Tubeless, all you know to know

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http://forums.farkin.net/showthread.php?t=86107

Author

Shorerider

This is a guide to Converting from Tubed tyres (ie; Tyres with a tube inside) to Tubeless tyres (ie; Tyres without a tube inside) I've included all the little tricks that I have learnt in my years of runing a Tubeless set up.

I've been using a Tubeless tyres set up for the last 2-3 years, and I love it. No flats, not one, EVER. This should be reason enough to convert to Tubeless. I mean lets face it, flat tire's suck. It takes time away from riding, and for those who race, could see a race lost.

Tyres:

There is no need to buy UST (Universal System Tubeless) tyres. They are often heavier than Non-UST tyres. The Sealant will seal ANY holes in the sidewalls or anywhere else. Non-UST tyres are fine. I don't think it matters what bead you use. I've only used wire beads, but I don't see why anything else would be a great problem.

UST Tyres:

If you are going to use UST tyres you don't need to run any kind of sealant but, I would recommend using it. If you choose to run UST tyres "without" sealant you will still get punctures. (less than a standard tube set up though) UST tyres used with sealant will hold air much better, and for a longer time too. UST tyres are also a bit more expensive than Non-UST tyres too.

Non-UST Tyres:

If you are going to use Non-UST tyres you MUST use a sealant of some kind. The sidewalls of Non-UST tyres are porous and will not hold air unless a sealant is used to seal these microscopic holes.

UST Rims:

UST Rims are air tight when used with the special UST Valve stem (supplied with your rim) and UST tyres. They usually have no spoke holes visible on the inner wall of the rim. This allows them to be used without the need of a rim-strip of any kind. This is the easiest system to use, but can be costly if you don't already have UST rims (see Rim Strips). If you plan on upgrading your rims in the future, buying UST specific rims would make your Tubeless set up a whole lot easier.

Non-UST Rims:

With Non-UST rims, just make a rim strip from a new 20" BMX tube cut to size. (see below)

Rim strips:

Rim strips, for use with Non-UST specific rims, are easily made using a new 20" BMX tube. The 20" size gives you a very snug fit all the way around the rim.This is to ensure there are no air leaks from the spoke holes.

Option A; Cut the tube in the center all the way around the "Outer" circumference of the tube. Then install the tube on the rim. About 5-10MM should be left to overhang each side of the rim-with the tire installed. Next you will need to cut off the excess tube from the sides of the rim. This is best done once you have centered the rim-strip perfectly over the rim.

Option B; Firstly clean the inside of the rim with some Alcohol, or something similar. Then check for any sharp corners or spoke nipples. Sand/file as necessary. Then starting opposite the valve hole, run some electrical tape one revolution in the center of the rim. Then, the second revolution to one side of the nipples/holes. And the third revolution to the other side, finishing where you started. Only use 1 piece of tape to avoid leaks. You may need a big roll. Also try not to stretch the tape when putting it on. This will make the tape want to unpeel itself. Once applied, press down firmly all the way around the tape.

Then with a Stanley knife or similar, carefully trim out the valve hole where the tape is covering it. Don't make it any bigger than it needs to be.

Next cut the 20" tube so it sits 1-2mm "inside" the rim walls, and install. Then your Non-UST rim should be completely UST friendly.

(Note; I have not tried the above, But if I still had Non-UST rims, this is the method I would use. If anyone has tried running the tube "inside" the rim, I would like to hear from you)

Sealant:

I've always used Liquid Latex as a sealant. Any decent Hobby store will have it. ($30 for 1 liter) Add water to the Latex. (it will be quite thick undiluted) The Latex to water ratio is not very critical. Just add water until the Latex is runny enough to move quickly and freely inside the Tyre. (Like milk for example.) But don't add too much.

The Latex will need to be refreshed as it does dry inside the Tyre, as do most other sealants. Every 5 months should adequate, but I've had it last up to 8 months.

I always peel the dry Latex from the inside of the Tyre, if it's going back on. Don't need the extra weight of dry Latex inside the Tyre. But I don't see a problem leaving it there and just adding more Latex.

Old/dry Latex will almost come off in one piece, like a big, long used................rubber glove.(ha,ha)

If you are changing the Tyre while the sealant is still wet, you can just soak the Latex up with an old sponge or pour it into a cup or something similar if you really want to reuse it. It's water soluble so clean ups are easy.

With Non-UST rims, the rim-strip should just wipe clean and be fine for reuse. UST rims don't get that much Latex on them.

Or

Add the sealant of your choice IE: Stans, Slime etc.............

Valves;

Weather you are using Rim strips or UST-Rims with UST-Valve stems, the valves are prone to clogging up with dry sealant over a period of time. So periodic valve cleaning is required to ensure a good flow of air into the tyre.

Schrader Type valves; This is the easiest type to clean. All you need to do is remove the valve core with a "Valve core removal tool" (available at most Auto shops)

Then simply clean off the build up of sealant from the valve core with your fingers (or tweezers if you bite your nails), and reinstall.

Presta Type Valves; Presta Valves are a bit trickier to clean, but still not very complicated.

You'll find that Presta valves don't unscrew. So you'll need to fix that first. At the end of the valve is the threaded, Brass-colored, core shaft. (not the body) Threaded onto this is a rounded silver/chrome nut. At the end of the brass colored threaded shaft, the thread at the very end stops. This is so you don't loose the silver/chrome nut. Well, you'll need to file down the portion of unthreaded shaft only just enough for the silver/chrome nut to unscrew all the way off the shaft.

Then lightly clamp the valve in a vice. With a 2-3mm pin punch (or an old spoke about 30mm long with its end filed nicely) and hammer, carefully tap out the valve core. Do this by tapping the Brass colored core shaft through the top of the valve, and out of the base.

Clean as necessary and reinstall.

Now when you go to inflate your tyres, don't forget you can't unscrew the silver/chrome nut all the way out. It WILL come off and you may loose it.

TIP: You can coat the valve core in grease prior to re installation to aid in cleaning the next time.

Tubeless Installation:

Firstly, seat only one side of the tyre and leave the other side off.

Note: This may be a good time to check the "direction" of the tread if it is directional.

Then, you'll need to soap up the beads with some soapy water. Dish-washing detergent, watered down, works well. If applied with a paintbrush, you'll get a nice lather happening. If not, soapy water in a spray bottle also works well.

Then, with the tyre leaning against something (like a wall) in an upright position, put the tyre valve at the 12 o'clock position. (so the air doesn't splash the sealant everywhere when you're seating the beads)

Pour in the sealant. About 1/2 to 3/4 a cup per tyre is heaps. Then seat the remaining side from the bottom up. (its less messy when your seating the last bit of tyre AWAY from the sealant)

You will need an air compressor. Those small ones for car tyres should be enough.

TIP:Try kinking the hose with the compressor connected to the tyre valve. When a high pressure is reached, unkink the hose quickly, which will release a sudden burst of air.

If you don't have one, or if you are having trouble with seating the beads, a trip to the local Service Station is in order. Don't forget your spray bottle.

Note: Service Stations with the Digital/Automatic fillers are Ideal. They have a "Flat Tyre Only" selection. It gives out sudden bursts of air which will seat the most stubborn of beads.

Disclaimer: Be careful filling tyres at Service Stations. They are designed for car tyres which hold a greater volume of air. This is most true for the "Flat Tyre Only" selection. If needed, start the "Flat Tyre Only" not connected to the valve, to see how it works . Connect it half way through it's cycle to first seat the beads.

Also, playing with compressed air is DANGEROUS, so be careful!!!

Then inflate to around 60-70 psi by which time you should have heard a loud "POP".

(Now go and change your pants. More than likely, you will soil yourself thinking you just burst your tire.)

Then put/spray some soapy water onto the sidewalls. Bubbles will appear where there are leaks. Where there are bubbles appearing, move it to the bottom of the tyre. Then let the sealant settle in the bottom of the tyre while holding it upright. Splash the sealant inside the tyre to where the bubbles are. They should stop soon enough.

Leave at around 60 psi overnight or longer. This will push the sealant out of every hole and seal it.

(NOTE: I take no responsibility for burst tire's or soiled pants.)

When in use, Tubeless tyres will sometimes "Burp" (when the tyre bead looses contact with the inside of the rim) on harsh impacts. This will release the smallest amount of air and sealant. Don't be alarmed. This is normal. You won't even notice the loss of air.

When you do "Burp the tyre, a tiny amount of sealant will squirt out. The Latex is white. It's easily visible against the black tire. This is a good way to see if the sealant is still active/not dried up. When you no longer see this happening, good chance is that the sealant is dry, and needs refreshing.