# Was going to buy Carbon Clinchers now I'm not so sure



## walamt (Jun 7, 2011)

I have done my research and was going to order a set of carbon clinchers 38/50 from Farsports, now I'm not so sure. Reading the various threads it seems even name brand rims are having issues mainly with braking on downhill descents and heat, as well as inferior braking over aluminium tracks.

It would be nice to finally not read about the failures of these carbon wheels because I would be extremely nervous on a downhill. Having said that, I have also noticed that there haven't been any reports of poor performance from the likes of Boyd, Williams, Lightweight and Fulcrum. Maybe spending double on the offerings from Boyd or Williams (there are others as well) will give me piece of mind.

At the moment I really don't know. My specific set of wheels need to be under 1450gms. Any way just felt the need to express my own anxiety.


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## TimV (Mar 20, 2007)

Personally I think the issue is overblown, but that might be just me. I am also about to purchase a set of 50mm carbon clinchers and have read about these braking issues. So I recently started paying attention to how much I use my brakes on downhills. Turns out it is very little. Even on a fast descent (45mph+), I only use my brakes for 2 or 3 seconds TOPS right as I enter a corner. Then I just lean it over and let the tires do their job. And this is only if the corners are tight. Otherwise, I don't use the brakes at all. But, I also have a lot of experience riding mountain bikes, motorcycles, etc. so maybe I'm just a little more comfortable at speed than others.


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## wetpaint (Oct 12, 2008)

+1 the overheating issue is made to sound a lot worse than it is. I've ridden in Colorado with Gigantex rims without any problems. I even felt them after coming down descents with alot of braking and the rims weren't even hot.


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## 2Slo4U (Feb 12, 2005)

I will take the opposite opinion. I ride with two people that have had blown front tires on long twisty descents due to overheating of their carbon clinchers. One person ended up with a couple of broken ribs.

I think you need to define the type of canyons and descents you ride. If you can let the bike roll and hardly touch the brakes, then why not. However, if you ride tight, twisty, narrow canyons where you sometimes can't pass cars and have to use the brakes alot, I personally would think twice about carbon clinchers.


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## stevesbike (Jun 3, 2002)

I've had 2 wheels fail from manufacturers that sponsor our team (both high end wheels, not generic rims). The issue is definitely real if you ride long, technical descents. The post from TimV about using brakes as the result of inexperience was funny. If you ride steep, technical descents you'll be on the brakes into every corner. The last rim failure I had was a delamination that caused a rear tire blowout nearing a right hand corner at 45 mph - the tire came off the rim, causing me to cross the centerline and hitting the cliff wall at speed - ripped the skin off most of the left side of my face, crushed my forearm, and resulting in losing consciousness for nearly half an hour. Required surgery on the arm and a plate installed and resulted in over $50k in hospital bills (luckily insured). Bottom line to me: carbon clinchers and long descents are a bad combination. If you want aero get a Hed Jet with an alloy rim or similar. Besides, if you're climbing you'll get more value out of something like a shimano c24.


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## Wines of WA (Jan 10, 2005)

As of 2011, there is no performance difference to be gained from carbon clinchers over aluminum (including wheels with deep carbon caps but aluminum brake tracks). The only benefit is aesthetics.


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## jmess (Aug 24, 2006)

I have been riding carbon 46MM clinchers for 3 years and haven't had any major drama but I can see where it could happen. I am always thinking about managing my brake temps during long downhills with a lot of heavy braking. Having to think about this makes me more cautious = slower. The hotter the weather the more cautious I get. If I was going to up my downhill game I would most likely run wheels with alloy braking surfaces.


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## coachboyd (Jan 13, 2008)

I get emailed about this all the time and will throw in my two cents.
It is possible to damage the rims from overheating but it is also blown out of proportion for how common it is. The stories or people's bad experiences spread through the forums to where people in Florida who are doing mainly triathlons are worries about overheating their rims. But it's really a very very small percentage of people that have any issues. It's almost like watching the nightly news, if you start to watch it enough you'll think that only thieves and murderers live in your town.

I live in the mountains of South Carolina and ride carbon clinchers as everyday training wheels. I do a lot of long steep descents with no issues, but am also not prolonged very hard braking. We do have a few descents around here where I wouldn't use them (3 miles with an average of 15-18%).

A lot of times proper brake pad selection helps a ton. Almost all of the rim manufacturers now produce their own brake pads to work with the rim. These are designed to help keep the temperature lower with the epoxy used on that particular rim. A lot of the times when you see an issue with any carbon rim overheating its because the person has been using Swissstop brake pads (at least from what I have seen lately). Swissstop does make a great brake pad and I don't hesitate to recommend them for tubulars at all. But they are in the business to make brake pads, and while they stop really well they can build up the heat on carbon clinchers. 

I think that if you are using the correct brake pads, modulate braking on the downhill, and know when a particular ride might be a better day to use an alloy or a tubular wheelset then carbon clinchers are perfectly safe to use. We can make a lot of components "fail" on our bikes if we try to, and knowing how to ride a certain component is part of the responsibility of owning it.


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## Hank Stamper (Sep 9, 2009)

Keep in mind for every failure you read about on the net there are thousands of people not experienceing one.

So the draw backs are overblown.

However, IMO so are the benefits.

The way I look at it the risk is greater than the benefits even with the risk being small. If I lived in a flat area or was willing to change wheels and brake pads depending on the ride I'd probably feel differently. I'm no pro but I think I do okay as far as knowing how to ride and changing the way I ride because I have to baby my wheels is out of the question.


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## Ramjm_2000 (Jan 29, 2005)

I think Boyd has hit the nail on the head, can’t say it any better. The reports are way over blown and since using the Cryo blue pads on my Reynolds attacks, I've noticed a significant decrease in rim temp compared to my Lew tubulars with both and Swiss stop/Koolstop pads. If your still hesitant you may also consider using TUFO tubular clinchers. They don't use a traditional tube rather a latex "layer". Reportedly this set up pretty much negates the effect of heat on tire/tube assembly. The negative is price, maybe some RR, and you have to either carry a can of tufo sealant or a spare tire (like a traditional tubluar) for flats. While I ride Vittoria open tubulars with latex tubes (and contrary to the TUFO haters) I think they (tubular clincher in 25c) ride pretty well.


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## spade2you (May 12, 2009)

With the OP worried about weight and the side wall, why not just get tubulars? It would seem to solve both problems.


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## ericm979 (Jun 26, 2005)

stevesbike said:


> I've had 2 wheels fail from manufacturers that sponsor our team (both high end wheels, not generic rims). The issue is definitely real if you ride long, technical descents. .



Agreed. It's not the length of the descents, its the amount of braking. Being a good confident descender means that you can safely ride carbon clinchers down steeper/more technical descents. But if the descent is steep and technical enough you will be braking too much no matter how good a descender you are, and be in danger of damaging the rim or having the tire come off the rim. I am a very confident descender with 35 years of motorcycling including track and competition experience, and 20 years of cycling. Yet I had a tire come off a carbon clincher going down a steep road with tight turns (12% avg with a lot of 10 mph hairpins).

As a result I won't use the carbon clinchers on these types of descents. But no races have descents this gnarly- people would die. So I think they are fine for races, including ones with very long descents.... as long as you're not on the brakes a lot you're fine.

Bottom line: if you brake a lot on descents then you don't want to use carbon clinchers on them.

While there is a small performance advantage due to the aerodynamics, it is pretty small. It's not worth the price of the wheels unless you a) race and b) have a lot of disposable income or get the wheels at a substantial discount. For training or if you don't race, they're not worth the cost.


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## spade2you (May 12, 2009)

Even in racing, sometimes the amount of braking isn't determined by you. Granted, I'm just Cat 4, but I've had more than a few road races that were attacks, followed by screeching stops, followed by attacks, then riding the brakes even more, more attacks, more brakes, etc. Damn peloton smelled like burning brake pads.


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## nightfend (Mar 15, 2009)

I'm still trying to figure out why his wheels HAVE TO BE under 1450grams? What's this magically number? It's not like you'll suddenly be dragging an anchor if you ride a 1600 gram set of wheels.

I agree as well, if the OP is concerned about wheel weight, then move to a tubular wheelset.


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## stevesbike (Jun 3, 2002)

is the issue overblown? Depends on what failure rates you compare it to. I don't know of another bike component that has even close to the failure rate of carbon clinchers. I don't know of a component even leaders in the industry are reluctant to produce: Zipp only starting producing them this year because of difficulties in R&D with heating issues. Hed does not make them. Both Mavic and Shimano use carbon/alloy hybrids. Specialized no longer makes them as far as I can tell. Velonews, who normally give only glowing reviews, gave a harsh review of carbon clinchers. A Williams carbon clincher even failed in their testing and blew a tire off the rim.


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## coachboyd (Jan 13, 2008)

stevesbike said:


> is the issue overblown? Depends on what failure rates you compare it to. I don't know of another bike component that has even close to the failure rate of carbon clinchers.


Chains snap all the time. Sram shifters had a big issue last year with the lever falling off (happened with 4 of my teammates). I have seen saddles break rails. Lots of components fail at a much higher rate than carbon clinchers, it's just they aren't paid much attention when they do. Can you imagine if everytime somebody snapped a chain there was a new thread about it on here?



stevesbike said:


> Velonews, who normally give only glowing reviews, gave a harsh review of carbon clinchers. A Williams carbon clincher even failed in their testing and blew a tire off the rim.


In all fairness to Williams, that test was done on a three year old set of the wheels. He doesn't use that rim anymore and they shouldn't have even included it in the test. It would be like me writing a review of the Ultegra Di2 based on riding some 105 that I have laying around here. I have not see any claims of blowout with the new Williams rims using their carbon brake pads.


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## pmf (Feb 23, 2004)

Wines of WA said:


> As of 2011, there is no performance difference to be gained from carbon clinchers over aluminum (including wheels with deep carbon caps but aluminum brake tracks). The only benefit is aesthetics.


Thank you. 

I don't get the carbon wheel craze. First, they're really expensive. Like thousands of dollars. Second, you have to use special brake pads. So if you ever want to swap back to those hideous aluminum wheels, you have to swap out the brake pads too. What a PITA. Third, they overheat quickly when the rider brakes a lot on descents. This can lead to bad consequences. Maybe if you're a serious racer and you think they give you an advantage. In a time trial for example. I see yo-yos riding these dumb things back and forth to work on the bike path around here. I just don't see how any recreational rider or amateur racer really needs them. More money than sense I guess.


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## TimV (Mar 20, 2007)

pmf said:


> I just don't see how any recreational rider or amateur racer really needs them. More money than sense I guess.


None of us _*needs*_ any of this stuff. We choose this hobby because it's something we enjoy spending our free time and discretionary income on. Once you get past that, it really doesn't matter. How much one spends is all relative.


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## stevesbike (Jun 3, 2002)

coachboyd said:


> Chains snap all the time. Sram shifters had a big issue last year with the lever falling off (happened with 4 of my teammates). I have seen saddles break rails. Lots of components fail at a much higher rate than carbon clinchers, it's just they aren't paid much attention when they do. Can you imagine if everytime somebody snapped a chain there was a new thread about it on here?
> 
> 
> 
> In all fairness to Williams, that test was done on a three year old set of the wheels. He doesn't use that rim anymore and they shouldn't have even included it in the test. It would be like me writing a review of the Ultegra Di2 based on riding some 105 that I have laying around here. I have not see any claims of blowout with the new Williams rims using their carbon brake pads.


other components fail, but the issue is whether their failure mode is due to an inherent design flaw or not. Chain failure is typically due to wear and the accumulation of shifting forces. New chains and seats typically don't fail. The issue with carbon clinchers is whether or not the brake track design is robust. Is it over-engineered like most other bike components? In destructive testing does it fail only when loads substantially exceed what would be seen on the road under normal circumstances? My concern is that many carbon clincher brake tracks are not designed to be robust in this sense. As Josh Poertner at Zipp has stated, there is also an issue with rim-tire compatibility and carbon clinchers, which doesn't get discussed much:

From Poertner:

"We have seen rim temperatures in testing exceeding 325F, which can be enough to raise the air pressure in the tire by 20-25psi, so this can be a blowout risk on loose fitting tires or rims at the low end of the ISO diameter spec."

I suspect this was the cause of one blowout I had with a tire that is on the low end of the ISO diameter spec. On a recent group training ride, as we stopped to regroup at the bottom of a descent, one rider had both tires blow off his rims - luckily as he was almost stopped! On inspection, it turned out the tires were very loose fitting - I think consumers should be aware of these issues. 

As for the Williams case, I don't think it was unfair of them. After all, there are people out there riding on this wheel, perhaps also doing long descents. This information is valuable for safety.


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## spade2you (May 12, 2009)

Yes, other components fail, but when it's your wheels, the results generally ain't good. 

Personally, I race carbon tubulars and just train on alloy clinchers. If I had a race with wet and twisty descents, I'd probably go with my clinchers and realize I have plenty of other things to worry about. I don't want my wheels to be one of them.

Perhaps one day they'll set up carbon clinchers to be virtually fail proof, but I'm not taking that risk today.


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## looigi (Nov 24, 2010)

ericm979 said:


> ...if the descent is steep and technical enough you will be braking too much no matter how good a descender you are, and be in danger of damaging the rim or having the tire come off the rim.


Yes. Cycling in areas where you can do steep descents of 3000+' over roads with lots of switchbacks or twisty trails will put a lot more demands on the braking system than otherwise. There was a mountain trail I would ride twice a week on my mtn bike that descended 1600' it 2 miles of fast trails. At night my brake discs would glow dull red at the end of spirited descents.

Riding full carbon rims in conditions that don't put extraordinary demands on rim brakes is probably OK and reasonably low risk. Subjecting them to more extreme conditions probably isn't a good idea.


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## foofighter (Dec 19, 2008)

walamt said:


> I have done my research and was going to order a set of carbon clinchers 38/50 from Farsports, now I'm not so sure. Reading the various threads it seems even name brand rims are having issues mainly with braking on downhill descents and heat, as well as inferior braking over aluminium tracks.
> 
> It would be nice to finally not read about the failures of these carbon wheels because I would be extremely nervous on a downhill. Having said that, I have also noticed that there haven't been any reports of poor performance from the likes of Boyd, Williams, Lightweight and Fulcrum. Maybe spending double on the offerings from Boyd or Williams (there are others as well) will give me piece of mind.
> 
> At the moment I really don't know. My specific set of wheels need to be under 1450gms. Any way just felt the need to express my own anxiety.


I was in the same boat as you. I was set on going carbon clincher route and read up on some of the issues encountered by SOME and felt that the risks didnt outweigh the benefits. I am currently rolling on DT Swiss Tricon 1450 and really like them, typical DT quality etc. I just wanted a bit more aero bling. 

I was going to order a set of staggard as well. 38/50 just like you and they were out of stock and i felt that the majority of my rides arent THAT windy that i would worry about being tossed around. So i went with tubie and ordered from *gulp* hongfu *gulp* the cost of entry was cheap to try out and I'll be mounting them tonight so I'm excited to see how this goes. I'll be injecting some Stan's into my conti's as well as preventative measure.

and just because you spend a boatload of money on brand names wheels you'll have less failure, i just read some posts with some people with the new ZIPP 404 firecrest that had their tires "blow" but i think i would attribute that to pensive riders grabbing too much brake on the descents


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## Eric_H (Feb 5, 2004)

To the OP, here's my $0.02:

If one does not live in a mountainous area and does not do a lot of steep technical descending, then carbon clinchers are a great choice. I do most of my racing and training on rolling courses with most climbs and descents being at most 3 km long. I use both Edge 45 and Reynolds 66 clinchers, SwissStop pads, no issues. These wheels give me aerodynamic advantages for the same weight as most aluminum clinchers, plus the ease of clincher convenience.


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## mimason (Oct 7, 2006)

Here is my $.02. Stop using Swiss stop pads with those clinchers and get the Reynolds blue or Enve gray.


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## looigi (Nov 24, 2010)

The problem with carbon rims and descending is the rim getting too hot from braking causing the epoxy to soften. Heat generated by braking is due the energy dissipated. The type of brake pad used will not affect the heating of the rim assuming they slow you down the same amount.


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## ericm979 (Jun 26, 2005)

But the Reynolds blue pads do work a lot better than the SwissStop Yellows, and cost less.
I have no idea about the heat the generate, they're just better brake pads.


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## sadisticnoob (Dec 6, 2009)

i have cracked a rim even without descents


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## mimason (Oct 7, 2006)

looigi said:


> The type of brake pad used will not affect the heating of the rim assuming they slow you down the same amount.


Both Enve and Reynolds developed their own pad to address heat build up...and actully require their use per warranty language. Swiss stop has good stopping power but has been linked to delamination cases so how effective are they? Besides the gray and blue pads work great so why risk it?


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## walamt (Jun 7, 2011)

Guys thank you so much for your contributions, well balanced discussion and I have to agree with what everyone is saying. Some quick replies to questions raised, for me component weight is always a consideration, there's no right or wrong here. I was also looking at areodynamics and clinchers for me is the practicle and cost effective wheel solution. I used to ride tubulars but got sick of repairing them. Lastly there is a little bling too.

My concern with failure is as some have pointed out, if wheel goes bang there's usually a very serious injury, hence my reservation. The other reason for my hesitation is I live in Adelaide and here we are very fortunate to have the Adelaide hills close to home where you can do some very long descents.

I have taken on board that braking style is a factor but it shouldn't be should it. No one ever thinks about brakes on alloy clinchers do they! Having to devote energy to managing your braking is just no fun at all.

In the end I guess I could buy a lighter pair of alloy clinchers to help with my climing and acceleration and wait to see how the carbon areo clincher reliability goes over the comming years. In the end riding enjoyment is made up of many factors.

Thanks again for all posts, I think this will be a good read for many others with similar thoughts on the topic.

Cheers


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## ManxShred (Mar 6, 2009)

The issue for me with carbon rims is riding in the rain. I only have one set of wheels and use my bike in all conditions so alu rims work better when wet.


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## foofighter (Dec 19, 2008)

sadisticnoob said:


> i have cracked a rim even without descents


what happened there? pothole?


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## Chris-X (Aug 4, 2011)

pmf said:


> Thank you.
> 
> I don't get the carbon wheel craze. First, they're really expensive. Like thousands of dollars. Second, you have to use special brake pads. So if you ever want to swap back to those hideous aluminum wheels, you have to swap out the brake pads too. What a PITA. Third, they overheat quickly when the rider brakes a lot on descents. This can lead to bad consequences. Maybe if you're a serious racer and you think they give you an advantage. In a time trial for example.* I see yo-yos riding these dumb things back and forth to work on the bike path around here*. I just don't see how any recreational rider or amateur racer really needs them. More money than sense I guess.


Funny, don't you understand they are 3 or 4 mph faster? I'm kidding but I actually heard this pitch at a LBS. I saw them sell a 8 or 9K??? bike to a woman who had never even ridden on the road before. Her husband was buying the bike and evidently they were loaded. It had the firecrest 404's, I don't even know about Di2, I was just a little disgusted so I didn't look closely. I mean if people want to blow the money fine, but riding in this area is kind of nuts with the traffic and to spend that kind of money for a first bike???

Vince at Racer's Edge in Boca Raton Fl actually gave a couple of potential customers advice to go to another store, not in a nasty way, but in a helpful, advice filled way. Racer's Edge doesn't stock much but they spend a lot of time on maintenance, fittings and sales/ building high end bikes up. Afterwards, I told him that that was the best advice I've every heard in a LBS.

O/P, why do they have to be under 1450 grams?


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## Eric_H (Feb 5, 2004)

mimason said:


> Both Enve and Reynolds developed their own pad to address heat build up...and actully require their use per warranty language. Swiss stop has good stopping power but has been linked to delamination cases so how effective are they? Besides the gray and blue pads work great so why risk it?


FYI: When I bought my Edge 46 rims the recommended pads were SS Yellow. I used them and had no issues, and the pads are still not worn out as I don't ride either wheelset in the rain. I am going to get the Reynolds pads, as the reviews are quite favorable for them.


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## mimason (Oct 7, 2006)

Eric H: Yep, but they have since change this. I think this occurred with the ENVE changeover. I really like the blue pads from Reynolds.


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## sadisticnoob (Dec 6, 2009)

foofighter said:


> what happened there? pothole?


no idea .. guess it was carbon failure .. underneath the crack u can see the inner wall is cracking


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## keppler (May 25, 2007)

walamt said:


> I have done my research and was going to order a set of carbon clinchers 38/50 from Farsports, now I'm not so sure. Reading the various threads it seems even name brand rims are having issues mainly with braking on downhill descents and heat, as well as inferior braking over aluminium tracks.
> 
> It would be nice to finally not read about the failures of these carbon wheels because I would be extremely nervous on a downhill. Having said that, I have also noticed that there haven't been any reports of poor performance from the likes of Boyd, Williams, Lightweight and Fulcrum. Maybe spending double on the offerings from Boyd or Williams (there are others as well) will give me piece of mind.
> 
> At the moment I really don't know. My specific set of wheels need to be under 1450gms. Any way just felt the need to express my own anxiety.


If you get a set of Boyd 38 front/50 rear you're looking at a wheelset weight of 1439 grams. I've talked with a few guys that ride on Boyd wheels (race and train) and all of them are very happy with their wheels and they speak highly of his responsiveness and support.

Keep something in mind: while everyone (myself included) is on or off the fence about the possibility of braking issues with overheating of carbon clinchers on long descents (that most of us will never even experience)....almost all of us ride on carbon seat posts and full carbon forks, and I'm sure there have been failures of either of these, we just don't read about them.


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