How to fill or refill your bike tyre with sealant

When I add tyre sealant in my bike tyres, MTB, Gravel, and now Road, I've always used a syringe with a tube that screwed on to the Presta valve, after taking out the inner valve, of course.

This has always worked well, but I never really liked it because it does tend to dirty the insides of the valve with the sealant, so I always tried to get a bit of rag in there to clean it up.

Uploaded image — A standard fitting the screws onto the valve

Having lost the syringe while moving house, I bought a cheapo version from Amazon that has no piece that screws off the valve; instead, its tube is far finer and just slides/fits inside the valve.

I thought that it would be crap when I ordered it, but lo and behold, it's far better :

Why?
Well, the tube extends all the way through the valve until it touches the tyre. If you have the tyre with the valve in the approximately 9 o’clock position, the sealant will flow down inside the tyre, away from the valve. Once finished, pull out the tube. The valve is still nice and clean.

Note: You must clean the syringe and the tube straight after use. Otherwise, it will clog up, and when dried, it's useless. Just use warm water.

No miracle science here, I just found out that the simplest version works better.

Two tips.
Use Stans No Tube tyre sealant or Joe's No Flats. Both are very good. They've been around for many years, and are, in my opinion, still the best. I use either depending on what I have in stock.

If you buy a cheapo syringe, you might have a Chinese copy of Park Tools Valve Core tool below with it. I did. It's crap and may damage the valve.
Buy the real one. Like all Park Tools, this will last you a lifetime.

Like this post? Buy me a coffee!
Your support means a lot and helps me keep creating useful content ☕😊
https://buymeacoffee.com/minty95