MOJO Tyres
A racing series without a top quality tyre cannot be successful. This was common knowledge when the Rotax MAX Challenge was launched in the year 2000. After many years of cooperation with a well known tyre brand, BRP (Rotax) decided to start a project to develop a tyre that perfectly matched the Rotax 125 MAX family of engines.
The birth of an independent kart racing tyre brand?
MOJO was born in 2006 from Rotax's desire for tyres that would bring out the best in their Rotax 125 MAX engine family in Rotax MAX Challenge races. Today, MOJO is one of the leading suppliers in the kart tyre market. The MOJO portfolio comprises four slicks and two rain tyres. Valued for their unique mix of reliability, grip level, and consistency, MOJO tyres are sold in 50 countries worldwide.
MOJO FAQs
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Mojo tyres keep their performance best if they are stored at
• a cool dry place, away from ultra violet light (Mojo tire bag or black garbage bag)
• normal ambient temperature (20°C/68°F) - do not store Mojo tyres below 0°C/32°F!
• low humidity -
The use of tyre softeners can alter the compound of the tyre which can result in a failure of the tyre - safety risk! Most tyre softeners are toxic and can cause cancer. Altering the compound of tyres is not in line with the philosophy of the Rotax MAX Challenge with regards to fair competition with equal equipment.
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Camber is the angle of the wheel relative to vertical, as viewed from the front. If the wheel leans in towards the chassis, it has negative camber (first picture); if the wheel leans away from the chassis, it has positive camber (second picture). The cornering force that a tyre can develop is highly dependent on its angle relative to the road surface, and so wheel camber has a major effect on the track surface holding of the kart.
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Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it's tilted forward, then the caster is negative.
Positive caster tends to straighten the wheel when the kart is traveling forward, and thus is used to enhance straight-line stability. -
When a pair of wheels are set so that their leading edges are pointed slightly towards each other, this is toe-in (first picture). If the leading eadges point away from each other, this is toe-out (second picture). The amount of toe can be measured as the difference between the track widths as measured at the leading and trailing eadges of the tires or wheels. Toe settings affect three major areas of performance:
• tyre wear,
• straight-line stability and
• corner entry handling characteristics.
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As of 2009 all MOJO tyres are marked with barcode always starting with H8 followed by 7 digits in random order.
The barcode is mainly meant to be used as control instrument at race meetings. The barcode shall guarantee that competitors are only using those tyres which are dedicated to them during an event (as indicated in the sporting regulations of the varies ROTAX MAX Challenges). -
• Set tyre pressures to preferred settings. Use a reliable tyre gauge • Complete 2 laps at a medium pace without sliding the kart. Gradually increase your speed to full pace allowing a good heat transfer throughout the tyres • Check pressures immediately after finish of driving to establish a good working tyre pressure and temperature. Pressure should not increase more than 0.35 bar • Check tyres for any unusual signs of wear or damage. Re-check tyre balance. -
You can find the recommended tyre pressure for each MOJO model on our website in the section "products" or by scanning the QR-code on the tyre.
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It is not possible to recommend a perfect tyre temperature for the various MOJO tyres, as this is influenced by different factors like the track condition, track temperature, ambient temperature or type of asphalt.
However, the idea is to set a cold tyre pressure that will allow the tyres to achieve the recommended hot pressure for best performance, in consideration with a number of further influencing factors such as ambient temperature, track surface temperature, chassis setting etc
> If the ambient temperature is cold (and also the track surface temperature), the starting pressure may be slightly higher than recommended to achieve the hot running pressure.
> If the ambient temperature is hot (and also the track surface temperature), then a slightly lower starting pressure will be required to achieve the recommended hot tyre pressure. -
It is an option to use a needle pyrometer at all your tests as the tyres cool down quickly and measuring just the surface temperature is not accurate enough.
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BEAD The bead of the tyre is the area that holds the tyre to the rim. The bead needs to be strong enough to hold the tyre on the rim whilst in use, without popping off the rim, and flexible enough for the tyre to be fitted to the rim and hold air pressure.
SHOULDER The tyre needs a solid shoulder to enable a good contact between the tyre and the track whilst cornering. The shoulder of the tyre is under continued high loads during usage and connects the contact area of the tyre with the sidewall.
SIDEWALL The sidewall takes the load of the kart and holds the tyre in place during use. If the sidewall is too soft the tyre will fold under during cornering. If the sidewall is too stiff it will be a very stiff ride and finding grip could be difficult.
CONTACT AREA The tyre needs to have as much contact area as possible to obtain 'maximum' grip. Tyre pressures also determine how much contact area is obtainable. -
The "tire label/QR safety info" sticker gives important informations about tyre pressure and safety instructions. Please read carefully before mounting the tires.
Tips & Tricks for MOJO Tyres
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• Tyres are one of the most important components of your kart and when they are looked after correctly, will have longer durability and better performance. • When your tyres are 'new' they will perform at their best. They will not only give you the best cornering grip, but better stability and balance through the corners, as well as maximum braking grip. • When your tyres wear out they lose grip. When your tyres are not looked after, they wear out even quicker, with dramatic performance loss. This results in an unstable handling kart with poor performance. • So it makes sense to take as much care of your tyres as possible!! • Always check wheel alignment before using your kart. Re-check alignment if you have been involved in an incident or hit a kerb heavily on the track. • Always check your preferred tyre pressure before and after you take to the track. • After use and when storing your tyres, remove excess air to retain the elasticity of the tyres. • When storing tyres keep away from direct sunlight, fluorescent lights, high temperatures and electric motors as ozone gases also affect your tyres. Store tyres in a sealed, non clear bag preferably in a cool area. • Be careful not to spill fuel or other hazardous liquids onto your tyres. -
MOJO D2MOJO D5 C2 CASTER Neutral Neutral Neutral CAMBER 0 to + 2mm 0 0 TOE OUT + 2mm + 2mm 0 to +2mm REAR TRACK 1385mm + 1390mm + SEAT STAYS YES YES OPTIONAL -
MOJO D2MOJO D5 C2 CASTER Neutral Neutral Neutral CAMBER 0 to + 2mm 0 0 TOE OUT + 2mm + 2mm 0 to +2mm REAR TRACK 1385mm + 1390mm + SEAT STAYS YES YES OPTIONAL -
Full wet track MOJO W5 MOJO CW Caster full caster (positive) full caster (positive) Camber "0" +/- 2mm "0" +/- 2mm Track toe-out 8mm - 12mm (positive) toe-out 8mm - 12mm (positive) Rear track optional to more rear track. Toe-in 5mm per side. Rear wet tyres are narrower than dry tyres. Fitting wet tyres automatically narrows rear track. Seat optional Tyre pressure 1,0 bar 0,85 bar -
Problem Solution Problem Solution Front of kart pushes when entering corner. Understeer Increase front tyre pressure 0.05 bar. Increase front track (e.g. 10mm to 14mm toe out) Rear of kart slides when entering corner. Oversteer Increase rear tyre pressure 0.05 bar. Decrease front track (e.g. 14mm to 10mm toe out) General overall lack of grip. Increase tyre pressures all around 0.05 bar. Lift seat position by 10mm Kart loses grip towards end of race Decrease tyre pressure all around 0.05 bar
Wet weather set-up is very difficult and requires patience and practice to get right. Getting as comfortable as possible (wet weather clothing) is essential as well as having a confident attitude. Make it as fun as possible whilst being safe.