "melting" to the tire so that removal is made easier - never thought of that before, but makes sense.
Unnecessary and only makes for a mess if you have to change a tube in weather.
 

alkemyst

No Lifer
Feb 13, 2001
83,981
14
81
if you are changing a flat in the rain, would some powder really make a different to the mess?
 

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
Agreed, I've changed a lot of tires and never seen a need for baby powder.
Where are you located roughly? In hotter climates, the melt could be made worse, but in the northern portions, not so much.

supposedly the baby powder helps to improve the life of the tube while it is sitting in your toolbag, but I don't have any verification for that other than the words of the bike shop workers...
 

GoSharks

Diamond Member
Nov 29, 1999
3,057
0
76
Where are you located roughly? In hotter climates, the melt could be made worse, but in the northern portions, not so much.
I've biked during the middle of summer in Salt Lake City (hot!), and my bike was stored in an outside, stand-alone garage. No problems at all with tubes and tires. You don't need baby powder.
 

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
I've biked during the middle of summer in Salt Lake City (hot!), and my bike was stored in an outside, stand-alone garage. No problems at all with tubes and tires. You don't need baby powder.
Cool, how often did you typically have to retube your wheels (avg per year, rough est. of miles ridden)? Have you ever had both wheels blow out at the same time (trying to minimize my tool bag while keeping whats necessary vs. risk).
 

edcarman

Member
May 23, 2005
172
0
71
Cool, how often did you typically have to retube your wheels (avg per year, rough est. of miles ridden)? Have you ever had both wheels blow out at the same time (trying to minimize my tool bag while keeping whats necessary vs. risk).
I’ve never had a tube last long enough to wear out. They usually get irreparably punctured before then. I’ve also had some that sheared off at the valve for no apparent reason (both times I wasn’t riding and the bike was just sitting there). Those were limited to a specific brand of tube that I’ve now stopped buying.

Punctures are pretty random things. Between April and December last year I did around 3000km on the road and got two punctures. This year to date I’ve done a similar mileage and I’m up to 8 punctures. I do, however, tend to get more punctures when it’s raining or the roads are wet.

I consider the risk of puncturing great enough that I’ll never ride anywhere without a spare tube. I once got three punctures within 10km (in three different places on my tyres), but those were some dodgy lightweight racing tyres (never again). Otherwise, it’s pretty unlikely that you’ll need more than one tube (unless you mess up the repair or don’t remove the original cause of the puncture from your tyre). That said, if I’m doing a very long ride in a remote are or if I know that there’s no-one I can easily call to come and fetch me if thing s go wrong, I’ll take a second tube just in case.

I usually carry tubes in my jersey pocket, but if you’re putting them in a saddle bag, keep them in and old sock. This stops them getting abraded by keys, coins, tools or whatever else is jammed into the bag with them. Also be sure to periodically check your spare tubes. It sucks to try and fix a puncture only to find your spare’s also got a hole in it.
 

bobsmith1492

Diamond Member
Feb 21, 2004
3,880
2
81
Also be sure to periodically check your spare tubes. It sucks to try and fix a puncture only to find your spare’s also got a hole in it.
Ha, you know it! We were riding the North Country Trail and were some miles out in the woods when my brother's tire blew out. My friend had a spare tube so we took it out and put it on. It wouldn't hold air, though!

We took the tube out and looked it over. It had one of those fat, low-quality patches on it and 3 other holes! The funny thing was that it was in a bike tube box wrapped up like it was brand new...
 

Tiamat

Lifer
Nov 25, 2003
14,079
4
71
Ha, you know it! We were riding the North Country Trail and were some miles out in the woods when my brother's tire blew out. My friend had a spare tube so we took it out and put it on. It wouldn't hold air, though!

We took the tube out and looked it over. It had one of those fat, low-quality patches on it and 3 other holes! The funny thing was that it was in a bike tube box wrapped up like it was brand new...
That is horrible, what a drag!

I didn't get to ride today :( The winds were gusting at 50mph with sustained 25mph, I just don't have the stamina for that :D
 

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