Search
Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

leak down

Thread Tools
 
Search this Thread
 
Old 05-20-10 | 07:45 AM
  #1  
Thread Starter
Senior Member
 
Joined: Apr 2010
Posts: 184
Likes: 0
leak down

I got a cheap, used bike a few weeks ago and just ride on weekends. But I air it up to 45psi before a ride and by the next week it is down to 25-30psi.

Is it normal for bike tires to lose pressure fairly quick or should a leak be suspected?

How often do you have to add air?

thanks
mjoekingz28 is offline  
Reply
Old 05-20-10 | 08:21 AM
  #2  
Senior Member
Titanium Club Membership
15 Anniversary
 
Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

It's normal for tires to bleed air slowly. The rate depends on the width and pressure, with narrow high pressure tires being faster than fat mtb tires. Your loss may be at the high end of the normal range. It's possible that you have a pin hole leak, or possibly it's leaking through a loose valve.

If you can live with it, just buy yourself a basic ($10-15) floor pump to keep your tires topped off. If you don't want to live with it you'll still need a pump because, even in the best of circumstances, you'll still need to top tires off every 2-3 weeks.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Reply
Old 05-20-10 | 08:25 AM
  #3  
Senior Member
 
Joined: Jul 2008
Posts: 502
Likes: 0
From: Eastern Iowa

Bikes: surly cross check

it depends on your setup, my commuter runs skinny tires at high pressure ~100psi and those tires get aired up once a week to maintain pressure. My mountain bike runs significantly lower pressure ~35-45 psi and I rarely air those up, unless I have a flat.

It may be just normal leakage, you could just keep airing it up every week, or if that is too much trouble change the tube. Its an easy change depending on how old your tires are.
ryanwood is offline  
Reply
Old 05-20-10 | 10:11 AM
  #4  
Senior Member
 
Joined: Nov 2008
Posts: 7,239
Likes: 8
From: Bay Area, Calif.
You either have a slow leak in the tubes or you've got some extra thin tubes which are more porous. In either case, get yourself some new tubes of at least normal weight and you shouldn't have to pump up your tires more than once a month or so.

Those who use narrow, high-pressure tires (~ 100 psi or more) need to pump them up much more often, especially since the narrower tubes are often made of thinner rubber as well (for decreased rolling resistance). But there's no need for such thin tubes on the wider low-pressure tires you have.
prathmann is offline  
Reply
Old 05-20-10 | 10:47 AM
  #5  
BCRider's Avatar
Senior Member
 
Joined: Mar 2008
Posts: 5,559
Likes: 53
From: The 'Wack, BC, Canada

Bikes: Norco (2), Miyata, Canondale, Soma, Redline

If they are both losing the same amount of air then it's the normal leakage for those tubes. If one is significantly lower than the other then you've got a leaky valve or a pinhole in the lower tube. It COULD be two identical pinholes but the chances of that are somewhere between slim and nil.
BCRider is offline  
Reply
Old 05-20-10 | 12:32 PM
  #6  
JiveTurkey's Avatar
Low car diet
 
Joined: Aug 2007
Posts: 2,407
Likes: 4
From: Corvallis, OR, USA

Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.

Pull the tube out, inflate it to more than normal size, submerge it in water, and look for air bubbles. Patch it.

My rear tire had a tiny hole that would slowly leak; it would be fine for a ride but within a couple days it would get down to a low PSI but not completely flat. It was impossible for me to find by just feeling for it without water.
JiveTurkey is offline  
Reply
Old 05-20-10 | 02:11 PM
  #7  
Senior Member
15 Anniversary
Community Builder
 
Joined: Sep 2007
Posts: 15,274
Likes: 1,764
From: Far beyond the pale horizon.
Originally Posted by FBinNY
If you can live with it, just buy yourself a basic ($10-15) floor pump to keep your tires topped off. If you don't want to live with it you'll still need a pump because, even in the best of circumstances, you'll still need to top tires off every 2-3 weeks.
Spend about $30 and get a good pump. (Topeak Joe Blow Sport is one good pump.)
njkayaker is online now  
Reply
Old 05-20-10 | 06:48 PM
  #8  
Thread Starter
Senior Member
 
Joined: Apr 2010
Posts: 184
Likes: 0
Originally Posted by BCRider
If they are both losing the same amount of air then it's the normal leakage for those tubes. If one is significantly lower than the other then you've got a leaky valve or a pinhole in the lower tube. It COULD be two identical pinholes but the chances of that are somewhere between slim and nil.

Good point....they do lose about the same amount per tire. It has 26" tires.


I don't have a frame nor floor pump but use an air compressor. I just plug it in until it hits 50psi or so then air up the tire until the air pressure tapers off.
mjoekingz28 is offline  
Reply
Old 05-20-10 | 06:50 PM
  #9  
Senior Member
Titanium Club Membership
15 Anniversary
 
Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Originally Posted by mjoekingz28
I don't have a frame nor floor pump but use an air compressor. I just plug it in until it hits 50psi or so then air up the tire until the air pressure tapers off.
Doesn't seem like a tone of work to do every week or so.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Reply
Old 06-01-10 | 05:33 AM
  #10  
Thread Starter
Senior Member
 
Joined: Apr 2010
Posts: 184
Likes: 0
Ok, so I went to check on my mountain bike the other day to check out and make sure this foot pump works since I may be getting a Trek 1200 today and the tires were full of air and they havent been touched in at least a year. But my Montgomery Ward 26" road tires both leaked down the same psi. So were they both punctured or do road bike tires differ from MTB in that regard.

thx
mjoekingz28 is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
pguru
Classic & Vintage
20
06-27-14 05:59 PM
vol
Commuting
11
05-15-13 11:48 AM
smasha
Bicycle Mechanics
17
02-14-11 10:02 PM
Jazzy Hands
Road Cycling
11
10-15-10 08:44 AM
nashvillwill
Bicycle Mechanics
18
07-14-10 08:15 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.