Because this is the fastest mountain bike tire I have tested yet, I've been using it as a rear tire for some time and it really is fast. Continental says the Race King RaceSport 29 x 2.2 is the ultimate race tire with World Cup performance. This is accomplished with an "optimal combination of ultra-lightweight and race-worthy puncture resistance". There used to be a SuperSonic version of the Race King, but it is no longer available. The RaceSport is now the fastest Race King you can buy.
RaceSport means this version has the Continental Black Chili Compound, 3/180 TPI casing and it's handmade in Germany. It does not have a Tubeless-Ready rating. If you want the Tubeless-Ready rating, you need the Protection series which has a reinforced casing.
Although the RaceSport does not have a Tubeless-Ready rating, my personal experience is that it works just fine with a tubeless conversion kit on standard rims. Although getting it to seal completely might take a few days because of the thin sidewalls.
|Model||Race King RaceSport|
|Supplied By||Bought in store|
|New or Used||New|
|Specified Weight||540 grams|
Size and Weight Measurements
|Size and Weight Measurements (Bike Wheel: 622-17C, Pressure: 35 psi / 2.4 bar)|
|Measured Weight||497 grams|
|Measured Width Carcass||55 mm|
|Measured Width Tread||51 mm|
|Measured Height||55 mm|
|Measured Knob Height Center||2.5 mm|
|Measured Knob Height Edge||2.5 mm|
|Measured Total Thickness Sidewall||0.45 mm|
|Measured Total Thickness Center (excluding knobs)||1.70 mm|
The actual weight of this RaceSport is only 497 grams while Continental claims it to have a weight of 540 grams. I'm not sure if this is normal or that I just got lucky and received an exceptionally light sample (I bought it in a store myself). I am also not sure how much the extra 40 grams will influence the results, I might test this in the future.
Rolling Resistance Test Results
|Rolling Resistance Test Results (Speed: 29 kmh / 18 mph, Load: 42.5 kg)|
|Rolling Resistance 55 psi / 3,8 Bar||18.0 Watts|
|Rolling Resistance 45 psi / 3,1 Bar||18.7 Watts|
|Rolling Resistance 35 psi / 2,4 Bar||20.0 Watts|
|Rolling Resistance 25 psi / 1,7 Bar||22.4 Watts|
|Rolling Resistance Coefficient (Crr) 55 psi / 3,8 Bar||0.00540|
|Rolling Resistance Coefficient (Crr) 45 psi / 3,1 Bar||0.00561|
|Rolling Resistance Coefficient (Crr) 35 psi / 2,4 Bar||0.00600|
|Rolling Resistance Coefficient (Crr) 25 psi / 1,7 Bar||0.00671|
At an air pressure of 25 psi / 1.7 bar which is the most important measurement for off-road usage, rolling resistance is 22.4 watts, which is very low. At higher pressures, rolling resistance is best in class as well. It will be very hard for other manufacturers to get close to the rolling resistance of the Race King RaceSport
Puncture Resistance Test Results
|Puncture Resistance Test Result (higher is better)|
|Puncture Resistance Tread||7|
|Puncture Resistance Sidewall||4|
Unexpectedly, this tire is able to get a score of 7 in the puncture resistance test, which is average but very good for such a fast tire. I did not expect the RaceSport to perform this well in the puncture resistance test because the tire feels very thin and flexible.
This really is a race tire, performance in the rolling resistance test is great! Although knob height at the edge of the tire is really low with a height of only 2.5 mm, there are a lot of knobs to make up for it. I probably wouldn't want to use it as a front tire unless you're riding a lot on a very hard surface. Volume is huge as well, with a carcass width of 55 mm and height of 55 mm this is the biggest 2.2 I've seen yet.
Low rolling resistance, average puncture resistance, low weight, low knobs: If you want to go really fast, buy a Race King!
VERDICT: Highly Recommended
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