Bringing back the Cycling Cap one Domestique at a time

Showing posts with label 4000s. Show all posts
Showing posts with label 4000s. Show all posts

Review: Continental Grand Prix 4000s 23c and 25c

Yes, there are lighter tires our there. There are grippier. There are sturdier. But, in our experience, nothing comes close to being the perfect all rounder as Continental's Grand Prix 4000s.

It has all those necessary qualities you would want in your road tire. Light enough, grippy enough, sturdy enough. Just dont expect it to beat an Ultremo in a race or go thru debris like a Gatorskin or a 4 Seasons.

The key to the Grand Prix 4000s' performance is Continental's judicious inclusion of a variety of features found across its offerings.



Technical Features

For puncture resistance, Continental decided to include only one Vectran anti-puncture layer where the Conti 4 Seasons has two. This sacrifices a bit of puncture protection but yields lighter weight and improves rolling resistance.  

Key to the GP 4000s' grip is the use of the Black Chili compound. First developed in 2005, Black Chili basically infuses the basic rubber base with microscopic carbon soot particles.  Continental claims that this technology produces 26% less rolling resistance, 30% more grip... all while decreasing wear by 5%.

This is remarkable since rolling resistance, grip and wear are opposing requirements. Say you want to increase grip, wear is usually sacrificed. With Black Chili, resistance and grip are improved as well as wear. Amazing.

Black Chili technology is said to be so sensitive that it can only be produced out of Conti's Korbach plant in Germany.

The GP 4000s' are quite average in terms of weight. We measured our 700x25 sample at 224 grams, a good six grams below the listed 230g.

 700x25 - A good 6 grams lighter than advertised

What got us dumbfounded was our used 700x23 sample. Our scales have them at 218 grams where it was only supposed to be 205! We were relieved upon measuring another used sample which went for 209 grams.  You'll have to take our word on that as we failed to photograph before mounting. Although we cannot be 100% sure, we attribute this major discrepancy to the way the tires were folded during measurement. This may have distributed the tire differently and may have affected the center of gravity putting more pressure on the scale's strain gauges. Again, only a theory. Regardless of this, the 4000s' are adequately light.

700x23 - Mysteriously overweight
Mounting

For people of moderate hand strength, the tires can be mounted without levers. In our experience, initial fitting (and dismounting) requires at least one lever to get that final inch or three of bead over the brake surface. Subsequent removals and mounts required only light-moderate hand strength and no tools.  These tires were meant to be mounted a certain direction. A vague direction arrow may be found somewhere in the sidewalls. Directionality aside, we have actually mistakenly ridden the tires backwards to no ill effect.

23c vs. 25c 

Perhaps the bigger question is 'which tire size to go for?'. We have been using 700x23 GP4000s' for quite a while. For a week or two, we had two 700x25's mounted purely for testing.

Lacking any sort of scientific testing equipment or data, what we can report on is subjective ride feel.

With fresh legs, what size tires you're on doesn't really matter. You have enough strength to spin either tire size equally well.

But.

Over a long ride, we found that the wider tires are somewhat harder to spin as the kilometers pass along.  Net effect is feeling a bit more tired after a ride on 25's than on 23's. During the course of testing, all pressures were constantly maintained at 8 bar (116 psi). Going wider, even by 2mm, would also produce a less aerodynamic wind profile compared to a thinner tire (if those things matter to you).

But.

Over rougher asphalt, the 25's are noticeably more comfortable than the 23's. This can be substantiated by the 'bounce' you feel when going over road imperfections. On 23's these can be jarring but 25's take the sting out of the same ruts and pits. If you take a look at the images below, this all makes sense as the 25's stretch out to almost 30mm (28mm to be exact) once mounted.
  
 When mounted, 25's round out to 28mm

23's round out to 25.5mm when mounted

In the end, we decided to make the most of the situation and go staggered on the tires. 23's in front 25's at the back. We get the most support in the rear where we put the most weight.  And we have a more responsive, lighter and more aerodynamically sound tire at the front.  

On the Road

Size differences aside, Continental's Grand Prix 4000s delivers a performance worthy of several Tour Magazine comparo awards. Indeed these feel spin easily, grip extremely well and have adequate puncture resistance. That said, we did have one puncture where a safety pin (which looks awfully like the ones used on runners' race bibs) hung on to the tire and eventually penetrated the casing through to the inner tubes. Compare this to more than two years of puncture free performance we had with Conti's own 4 Seasons tire. However, we would readily trade the 4 Season's armored hide for the 4000s' slick and light rolling performance any day.

Getting back to the 23 vs. 25 choice. Ultimately, it's up to the rider and the road. If your'e a Clyde or  frequent rough asphalt, go for the 25's; your butt will thank you for it. If you're a lighter weight rider who prioritizes weight and performance over vertical compliance, by all means go for the 25's.

.... or maybe be like us and get the best of both?

Vedrict

With so many things going for it and virtually nothing going against it, the GP4000s gets top marks and top recommendation from us.

Read more »

Review: Shimano Dura Ace WH-9000 C24 TL

With the foray into the world of 11-speed, Shimano suddenly needed a new team of wheelsets  to cater to its new super-gruppo.  Thus, the WH-9000 series wheelsets came to be. 

While most of these hoops are updates to previous WH-7900 offerings, Mr. Shimano and Co. have incorporated some innovations into their current lineup to bring them up to speed with current cycling trends.   Shimano has set two philosophical design goals with their latest wheels. These are the 'Blade Concept' and the 'Accelerating Speed Concept'. The Blade Concept, as the name implies, prioritizes slicing the wind. The Accelerating Speed Concept, on the other hand, deprioritizes aerodynamics in favor of being all-rounders. Aero considerations are still there, but acceleration and climbing come first. 


Today, we take a look at the WH-9000 C24 TL wheelset, a product of the Accelerated Speed Concept.  An evolution of the WH-7900 C24 TL, the 9000 series C24 natively supports the Dura Ace CS-9000 cassettes. Since Shimano chose to maintain their current spline pattern, the C24's can also be used with 10-speed cassettes. You do have to use the supplied 1.85mm spacer though since there's a difference in cassette length between 10 and 11 speed. 



Shimano reprised the carbon laminate approach to the C24. They bonded a layer of carbon fiber over thin aluminum to provide additional stiffness and strength to the rim while shaving weight.


Shimano lists rim width at 20.8mm wide. As can be seen in the image below, the sidewalls are almost flush with the brake surface. Rim depths are listed as 21mm for the front and 23mm for the rear. 



TL indicates that this is the RoadTubeless variant. 90g heavier per pair than the plain clincher (CL) version, the weight disadvantage is partially offset by discarding wheel tape altogether (~30g). Manufacturer claimed weight is 1,454 grams. While not exactly flyweight, the hoops are light enough for some extended climbing action.





The hubs got a major level up as they are now full Titanium whereas the 7900 was only part-Titanium.  These come in a sexy satin black painted finish. Unchanged is Shimano's traditional cup and cone bearing design. Shimano is known for its durability (hence DURA(bility)-ACE) and per their dictum, cup and cone is the way to go. Indeed this is a reliable and robust arrangement. As a bonus, the hubs can be serviced by any reasonably competent mechanic with basic shop tools. 

Also carried over are the 16 and 20 spoke count and thin bladed spokes which both contribute to aerodynamics and weight reduction. These also promise not to give nasty surprises in sudden heavy crosswinds.



We're not too hot on this year's graphics though. The labels are smaller, subdued, monochromatic and tame compared to the 7850/7900's, which flaunt the brand for all the world to see. Adding to our eyesore are the funky wavy/tribal silver-gray colored swoops which adorn the rims.  The look comes out as neither stealthy nor sporty.  While not downright ugly, these take some getting used to.... and when you do, you still know at the back of your head that they will never be as sexy as the graphics on the old C24. 
      

Mr. Shimano, can we have these graphics back? Pretty Please???

We initially mounted RoadTubeless Hutchinson Fusion 3's to these fine wheels. However, we gave up due to some major issues with the tires. Most locally available Fusion 3 stocks have developed cracks where they were folded, necessitating the use of sealant to hold air. To add to our frustration, even the sidewalls of the Fusion 3 began to leak air near the logo. This is very disappointing considering our positive past experience with their Fusion 2's. 

Keeping in mind previous issues with Dura Ace wheels and some sealants, we decided to forego RoadTubeless altogether and mount our erstwhile favorite tires, the Continental GP4000s. In went matching Race 28 Light inner tubes to complete the combo. As previously mentioned, rim tape is not required as the inside surface is perfectly smooth.  


On the road, the new generation C24's deliver what C24's of old always have: stiffness and comfort. While these two properties are often at odds with each other, the C24 somehow manages to deliver both in spades! Rough asphalt vibrations are muted enough to give road feedback without being uncomfortable... and take note, we tested at 120psi. There is no doubt in our minds that lowering this to between 90-115 PSI would result in an even better ride.  

When the time came to amp up the watts, the rear springs into life, and rapidly propels the bike forward... almost taunting us if we're giving it all we've got!   

Freewheeling is silky smooth. If you're after the tunog mayaman (loud ratchety metallicsound, then these hoops aren't for you.  The sound the C24s make is suave and muted. Easily drowned out by traffic.  

Braking is very good, although we have to give half the credit to the excellent BR-9000 stoppers  we have in our Foil. 

Looks aside, The 9000 series C24-TL's are hard to fault. Neither a purist climber nor full on aero, these wheelsets do everything else perfectly and then some. It takes what's great about the C24's of old, adds incremental - but much appreciated improvements and gives us a new standout all rounder.  Add to that Shimano's bulletproof reliability and you have yourself a winner. 

Verdict

Solid all rounder. Bulletproof and tubeless-ready. Graphics are a somewhat off but only by a little bit.

Click here for my review of the Dura Ace 9000 C50!







Read more »