HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Articles FAQ Contact About




Post new topic Reply to topic  [ 65 posts ] 
Go to page Previous  1, 2, 3, 4, 5  Next
Author Message
PostPosted: Fri Aug 26, 2011 11:22 pm 
Offline

Joined: Sat May 07, 2011 12:23 am
Posts: 160
parajba wrote:

Looking at the picture, how do I know whether it's a structural crack or just something else? I can see something grey underneath the white paint, but doesn't look like carbon to me...there is a crack in the 'grey' thing. Will HQ Fibre x-ray it for me or do I have to call Cervelo Canada for this service...?


From my experience in taking x-rays of humans, it's by no means an absolute guarantee of locating a crack. because an X-ray picture is two-dimensional, the beams have to pass parallel through the actual plane of fracture. If they pass perpendicular, since x-rays are only an image of material density, it won't appear any different.

Send your frame to whomever you feel most confident will do a good repair, and you'll probably be quite pleased.


Top
 Profile  
 
Posted: Fri Aug 26, 2011 11:22 pm 


Top
  
 
PostPosted: Sat Aug 27, 2011 7:29 am 
Offline

Joined: Tue Oct 28, 2008 9:00 pm
Posts: 383
Location: London, United Kingdom
@Clarkson: thanks for the reply. But confidence and probability have little to do with science, in order to ride this frame again I need to be 100% sure that there are no other cracks or issues caused by the crash.

How can the repair man ensure this? I'm an engineer myself and hence I need data to feed my brain.

I googled last night and found out that unfortunately there is no way of checking a CF (due to its thickness 1mm wall is too thin for normal x-ray equipment) unless someone has military or aerospace grade equipment.

So, to me, you crash once and you need to assume that your CF is potentially shot and at risk even if there are no visual cracks. Can anybody prove the contrary? I'd be very happy to be proved wrong as it'd save me £1800 for a new S2 or a little more for an S3.

Right now I've lost all the confidence. No data = no confidence = no repair :(


Top
 Profile  
 
PostPosted: Sat Aug 27, 2011 11:03 am 
Offline

Joined: Wed Feb 24, 2010 12:02 pm
Posts: 101
Location: Sydney
@parajba, my frame had one crack like yours (you could not press in the tube), and one where there was daylight in the crack. In both cases paint damage was a giveaway.

It would be quite an effort if you managed another crack without any visible damage to the paint (or at least the clearcoat).

Was it a solo crash or were others involved? Did your frame come into contact with anything (apart from you, the road, and itself)? The answers might help dispel further doubt, but absolute certainty might have to take a backseat to careful inspection, common sense, and the knowledge that Cervelo make tough frames.

I didn't want to influence you unduly but looks like you need some extra reassurance so...my cracked frame was also an R3, same vintage as yours. Two years on, I'm still happily racing on it.

_________________
"24/7 Im always in spandex, cut through the wind, cos Im aero-dy-na-mic"
http://www.youtube.com/watch?v=Vn29DvMITu4


Top
 Profile  
 
PostPosted: Sat Aug 27, 2011 11:57 am 
Offline
in the industry
User avatar

Joined: Thu May 29, 2008 12:22 am
Posts: 597
parajba wrote:
How can the repair man ensure this? I'm an engineer myself and hence I need data to feed my brain(


What I would suggest you do is give us a call and speak to either John (the special projects engineer) or Martin (the company owner). Email the pics you have first to our works address so they can have a look and then they will explain any worries that you might have. They would definitely need to see the frame in the flesh to check over it but they could give you a good idea/overview of the general procedures.

I understand your need for data, I'm similar myself, but in reality data for laminates is not the easiest to come by and building/repairing carbon frames by hand is more an art form.

As far as x-rays are concerned they're not ideal. As mentioned above, they're not perfect in areas where they are good such as x-raying bones but carbon fibre is almost x-ray transparent. We manufacture carbon fibre/foam laminate x-ray beds for x-ray machines due to their x-ray transparency. Ultrasonics are probably a far better way of detecting cracks but then costs comes into it. The other thing you have to bear in mind is that the tube wall thickness on frames is so small these days that if there is damage it will almost certainly be visibly apparent.

To try and put your mind at ease a little, if we don't think it's safe to repair, we won't repair it.


Top
 Profile  
 
PostPosted: Sat Aug 27, 2011 3:06 pm 
Offline
in the industry

Joined: Thu Jan 08, 2009 12:16 pm
Posts: 159
Location: Melbourne Australia
We use ultrasound to find damage and also validate the repair, as used primarily in aerospace repair. X ray is not that useful for typical damage such as delamination, although it can be useful for cracks, multiple angle shots need to be taken to ensure alignment of the crack so it shows up on the shot as the laminates are so thin. Delamination is the most common accident damage and Ultrasound is the preferred method for finding this.

Often when I ultrasound scan a frame I will find small manufacturing defects such as porosity or voids within the structure and have even found foreign object. This scan is many times more sensitive than the factory QC.

Also from the photo the zig zag crack is typical as it follows the bias plies on the tube, there will be some delamination associated with this. We have repaired many of these, it is very common for the bar to swing around during a crash and strike the top tube, the other area that can get damaged in this type of accident is the down tube where the brake adjuster strikes it.

_________________
Specialist Sports Technology
http://www.luescherteknik.com.au
Zerocompromise High Performance Footwear
http://www.zerocompromise.com.au
Carbon Bike Repairs
http://www.carbonbikerepair.com.au


Top
 Profile  
 
PostPosted: Sat Aug 27, 2011 9:32 pm 
Offline
in the industry
User avatar

Joined: Thu May 29, 2008 12:22 am
Posts: 597
I think if you ultrasound frames regularly you would find all sorts that riders aren't aware of. From general repair we've come across anything from poorly bonded bottom brackets, filler, large voids etc. Not sure we've found any foreign objects yet though. :D


Top
 Profile  
 
PostPosted: Sun Aug 28, 2011 7:48 am 
Offline

Joined: Tue Oct 28, 2008 9:00 pm
Posts: 383
Location: London, United Kingdom
@Whodesigns, Stephen (Fibre-Lyte): many thanks for the reassurance and kind replies, you inspire confidence!
Could you please both PM me with a quote? I would really appreciate it. I'm based in London.

Just an update, I bit the bullet and decided that the crash was a good chance to try the 'other side', the 'S' line, given that I race only. When I bought the R3 I wasn't into racing. Got a 2011 black S2 (still size 54) for £1,750 from my LBS and quite please with it. The two bikes have identical geometry if you exclude the -17mm setback of the new saddle rail. I'm sure I can work on that.

My plan is to repair the R3 and, maybe, sell it...


Top
 Profile  
 
PostPosted: Sun Aug 28, 2011 3:17 pm 
Offline

Joined: Tue Dec 14, 2010 6:09 pm
Posts: 43
Hi, I assume you are in the UK (sorry never checked your profile).

I had incident a few months back and cracked the top tube on my Tarmac sl3. See this link viewtopic.php?f=3&t=86464&start=15

There is a place in Swadlincote that does repairs. I took the above frame to him on Friday and he's said easy repair, will be done from the inside via the head tube and will be unnoticeable. He will blend the paint and relacker it.

He is doing mine for £180 and says it'll be 2 and a half weeks (he is stacked out).

He was also showing me the work he'd done on other frames which was quite impressive, give me confidence to leave my frame in safe hands.

The guys name is Darren and you can find him at http://www.carboncyclerepairs.co.uk/index.html

Good luck! :wink:


Top
 Profile  
 
PostPosted: Sun Aug 28, 2011 3:34 pm 
Offline
in the industry
User avatar

Joined: Thu May 29, 2008 12:22 am
Posts: 597
flaydog wrote:
will be done from the inside via the head tube and will be unnoticeable.


I'll be curious to hear how that will be done. By the looks of the damage it's half way along the tubes so access from the inside will be very limited. Once frames are painted after a repair the damage is usually either very hidden or in most cases not noticeable.


Top
 Profile  
 
PostPosted: Tue Aug 30, 2011 4:53 am 
Offline

Joined: Thu Sep 30, 2010 5:50 am
Posts: 315
Wonder if he had really skinny arms and really small hands. :noidea:


Top
 Profile  
 
PostPosted: Tue Aug 30, 2011 5:17 am 
Offline
Shop Owner

Joined: Sat Jun 13, 2009 4:02 am
Posts: 1965
Location: NoVA/DC
this one engineer guy i know is testing out using a very large ct scanner to inspect carbon components. he says this big new one is one of only a few in the country.
i had a couple sample scans, misplaced now. but interesting.


Top
 Profile  
 
PostPosted: Tue Aug 30, 2011 1:31 pm 
Offline

Joined: Tue Sep 22, 2009 1:29 pm
Posts: 618
Location: UK
I guess deep down you wanted to buy the S2 all along right?

It’s entirely possible that all you’ve done is crack the paint, I would have thought having the frame inspected by someone like FibreLyte would have been a more frugal option, but you earned your money so you decide how to spend it!

Enjoy the S2!

_________________
"We live in an age when unnecessary things are our only necessities." Oscar Wilde

Pegoretti Responsorium
Parlee Z5i
Donhou Commuter
1946 MacLeans Featherweight (L'Eroica!)
1991 Cannondale SM1000 (currently being renovated)


Top
 Profile  
 
PostPosted: Tue Aug 30, 2011 8:22 pm 
Offline

Joined: Tue Oct 28, 2008 9:00 pm
Posts: 383
Location: London, United Kingdom
bikewithnoname wrote:
I guess deep down you wanted to buy the S2 all along right?

It’s entirely possible that all you’ve done is crack the paint, I would have thought having the frame inspected by someone like FibreLyte would have been a more frugal option, but you earned your money so you decide how to spend it!

Enjoy the S2!


True. When I bought the R3 I wasn't into racing. Now, all I do is just racing. Nothing else. The S2 seems the natural choice. And given that life is too short...You know how it ends ;-)

About the crack, although I'm no carbon expert I doubt the paint cracks in a zig-zag line...looks to me the lines are following the pattern of the fibres of the carbon...

PS: I emailed Fiber-Lyte for a quote.


Top
 Profile  
 
PostPosted: Mon Sep 05, 2011 9:23 pm 
Offline

Joined: Sun Mar 14, 2010 7:08 am
Posts: 95
Calfee repaired an orca for me. A cracked seat stay and top tube. Looked super sharp afterwards. I had them paint match the top tube but not the seat stay, didn't want a super obvious repair job but wasnt going to pay 200$ for paint. Looked good though. I can take pics if you want.

_________________
There is nothing lighter than a hole


Top
 Profile  
 
PostPosted: Mon Sep 05, 2011 10:14 pm 
Offline
User avatar

Joined: Mon Feb 12, 2007 12:08 pm
Posts: 224
celeste55 wrote:
Calfee repaired an orca for me. A cracked seat stay and top tube. Looked super sharp afterwards. I had them paint match the top tube but not the seat stay, didn't want a super obvious repair job but wasnt going to pay 200$ for paint. Looked good though. I can take pics if you want.



Please show the pics :!: I have a cracked frame also - and want to know if could be repaired.

viewtopic.php?f=3&t=92652

_________________
The sisters


Top
 Profile  
 
Posted: Mon Sep 05, 2011 10:14 pm 


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 65 posts ] 
Go to page Previous  1, 2, 3, 4, 5  Next


Who is online

Users browsing this forum: Bing [Bot], Google [Bot], KWalker and 30 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Cracked Paint or Cracked Fork?

[ Go to page: 1, 2 ]

in Road

Romper

19

1192

Tue Feb 11, 2014 8:39 pm

whodesigns View the latest post

There are no new unread posts for this topic. Cracked dropout LOOK 586 SL

in Road

ave

6

814

Fri Apr 11, 2014 10:10 am

latman View the latest post

There are no new unread posts for this topic. Cracked AX Lightness Stem

[ Go to page: 1, 2 ]

in Road

audiophilitis

20

3523

Thu Oct 17, 2013 4:32 am

vlastrada View the latest post

There are no new unread posts for this topic. Campagnolo Zonda cracked rim

in Road

marcio riva

12

1453

Fri Jul 04, 2014 11:26 am

kavitator View the latest post

There are no new unread posts for this topic. Opinion Please [cracked Cannondale]

in Road

nfecyle

12

1475

Mon Jun 16, 2014 2:03 am

TheDarkInstall View the latest post


It is currently Sat Sep 20, 2014 1:18 am

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB