How To SLIME Presta Valve Tubes

For the most part putting Slime into presta valves was a bit of a mystery for most consumers. But you’d be surprised to know that you could actually get it done for half the price it would have cost to buy 1 pre-Slimed tube.

I went back to Jax Bicycle Center in Fullerton to get some advice from Scott Moore, a resident mechanic of the shop.

He was able to show me how they Slime presta tubes at the shop. We used the Redline 925 as the test subject.

First things first, remove the tube from the wheel.

Keep the valve closed and take some pliers and cut the very tip of the valve.

This next step is the most crucial part. Place your thumb below the valve to prevent the needle from falling into the tube. Hold the pin in place during the whole time. If you lose the valve in the tube, it could mean you buying a new tube.

Then place a Shrader valve adapter on the stem. Make sure you keep your thumb under the valve…

Since we’re at the shop, we used the Slime pump to fill the tube up with the green stuff. Don’t hold the pin too tightly.

If it’s too tight, you can get Slimed from the back pressure.

If you’re doing this at home, you can still use a bottle of Slime for this project. Just simply fill your tube as the direction states. But remember, don’t let go of the pin!

Now here’s the magic of it all. Once you’ve got enough Slime in there, blow pressurized air into the valve. See how Scott is still holding the pin. What happens after the tube gets enough air, the pin will shoot forward, making it visible.

Here’s a shot of the pin out of the valve stem after getting air in the tube.

Then what you want to do is grab your pliers, hold the pin, then screw on the valve top.

Mount the tube back in to the wheel, fill it up with air, and you’re back in business!

Just keep in mind that the valve head can screw off completely. So when you need to fill it back up with air, just don’t unscrew it all the way.

Thanks again to Scott Moore fo Jax Bicycles of Fullerton.

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