Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New

May 31, 17 14:31

Post #1 of 20 (4473 views)

After a service a trainings buddy's carbon rim wheel set got a bad evaluation just by view. Now we try to identify if there is possibly a delamination by heat symptom at the brake track. The rims have 40k km and the brake tracks are not worn. Pics will follow, we try to catch the appearance ..

The first pic shows the good evaluated rear wheel for reference with a visible structure of the lay up ..

.. the next pics show the front wheel with the obstacles in question, slick areas, radial groves and little wear at the valve. The brake track surface is still hard and the brake power didn't change .. thanx for tips and hints .. as we don't take any incalculable risk they are essentially for our interest! These are Reynolds rims ..

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Last edited by: sausskross: Jun 5, 17 12:48

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 12:36

Post #2 of 20 (4324 views)

Now with pics, see above ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 14:59

Post #3 of 20 (4236 views)

From another site -

Quote:

“Reynolds has built a brake-wear indicator (BWI) into the carbon brake track. The BWI is a red line that is 10mm wide (left to right) and centered over the valve hole on both sides of the rim. When the red line becomes visible, this indicates that the rim needs replacing due to wear.”

Can you see it? Fairly obviously you can get types of damage that weaken the rim before you see the indicator and then it's a judgement call. You'd really hope they put the BWI on every single wheel ever made else someone might ride one down to the last micron waiting for something that isn't there to show.

Edit - BTW, that rear brake pad in the first shot looks a bit ratty and I guess it is rubbing part of the tire which could be trouble.

Last edited by: OddSlug: Jun 5, 17 15:02

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 15:16

Post #4 of 20 (4218 views)

That rim is delaminating due to excessive heat build up.

Was your friend riding on some steep mountains?

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 15:42

Post #5 of 20 (4199 views)

1. Reynolds rims require 'blue' brake blocks.
2. a carbon rim would not have the 'seam' near the valve stem (image #5)
3. I don't think this is a carbon rim
4. I don't think this is a Reynolds wheel.

Anne Barnes
ABBikefit, Ltd
FIST/SICI/FIST DOWN DEEP
X/Y Coordinator
abbikefit@gmail.com

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [ABarnes] [ In reply to ]

Jun 5, 17 15:55

Post #6 of 20 (4187 views)

That "seam" might just be a mold mark.

Reynolds used to make rims that looked very similar to that.

If the OP removes the tire and posts a picture of the serial number, I can tell if it is made by Reynolds.

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 17:41

Post #7 of 20 (4151 views)

From the first photo and wear marks I don't think your friend properly adjusted his brake pad position. He has them way too high. I suggest that he is braking on the top edge of the rim leading to his tire and rim damage. See my analysis below:

Last edited by: Pantelones: Jun 5, 17 17:42

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [jimatbeyond] [ In reply to ]

Jun 5, 17 20:06

Post #8 of 20 (4098 views)

jimatbeyond wrote:

That "seam" might just be a mold mark.

Reynolds used to make rims that looked very similar to that.

If the OP removes the tire and posts a picture of the serial number, I can tell if it is made by Reynolds.

that's a pretty craptastic mold mark.
always thought reynolds exterior finish was that 'flat' unidirectional look?
yes, serial number would reveal all :) =:o

Anne Barnes
ABBikefit, Ltd
FIST/SICI/FIST DOWN DEEP
X/Y Coordinator
abbikefit@gmail.com

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [ABarnes] [ In reply to ]

Jun 5, 17 22:51

Post #9 of 20 (4055 views)

For the sn a tire flat would be needed, sorry. But anyway it's a Reynolds MV32T carbon rim. For the brake pad, it's really adjusted very, very exact on place and the pics just show a perspective difference and some kit .. thanx for the eagle eyes ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 23:02

Post #10 of 20 (4042 views)

You don't need a flat tire to remove it.

In fact, I would recommend that Tufo tire be removed and thrown in the garbage.

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [jimatbeyond] [ In reply to ]

Jun 5, 17 23:03

Post #11 of 20 (4041 views)

jimatbeyond wrote:

That rim is delaminating due to excessive heat build up.

Was your friend riding on some steep mountains?

That is what the service said and we ask for a more differential/technical insight .. and yep, we use mountains to race up and down ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 5, 17 23:31

Post #12 of 20 (4031 views)

This is good to know. I ride carbon rims and never thought about this occurring. Hope you itball turned out okay for you.

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [OddSlug] [ In reply to ]

Jun 6, 17 3:32

Post #13 of 20 (3983 views)

No, we can't see any BWI and thank you for the link to the site with interesting infos (we found, too) ..

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Last edited by: sausskross: Jun 6, 17 3:35

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 6, 17 22:48

Post #14 of 20 (3884 views)

We learned that it depends on how deep the delimitation got into the structure and how the structure is build up by the producer .. with the pics a check at Reynolds is the next step, to ask what they can say technical. With that usage it's not a warranty claim ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 7, 17 9:20

Post #15 of 20 (3808 views)

Reynolds is going to say that you overheated the rim, sorry.

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [jimatbeyond] [ In reply to ]

Jun 7, 17 14:41

Post #16 of 20 (3747 views)

No reason to be sorry, we will ask them ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 7, 17 15:37

Post #17 of 20 (3729 views)

What are you going to ask them?

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 16, 17 10:52

Post #18 of 20 (3518 views)

Reynolds responded .. the outer scrim which is applied over the brake track around the diameter of the fw is worn away. The chance for a heat failure on this front rim rises as the brake track gets thinner and thinner and there is less heat dissipating material left where your pads contact your wheel .. a new race wheel set is to choose ..

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Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [sausskross] [ In reply to ]

Jun 16, 17 11:08

Post #19 of 20 (3501 views)

Yep, they told you that the rim was overheated.

Re: Are there any visible indications a carbon rim brake track struktur got weak? (now with pics) - New [jimatbeyond] [ In reply to ]

Jun 16, 17 13:20

Post #20 of 20 (3451 views)

jimatbeyond wrote:

Yep, they told you that the rim was overheated.

Yep, but I wanted Reynolds to answer .. and .. as they say .. the rim scrim is worn and with that the risk of overheat failure while braking gets bigger ..

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