Making Your Own Self-sealing Presta Valve Bicycle Tube

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Introduction: Making Your Own Self-sealing Presta Valve Bicycle Tube

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.

Step 1: Find Something to 'push' the Slime Through

As we can't push the slime through the valve of a Presta tube, we need to make a hole in the tube in order to inject the slime. Obviously we want to make this puncture hole as small as possible so that it is easy to patch later.

I used the tip of this pen in order to push slime through the small hole we are about to make in the tube.... you can use anything though, just remember that the slime clots if the hole is too small (it guarantees to self-seal any hole 3mm or smaller in the tube), making it impossible to push any more through, so you need a balance between the ease of patching the hole and having it big enough to actually get the slime in there.

Step 2: Put Your 'funnel' on to the End of the Provided Slime Tube

My pen tip was slightly too wide for the provided slime tube, so I cut the tube a little, and then forced it in.

I used standard sticky tape (cellotape) which was lying around the house to provide a better seal.

Step 3: Puncture the Tube!

This is hard to bring yourself to do, but get a sharp knife and use it to make a hole in the tube just big enough to slip your slime injector nozzle in to.

Step 4: Squirt in the Slime

Carefully insert your slime-nozzle through the hole. Squeeze the bottle gently, and go slowly. Wriggle the nozzle around to ensure that some air gets back into the bottle, allowing you to squeeze in more slime. The slime manufacturers recommend 1/4 of this bottle per tyre (8 oz) but I put a little less in and it's still effective.

Step 5: Clean and Dry the Tube

Wipe the tube with a bit of toilet paper to get rid of any excess or overflowing slime. This is very important because the vulcanising glue does not work so well when there's still slime on the surface.

Step 6: Prepare for Patching

Rough up the surface of the tube with one of those metal things that look like cheese graters - you should be able to find one in any bicycle patch kit.

Then apply the vulcanising glue over an area which is approximately the same size & shape as the patch you are going to use.

Let the glue dry (i.e doesn't feel 'tacky' to the touch)

Step 7: Apply the Patch

Peel the patch from it's foil backing, place it on the patch of glue, and then using a mug or tin or rolling pin, roll back and forth over it very vigourously until the plastic on the surface of the patch gets wrinkly and splits.

Peel off the plastic, and there you have a patched self healing tyre. Make sure that when you are peeling the plastic off the patch that you peel it from the middle of the patch to the edge of the patch - otherwise the edges could stretch up off the tube and affect the quality of the seal.

Now put the tube back in the tyre, the tyre back on the wheel, and make sure that you rotate the wheel straight after inflating it to distribute the slime evenly - it will also seal any small holes that may have triggered this slime-ing tyre surgery in the first place ;)

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    58 Comments

    user

    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???

    valve.jpg
    1 reply

    What happens to the "be nice" comment policy? Surely you are aware that not all presta valves have removeable cores, don't you? By the eighth pic it seems that the tube used in this 'ible has a no removeable one.

    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.

    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

     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?

    5 replies

    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

    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

    4 to 5 tyres I mean!~

    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.

    8 replies

    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...

    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 :)