Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-06-08, 12:26 AM   #1
TalkingHead
Commie
Thread Starter
 
Join Date: Jun 2008
Location: Las Vegas
Bikes: Trek 7.3 FX, old Haro(92)
Posts: 278
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
ok whats going on here

I switched over to 700x28C tire a few weeks ago. Im on my second flat already, but both times the hole where the leak starts was around the valve stem. I made sure to put the tube/tire on properly after looking up the method on a website. I dont understand why it tears near the valve. The sidewall states 120PSI max, so i put anywhere from 115-120 PSI(going by the gauge on the pump, topeak Joeblow sport)

the tubes are bontrager 700x28-32c -1/8-1/4

the wheel is a Bontrager camino 622-32 wheel

this last flat happned over night, i rode yesterday morning several miles, came home and today the tire was flat when i went to go ride...

is it getting pinched? should i not inflate so high, do i need a different wheel?

thanks
TalkingHead is offline   Reply With Quote
Old 08-06-08, 01:43 AM   #2
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Bikes: Norco (2), Miyata, Canondale, Soma, Redline
Posts: 5,456
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like a bad batch of tubes to me.

I'd try a different brand at least for the near future just so you avoid this issue.
BCRider is offline   Reply With Quote
Old 08-06-08, 02:14 AM   #3
TalkingHead
Commie
Thread Starter
 
Join Date: Jun 2008
Location: Las Vegas
Bikes: Trek 7.3 FX, old Haro(92)
Posts: 278
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i hope that is all it is. I will keep my speed lower for a couple of weeks just in case, dont want to have a blow out going 25+
TalkingHead is offline   Reply With Quote
Old 08-06-08, 02:26 AM   #4
SPlKE 
Senior Member
 
Join Date: Sep 2007
Bikes:
Posts: 830
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Is your tube touching metal where the valve goes through the rim?

If so, cover the metal with something.
SPlKE is offline   Reply With Quote
Old 08-06-08, 03:00 AM   #5
Matt Gaunt
Senior Member
 
Matt Gaunt's Avatar
 
Join Date: Oct 2004
Location: London, UK
Bikes:
Posts: 2,244
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by SPlKE View Post
Is your tube touching metal where the valve goes through the rim?

If so, cover the metal with something.
+1 for a check. Also, try filing any sharp edges off the hole in the rim. Having said that, if you weren't experiencing problems before switching, it does sound like either a change in technique on your part or faulty tubes may be to blame.
__________________
Matt
2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics
Matt Gaunt is offline   Reply With Quote
Old 08-06-08, 03:01 AM   #6
mike
Senior Member
 
mike's Avatar
 
Join Date: Jul 2000
Location: Snowy midwest
Bikes:
Posts: 5,392
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Of course, check the condition of your rim tape and check the hole for sharp edges.

Next, when you install the tube/tire, be sure to inflate about 30%, then push the stem back into the tire (push the stem back into the rim hole so it goes into the tire, but not so much that the stem falls inside the tire).

This assures that the tube around the valve is seated properly inside the tire and helps make sure there are no tube wrinkles around the stem.

I assume that you are also making sure the valve is 90 degrees to the rim and not laying cattywhompus sideways.
mike is offline   Reply With Quote
Old 08-06-08, 03:08 AM   #7
Matt Gaunt
Senior Member
 
Matt Gaunt's Avatar
 
Join Date: Oct 2004
Location: London, UK
Bikes:
Posts: 2,244
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by mike View Post
Of course, check the condition of your rim tape and check the hole for sharp edges.

Next, when you install the tube/tire, be sure to inflate about 30%, then push the stem back into the tire (push the stem back into the rim hole so it goes into the tire, but not so much that the stem falls inside the tire).

This assures that the tube around the valve is seated properly inside the tire and helps make sure there are no tube wrinkles around the stem.

I assume that you are also making sure the valve is 90 degrees to the rim and not laying cattywhompus sideways.
What's that now?

edit: nice vocab.
__________________
Matt
2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics

Last edited by Matt Gaunt; 08-06-08 at 03:09 AM. Reason: I used google
Matt Gaunt is offline   Reply With Quote
Old 08-06-08, 09:02 AM   #8
TalkingHead
Commie
Thread Starter
 
Join Date: Jun 2008
Location: Las Vegas
Bikes: Trek 7.3 FX, old Haro(92)
Posts: 278
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thanks all, will try suggestions.
TalkingHead is offline   Reply With Quote
Old 08-06-08, 08:40 PM   #9
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus
Posts: 2,926
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
We sell Bontrager and had a run of bad tubes in that same size. Punctured five tubes on a customer's bike, all where the valve stem is bonded to the tube, before we decided to try the next smaller size. Problem solved.
oldbobcat is offline   Reply With Quote
Old 08-07-08, 01:52 AM   #10
TalkingHead
Commie
Thread Starter
 
Join Date: Jun 2008
Location: Las Vegas
Bikes: Trek 7.3 FX, old Haro(92)
Posts: 278
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
smaller size as in 48mm valve stem or 36mm? My lbs only stocks 48mm. I should find a new tube. So far i have not had a flat with 40+ miles on the new tube i replaced a few days ago. But i have a feeling in few days i will wake up with one.

what are other brands of tube that are good quality, that isnt over 7 bucks

I would like to mention i rode on the 32c tires for about 6 weeks without an issue at all, i kept them at 85 psi at all times. A week after i switched over to the bontrager 28c tire, now i have these slices near the valve..twice now..and a third is probably coming up soon, hopefully not at high speed.*knock on wood*

Last edited by TalkingHead; 08-07-08 at 01:56 AM.
TalkingHead is offline   Reply With Quote
Old 08-07-08, 06:03 AM   #11
Matt Gaunt
Senior Member
 
Matt Gaunt's Avatar
 
Join Date: Oct 2004
Location: London, UK
Bikes:
Posts: 2,244
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by TalkingHead View Post
smaller size as in 48mm valve stem or 36mm? My lbs only stocks 48mm. I should find a new tube. So far i have not had a flat with 40+ miles on the new tube i replaced a few days ago. But i have a feeling in few days i will wake up with one.

what are other brands of tube that are good quality, that isnt over 7 bucks

I would like to mention i rode on the 32c tires for about 6 weeks without an issue at all, i kept them at 85 psi at all times. A week after i switched over to the bontrager 28c tire, now i have these slices near the valve..twice now..and a third is probably coming up soon, hopefully not at high speed.*knock on wood*
Michelin AirComp. Dunno how much they retail for in the US but for 4 over here they're fantastic.
__________________
Matt
2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics
Matt Gaunt is offline   Reply With Quote
Old 08-07-08, 06:08 AM   #12
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What do you mean by "good quality"? A $4 MSRP kenda tube holds air perfectly fine.
operator is offline   Reply With Quote
Old 08-07-08, 09:22 PM   #13
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus
Posts: 2,926
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Quote:
Originally Posted by TalkingHead View Post
smaller size as in 48mm valve stem or 36mm?
Sorry for not being more specific. Smaller as in 27x7/8-1", or 700cx20-25. These are actually easier to work with under a slightly wider tire, and the smaller cross section means they just stretch a little more.

All road presta tubes that we stock have 48mm stems.

I've personally had good luck with CST lightweight tubes purchased on an ebay store called nicebiketires.
oldbobcat is offline   Reply With Quote
Old 08-08-08, 02:22 AM   #14
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Bikes:
Posts: 11,600
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Don't tighten down the valve-stem nut too far, just enough so you don't lose the stem into the tyre when installing the pump. Also only use floor-pump, no hand pumps allowed.
DannoXYZ is offline   Reply With Quote
Old 08-08-08, 10:23 AM   #15
brucewiley
deep stuff
 
brucewiley's Avatar
 
Join Date: Jun 2007
Location: Nampa, ID
Bikes: Road, Touring, Mountain Bike
Posts: 250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Leave the stem nut off, I haven't run any for years since I discovered the reason I kept busting stems was from tightening the nut because it rattled. Think of all the weight you save too!
brucewiley is offline   Reply With Quote
Old 08-08-08, 11:38 AM   #16
tellyho
Your mom
 
Join Date: Aug 2006
Bikes:
Posts: 2,541
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Are you inflating with a mini-pump? I killed tubes with mine for years before I invested in a stand pump. Haven't had a problem since.
tellyho is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 06:41 PM.