- What is the correct way to fit a tire?
- Why is it sometimes so difficult to fit a tire?
- What can be done, if the tire cannot be centered?
- What is a tubeless tire?
- How are tubeless tires fitted?
- How are tubeless tires removed?
- How are tubeless tires repaired?
- How is a tubular tire fitted?
What is the correct way to fit a tire?
- All spoke holes must be completely and securely covered with an appropriate rim tape.
- Observe any rolling direction markings on the tire sidewall.
- Never use sharp fitting tools.
- Pull one tire side onto the rim (fig.1)
- Slightly inflate the tube until it is round.
- Fit the valve through the valve hole in the rim.
- Place the tube into the tire. (Fig. 2)
- Starting at the opposite side to the valve fit the other tire side onto the rim.
- Ensure the tube is not pinched between the rim and the tire.
- The valve should be in an upright position.
- Center the tire before inflating it to the required pressure.
- Adjust the inflation pressure using a pressure gauge, e.g. the AIRMAX pressure gauge. The permissible pressure range is marked on the tire sidewalls. The higher the inflation pressure, the lower the rolling resistance, the tire wear and the less likelihood of a puncture.
- The inflation pressure should be checked at least once a month.
Why is it sometimes so difficult to fit a tire?
Fitting difficulties often arise when the diameters of the rim and the tire do not match perfectly.
Rims may have a tolerance in diameter of +/- 0,5 mm. In addition, the height of the rim flank also may have a tolerance of +/- 0,5 mm. This adds up to a complete tolerance of +/- 1,55 in the outside diameter, or of +/- 4,7 mm in the outer circumference. This corresponds to a maximum possible circumferential difference of 9.4 mm between the largest and the smallest rim.
A tire must fit on both extremes. Because a safe fit must be ensured even on the smallest permissible rim diameter, the proper centering of the tire on the largest permissible rim can prove quite difficult.
The circumferential tolerance of Schwalbe tires is ± 1 mm. The Marathon Plus has proven to be extremely difficult to fit, particularly in the very narrow version. Through the rigidity of the tire, the tire slips repeatedly from the drop-center and it is extremely hard to pull the last piece of the tire over the rim flange.
A third hand, holding the tire tight in the drop-center on the opposite side, is very helpful here. Instead of a “third hand”, a zip tie or an old pedal strap can help keep the tire firmly in the drop-center during fitting.
D1 Bead Seat diameter
± 0,5 mm
G Rim flank height
± 0,5 mm
D2 Rim outer diameter,
D1 + 2 x G = ± 1,5 mm
U Rim Circumference,
D2 × π = ± 4,71 mm
What can be done, if the tire cannot be centered?
When the rim diameter is at maximum tolerance and the tire diameter is at minimum, it is difficult to get the tire beads onto the rim bead seat.
Solution: Slightly over-inflate the tire for a short time, or put soapy water onto the tire beads to make them slip into place more easily.
Our assembly fluid, Easy Fit, can be easily applied to the tire by use of the sponge applicator and without using extra tools or dirtying fingers. When inflating, the tire bead then glides easily into the right position onthe rim. After approx. 10 minutes the liquid evaporates completely.
When the rim diameter is at minimum and the tire diameter at maximum, the tire cannot be seated properly regardless of the tire pressure. This situation can generally be addressed by centring the tire by hand at low inflation pressure. Move the tire until the rim line is parallel to the rim all around the tire.
What is a tubeless tire?
As the name implies the tubeless system needs no tube. The tire and the rim are made in such a way that fitting them together provides an airtight seal. So special tires and rims are necessary and at the moment tubeless tires are only available for mountain bikes. The Mavic UST (Universal System Tubeless), which was introduced in 1999 has become, to all intents and purposes, market standard. The advantage of tubeless tires is that there is no sudden loss of pressure in case of a puncture. The perforating object either remains in the tire, sometimes even sealing itself, or it is dislodged and the air escapes very gradually. It also provides better impact resistance and valve tear off due to the tire slipping on the rim is impossible. It is important to note that fitting requires more effort and is significantly different from the fitting of traditional tires, so the fitting instructions must be followed closely (see section on fitment). The tire and the rim must be perfectly clean, especially in the contact area, in order to have an airtight seal. A puncture can be repaired from the inside with a traditional repair patch. But because the hole can often be hard to find, it is recommendable to insert a standard tube to repair a roadside puncture. In order to fit a tube, the valve first has to be removed from the rim.
How are tubeless tires fitted?
- Wet the rim well with a recommended lubricant or soapy water (1).
- Fit one of the tire beads onto the rim (2).
- Fit the other tire bead onto the rim. It is important to start on the side that is opposite to the valve. (3) (4).
- Verify the tire is correctly seated all around the rim (5) (6). Check that the valve is between the tire beads.
- Inflate the tire quickly until both beads jump up into place, confirmed by an audible pop(7) (8).
- Using the rim line, make sure that the tire is properly in place. The rim line must be parallel to the rim flange all the way around.
- Adjust the inflation pressure to your requirements taking into consideration the pressure markings on the tire and the manufacturers recommendations.
How are tubeless tires removed?
- Deflate the tire.
- First loosen only one tire side by pressing the tire bead into the rim well (2) (3) (4).
- Starting next to the valve, lift the tire bead over the rim flange (5).
- Loosen the opposite tire bead by pushing it into the rim well (6) (7).
- Remove the tire (8).
How are tubeless tires repaired?
Many Tubeless tires have an airtight coating on the inside. They can be repaired from the inside with a conventional tube patch. But because the hole can often be hard to find, it is recommended to insert a standard tube to repair a roadside puncture. In order to fit a tube, the valve first must be removed from the rim.
With extremely light tubeless tires the airtight coating is integrated on the outside of the normal rubber compound (e.g. Schwalbe Evo- Tubeless). A repair with patches is not possible in this case.
Another possibility to repair a tubeless tire is a latex based puncture protection liquid, such as Schwalbes Doc Blue. 50 ml of this liquid will reliably seal all punctures. Leaks will automatically be sealed by the liquid and at the same time it prevents further punctures for approx. 3 months.
How is a tubular tire fitted?
Attention: Tubular tires should be professionally fixed to rims using special contact cement!
As a test, first fit the tire without the contact cement (4-8). Check the valve length, using an extender if necessary. Recommendation: Fitting the tire on the rim beforehand using light pressure facilitates later permanent fixing.
Tire: Evenly coat the protective tape with a layer of contact cement (3) and let it dry for at least 6 hours.
New rim: Remove grease and if necessary roughen the rim well with fine sandpaper (1). Follow the rim manufacturer’s instructions! Evenly apply a layer of contact cement to the rim and let it dry for at least 6 hours! (2).
Used rim: Examine the existing contact cement layer. An even and intact contact cement layer can be re-used. If the layer is very uneven, completely remove all remnants of the contact cement from the rim and apply new cement.
Apply a fresh layer of contact cement to the rim (2). Immediately fit the tire. Insert the valve. Pull the tire as firmly as possible, so that the final section of tire slips over the edge of the rim in an easy and controlled manner (4-7). Slightly inflate the tire and center its position. The edge of the protective tape serves as orientation (8). Inflate to approx. 9 Bar and push down on the whole of the tire’s circumference using your full bodyweight. Clean off any remnants of contact cement from the rim braking surface.
Important: Leave the assembly to rest under pressure for at least 24 hours! Check tires regularly. Never ride on tires with a damaged or loose protective tape.