Notices
General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Presta valve caps

Old 12-29-21, 12:47 PM
  #1  
LarrySellerz
Senior Member
Thread Starter
 
Join Date: Mar 2021
Posts: 1,175
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1554 Post(s)
Liked 255 Times in 187 Posts
Presta valve caps

You know those plastic valve caps that everyone throws away? Well my presta valve is leaking and I have to throw the tube away. It looks kind of bent. Think I should have kept the valve cap? Has anyone else had a presta valve leak, and think its because you didn't keep the protector on it?
LarrySellerz is offline  
Old 12-29-21, 12:49 PM
  #2  
indyfabz
Banned.
 
Join Date: Jan 2010
Posts: 34,830
Mentioned: 202 Post(s)
Tagged: 1 Thread(s)
Quoted: 15909 Post(s)
Liked 10,155 Times in 4,950 Posts
No. But I have metal valve caps. They are red, so they are the fastest.
indyfabz is offline  
Old 12-29-21, 01:00 PM
  #3  
Rick
Senior Member
 
Join Date: Feb 2007
Posts: 972
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 410 Post(s)
Likes: 0
Liked 260 Times in 169 Posts
Some presta valves can be unscrewed so check the tightness. You can also use a pair of plyers to straighten the presta valve stem. I have florescent green valve caps.
Rick is offline  
Likes For Rick:
Old 12-29-21, 01:12 PM
  #4  
Iride01
MotuekaCascadeChinook
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 11,062

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 4470 Post(s)
Liked 2,991 Times in 2,085 Posts
I always use the plastic caps on both presta and Schrader. I've always felt they are another layer of protection for keeping dirt out that might cause a valve to leak. Maybe it only happens once every other blue moon but once anytime is probably going to be the worst time for it to happen.

I don't look at other peoples wheels to see what they do for their valve stems. I don't know why they should be looking at mine and care whether I do or don't.

I even use the little nut that goes on the presta stem too. I guess I'm a maverick?!
Iride01 is offline  
Likes For Iride01:
Old 12-29-21, 01:19 PM
  #5  
GlennR
On Your Left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,370

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,422 Times in 1,184 Posts
It was bent by the pump head.

Just replace the core with a new one.
GlennR is offline  
Old 12-29-21, 01:28 PM
  #6  
urbanknight
Over the hill
 
urbanknight's Avatar
 
Join Date: Mar 2006
Location: Los Angeles, CA
Posts: 23,305

Bikes: Giant Defy, Specialized Allez, Raleigh Pursuit tandem

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 439 Post(s)
Liked 477 Times in 293 Posts
I don't use the cap because it's inconvenient to unscrew them every time I inflate the tires, and I rarely get a bent valve, but it does happen. As mentioned above, you can just swap the core out. You could even start collecting cores from tubes you're about to throw away, giving you a stash of spares.

Originally Posted by Iride01 View Post
I even use the little nut that goes on the presta stem too. I guess I'm a maverick?!
These are very useful for when the tube goes completely flat and the pump head tries to push the whole valve inside the rim before engaging fully.
__________________
It's like riding a bicycle
urbanknight is offline  
Likes For urbanknight:
Old 12-29-21, 01:38 PM
  #7  
indyfabz
Banned.
 
Join Date: Jan 2010
Posts: 34,830
Mentioned: 202 Post(s)
Tagged: 1 Thread(s)
Quoted: 15909 Post(s)
Liked 10,155 Times in 4,950 Posts
Originally Posted by urbanknight View Post

These are very useful for when the tube goes completely flat and the pump head tries to push the whole valve inside the rim before engaging fully.
And if you use a hand pump on the road. Less chance of tearing the valve off the tube, which I have seen done.
indyfabz is offline  
Likes For indyfabz:
Old 12-29-21, 01:59 PM
  #8  
Rolla
Victimless Criminal
 
Rolla's Avatar
 
Join Date: Sep 2020
Posts: 2,536
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1124 Post(s)
Liked 2,715 Times in 1,208 Posts
Originally Posted by LarrySellerz View Post
Has anyone else had a presta valve leak, and think its because you didn't keep the protector on it?
Nope. The plastic cap won't keep air in the tube; they don't seal tight enough, and if the valve is open, the cap will just push down on it and make it leak faster.

The only use I have for a presta cap is as an emergency shraeder adapter. Cut off the tip, turn it upside down, and screw it on. You can then use a shraeder pump or gas station compressor.






https://www.purecycles.com/blogs/bic...hrader-adapter

Last edited by Rolla; 12-29-21 at 02:03 PM.
Rolla is online now  
Old 12-29-21, 04:10 PM
  #9  
GlennR
On Your Left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,370

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,422 Times in 1,184 Posts
Originally Posted by Iride01 View Post
I even use the little nut that goes on the presta stem too. I guess I'm a maverick?!
Sorry, but my stem extensions are not threaded.
GlennR is offline  
Likes For GlennR:
Old 12-29-21, 04:36 PM
  #10  
Branko D
Senior Member
 
Join Date: Feb 2018
Posts: 626
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 261 Post(s)
Liked 332 Times in 199 Posts
I have metal valve caps in blue to match the decals on the bike.

If you have to have a fault, vanity isn't the worst choice.
Branko D is offline  
Likes For Branko D:
Old 12-29-21, 04:54 PM
  #11  
jaxgtr
Senior Member
 
jaxgtr's Avatar
 
Join Date: Jul 2006
Location: Jacksonville, FL
Posts: 5,831

Bikes: Trek Domane SLR 7, Trek Emonda ALR 6, Trek FX 5 Sport

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 420 Post(s)
Liked 844 Times in 515 Posts
My tubeless presta covers are metal and also a core remover.
__________________
Brian | 2021 Trek Domane SLR 7 | 2016 Trek Emonda ALR 6 | 2022 Trek FX Sport 5 (On Order)
Originally Posted by AEO View Post
you should learn to embrace change, and mock it's failings every step of the way.







jaxgtr is offline  
Likes For jaxgtr:
Old 12-29-21, 04:59 PM
  #12  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 5,350
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 5091 Post(s)
Liked 7,448 Times in 3,233 Posts
Originally Posted by GlennR View Post
It was bent by the pump head.
.
Correct answer.

I don't see how the valve could be bent by anything else, since that would probably impact the spokes, too.

Valve caps are useless.
Koyote is offline  
Likes For Koyote:
Old 12-29-21, 05:38 PM
  #13  
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Posts: 12,189

Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, Catrike Speed

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1395 Post(s)
Liked 593 Times in 370 Posts
Yeah, bent presta valves are user-induced, usually by being rough when putting the pump chuck on or taking it off. Presta valve caps are strictly for style.


BlazingPedals is offline  
Likes For BlazingPedals:
Old 12-29-21, 06:00 PM
  #14  
Chuck M 
Butted Hi-Tensile
 
Chuck M's Avatar
 
Join Date: Sep 2020
Location: Oklahoma
Posts: 1,131

Bikes: Hi-Ten bike boomers, a Trek Domane and some projects

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 371 Post(s)
Liked 969 Times in 480 Posts
I use the caps like I give a damn until I lose one or break one, Then I remove it from the other wheel and ride like I don't give a damn.
__________________
"It is the unknown around the corner that turns my wheels." -- Heinz Stücke

Chuck M is offline  
Old 12-29-21, 06:27 PM
  #15  
downtube42
Senior Member
 
downtube42's Avatar
 
Join Date: Oct 2008
Location: Portland, OR
Posts: 3,249

Bikes: Soma Fog Cutter, Volae Team, Focus Mares AL, Nimbus MUni, Trek Roscoe 6.

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 647 Post(s)
Liked 1,447 Times in 734 Posts
I was sure Sheldon Brown argued they were useless once the tube was unfurled, but I can no longer find that quote. Lacking Sheldon's backing, I may have to reconsider my position as a Presta valve cap denier.

With a sharp instrument you can modify a (plastic) Presta cap to be a functional Schrader adapter, thus fill your fancy bike tire at a gas station. So I guess that's an argument to carry a sharp knife and mount your Presta caps.
downtube42 is offline  
Old 12-29-21, 06:58 PM
  #16  
ThermionicScott 
working on my sandal tan
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 22,050

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)

Mentioned: 95 Post(s)
Tagged: 0 Thread(s)
Quoted: 3628 Post(s)
Liked 2,061 Times in 1,309 Posts
Originally Posted by downtube42 View Post
I was sure Sheldon Brown argued they were useless once the tube was unfurled, but I can no longer find that quote. Lacking Sheldon's backing, I may have to reconsider my position as a Presta valve cap denier.

With a sharp instrument you can modify a (plastic) Presta cap to be a functional Schrader adapter, thus fill your fancy bike tire at a gas station. So I guess that's an argument to carry a sharp knife and mount your Presta caps.
You're not crazy; I remember reading Sheldon (or maybe Jobst Brandt) saying that the only purpose of the cap was to keep from poking a hole in the tube while it was rolled up.

I no longer throw away valve caps, though -- I patched up a bunch of old tubes a year or two ago and wasn't able to roll them up properly since I was short on caps.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Likes For ThermionicScott:
Old 12-29-21, 07:21 PM
  #17  
LarrySellerz
Senior Member
Thread Starter
 
Join Date: Mar 2021
Posts: 1,175
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1554 Post(s)
Liked 255 Times in 187 Posts
So it was damaged by the pump and the cap didn't matter.. got it, makes sense. I wish I could just use shrader but I don't think my wheels allow it.
LarrySellerz is offline  
Old 12-29-21, 07:46 PM
  #18  
GlennR
On Your Left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,370

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,422 Times in 1,184 Posts
Originally Posted by LarrySellerz View Post
So it was damaged by the pump and the cap didn't matter.. got it, makes sense. I wish I could just use shrader but I don't think my wheels allow it.
Drill the valve hole larger... if you must.
GlennR is offline  
Old 12-29-21, 07:54 PM
  #19  
Chuck M 
Butted Hi-Tensile
 
Chuck M's Avatar
 
Join Date: Sep 2020
Location: Oklahoma
Posts: 1,131

Bikes: Hi-Ten bike boomers, a Trek Domane and some projects

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 371 Post(s)
Liked 969 Times in 480 Posts
Originally Posted by LarrySellerz View Post
So it was damaged by the pump and the cap didn't matter.. got it, makes sense. I wish I could just use shrader but I don't think my wheels allow it.
Don't do that. Just take care when using your pump. Presta valves without caps look way sexier than Schrader valves without caps.
__________________
"It is the unknown around the corner that turns my wheels." -- Heinz Stücke

Chuck M is offline  
Old 12-29-21, 08:02 PM
  #20  
TomM
Senior Member
 
Join Date: Sep 2004
Posts: 1,023

Bikes: Trek5000

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Likes: 0
Liked 32 Times in 20 Posts
Originally Posted by urbanknight View Post
I don't use the cap because it's inconvenient to unscrew them every time I inflate the tires, and I rarely get a bent valve, but it does happen. As mentioned above, you can just swap the core out. You could even start collecting cores from tubes you're about to throw away, giving you a stash of spares.


These are very useful for when the tube goes completely flat and the pump head tries to push the whole valve inside the rim before engaging fully.
Plus the caps add additional rotating weight to the wheel
TomM is offline  
Likes For TomM:
Old 12-29-21, 08:04 PM
  #21  
Random11
Full Member
 
Join Date: May 2020
Location: North Florida
Posts: 356

Bikes: 2019 Specialized Diverge, 2021 Cervelo Caledonia

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 187 Post(s)
Likes: 0
Liked 239 Times in 125 Posts
I use metal caps myself, but my cycling son doesn't use caps. He says he doesn't want to carry the extra weight.
Random11 is offline  
Old 12-29-21, 08:13 PM
  #22  
GlennR
On Your Left
 
GlennR's Avatar
 
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,370

Bikes: Trek Emonda SLR, Sram eTap, Zipp 303

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,422 Times in 1,184 Posts
Originally Posted by Chuck M View Post
Presta valves without caps look way sexier than Schrader valves without caps.
If you want "sexy" just ride behind me
GlennR is offline  
Likes For GlennR:
Old 12-29-21, 08:21 PM
  #23  
urbanknight
Over the hill
 
urbanknight's Avatar
 
Join Date: Mar 2006
Location: Los Angeles, CA
Posts: 23,305

Bikes: Giant Defy, Specialized Allez, Raleigh Pursuit tandem

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 439 Post(s)
Liked 477 Times in 293 Posts
Originally Posted by TomM View Post
Plus the caps add additional rotating weight to the wheel
Too bad I have more added rotating weight in my little toe.
__________________
It's like riding a bicycle
urbanknight is offline  
Old 12-29-21, 08:33 PM
  #24  
70sSanO
Senior Member
 
70sSanO's Avatar
 
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,038

Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970

Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked 1,681 Times in 1,053 Posts
Originally Posted by urbanknight View Post
Too bad I have more added rotating weight in my little toe.
I don’t have a good use for my little toes either.

John
70sSanO is offline  
Likes For 70sSanO:
Old 12-29-21, 09:18 PM
  #25  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 10,596

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3490 Post(s)
Liked 2,270 Times in 1,476 Posts
Originally Posted by ThermionicScott View Post
You're not crazy; I remember reading Sheldon (or maybe Jobst Brandt) saying that the only purpose of the cap was to keep from poking a hole in the tube while it was rolled up.

I no longer throw away valve caps, though -- I patched up a bunch of old tubes a year or two ago and wasn't able to roll them up properly since I was short on caps.
I fold my tubes from opposite the valve. Valve is last and lays on the rolled tube. Held in place by the elastic. Haven't punctured a tube yet in many years. (I sometimes have to roll twice to get the valve to lie on the tube, not be at the folds.)
79pmooney is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.