What's the presta valve ring thing for?
05-06-08, 12:31 AM
#1
Senior Member
Thread Starter
What's the presta valve ring thing for?
So I misplaced the little metal ring that goes around the presta valve and apparently seals the rim. Also, the valve cap. What will happen if I don't replace them?
Steve
Steve
05-06-08, 12:38 AM
#2
Senior Member
Join Date: Jul 2006
Location: Oakland, CA
Posts: 1,300
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Nothing happens, its fine not to use them
I find that they aid in keeping the valve stem lined up perpindicular to the rim when initially inflating the tube
I find that they aid in keeping the valve stem lined up perpindicular to the rim when initially inflating the tube
05-06-08, 01:33 AM
#3
Senior Member
Many riders on tubulars throw them and the valve covers away, anyway. Matter of fact, some tubes are sold without the knurled nut and threads anyway. That way, the pump doesn't hang on the threads.
__________________
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
05-06-08, 03:04 AM
#4
Membership Not Required
Join Date: Jan 2005
Location: On the road-USA
Posts: 16,855
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Likes: 0
Liked 15 Times
in
14 Posts
With exception of the sew-ups I usually put at least the ring back on to keep the valve centered up, occasionally I have had one creep on me. Usually when the tire pressure got a bit low. I like to keep the caps on there too to keep the valve clean, but I am funny that way...
Aaron
Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
05-06-08, 07:39 AM
#5
Senior Member
Join Date: Apr 2007
Location: South Bay Area
Posts: 163
Bikes: trek 7.2, 7.3FX, 5200 OCLV
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Assuming the bike is going straight not turning:
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
It took me a while to find out where was the slow leak on my tube by examining the edge base of the valve. The rim tape did what it was supposed to do. It wasn't supposed to protect the edge base like I thought it was supposed to do. Yeah put the valve ring back in or you will go through the frustrations like I did on finding out that leak.
H23NC,
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
It took me a while to find out where was the slow leak on my tube by examining the edge base of the valve. The rim tape did what it was supposed to do. It wasn't supposed to protect the edge base like I thought it was supposed to do. Yeah put the valve ring back in or you will go through the frustrations like I did on finding out that leak.
H23NC,
Last edited by H23Nutcase; 05-06-08 at 07:44 AM.
05-06-08, 10:40 AM
#6
Caustic Soccer Mom
Join Date: Jun 2005
Location: Millstone WV
Posts: 1,761
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
especially in a racing situation - if you're going to change a flat in under 2 minutes, you're NOT dealing with those little things!
__________________
As with mud, life, too, slides by.
As with mud, life, too, slides by.
05-06-08, 10:53 AM
#7
Senior Member
Join Date: Sep 2004
Location: Podunc, Minnesota
Posts: 416
Bikes: '14 Bacchetta Corsa, '93 Ryan Vanguard, Action Bent SWB USS
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Mine end up as balast in the garbage can!
05-06-08, 10:59 AM
#8
Senior Member
Join Date: Aug 2005
Posts: 1,936
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Neither the ring nor the valve cap have any importance whatsoever. Many quality road tubes don't even have threads to screw a ring onto. No, it doesn't seal anything, and no it doesn't help keep the tube and valve centered over the hole. Keep one ring in your seat pack or tookit. Sometimes it's useful to keep the valve stem up when pumping the tire after fixing a flat.
I think they put these on new tubes for the same reason they put even a minimal amount of thread pattern on road tires. No use, just reassures people who expect them to be there.
I think they put these on new tubes for the same reason they put even a minimal amount of thread pattern on road tires. No use, just reassures people who expect them to be there.
05-06-08, 11:05 AM
#9
You need a new bike
Join Date: Aug 2002
Posts: 5,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 4 Times
in
3 Posts
Assuming the bike is going straight not turning:
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
It took me a while to find out where was the slow leak on my tube by examining the edge base of the valve. The rim tape did what it was supposed to do. It wasn't supposed to protect the edge base like I thought it was supposed to do. Yeah put the valve ring back in or you will go through the frustrations like I did on finding out that leak.
H23NC,
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
It took me a while to find out where was the slow leak on my tube by examining the edge base of the valve. The rim tape did what it was supposed to do. It wasn't supposed to protect the edge base like I thought it was supposed to do. Yeah put the valve ring back in or you will go through the frustrations like I did on finding out that leak.
H23NC,
05-06-08, 11:14 AM
#10
Senior Member
Join Date: Apr 2007
Location: South Bay Area
Posts: 163
Bikes: trek 7.2, 7.3FX, 5200 OCLV
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
You're going to get one today....j/k
3000 miles for me. I have a cheapo rim and the finishes on the rim is not smooth. There are quite of few rough edges on my rim. And the tolerance on the rim hole is quite large.
Plus there are too many factors we are not considering here. My bike weighs 50lbs and myself is quite a heavy person. In addition, the tire max pressure is 80 psi. Roads in Atlanta are quite beat-up.
If you are light person with a light bike and quality rim with high pressure tire on nice paved road all the time, your chances of seeing a rupture on the edge base is very slim.
H23NC,
3000 miles for me. I have a cheapo rim and the finishes on the rim is not smooth. There are quite of few rough edges on my rim. And the tolerance on the rim hole is quite large.
Plus there are too many factors we are not considering here. My bike weighs 50lbs and myself is quite a heavy person. In addition, the tire max pressure is 80 psi. Roads in Atlanta are quite beat-up.
If you are light person with a light bike and quality rim with high pressure tire on nice paved road all the time, your chances of seeing a rupture on the edge base is very slim.
H23NC,
05-06-08, 12:01 PM
#11
Senior Member
That is one heavy bike to be set up with a rim fit for Presta valve stems.
__________________
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
05-06-08, 12:16 PM
#12
Senior Member
Join Date: Apr 2007
Location: South Bay Area
Posts: 163
Bikes: trek 7.2, 7.3FX, 5200 OCLV
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes sir, actually the bike itself weighs 25 # ish. But with two 12 amp hour sealed lead acid battery (10 # each) strapped in the front and back powering one HID headlight (3000 lumens) and a 55 watt fog light that would add up to 50 #.
Trek 7.2FX rim came with a presta valve type.
Trek 7.2FX rim came with a presta valve type.
05-06-08, 12:19 PM
#13
Senior Member
Oh.
__________________
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.
05-06-08, 12:36 PM
#14
Senior Member
With exception of the sew-ups I usually put at least the ring back on to keep the valve centered up, occasionally I have had one creep on me. Usually when the tire pressure got a bit low. I like to keep the caps on there too to keep the valve clean, but I am funny that way...
Aaron
Aaron
05-06-08, 12:39 PM
#15
Administrator
Join Date: Feb 2005
Location: Delaware shore
Posts: 13,558
Bikes: Cervelo C5, Guru Photon, Waterford, Specialized CX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1106 Post(s)
Liked 2,173 Times
in
1,464 Posts
05-06-08, 12:48 PM
#16
Infamous Member
Join Date: Sep 2005
Location: Ohio
Posts: 24,360
Bikes: Surly Big Dummy, Fuji World, 80ish Bianchi
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 4 Times
in
3 Posts
Assuming the bike is going straight not turning:
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
if you draw a free body of the tire tube when it's under load (valve being perpendicular to ground/road), there are two forces acting on the tire/tube.
The normal force acting on the tire/tube will cause shear on the tire/tube and the weight will cause compression/tension on tube. With the ring in place, all forces will remain static and no movement will occur on the valve.
However if you take out the valve ring, things become dynamic. Shear force will cause the valve bend forward or aft and weight will cause valve to slide in and out of the rim hole. Overtime, this will cause RUPTURE on the edge base where the valve mates with the tube.
PS I weigh in at 240+ all by my lonesome and run tires that use anywhere from 65 - 120psi
__________________
"Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey
"Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey
Last edited by chipcom; 05-06-08 at 01:02 PM.
05-06-08, 12:57 PM
#17
Senior Member
Join Date: Apr 2007
Location: South Bay Area
Posts: 163
Bikes: trek 7.2, 7.3FX, 5200 OCLV
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
05-06-08, 04:17 PM
#19
Dan J
Join Date: Jul 2006
Location: Iron Mountain, MI
Posts: 1,244
Bikes: 1974 Stella 10 speed, 2006 Trek Pilot 1.2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
05-06-08, 04:19 PM
#20
Membership Not Required
Join Date: Jan 2005
Location: On the road-USA
Posts: 16,855
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Likes: 0
Liked 15 Times
in
14 Posts
?? The added weight of ? The cap and ring? I ain't no roadie weight weenie. My lightest bike weighs around 25# and they go up from there.
Aaron
Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
05-06-08, 04:35 PM
#21
Senior Member
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225
Bikes: Catrike 559 I own some others but they don't get ridden very much.
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 643 Times
in
364 Posts
That's actually a positive. If you put your bike in a workstand and have a well adjusted front wheel, notice where the valve stem is when the wheel comes to rest. Most often it's near the top. That's mostly due to the weight of the pins that are used to hold the rim together at the seam.
05-07-08, 06:36 AM
#23
Senior Member
05-07-08, 07:11 AM
#25
Membership Not Required
Join Date: Jan 2005
Location: On the road-USA
Posts: 16,855
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Likes: 0
Liked 15 Times
in
14 Posts
Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon