ALL ABOUT YOUR MOUNTAIN BIKE’S MOST IMPORTANT COMPONENT: TUBELESS RIM TAPE

Rim tape is the unsung hero of most tubeless tire and wheel setups. At its most basic form, your wheel’s rim tape is a strip of non-porous adhesive tape that creates a seal between the spokes/nipples, the rim and the air pocket that inflates your tire. When installed correctly, good-quality rim tape will last for quite a while and prevent your wheels from slowly leaking air over time.

Rim tape generally goes unnoticed until it quits working. And, it seems to quit working at the worst possible times. Failed rim tape can also allow sealant to wreak havoc and cause corrosion on alloy nipples or exposed metal in the rim, so it’s best to keep it in tip-top shape.

TYPES OF TAPE

Unlike many other things that adorn our mountain bikes, there is really only one type of tape that will effectively seal your rim and prevent air from escaping—any non-porous tape with a strong adhesive. There are many different brands out there, but they are all essentially the same thing and perform the same function. Tubeless rim tape is a simple product with an important job that often gets overlooked until it becomes a problem.

Some brands use an adhesive that can leave a residue behind, while others use an adhesive that leaves a clean finish without any residue (it should still be thoroughly cleaned before installing new tape, however).

There are some rim tapes that can have more stretch than others as well, which can help with installation and create a more taut seal around the rim. At the end of the day, the rim tape acts as a barrier between the air and sealant in your tire and your wheel.

COMMON FAILURES

One of the most common causes of rim-tape failure is simply disturbing it during a tire change, especially if you change them often. Sometimes, the tire’s bead can stick to the tape and peel up the edge as you unseat the tire. In rare cases, you can stick it back down, but most of the time the adhesive gets compromised by sealant or just isn’t working well any longer since it came loose in the first place, so it’s always best to replace it.

Another cause of failure is heavy-handed use of tire levers that can go in and puncture or damage the tape. If you remove the tire and see damaged or bubbling tape, the best practice is to replace it before a ride is ruined.

DIAGNOSE AND REPLACE

If you have a slow leak that you can’t find on the tire and you suspect the rim tape, simply spray the valve stem and spokes with soapy water to diagnose. If you see bubbles at either, you need to re-tape your rim.

Choosing rim tape is easy, but it’s a step that many get incorrect. You need to pick a tape that goes from rim wall to rim wall without climbing up the sides. It’s easy to get a tape that’s too narrow, because the inner drop channel takes up some width.

Most rims need a tape that is 2–5mm wider than the inner rim width to compensate. For example, if you have a 30mm-wide inner rim, you’ll need to choose a 32–35mm-wide tape. The exact width needed will vary depending on the shape and depth of that drop channel. An easy way to find out what you need is to ask the rim’s manufacturer.

INSTALLATION STEPS

Step 1: Cleaning the Rim

The first step to re-taping your rims is to remove the old tape and give your wheel a good cleaning. The old tape will leave adhesive or some sort of residue on the rim, so it’s paramount that you clean all of this off before beginning to apply new tape.

We like to use a clean shop rag or microfiber cloth and isopropyl alcohol to make sure that any sort of residue or tire sealant is removed from the rim and that the surface is as sterile as possible. If you have access to one, we also like to use an air compressor to give the wheel a final cleaning and ensure that any dust or fibers are removed.

Step 2: Prepping the Rim

After the old tape has been removed and the wheel cleaned, it’s time to prepare the rim for the new tape. Whether we’re running alloy or carbon wheels, we always inspect the rim to look for any dents, cracks or compromises. Alloy rims can get away with small dents that don’t break the tire’s bead or significantly affect the wheel’s spin, but any sort of imperfection in carbon wheels should be addressed immediately with the manufacturer or your local bike shop.

Some alloy rims have a smooth inner surface that can make it difficult for the rim tape to stick, but using a super-fine-grit sandpaper to lightly scuff the surface can create texture and give the tape something to adhere to. If you need to texture the rim’s surface, be sure to thoroughly clean it again to get rid of any metal shavings or debris.

Step 3: Applying New Rim Tape

Once the rim has been cleaned of any residual residue, dirt and debris, it’s time to apply the new rim tape. This is the most tedious part of the process, but it’s the most crucial to ensure a complete and long-lasting seal for your rim.

Start at an area of the rim in between spoke holes (we like to start next to the valve hole), and press firmly with your thumb to make sure the beginning of the tape adheres sufficiently to the rim. As you begin to move around the diameter of the wheel, make sure there is tension on the tape and that it is sticking smoothly to the rim without any air bubbles or creases. If there are any imperfections, simply lift the tape back up and reapply to try and get rid of any bumps or air bubbles that will affect the airtight seal.

It can take some time, but it will save you the headache of dealing with a wheel that slowly leaks air. Once you’ve made it around the diameter of the rim and are back where you started, we like to overlap the tape by about 4 inches to make sure it is completely sealed and that it won’t start peeling up over time.

Step 4: Install Valve Stem

After you have the tape applied and everything is sealed, use a small pick or screwdriver to pierce the tape at the valve hole and install your tubeless valve. Now you have a wheel that is freshly taped, sealed and is ready to have a new tire installed.

Bonus pro tip: We first saw this technique used by Kyle Strait. He used a Hot Wheels or Matchbox car that is thinner than the rim’s width to firmly press down the edges of the tape and ensure that there is an airtight seal around the entire wheel.

Looking for new rim tape? Check out our list of the top ten rim tapes here: https://mbaction.com/the-ten-best-mountain-bike-tubeless-rim-tapes/

Need new valve stems? See our ten favorites here: https://mbaction.com/the-ten-best-tubeless-tire-valve-stems-an-underrated-upgrade/

No tubeless setup is complete without sealant. See the wrecking crew’s favorite’s here: https://mbaction.com/the-ten-best-tubeless-tire-sealants-for-your-mountain-bike/