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My Full Carbon Clinchers overheating (pics)

 

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toebeeh

May 24, 11 0:03

Post #1 of 56 (8874 views)
My Full Carbon Clinchers overheating (pics) Quote | Reply

[URL=http://yfrog.com/12img5381rj][/url]

[URL=http://yfrog.com/mwimg5384sj][/url]

[URL=http://yfrog.com/nfimg5387zj][/url]


This is the result of being stuck behind a car @ 65KMPH causing overbraking/overheating on my two week old rims, just tought i'd share my experience incase any one else was thinking of buying these.


(This post was edited by toebeeh on May 24, 11 0:08)


missinglink

May 24, 11 0:10

Post #2 of 56 (8857 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

That happened when you slammed on the brakes?


Rouleur

May 24, 11 0:43

Post #3 of 56 (8822 views)
Re: My Full Carbon Clinchers overheating (pics) [missinglink] [In reply to] Quote | Reply

What make of rim?

How long were the brakes continuously applied for or did you modulate your braking on and off?

Bad stuff, glad you didn't have an accident. I would be asking for a refund or replacement.


CokeZero

May 24, 11 0:54

Post #4 of 56 (8809 views)
Re: My Full Carbon Clinchers overheating (pics) [Rouleur] [In reply to] Quote | Reply

Same thing happened to my Eastons EC90 Carbon Clinchers!


toebeeh

May 24, 11 1:05

Post #5 of 56 (8794 views)
Re: My Full Carbon Clinchers overheating (pics) [missinglink] [In reply to] Quote | Reply

i didn't have the brakes on continuously but more than normal as i was going quicker than the car on a windy but steep hill. i'd heard this happen to a few people but thought they were just riding the brakes all the way down. Matrix wheels, looked the bomb but failed to impress. to be fair the Bike shop has given me a full refund so looking at getting Carbon with alloy braking surface next as don't trust full carbon clinchers any more


oxidefilm

May 24, 11 2:48

Post #6 of 56 (8698 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

YAY CARBON!!! CARBON CARBON CARBON. I don't care, I only want Carbon...

Seriously though, sucks about the wheels. Good on your shop for the refund. Glad you didn't crash. I have 10 year old metal Mavics that have never once failed or broken even with my fat ass riding the brakes down some pretty gnarly descents.

I also have a set of Zipp 404 normal clinchers that are great. I would definitely recommend those.


DarkSpeedWorks

May 24, 11 3:16

Post #7 of 56 (8664 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

That is too bad about your rims. But is is a good thing you didn't have a catastrophic rim failure at 65 kph.

For this reason and for others, a better application of carbon rims is with road disc brakes. No heat of any kind is applied to the rims, it is all applied to the disc rotor.




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Glade Runner

May 24, 11 4:32

Post #8 of 56 (8545 views)
Re: My Full Carbon Clinchers overheating (pics) [DarkSpeedWorks] [In reply to] Quote | Reply

I've always wondered about disc brakes for road wheels. Are there viable options for this? Are they mountain bike discs, or purpose built road discs?
I guess I could research, but this is way easier...


It's simple, but it isn't easy.


DarkSpeedWorks

May 24, 11 4:54

Post #9 of 56 (8484 views)
Re: My Full Carbon Clinchers overheating (pics) [Glade Runner] [In reply to] Quote | Reply

Glade Runner wrote:
I've always wondered about disc brakes for road wheels. Are there viable options for this? Are they mountain bike discs, or purpose built road discs?
Yes, there are disc brakes for road use. The best ones that I know of are Avid BB7 brakes. They have 2 versions: one is compatible with mountain brake levers, and the other is compatible with road/STI/doubletap brake levers (the different versions accommodate the differences in cable pull between the levers).




Advanced Aero Storage for Tri Bikes, Superbikes, & Aero Cabling.>Made in the USA.
DarkSpeedWorks.com.......Speedpack Reviews.......Twitter.......Facebook


jackmott

May 24, 11 5:26

Post #10 of 56 (8402 views)
Re: My Full Carbon Clinchers overheating (pics) [oxidefilm] [In reply to] Quote | Reply

posts like this make me want to post a picture of my aluminum rims that are cracked

METAL METAL METAL

oxidefilm wrote:
YAY CARBON!!! CARBON CARBON CARBON. I don't care, I only want Carbon...


Quintana Roo - history and technology
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter


toolguy

May 24, 11 5:42

Post #11 of 56 (8340 views)
Re: My Full Carbon Clinchers overheating (pics) [jackmott] [In reply to] Quote | Reply

i have seen more carbon breakage then steel/alum in frames,,carbon is new to this game,i have been cycling over 20 years built frames etc, my first carbon part failed pretty quickly. i know all materials fail,but just think of the carbon parts you have seen fail.


jackmott

May 24, 11 5:51

Post #12 of 56 (8297 views)
Re: My Full Carbon Clinchers overheating (pics) [toolguy] [In reply to] Quote | Reply

Failures I can recall:

seen a cracked steel frame
cracked aluminum rim
cheap carbon seatpost

thats it...got a carbon frame, carbon seatposts, carbon road bars, carbon wheels in the household. they have all been fine. only carbon part ive had break was a cheap seatpost that I overtorqued.

yeah carbon is tricky to do well, wheels need a good epoxy that doesn't melt, layup has to be done right to be strong in all directions.

but then welding metal is tricky too.


toolguy wrote:
i have seen more carbon breakage then steel/alum in frames,,carbon is new to this game,i have been cycling over 20 years built frames etc, my first carbon part failed pretty quickly. i know all materials fail,but just think of the carbon parts you have seen fail.


Quintana Roo - history and technology
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter


toolguy

May 24, 11 6:01

Post #13 of 56 (8247 views)
Re: My Full Carbon Clinchers overheating (pics) [jackmott] [In reply to] Quote | Reply

i have about 4 parts made from carbon fork/aerobar couple of rims,,,,have had fork rim break on me SEEN to many carbon frame break to even remember cranks/rims/bars aero and drop/ very expensive rim break for no good reason


-BrandonMarshTX

May 24, 11 6:03

Post #14 of 56 (8239 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

Were you using carbon specific brake pads? Did these have a 'lowered' braking surface? I only ask because I have seen the same thing in the same rim (different stickers) happen. But that person was not using carbon specific pads and did not adjust the brake pads to hit the braking surface.



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Tom A.

May 24, 11 6:54

Post #15 of 56 (8082 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

toebeeh wrote:
i didn't have the brakes on continuously but more than normal as i was going quicker than the car on a windy but steep hill. i'd heard this happen to a few people but thought they were just riding the brakes all the way down. Matrix wheels, looked the bomb but failed to impress. to be fair the Bike shop has given me a full refund so looking at getting Carbon with alloy braking surface next as don't trust full carbon clinchers any more


That would depend on the particular brand. It's for THIS reason alone that Zipp apparently spent a ton of engineering time working with their resin suppliers to find a resin that not only has a high Tg (glass transition temperature - i.e. the temperature it gets "soft") but also exhibits good toughness as well (important for a part of the wheel that may see impacts) before they came out with their 404 and 808 carbon clinchers. Those 2 properties (high Tg and good toughness) are typically competing properties (i.e. "pick one, but not both"), but Zipp managed to find/develop a resin system that gave them both at the same time. You aren't going to get that sort of engineering from some generic wheel brand...

That's also the reason that the 404 and 808 carbon clinchers don't have a rider weight limit. Most (if not all) other carbon clinchers have a rider weight limit in an attempt to prevent the type of rim heating upon braking that caused the sort of deformation you show above.

I hope this failure didn't cause any injury to you...


http://bikeblather.blogspot.com/


Tom A.

May 24, 11 6:59

Post #16 of 56 (8061 views)
Re: My Full Carbon Clinchers overheating (pics) [DarkSpeedWorks] [In reply to] Quote | Reply

DarkSpeedWorks wrote:
That is too bad about your rims. But is is a good thing you didn't have a catastrophic rim failure at 65 kph.

For this reason and for others, a better application of carbon rims is with road disc brakes. No heat of any kind is applied to the rims, it is all applied to the disc rotor.

That's just ignoring the real issue (poorly engineered carbon rims) and creating a whole 'nuther set of problems...such as aerodynamics and weight, 2 things that are important for road wheels (the aero much more so than the weight, however).

Just engineer the rims properly and use the GIANT disc that is the rim ;-)


http://bikeblather.blogspot.com/


Tom A.

May 24, 11 7:00

Post #17 of 56 (8050 views)
Re: My Full Carbon Clinchers overheating (pics) [toolguy] [In reply to] Quote | Reply

toolguy wrote:
i have seen more carbon breakage then steel/alum in frames,,carbon is new to this game,i have been cycling over 20 years built frames etc, my first carbon part failed pretty quickly. i know all materials fail,but just think of the carbon parts you have seen fail.

All of these failures everyone is talking about are engineering failures, not material failures...


http://bikeblather.blogspot.com/


toolguy

May 24, 11 7:12

Post #18 of 56 (7981 views)
Re: My Full Carbon Clinchers overheating (pics) [Tom A.] [In reply to] Quote | Reply

good point,but carbon could crack at a place that is not a joint/overlay ,at a point where the stress is to high?


DarkSpeedWorks

May 24, 11 7:15

Post #19 of 56 (7963 views)
Re: My Full Carbon Clinchers overheating (pics) [Tom A.] [In reply to] Quote | Reply

While, as you say, a bicycle rim is essentially a giant disc, it is a disc with some big limitations. For one, whether it be a clincher or tubular rim, it is a thin-walled and very light disc. Then, attached to this giant disc is a very temperature-sensitive device, a clincher tire, or a glued tubular tire. These highly limit the full functionality of the rim as a giant disc rotor.

Also, I have used carbon disc brakes very extensively (in aircraft) and I can say that even highly engineered and highly refined carbon disc brakes have some very significant shortcomings. I have also used disc brakes very extensively on a series of different road bikes. While I would agree that disc brakes are on a bike may not be super aero or super light, they do stop and modulate very, very, very well in a remarkably wide range of harsh and challenging environmental conditions. And those are just mechanical discs. In my experience, disc brakes work far better than any other bicycle brakes in ALL conditions, whether they be on AL or carbon rims. Once you try them, it is very hard to go back.




Advanced Aero Storage for Tri Bikes, Superbikes, & Aero Cabling.>Made in the USA.
DarkSpeedWorks.com.......Speedpack Reviews.......Twitter.......Facebook


Silver Comet

May 24, 11 7:16

Post #20 of 56 (7961 views)
Re: My Full Carbon Clinchers overheating (pics) [Tom A.] [In reply to] Quote | Reply

That's just ignoring the real issue (poorly engineered carbon rims) and creating a whole 'nuther set of problems...such as aerodynamics and weight

I'm saving this. I may need to use it against you some day down the road. ;-) (Yes, I'm aware that it's not the whole statement.)


Tom A.

May 24, 11 7:32

Post #21 of 56 (7890 views)
Re: My Full Carbon Clinchers overheating (pics) [toolguy] [In reply to] Quote | Reply

toolguy wrote:
good point,but carbon could crack at a place that is not a joint/overlay ,at a point where the stress is to high?

Sure...if the design is poorly engineered...but, that's true of ANY material.


http://bikeblather.blogspot.com/


TriBriGuy

May 24, 11 7:42

Post #22 of 56 (7854 views)
Re: My Full Carbon Clinchers overheating (pics) [Tom A.] [In reply to] Quote | Reply

One of the things that is missing in the discussion is that cyclists should understand the capabilities and limitations of the gear they are on. Every single piece of our bikes can and will fail if we take it outside of its performance parameters. Riding 65kph downhill behind a vehicle, grabbing handfuls of brakes is not going to work well for most of these early carbon clinchers (Zipp and maybe the latest Reynolds excepted). And if you do it often, even your aluminum rims are going to wear out at some point. It's not a "good" or "bad" equipment thing. It just is. Accept it. Know the limits of the equipment you're on. Ride accordingly.

And it is not always a "more" or "less" issue between the different materials. Many times it is just that the failure modes are different. Get a tiny dent in your steel top tube? Probably ok to ride on. Aluminum frame? Start looking for a new frame. Carbon? Maybe just a glancing blow...as long as the carbon isn't cracked...ride on.

For the OP...now that you understand the limits of those wheels...you have three choices: 1. Ride your aluminum rims on that course if there is open traffic that might require substantial braking. 2. When finding yourself behind a vehicle like that, pull over and put some distance between you and the vehicle so that you can let the bike roll without braking so much. 3. Spend a lot more $$$$ on wheels engineered to withstand that kind of stress. Only you can answer which of those works best in your own athletic pursuits.



For Tom...I think we can only call them "engineering failures" if we have the performance envelope they were designed to meet in front of us and see that the failure did not exceed the requirement. As you surmised above, I doubt these were designed to the same criteria Zipp used. But surely the manufacturer used some sort of design criteria. Did the OP exceed that criteria? If so...his fault (assuming the manufacturer/vendor did not falsely advertise). If not? Then, yes....perhaps engineering OR quality control failure.

***********************

AmZof Lemming! Target AmZof SC 2013!


SoberBySaturday

May 24, 11 7:42

Post #23 of 56 (7850 views)
Re: My Full Carbon Clinchers overheating (pics) [toebeeh] [In reply to] Quote | Reply

Same thing happened to some Matrix's I was riding. Only mine completely delaminated did one revolution and caught the brake pads on an incredibly steep decent and sent me skidding down the hill. Luckily I only ended up with a few cuts and bruises and was fortunate that a truck stopped and actually took me back to my car.


Tom A.

May 24, 11 7:55

Post #24 of 56 (7800 views)
Re: My Full Carbon Clinchers overheating (pics) [TriBriGuy] [In reply to] Quote | Reply

TriBriGuy wrote:
...But surely the manufacturer used some sort of design criteria...

I think you might underestimate the level of "seat of the pants" design there is in the bike business ;-)


http://bikeblather.blogspot.com/


TriBriGuy

May 24, 11 8:03

Post #25 of 56 (7773 views)
Re: My Full Carbon Clinchers overheating (pics) [Tom A.] [In reply to] Quote | Reply

You're absolutely correct. Truth be told, Tom....I just didn't want to go into that whole side of things. It just would have made my post overly long to make the same point that we ought to know what we're riding. Just because something is round, measures to fit 700, and mounts the tires we want doesn't mean it will do what we're thinking of asking it to do.

***********************

AmZof Lemming! Target AmZof SC 2013!

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