The Schwalbe Ironman is a road bike tire specifically designed for triathlon athletes. This tire has been optimized for use on aerodynamic rims which are often used by triathlon athletes. Schwalbe also claims this tire to have an exceptionally low rolling resistance and high puncture resistance. The tubeless, clincher and tubular versions are all available in 700x22C and 700x24C sizes. The tire I'm testing is the 700x24C Tubeless Ironman.
This review has been funded by a donation from a very generous reader. Thanks, GS! This donation was made in December 2014. I ordered the tire several days later with an expected delivery time of 20 days. Unfortunately, it arrived at my door more than 3 months later. Manufacturer stock of the 24 mm Schwalbe Ironman seems to be very low while the 22 mm version seems to be in stock almost everywhere.
The Schwalbe Ironman is a close cousin to the Schwalbe One. They both share a 127 TPI V-Guard carcass with the new Triple OneStar compound. The biggest difference seems to be the slight rib profile and slightly smaller sizing. According to Schwalbe, the slightly smaller Ironman can save up to ten watts of aerodynamic drag at 40 km/h when used with aero wheels. I can't measure this to confirm, but let's see how it performs in the rolling resistance test.
|Supplied By||Bought in store|
|New or Used||New|
|Specified Weight||330 grams|
Size and Weight Measurements
|Size and Weight Measurements (Bike Wheel: 622x17C, Pressure: 100 psi / 6.9 bar)|
|Specified Weight||330 grams|
|Measured Weight||336 grams|
|Measured Width||25 mm|
|Measured Height||23 mm|
|Total Tire Thickness Center||3.2 mm|
|Total Tire Thickness Sidewall||1.2 mm|
This particular Schwalbe Ironman Tubeless 24C comes in at 336 grams while claimed weight is 330 grams. 6 grams extra isn't so bad but seems to be typical with Schwalbe bike tires. Measured width is 25 mm and height is 23 mm on a 17C rim, this seems to be similar to the slightly wider One Tubeless 25C which came in at 26 and 24 mm.
Rolling Resistance Test Results
|Rolling Resistance Test Results (Speed: 29 kmh / 18 mph / 8 m/s, Load: 42.5 kg / 417 N)|
|Inner Tube||None (0 ml sealant)|
|Rolling Resistance 140 psi / 9.7 Bar||
CRR: Not Tested
|Rolling Resistance 120 psi / 8.3 Bar||
|Rolling Resistance 100 PSI / 6.9 Bar||
|Rolling Resistance 80 PSI / 5.5 Bar||
|Rolling Resistance 60 PSI / 4.1 Bar||
|Use the formula: RR (watts) = CRR * speed (m/s) * load (N) to calculate rolling resistance at a given speed and load|
Just like the One Tubeless 25C, indicated maximum air pressure on the sidewall is 110 psi. The Schwalbe website indicates maximum air pressure of 125 psi, I'm guessing the website is wrong. I did inflate the Ironman 24C to 120 psi to keep all test results consistent.
When compared to the Schwalbe One Tubeless, rolling resistance of the Ironman Tubeless is slightly higher. At 120 psi, rolling resistance of the Ironman is 12.9 watts Vs 11.8 watts for the One Tubeless. At a slightly lower air pressure of 100 psi, rolling resistance is 13.5 watts Vs 12.5 watts for the One Tubeless. When dropping the air pressure to 80 psi, rolling resistance of the Ironman Tubeless rises to 14.5 watts, which is 0.7 watts higher than the One Tubeless.
Puncture Resistance Test Results
|Puncture Resistance Test Results (higher is better)|
|Puncture Resistance Tread||13|
|Puncture Resistance Sidewall||8|
The Ironman does seem to be a little bit more puncture resistant with a score of 13 in the puncture resistance test Vs a score of 12 for the One Tubeless. A score of 13 is slightly above average for an all-round tire.
The Schwalbe Ironman Tubeless isn't the ultra-fast road bike tire with low puncture resistance I was hoping it would be. Rolling resistance comes in a little higher than the One Tubeless while puncture resistance is a little better. This seems to be consistent with the never ending puncture resistance / rolling resistance trade-off that always has to be made. When using this tubeless tire with tubeless sealant it should be virtually impossible to flat.
I'm still waiting for an ultra fast and light tubeless tire from Schwalbe, something like the old Ultremo ZLX which didn't have the puncture resistance layer. When using a ZLX style tire with tubeless sealant it should still have good puncture resistance. Still, the Schwalbe Ironman isn't a bad tire and might have the aero advantages Schwalbe claims it to have.
TEST VERDICT: Recommended