The Continental Grand Prix TT is a tire optimized to gain those last few seconds in the race against the clock. While the Grand Prix TT has been available for some time in the 23-622 size, I'm testing a brand new 25-622 version. After waiting for more than a year for this tire to become available, it finally arrived at my door 2 weeks ago. I'm not sure if this new 25 mm version will be easy to get a hold of, but the 23 mm version is readily available.
To make the Grand Prix TT a true no compromise tire, it's marked as a limited tread depth tire. You shouldn't buy these tires if you want your tires to last a long time. The TT does come with a Vectran Breaker under the tread that helps protect against punctures. Continental claims the Vectran layer only adds a very small amount of rolling resistance.
Just like the Continental Grand Prix 4000S II (read review), the Grand Prix TT uses the well known Black Chili compound and a 3/330 carcass. On paper, both these tires seem very closely related. The Grand Prix 4000S II has proven to be a great mix between speed, puncture resistance and tread life. Let's see how much lower rolling resistance can go at the cost of puncture resistance and tire life.
|Model||Grand Prix TT|
|Tire Type||Tubetype (clincher)|
|Supplied By||Supplied by Continental|
|New or Used||New|
|Specified Weight||190 grams|
Size and Weight Measurements
|Size and Weight Measurements (Bike Wheel: 622x17C, Pressure: 100 psi / 6.9 bar)|
|Specified Weight||190 grams|
|Measured Weight||195 grams|
|Measured Width||27 mm|
|Measured Height||24 mm|
|Total Tire Thickness Center||1.9 mm|
|Total Tire Thickness Sidewall||0.45 mm|
Claimed weight of the 25-622 Grand Prix TT is 190 grams, my sample came in at a weight of 195 grams. Just like the Grand Prix 4000S II, the 25-622 TT measures 27 mm wide at an air pressure of 100 psi on a 17C rim. Height is 24 mm, which is 1 mm less than the 4000S.
Continental claims this tire to be a limited tread depth tire, but how limited is limited? With a total tire thickness of 1.9 mm, the TT is the thinnest tire to date. The GP4000S II came in at a more average 2.9 mm. After subtracting the thickness of the carcass and Vectran layer, I'm estimating the TT to have close to 0.7 mm of usable tread to wear down. The GP4000S II should have closer to 1.7 mm of usable tread. This means tire life will be 35 - 40% of a GP4000S II.
Rolling Resistance Test Results
|Rolling Resistance Test Results (Speed: 29 kmh / 18 mph, Load: 42.5 kg)|
|Inner Tube||Conti Race28 (100gr butyl)|
|Rolling Resistance 120 psi / 8.3 Bar||9.9 Watts|
|Rolling Resistance 100 PSI / 6.9 Bar||10.5 Watts|
|Rolling Resistance 80 PSI / 5.5 Bar||11.8 Watts|
|Rolling Resistance 60 PSI / 4.1 Bar||13.9 Watts|
|Rolling Resistance Coefficient (Crr) 120 psi / 8.3 Bar||0.00297|
|Rolling Resistance Coefficient (Crr) 100 psi / 6.9 Bar||0.00315|
|Rolling Resistance Coefficient (Crr) 80 psi / 5.5 Bar||0.00354|
|Rolling Resistance Coefficient (Crr) 60 psi / 4.1 Bar||0.00417|
The Grand Prix TT performs great in the rolling resistance test and is the first tire to go under 10 watts in my test. Especially at the higher end of the air pressure range, performance is very strong. At an air pressure of 120 psi / 8.3 bars, there is 2.3 watts less rolling resistance when compared to the GP4000S II. At an air pressure of 100 psi / 6.9 bars, this advantage grows to 2.4 watts.
Please note that all these tests are performed with the same 100 grams butyl inner tube. When substituting the 100 grams butyl tube with a latex tube, rolling resistance will be another 1.5 - 2.5 watts lower (link). Fitted with a latex tube, this should be one of the fastest tires available.
Puncture Resistance Test Results
|Puncture Resistance Test Results (higher is better)|
|Puncture Resistance Tread||8|
|Puncture Resistance Sidewall||4|
Low rolling resistance and low tread thickness don't relate to a great performance in the puncture resistance test. In the puncture resistance tread test, the Grand Prix TT scores a low 8 points. Although tread thickness is very low, it does have a Vectran layer that provides some puncture protection. 8 points is comparable to the Vittoria Rubino Pro Speed (read review) but much lower than the all-round tires like the GP4000S II etc that score 11 - 12 points in the same test.
In the sidewall test, performance is average. With a score of 4 points, the TT scores in line with most other road bike tires without reinforced sidewalls.
If you're looking for a very fast road bike tire that will shave those last few seconds off of your time-trial, and you don't care about tire life or puncture resistance, the Continental Grand Prix TT is an awesome tire. For a pair of tires, these will save you 5+ watts over the popular GP4000S II (read review) or other all-round tires that do provide higher mileage and better puncture resistance.
Fitted with latex tubes, the Grand Prix TT is one of the fastest tires on the market and will be hard to beat by even the best tubular tires. Although the 25-622 TT will be very hard to find in stores, the 23-622 is easier to find as I've seen it in stock in lots of (online) shops.
TEST VERDICT: Highly Recommended
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