The Continental Speed King II RaceSport 29 x 2.2 is Continentals fastest mountain bike tire. Although the Speed King II is a newer version of the original Speed King, it's a completely different tire and the only thing they have in common is the name. While the original Speed King actually did have some decent knobs, the Speed King II is pretty much a semi-slick with a knob height of 0.5 mm at the centre of the tire and 1.5 mm at the edge of the tire.
While most other Continental mountain bike tires are available as Protection, RaceSport, Performance, and Sport versions, the Speed King is only available as a RaceSport version. The RaceSport versions are the fastest and lightest tires produced by Continental. The RaceSport version comes with an 180 TPI canvas, Black Chili Compound and are handmade in Germany. Being only available as a RaceSport version further indicates that this tire was designed with only one thing in mind: Speed.
I wouldn't dare use this tire as a front tire, but would consider it as a rear tire in dry conditions. It could also be a good fit when riding over very soft sand or as an asphalt tire. If you're expecting even a single drop of rain, grab something else. This is the first semi-slick mountain bike tire I'm testing so this should definitely give some interesting data about how much big knobs slow you down.
|Model||Speed King II RaceSport|
|Supplied By||Bought in store|
|New or Used||New|
|Specified Weight||465 grams|
Size and Weight Measurements
|Size and Weight Measurements (Bike Wheel: 622-17C, Pressure: 35 psi / 2.4 bar)|
|Measured Weight||467 grams|
|Measured Width Carcass||54 mm|
|Measured Width Tread||49 mm|
|Measured Height||53 mm|
|Measured Knob Height Center||0.5 mm|
|Measured Knob Height Edge||1.5 mm|
|Measured Total Thickness Sidewall||0.45 mm|
|Measured Total Thickness Center (excluding knobs)||1.70 mm|
I've measured this sample of the Speed King 29 x 2.2 at 467 grams, specified weight by Continental is 465 grams. Width and height of the carcass is 54 and 53 mm respectively, which is very close to the size of the Race King. As noted previously, "knob" height at the center of the tire is 0.5 mm, which is virtually non-existent. The small knobs at the edge of the tire have a height of 1.5 mm.
Rolling Resistance Test Results
|Rolling Resistance Test Results (Speed: 29 kmh / 18 mph, Load: 42.5 kg)|
|Rolling Resistance 55 psi / 3,8 Bar||14.5 Watts|
|Rolling Resistance 45 psi / 3,1 Bar||15.1 Watts|
|Rolling Resistance 35 psi / 2,4 Bar||16.6 Watts|
|Rolling Resistance 25 psi / 1,7 Bar||19.1 Watts|
|Rolling Resistance Coefficient (Crr) 55 psi / 3,8 Bar||0.00435|
|Rolling Resistance Coefficient (Crr) 45 psi / 3,1 Bar||0.00453|
|Rolling Resistance Coefficient (Crr) 35 psi / 2,4 Bar||0.00498|
|Rolling Resistance Coefficient (Crr) 25 psi / 1,7 Bar||0.00573|
Yes! Rolling resistance is very very low. Much lower than all other mountain bike tires tested to date. At an air pressure of 25 psi, rolling resistance is 19.1 watts. This is 3.2 watts less than the Schwalbe Thunder Burt (read review) which was the previous record holder. Compared to the Continental Race King (read review), rolling resistance is 3.3 watts lower. At higher pressures, the advantage increases to 3.5 - 4.0 watts. This tire will fly on asphalt.
What's interesting is that if you use the Speed King in a tubeless configuration (read tubeless comparison), rolling resistance at 55 psi will be close to 12.0 watts. 12.0 watts means it would have less rolling resistance than a Continental Grand Prix 4000S II road bike tire (read review) at 120 psi.
Puncture Resistance Test Results
|Puncture Resistance Test Result (higher is better)|
|Puncture Resistance Tread||7|
|Puncture Resistance Sidewall||4|
In the puncture resistance test, the Speed King scores an average score of 7 points. This is just as good (or bad) as the Race King and slightly worse than the Thunder Burt.
I can't conclude anything else than that the Continental Speed King II is a very very fast semi-slick mountain bike tire. Of course, it doesn't give you a lot of grip but if the conditions suit this tire, you should be flying. It might be best to use the Speed King as a rear tire with a Race King (read review) or X-King (or any other tire) on the front, but this should be totally dependent on the conditions.
Highly recommended as a dry weather rear tire or maybe even as a front tire if conditions allow. I'm almost 100% certain you won't find a faster mountain bike sized tire anywhere. If you think otherwise, please let me know.
VERDICT: Highly Recommended
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