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Making your own self-sealing presta valve bicycle tube

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Out here, in the desert town of Kalgoorlie, Western Australia, my bicycles and I have one mortal enemy. It is Zygophyllaceae, Caltrop Family - known as puncture vine, goats heads, double gees and sometimes bindi-bindi. There's a photo of these horrible plants here. They are a noxious weed out here, and this year we had more rain than usual so there are lots of them around.

I have two bikes - one is a mountain bike running Sun Rhynolite rims, with presta valves (26" wheels), the other is a flat bar roadie running 28mm 700c tyres. I have had 10 punctures across both the bikes in the 3 months I have been living in town, despite running 'Mr Tuffy's' tyre liners and heavy duty tubes.

I am told that there are only two effective ways to save my sanity by reducing the number of punctures I get - one involves spending $120 on a set of tyres, the other is putting slime in the tubes. Problem with slime is that you can't push it in through a presta valve and tubes with presta valves with removable cores are rare in 28mm or 26" x 2.125 versions.

So I decided to go old school. In this instructable I will show you how to make your current presta valve tubes into self sealing slime tubes with a little bit of surgery.

PS - slime in your tyres will add a noticable amount to the rolling weight of your bike, so it takes some getting used to, but it's worth it in order to prevent those annoying punctures.
 
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FuR13 months ago

You fool! If you grab the flat side of the cap threads on a presta valve, the whole valve unscrews from the stem. Wrap some tape on it > Fill it> Screw valve back in.

Why on earth would you cut a perfectly good tube???

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Solidwrks2 years ago
I need to make a small inner tube for a project. I cannot get a custom one made at a smaller size. The length of the tubing should be just 110 mm. i have to use a valve that is made of rubber, plastic or stainless steel ( last option) . The tube goes into a magnet, so i have to be careful that the valve i use must not be iron or any attracting materials. Is there a possibility to make it at home.
knx bandit3 years ago
some presta valve tubes come with removable valve core, "continental" brand tubes are one but there are others. Then use a 50ml syringe from your local hospital or pharmacy to squirt in some slime in. It's that easy. I like in Kununurra WA and too have loads of prickles. Try tyres like "continental protection series MTB 26" or continental gator hard shell road tyres, or any tyre that offers an extra layer of kevlar or tough materal in the manufacture. Good luck
getack4 years ago
 Well, the newest in thing is to go TUBELESS...
Apparently the probability of a puncture is next to nil.
Very expensive ($100) conversion, but I think it's worth it. 

You can always just buy a tube with slime in it already. I have a slime tube in my saddle bag by default. In South Africa's bike shops we usually have a whole shelf dedicated to anti-puncture products.

Regarding increased rolling-inertia: If you are on a road bike in a race speeding at 50-60 km/h rooting for a record, THEN only will rolling inertia make a difference. And in that case you will have no punctures to worry about. Slower XC's or MTB's will be unnafected. If you are still worried about it, use slime and tyre-liners, with tyres that has less knobblies. Increased rolling inertia with decreased rolling resitance will cancel eachother out.
do you have to fill the whole tire with slime? If so, wouldnt that make the tires heavy and make riding your bike a chore? If you dont fill the whole tire up wouldnt the slime settle at the bottom of the tire and make it harder to peddle or something?
jet_ski (author)  creative zen6 years ago
Nah, just maybe 100ml - it does add to the rolling weight of the bike but it only took me a couple of days of riding to adjust - the rims are heavy anyway as this is bike is built for dirtjumping so it's not that much extra
how much does the slime cost
jet_ski (author)  creative zen6 years ago
I got it from a bike shop for $30, that bottle does 4 to 5 bottles
seroiusly i used it in my 20 inch bmx tires and it only lasted me 2 syres
jet_ski (author)  jet_ski6 years ago
4 to 5 tyres I mean!~
lasersage6 years ago
don't know about your particular wheels, but i find standard 26" rims often come with the presta valve size, but i just drill it out to fit a schrader.
jet_ski (author)  lasersage6 years ago
You can run higher pressure with presta valves, I like having the option therefore I am loathe to drill out my Sun Rhynolites.
The valve suyppied with an innertube means nothing to how much pressure the tire can take. Schrader valves can take over 3000PSI, but are more common. Presta valves are a failing attempt to change a stubborn american standard to accept a metric standard with the rest of the world. There are adapters available to adapt the primitive Schrader air chucks for use with a Presta valve, just ask your local bike shop. These allow you to use 19th century technology to inflate your Presta valves until the USA catches up to the rest of the world (don't hold your breath).
just because Shrader valves have been around a while doesn't mean they aren't any good! Yes presta might be a slightly more advanced valve that does not use springs but nothing beats the simplicity of just pushing the shrader air chuck up to the valve to fill it with air. With a presta you have to unscrew it, fill it, and then re screw it. Also on a presta valve the parts are exposed but on the shrader vales everything is inside the valve tube. another thing is I can completely replace the shrader valve if needed; can you do that with presta valves? what happens if you take a well placed hit to the presta valve that bends the screw such that you can no longer fill it with air? so its not a matter of metric vs. standard. I am all for the metric system but shrader all the way!!
The advantage to Presta valves is that there is no fear of a leaky core, allowing a guaranteed seal. Compatibility, I agree with, but taking a hit on a Presta valve is immeasurably improbable. Bends on the core spindle are always the result of improper handling. Also, it is uncommon for even a bent core not to seal unless it breaks off. Presta has the advantage of a greater flow rate through the valve, and not relying on spring-pressure to retain a seal. The greater flow rate makes hand-pumping faster and less physical work. While it appears exposed, openings are far too small to allow the ingress of water, which is a vehicle for dirt. A Presta valve's main advantage is fitting into ultra-narrow rims on road bikes, since a Schrader valve's required dimension would dangerously weaken the rim beyond an acceptable standard, such as with rims 10mm wide on 700C wheels. You simply can't use a Schrader valve on that rim, and no Tour De France rider will ever take wider rims just to fit a Schrader valve. IMHO, no mountain-bike should be equipped Presta, as using 10mm wide rims on such is simply unreasonable, despite alleged performance. Too narrow, and the tire/tube combo could simply roll of the rim when cornering. Also why I will never use a tubular tire...I can never feel safe relying on glue to keep the tire on (I don't think weight-savings is worth the risk, but I used to have diesel-powered legs that bent many frames and broke many chains, so weight is less important to me (I broke chains by pin/plate separation on links not related to the link I mounted it on by sheer power alone...I know because I always marked links that were mounted or dismounted, and never was a pin driven to or from any link more than once. I promise not from poor chain mounting). Presta has it's superiorities, but I agree that despite that, Schrader valves should be the standard due to a replaceable core and it's current prevalence. While it has it's troubles with sealing perfectly, and dirt ingress, it's probably an acceptable standard. Always keep them capped firmly to protect from water, dirt, and dust. Don't bother cleaning cores, just replace them, even if you have to go to a junkyard and nab one off a tire, or by getting them from old innertubes. If you do clean them, use only rubbing alcohol. Screw in finger-tight only.
i think i have a presta valve stem that has gone bad; are they replaceable like schrader stems or are you stuck buying a new tube? thanks very much.
You are stuck buying a new tube, Presta valves are not in any way serviceable. If your rim is greater than 18mm wide, you could consider drilling it out for Schrader valves... Save the innertube itself though, they are remarkably-versatile, and is the best patch material you can use, far better than the patches included. All you really need is the vulcanizing glue...They have many other uses as well...
fuzvulf jet_ski5 years ago
30 years ago I had some lace-ons with tubes that had Schraeder valves which took 200 psi, how much pressure do you want? Not meaning to sound rude but I don't think the pressure holding capability is a matter of the design but of where you get them. Prestas are smaller thereby the rim is not weakened as much, there is not as much air resistance, the weight of the valve itself is less providing greater balance to the wheel, also due to the nut on many designs*(which Schraeder used occasionally have but due to market pressure they became harder and harder to find.) it is more durable for riding in areas where rocks or other foreign objects might damage a Schaeder. This same feature also allows one to run at lower pressures when rock climbing on bike without the tube sliding within the tire and rim.
fair enough, I know a lot of cross country riders who swear by presta, quicker to inflate/deflate from what i hear as well. I'll stick with my schraders for simplicity. Don't be to precious about you rhynolites though, i drilled my sun big fat mammoth (i didn't care how expensiver rim it was, it needed to do a job :)
are presta valve stems unscrewable and replaceable like schrader stems? any one know? thanks.
lasersagesays: don't know about your particular wheels, but i find standard 26" rims often come with the presta valve size, but i just drill it out to fit a schrader. ROFLMAO. I thought I was the only one who did that?
7O76 years ago
This almost seems like its a bit too late but you don't have to cut the tube at all. Okay you have to follow me on this one and I will instruct you through a better way to do it. You know the little knurled nut that threads up and down to allow you to put air in/out. Well pinch the tube with your fingers right by the valve to prevent the valve from falling inside the tube after you take that knurled nut all the way off. Yea that's right just unscrew it all the way off (use some small pliers if you need to). BUT be careful to catch the valve core by feeling through the tube (it's like holding the valve core with a rubber glove on so don't let it get away). Once you are holding the valve core, put the sealant tube and bottle FIRMLY over the valve and add 1/2" bottle. Of course hold the valve up to allow room for the sealant to flow. Now since you are still holding the valve core through the rubber and hopefully with the tip of it pretty close to the hole, feed it back into the valve and wiggle or tap it until it falls back through. once you see the threads you're home free. Now just pinch the tube with you fingers again to keep it from sneaking back inside, then thread the little nut back on. Thread the nut down and pinch the tip of the threads with the pliers to mess up the threads just a little and there you have it sealant in the tube with out cutting it. I hope I didn't make it sound too complicated, I can do this in about 5 minutes and have done hundreds of prestas this way.
runner12126 years ago
I would just like to know whether or not anyone has done this and can attest that doing this DOES in fact prevent puncturing?
night6 years ago
hey, any problems letting air out of the tyres, i have heard stories of the slime coming out too and ruining the valve,
you can avoid this if you orient the valve so that it is just below the horizontal axis of the wheel such that it slants back towards the wheel to let the slime run out of it and back into the wheel but sits high enough on the wheel that it is above the pool in the bottom of the tube. sorry its an easy concept just hard to describe.
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The picture should say enough here, and good advice to all.
jet_ski (author)  night6 years ago
this can happen, but it hasn't happened to me yet... I've heard similar stories though...
lynzay_6 years ago
INSIDER SECRET. for anyone wanting to make an instructable on puncture proof tyres, here it is. line the inside of your bike tyre with an old car seatbelt, seatbelts are made with such a strong heavy weave you wont be getting punctures anytime soon , and for safety, use the thicker inner tubes. INDESTRUCTABLE.
jongscx lynzay_6 years ago
Seatbelts are WOVEN NYLON. They are good at resisting lateral stresses (like when they hold a person back) but a thorn will go right between the weaves... You can sew through a seatbelt with a needle by hand, it's not that hard. This is also the same way that a person can stab through a kevlar vest with a really sharp spike. If you've done it, I'm betting it's the added thickness that is keeping your tube safe, not necessarily that the belt is is . Thicker Inner-tubes do work. But they're not puncture-proof, just puncture-resistant...
jet_ski (author)  jongscx6 years ago
the seatbelt is a good way of adding thickness without adding as much weight as the same amount of rubber - but yeah it would stab through the weave easily enough.
autolycos6 years ago
You can take insert slime into a presta valved tube provided you use some dexterity and pliers. Use the pliers to take the nut off, just keep screwing it past the mashed threads, it'll come off--but when it does, prepare to capture the inner part as it falls into the tube. Then, just add your slime. Screw the nut back on, and using the pliers, crush the top one or two turns of the threads so that the nut can't be removed by fingers.
I have used a different method so as not to damage any of the threads. You take a metal file and just file a little off from the screw and then you can unscrew the nut with ease. After filling the tube with slime, you just twist the nut back on and just tap the end with a ballpeen hammer a few times (not too hard or you will bend the screw) it works great and my slime tubes last me a really long time, plus it is cheaper than buying tubes that already have the slime in them.
skeptikool6 years ago
The fix seems incredibly easy. I would remove the tube to inject the latex, or pre-prepare a spare. It would be easier to clean and roughen where you were going to puncture the tube, before doing so. For this, I favor something like a medium sized knitting needle . With care one need not end up with two holes - though this would not be serious. If one were putting the latex into a tube punctured in use, even a hole that had been made by a thumb tack may be stretched to accept the nozzle of the latex bottle. A properly patched tube is in no way inferior to one that has received no puncture at all.
toilofday6 years ago
You shouldn't use a knife. Slime isn't recommended for the type of puncture a blade inflicts. You should use a nail then stretch the rubber over your funnel. It may be more difficult, but there is less risk of ruining the tube.
jet_ski (author)  toilofday6 years ago
that's why it's patched with vulcanising glue - the slime doesn't heal the slash hole, the patch does!
True, but not everybody may be as careful when removing the excess slime residue when patching the tire. If you are going to puncture the tire, you might as well make it so there are 2 forces actively sealing the hole, rather than 1 which can fail if not done just right. Maybe I'm just a fan of overkill. Either way 2 is better than 1 Nice Instructable.
But that's not really his problem. The instructables clearly state to clean it well, any failure caused by the user's lack of diligence should not be pushed onto the author.
jet_ski (author)  toilofday6 years ago
I still think that even if you make a round, nail shaped hole it would be too big for the slime to seal well....and if it's too small it is hard to push the slime through. Thanks for your input though!
If Slime® won't seal it, the tube is bey9ond a patch anyway.
Lucky6 years ago
This is nice, but at this point I'd have to wonder if a more direct approach would be better. What I mean to say is that it seems a lot of work to avoid a problem that shouldn't exist in the first place. Maybe inner-tubes could be replaced by multiple layers of shock/bump absorbing soft rubber and foam. Maybe then the tires would never "go flat". I've seen R.C. cars with a rudimentary form of this. I forsee a layer of foam nearest the tire for small rocks and such, which precedes gradually more dense materials until the rim itself be reached. I would only suppose that overal performance loss would occur, even with proper application. However the detriments of the environments traveled through where such a system would be implemented would surely provide adequate hinderance to ensure said system's usefullness.
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