# Zipp 303 Firecrest Carbon Clincher or Mavic Cosmic Carbone 40c ?



## NGAcyclist (Apr 2, 2014)

I really can't decide on purchasing the Zipp 303 Firecrest Carbon Clincher or Mavic Cosmic Carbone 40c. I can purchase either set for just about the same price with the REI coupon out right now. 

Anyways, I live in the North Georgia Mountains where a 20+% grade is not uncommon on many many roads, plus many roads are "pebbly" and not very smooth at all in surface quality. I currently have Ridley Fenix with a pair of Fulcrum Quattros, but descending down long descents is very frightening because of the "thudding" motion coming from braking. If anyone has descended Brasstown Bald or Wayah Rd. before, you will know what I mean! 

I would just rather receive some personal reviews from cyclists that may know more detailed information about each wheelset? Mavic seems to be great with quality and braking abilities, but Zipps seem to be the "fad" choice of many that I have seen in the past. Any help or insight would be greatly appreciated.


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## cxwrench (Nov 9, 2004)

The Mavic 40C is not a true 'carbon clincher'. There is an aluminum rim 'insert' that is covered w/ a structural carbon fairing that the spokes anchor to via 'FORE' inserts. I'm not really sure why you'd make a wheel like this and not use aluminum for the braking surface but I'm sure Mavic has a reason. 
The Zipp is a true carbon clincher, in that there is no metal in the construction of the rim. How much do you weigh? How much do you ride the brakes down Brasstown Bald? I've been up it twice and it's a screaming descent. If you're heavy and/or ride the brakes a lot I'd be somewhat hesitant to go w/ a true carbon clincher even w/ all of the recent technological advances. That would make the Mavic a better choice given you want one or the other, but I just don't understand why they cover an aluminum brake track w/ carbon. They say right on their own site that aluminum dissipates heat and carbon accumulates heat...:shocked: So why make your brake track w/ a material that does this?


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## NGAcyclist (Apr 2, 2014)

cxwrench:

Thank you for your reply. As for my weight....I am 152 lbs. and 6'2'' (lean to say the least). 

I try not to hit the brakes too much, but I definitely do not ride them down at all.....mostly just rotate from front, front and back, back and repeat if it is really steep. As for the Mavic, I have also noticed some comments by Mavic seem to contradict themselves from what I have read. Anyways, I am still considering the Cosmic Carbone 40c but also now the Ksyrium SLR. I just don't want to regret my choice after purchasing either or after riding them after a few times knowing that I should have bought the opposite of what I originally bought. It seems to me that the 40c would benefit myself more in a racing scene, but maybe would find it more enjoyable climbing with the SLR's. Tough decision to make.


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## sneakyracer (Dec 1, 2007)

Carbon clinchers are great for flat terrain but not great for hilly areas and bad weather. From what you mention you would be better served by an aluminum wheel that is light. No need for an aero wheel whether its an aluminum and carbon mix or full carbon clincher. Check fair wheel bikes for a light custom set (tune hubs, kinlin or H Plus sun rims). There are plenty of options. The 303's are great wheels. The hubs are not great though. The best option would be a Enve 3.4 Smart set with tune or DT swiss hubs. Very durable wheel set that is easy to repair if needed.


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## dkilburn (Aug 1, 2009)

Good Morning,
I'm sure the Mavic hubs are very durable.
The rear hub on my 303 FC have had the bearings and axle replaced.
Front wheel no problems at all.
For me I like the feel of the 303 FC, maybe in my mind but they make me feel faster.
I never rode the Mavic Carbone, only the R SYS... with no problems. 
Sneakyrace is correct about wet braking. 
The wet brake for me is a little better on the Zipp 303 vs. my Reynold Assualt.
If you ride in a lot of wet or rain I would say stay on the other brake surface. 
I have not gone down long hills like the folks out west.
In upstate New York I have not run out of brakes in dry. In wet it is easy to run out of braking on the hills and flats.



Now, I have not rode my ENVE 3.4 SES, as they are on the new bike.
I'm hoping the reviews are correct for the ENVE 3.4

If you buy the Zipp 303 FC, suggest you see what version the hubs are, I think the newest is V9.

Good Luck with your choice. You will make the correct one.

.


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## Mr645 (Jun 14, 2013)

I think for hills like that I would be looking for aluminum brake tracks and light weight as the priority and then aero design. Perhaps the Zipp 60? Oval 945?

Carbon brakes downhill should be ok until it rains, then gets scary.


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## robdamanii (Feb 13, 2006)

If you're looking to drop that kind of cash, look to Enve.

Much cheaper but still respectable would be Reynolds or ROL.

And there's nothing wrong with carbon braking as long as you are used to the difference in braking power and feel. Ride for what tools you have in the conditions you have (or something like that, according to Sean Kelly during MSR last year.)


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## nhluhr (Sep 9, 2010)

cxwrench said:


> The Mavic 40C is not a true 'carbon clincher'. There is an aluminum rim 'insert' that is covered w/ a structural carbon fairing that the spokes anchor to via 'FORE' inserts. I'm not really sure why you'd make a wheel like this and not use aluminum for the braking surface but I'm sure Mavic has a reason.
> The Zipp is a true carbon clincher, in that there is no metal in the construction of the rim. How much do you weigh? How much do you ride the brakes down Brasstown Bald? I've been up it twice and it's a screaming descent. If you're heavy and/or ride the brakes a lot I'd be somewhat hesitant to go w/ a true carbon clincher even w/ all of the recent technological advances. That would make the Mavic a better choice given you want one or the other, but I just don't understand why they cover an aluminum brake track w/ carbon. They say right on their own site that aluminum dissipates heat and carbon accumulates heat...:shocked: * So why make your brake track w/ a material that does this?*


So they can have a "carbon clincher". The only benefit may be that the heat buildup won't affect the aluminum skeleton too much so you are less likely to get a blowout. But you'll still be smoking/glazing pads because the system won't dissipate heat as well. Still, it's a terrible design: heavy as hell, with a carbon braking surface and only 20 spokes in the rear which won't last long in a high-torque 20% climbing environment. Seems like an all around failure to me.

I couldn't think of a worse wheel to ride in that region. I think sneakyrace's suggestion to go with a shallow all-aluminum rim is good. I've cycled near that area (Robbinsville, Fontana, etc) and it can get really windy there. I wouldn't really want any kind of deep wheel in that situation.


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## SauronHimself (Nov 21, 2012)

If you're dead set on full carbon clinchers, the Rail 52 by November will work as well. With T11 hubs and CX-Ray spokes it's a $1525 build that weighs approximately 1545 grams. Dry braking is pretty good with the Black Prince pads. Wet braking is _okay_ and not any worse than other full carbon clinchers. Otherwise, I'd stick with a light aluminum rim like the HED C2.


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## Robot Ceiling Man (Jul 27, 2011)

I'm 195 pounds and I've had a pair of Mavic Cosmic Carbone SLCs for about 18 months. I guess they no longer make this wheelset. It has an exalith braking surface and a carbon fairing. Although I'm a sprinter and big and heavy these wheels have never needed to be trued. The braking is the best I've experienced in 25 years of racing including at a Cat 1/2/3 level. The quality is great and I've been super happy. I know that doesn't answer your question directly, but I just wanted to say I've had a great experience with Mavic, with about 7500 miles on this wheelset.


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## NealH (May 2, 2004)

I've ridden Wayah, as well as most all mountains in WNC, VA, and some of GA. Forget the full carbon wheels. They are not a good solution for the hills. None of them. 

Consider the Shimano DA C24 wheels, they are superb in the mountains. They have excellent hubs, no weight limit, and the rim weight is probably lighter than on any of those boutique carbon wheels. And, with 16 spokes on the front the DA wheels are more aero than one might think. The C24's are the wheels I recommend and I've been over those mountains many times. I have a set of carbon tubulars yet they fall short of the performance of the DA wheels.

Having said this, I believe Zipp has the best braking on full carbon wheels but, I would only use them for main events. Not for an everyday mountain wheel.


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## pmf (Feb 23, 2004)

SauronHimself said:


> If you're dead set on full carbon clinchers, the Rail 52 by November will work as well. With T11 hubs and CX-Ray spokes it's a $1525 build that weighs approximately 1545 grams. Dry braking is pretty good with the Black Prince pads. Wet braking is _okay_ and not any worse than other full carbon clinchers. Otherwise, I'd stick with a light aluminum rim like the HED C2.


I recently had a wheel set built up for around $800 -- T11 hubs, cxray spokes (24/28), HED Belgium rims. They weighed 1550 grams. I guess carbon rims look cool, but is that about it? Do they have a better ride? If you swap wheel carbon to aluminum, you have to swap brake pads, right? I don't understand what the allure is. I see guys riding to work on the bike path on $2500 wheels everyday. Seems kinda silly.


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## tvad (Aug 31, 2003)

pmf said:


> I recently had a wheel set built up for around $800 -- T11 hubs, cxray spokes (24/28), HED Belgium rims. They weighed 1550 grams. I guess carbon rims look cool, but is that about it?.


If your point is low cost, relatively low weight and high quality, then I offer the Dura Ace 9000 C24 carbon/aluminum clincher wheels as a comparison.

I recently bought a set for $775 including shipping (no tax). They weigh 1364 grams. Dura Ace hubs. The rims each weigh 384 grams versus 462 grams for the H2 Belgium clincher (which I also own and love).

My experience with carbon rims is that they ride a little more smoothly than aluminum, but the difference isn't significant.

To the OP...considering your terrain (+/-20%), I'd look into the Zipp 202 Firecrest (for either Shimano or Campy), or Dura Ace C24, or Dura Ace C35 (Shimano components).


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## pmf (Feb 23, 2004)

tvad said:


> If your point is low cost, relatively low weight and high quality, then I offer the Dura Ace 9000 C24 carbon/aluminum clincher wheels as a comparison.
> 
> I recently bought a set for $775 including shipping (no tax). They weigh 1364 grams. Dura Ace hubs. The rims each weigh 384 grams versus 462 grams for the H2 Belgium clincher (which I also own and love).
> 
> ...


The claimed weight of the C24 is 1492 grams. Yours really weighed that much under? The C35's aren't much lighter (1488 grams). For me, a rear wheel with only 20 spokes isn't worth the 50 or so gram weight savings you get over a 28 spoke wheel. The latter is alot stronger. I'll gladly trade off some weight for strength. But the bottom line is that you can get nice aluminum wheels for half of what carbon rims cost. 

It's funny. When I got into riding bikes years ago, bike shops built the wheels. I even built a few sets myself. Mavic Open Pro rims, Ultegra hubs and DT Swiss double butted spokes were the wheels to have. Mavic came out with the first pre-built wheel called the Helium which was a light weight wheel, at least at the time. I bought a set -- they looked great on my red Kestrel 200 sci. I went on and bought several sets of pre-builts -- Spinergy, Mavic, etc. In the past 3-4 years, I've rediscovered custom built wheels. The last two sets of wheels I bought have been custom. I really like them and can't see ever buying pre-built wheels again. It's taken me 25 years to come full circle.


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## tvad (Aug 31, 2003)

pmf said:


> But the bottom line is that you can get nice aluminum wheels for half of what carbon rims cost.


The Shimano Dura Ace 9000 C24 clincher are _carbon_ wheels with aluminum brake tracks. So, in this case, one can get _carbon_ wheels for the price (or lower) than a nice set of aluminum wheels.


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## pmf (Feb 23, 2004)

tvad said:


> The Shimano Dura Ace 9000 C24 clincher are _carbon_ wheels with aluminum brake tracks. So, in this case, one can get _carbon_ wheels for the price (or lower) than a nice set of aluminum wheels.


Do you consider wheels with aluminum braking surfaces "carbon wheels"? I don't. I had a set of Spinergy Rev-X wheels years ago. I wouldn't consider them to be carbon wheels. Not that I see any advantage to a carbon braking surface -- you need special brake pads for the wheels that you have to swap out if you decide to use wheels with aluminum braking surface. Seems like a needless PITA to me.


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## tvad (Aug 31, 2003)

pmf said:


> Do you consider wheels with aluminum braking surfaces "carbon wheels"? I don't.


OK. I'm not going to engage in that debate.

I offered the Shimano wheels as an alternative to the custom build you mentioned, and I'm going to leave it for others to decide if they're suitable for their purposes.


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## Jay Strongbow (May 8, 2010)

tvad said:


> *The Shimano Dura Ace 9000 C24 clincher are carbon wheels with aluminum brake tracks.* So, in this case, one can get _carbon_ wheels for the price (or lower) than a nice set of aluminum wheels.


Not exactly. They are alloy rims with carbon used to suppliment the thin alloy walls. The entire rim and not just the brake track has alloy.


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## tvad (Aug 31, 2003)

Jay Strongbow said:


> They are alloy rims with carbon used to suppliment the thin alloy walls. The entire rim and not just the brake track has alloy.


Thanks for the clarification.

REI has a good description of the rim construction (unlike Competitive Cyclist). REI lists the wheel weight at 570 (front) / 794 (rear) for a combined weight of 1364 grams (without skewers).


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## cxwrench (Nov 9, 2004)

tvad said:


> The Shimano Dura Ace 9000 C24 clincher are _carbon_ wheels with aluminum brake tracks. So, in this case, one can get _carbon_ wheels for the price (or lower) than a nice set of aluminum wheels.


No...that's not how they're made. They use an aluminum rim w/ a carbon cap/fairing over it. NO ONE (that I've seen) makes a carbon rim w/ an aluminum brake track bonded to it.


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## nhluhr (Sep 9, 2010)

cxwrench said:


> No...that's not how they're made. They use an aluminum rim w/ a carbon cap/fairing over it. NO ONE (that I've seen) makes a carbon rim w/ an aluminum brake track bonded to it.


I guess it depends how you define "rim". I reckon the Shimano C50 is a carbon rim (since the spokes screw directly into the carbon) with aluminum brake surfaces (as part of a substructure) bonded...


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## tvad (Aug 31, 2003)

cxwrench said:


> No...that's not how they're made. They use an aluminum rim w/ a carbon cap/fairing over it. NO ONE (that I've seen) makes a carbon rim w/ an aluminum brake track bonded to it.


Hey, thanks. If you had _read the earlier posts_, you would have seen this had already been addressed in post #18, and acknowledged in post #19.


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## pmf (Feb 23, 2004)

tvad said:


> Hey, thanks. If you had _read the earlier posts_, you would have seen this had already been addressed in post #18, and acknowledged in post #19.


Someone getting a little touchy? 

Alright, I'll say it ... Shitmano wheels suck


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## tvad (Aug 31, 2003)

pmf said:


> Someone getting a little touchy?


Not really, but it is nice when people read all thread posts before sharing info that has already been covered.

I love my Shimano, HED/Alchemy and Zipp 202 Firecrest wheels. They all bring positives to my cycling experience.

I also equally enjoy my Campy Record equipped bike and my Shimano Dura Ace equipped bike. Both group sets work exceptionally well, and are built to high standards. I never understand why people have enmity toward certain brands.


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## stevesbike (Jun 3, 2002)

the bottom line is that the 2 wheels the OP is thinking about aren't great fits for what he wants. He should also be concerned about the 303 width - it is over 28mm and incompatible with a lot of frames. Even where it does fit, the clearances are often pretty small. The Mavic wheels didn't strike reviewers are particularly aerodynamic, so what's the point in a 1550 gram wheelset? They seem awfully over-priced for their specs (even if the insert deals well with heat dissipation). 


The OP should go with a lightweight build, preferably with an alloy brake track. The c24 is a good option. The best carbon clincher is going to have a tough time with 20% descents.


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## dkilburn (Aug 1, 2009)

Hi,
Just an update, the ENVE 3.4 are a little more stable in 15 to 20 MPH breeze / wind tonight. Maybe due to the two different depth rims? 
Not sure how big your budget could be, but something to thinks about for sure.


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