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Posted

This is a valid question and also why I choose my jobs carefully when it comes to repairs as not all repairs are equal. To carry the insurance is very expensive and I for one can not afford it. Therefor when a repair is a dangerous repair i would much rather walk away and loose the income. Not because i doubt in my ability or the quality of my repair but merely for the peace of mind of what if and not being overly arrogant. And i say again and i will say it over and over, my clients lives are more important than me making a few bucks or them saving a few.

 

The guys at carbon repair in Jhb also told me that there are certain areas on a bike's frame that are too risky to repair, and they wouldn't touch it. 

 

At the end of the day though it's up to you, the bike owner, to decide whether you feel comfortable to repair or not. All the guys questioning the repairers knowledge and credibility - if you don't feel comfortable then simply don't do it. 

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Posted

I'm obviously totally unqualified to comment knowing little about either carbon, or insurance. But there are some questions to be raised with the insurer, in my opinion.

 

First, how do they account for the voiding of the manufacturer warrantee? Will they be assuming this after the repair?

 

Second, how does the carbon specialist ensure they use the exact type of carbon, the same type of resin, and the same layup directions and thickness to ensure frame characteristics are what you bought and paid for, and paid to insure so you would not risk those qualities?

 

Third, from what I know about frame building, the jigs used are extremely important in lining up bearings, tubing, and frame straightness. Is the repairer able to accurately mirror these in how own environment during the repairs to make sure bearings line up perfectly, gaps are correct, and will not result in longer term damage and wear to headset or BB bearings, wheel axles and bearings, and ensuring alignment is correct for safe braking and no additional wear or shifting issues on the drivetrain?

 

Once those are answered by both parties then the call can be made. I doubt they'll be able to answer all of those to your comfort.

Posted (edited)

I'm sure you are a skilled and professional craftsman who wouldn't let a dangerous frame out of his workshop.

 

As a layman however, I cannot see how the frame under discussion in this thread could ever be restored to as good as new condition. There must be some compromise involved - in weight, in the distribution of weight, in comparitive strength across different parts of the structure. I simply don't believe it.

 

My ortho told me after he pinned my bones together that I would get full function back but we'd have to wait and see about long term impact of the injury in terms of early arthritis and a few other things. I would need some serious science and explanation to help me understand how this frame could ever be reliable again - right now I simply don't believe it.

I can well understand how you might be incredulous, and I am glad that you acknowledge that you are a layman. This is where trust in the expertise that I have (and you don't) is required.

 

Fortunately no one forces you to ride a repaired frame, if you can't get your head around it then you must simply opt for another solution.

 

As for the science, there's plenty but I'll make an attempt to summarise :

 

CFRP or carbon fibre reinforced plastic comes essentially in two versions, thermoplastic and thermoset. Bikes are made with thermoset resin and this is imminently repairable because it is imminently bondable.

 

New frames are made in multiple pieces that are glued together, typically stays are glued via lugs to the one piece front triangle. The join is then "taped" to make it one piece. In a job like the one that is the subject of this thread, I would emulate this process by creating an internal lug that joins the two halves of the head tube together, then I would tape the two halves. (Taping is just a term for wrapping carbon fabric on a closed surface, it's not taping like sellotape)!

 

I have a big that maintains alignment and the lug that I make is largely geometrically conformal with the internal surfaces of the original head tube. In this way a repair adds only 10s of grams to the original mass, rather than hundreds.

 

Appropriatly selected reinforcing carbon fabric and epoxy matrix then merge the two halves of the head tube via an appropriate consolidation and fibre volume fraction maintaining process. I use VI mostly, sometimes vacuum bagging. You won't find insulation tape in this workshop, no "Pap en Lap" as my colleague Anton calls it!

 

My methods are all derived from repair method standard best practice from the civilian aerospace industry. These manuals are published by Boeing, Airbus and so on for technicians to make repairs to their planes which are increasingly composite intensive.

 

Oh, and lastly, I've had the quality of my laminates tested independently. I did this to ensure a low void and high fibre volume fraction laminate a was being repeatably achieved by my repair methodology.

 

Lastly, I forgot to add, the analogy with orthopedic science is not totally valid, medicine is not an exact science where composites are, pretty much. There are many variables and unknown unknowns in the world of medicine, but luckily in this arena, its far more exacting.

Edited by Carbon Ninja
Posted (edited)

to Carbon Ninja and all other carbon experts.

 

"I, as a carbon repair specialist am approached by insurance to provide quotations on repair costs and this I do honestly and fairly."

 

Carbon is not just carbon - different resins, layup, processes, etc

 

my questions.

 

1.how do you address this issue of different carbon - also how would a Bianchi that has CV incorporated into the carbon be dealt with - can this be repaired/done due to patent issues.

 

2.which other insurance companies are pressing ahead with this type of repairs besides Santam ( i need to change from them asap then :eek: )

I can't answer 2, but I can have a go at 1.

 

Bikes use more, thinner laminates as they increase in quality. When I am repairing, the process of removing the cracked and delaminated carbon allows me a pretty good view of how the manufacturer designed the laminate. Then, within the limitations of the material available to me, I emulate as far as possible the original layup.

 

I do this to minimise the creation of stress raisers that will crack the frame layer and to keep the frame strength and stiffness the same.

 

For this reason I keep stock of a variety of carbon facrics in various areal masses and weaves. I keep plain, twill, satin, ud and biaxial fabrics in stock. I keep some of them in high strength carbon, some in standard modulus, high modulus and some UHM fibre too. I also keep various epoxy systems that are utilised appropriately.

 

Your specific question on Bianchi CV - a single and outermost laminate of a 163gsm carbon/aramid balanced plain weave over the structural ud HM fibre is what I usually do, and as far as I am concerned this is what Bianchi do too.

Edited by Carbon Ninja
Posted

The guys at carbon repair in Jhb also told me that there are certain areas on a bike's frame that are too risky to repair, and they wouldn't touch it. 

 

At the end of the day though it's up to you, the bike owner, to decide whether you feel comfortable to repair or not. All the guys questioning the repairers knowledge and credibility - if you don't feel comfortable then simply don't do it. 

Look at the end of the day no area on a bike is not repairable... Should it be done? Probably not... Could it be done? It certainly could as anything is possible with carbon...

Will I do it for a client.... it depends on the circumstances... 

Will i do it for myself HELL YESS. If i die riding it i die doing something i love.

 

At the end of the day though when it comes down to the business aspect of it choose to do the right thing and dont be scaly about it.

 

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Posted

I'm obviously totally unqualified to comment knowing little about either carbon, or insurance. But there are some questions to be raised with the insurer, in my opinion.

 

First, how do they account for the voiding of the manufacturer warrantee? Will they be assuming this after the repair?

 

Second, how does the carbon specialist ensure they use the exact type of carbon, the same type of resin, and the same layup directions and thickness to ensure frame characteristics are what you bought and paid for, and paid to insure so you would not risk those qualities?

 

Third, from what I know about frame building, the jigs used are extremely important in lining up bearings, tubing, and frame straightness. Is the repairer able to accurately mirror these in how own environment during the repairs to make sure bearings line up perfectly, gaps are correct, and will not result in longer term damage and wear to headset or BB bearings, wheel axles and bearings, and ensuring alignment is correct for safe braking and no additional wear or shifting issues on the drivetrain?

 

Once those are answered by both parties then the call can be made. I doubt they'll be able to answer all of those to your comfort.

We build jigs as needed, we have a 3D printer to assist as well as a cnc mill and manual lathe. I agree 100% with you, doing the job properly is absolutely necessary to avoid dangerous and/or annoying comebacks.

 

Your second point I answered in another post.

Posted

I suspect you are wrong there Graeme.... big time - almost EVERY diagnosis these days is questioned extensively by every googler around... fact of professional life.

 

I agree it's most annoying that my 14 year education and judgement is questioned a lot and often in arrears - at vast cost in professional lost time and additional insurance costs - that said - if it saves 1 life - is it not worth the additional effort?

 

As an aside - and just because I am curious - do you hold professional indemnity and liability insurance against a claim relating to a failure of a repair with concomitant injuries and lifetime incapacity? or do you expect or assume the insurer or customer takes that risk? I certainly do - my family certainly cannot afford a successful claim given the size of the judg

ements these days

Absolutely Doc (may I call you Doc)?

 

My father in law is a neurosurgeon, so I know all about both the utterly compelling and reasonable act of collecting multiple professional opinions, but I also see how his 14 years of study and 25 years of experience is questioned by laymen with Google. It makes no sense and is silly.

 

As for professional indemnity, you're absolutely right but as Bogus mentions, it's unaffordable unless you're a private practice medic. That fact alone keeps me well and truly motivated to do the best and safest work that I can.

 

If I could afford it, I would have it.

Posted

This is a very valid question. Carbon isn't just carbon. A lot of R&D goes into producing these frames. Some manufacturers have patents on their technology. How do we know the local carbon specialists have the correct tooling and tech available to fix it properly? Do we just take their word that they are experts?

I don't have a good answer other than to invite you to engage with me personally, and perhaps to visit my facility to see for yourself what I do. This and check with the public on how well my work is rated?

Posted (edited)

Just ask for a copy of the math used to prove the layup planned and repair is going to be structurally sound.... if you get it and it's correct then I would assume the repairer knows what he is doing.

 

Heuristics don't always provide correct answers...

This is possible, simple calculations can be made with composites but the accuracy is not great. What is really needed is an FEA based simulation with a laminate modeler where the directional properties of each layer of reinforcing fabric is modeled along with predicted loads and constraints. This is more of a design tool than a maintenance /repair tool and as such is out of reach of the modestly remunerated... I think a single seat is over R100k/year. Still, it can be done.

 

There is a design code in aerospace called black aluminium. A quasi isotropic laminate of carbon fibre of equivalent thickness to the aluminium more than double the factor of safety of the original part. This was state of the art in the 80's!

 

I think you're right about heuristics and I do think that this approach is prevalent in our tiny carbon repair industry (with some exceptions). It's not present at Carbon Craft though. We learned our craft academically.

Edited by Carbon Ninja
Posted

I don't have a good answer other than to invite you to engage with me personally, and perhaps to visit my facility to see for yourself what I do. This and check with the public on how well my work is rated?

I did take a generalised swipe and I do apologise for that. Wasn't meant directly at you Ninja. After reading your post #99 and #100 I do get a sense that you know your shyte.

Posted (edited)

Absolutely Doc (may I call you Doc)?

 

My father in law is a neurosurgeon, so I know all about both the utterly compelling and reasonable act of collecting multiple professional opinions, but I also see how his 14 years of study and 25 years of experience is questioned by laymen with Google. It makes no sense and is silly.

 

As for professional indemnity, you're absolutely right but as Bogus mentions, it's unaffordable unless you're a private practice medic. That fact alone keeps me well and truly motivated to do the best and safest work that I can.

 

If I could afford it, I would have it.

Will chirp in here with regard to Professional Indemnity and do not accept your argument, with regard to cost.  I am in the construction industry, a consultant and HAVE to have PI.  For a cover of R5m it costs me just over R6000 pa.  The cost is also relative to the size of projects that I do. Not a large cost in the scheme of things and if a building collapses with people in it am more at risk than someone coming off a bike.

 

Further you can also mitigate your risk profile.  Each year when I renew my PI, I am required to complete a very detailed pages and pages questionnaire of what work I will and wont carry out.  Should I be found to carry out work I previously said I would not do because I know it would increase my premiums I will get screwed by my insurer.  Similarly if I outsource work my PI will be affected.

 

So this being your formal work line and not just a hobby to say you do not have PI and cannot afford it is BS.  The type of work and the value of work that I need cover for runs into the hundreds of millions of Rands project cost, considerably more than repairing a tens of thousands priced bike and my PI is only R6k pa.

Edited by shaper
Posted

a question to the 2 bike repairers, 

In the case of the bike this topic refers to, would it not be feasible to get a replacement part (sorry I've gone blank on the term [head tube ??], the part where the steerer fits into) and bond that in rather than trying to fix the break ?

Posted

Will chirp in here with regard to Professional Indemnity and do not accept your argument, with regard to cost. I am in the construction industry, a consultant and HAVE to have PI. For a cover of R5m it costs me just over R6000 pa. The cost is also relative to the size of projects that I do. Not a large cost in the scheme of things and if a building collapses with people in it am more at risk than someone coming off a bike.

 

Further you can also mitigate your risk profile. Each year when I renew my PI, I am required to complete a very detailed pages and pages questionnaire of what work I will and wont carry out. Should I be found to carry out work I previously said I would not do because I know it would increase my premiums I will get screwed by my insurer. Similarly if I outsource work my PI will be affected.

 

So this being your formal work line and not just a hobby to say you do not have PI and cannot afford it is BS. The type of work and the value of work that I need cover for runs into the hundreds of millions of Rands project cost, considerably more than repairing a tens of thousands priced bike and my PI is only R6k pa.

Wow, my quotations a year ago or so were in the order of R5k/month. I guess the insurers went safe on an industry they did not fully understand? Anyway, as much as you call BS, I am unable to afford it at present.

Posted

Will chirp in here with regard to Professional Indemnity and do not accept your argument, with regard to cost.  I am in the construction industry, a consultant and HAVE to have PI.  For a cover of R5m it costs me just over R6000 pa.  The cost is also relative to the size of projects that I do. Not a large cost in the scheme of things and if a building collapses with people in it am more at risk than someone coming off a bike.

 

Further you can also mitigate your risk profile.  Each year when I renew my PI, I am required to complete a very detailed pages and pages questionnaire of what work I will and wont carry out.  Should I be found to carry out work I previously said I would not do because I know it would increase my premiums I will get screwed by my insurer.  Similarly if I outsource work my PI will be affected.

 

So this being your formal work line and not just a hobby to say you do not have PI and cannot afford it is BS.  The type of work and the value of work that I need cover for runs into the hundreds of millions of Rands project cost, considerably more than repairing a tens of thousands priced bike and my PI is only R6k pa.

To call BS on someone without knowing that persons financial status is uncalled for so your statement is uncalled for. If you can afford R6000 a year good for you. Me on the other hand with a current bank balance of R7 , Yes you read it right R7, so when i say i cant afford it I cant damn well afford it. Just stop for one second and think that not everybody on here is actually in the same situation as what you are. Not everyone on here can afford the best of everything. FFS.

Posted (edited)

Never took any offence!

 

I did take a generalised swipe and I do apologise for that. Wasn't meant directly at you Ninja. After reading your post #99 and #100 I do get a sense that you know your shyte.

This is precisely where the problem comes in. An insurer sends your frame for repairs. How does the insured know the quality of the work?

 

Unless there is a wall with certificates of competence and industry accreditation, the insured will never know if the repairer is the best carbon repair guy in SA or if he is a self taught repairer using repair kits bought of eBay (yes these are available to anyone who wants to try their hand at repairing carbon).

 

In fact, how does even the insurance company know how good or bad a repairer is?

 

Then of course, it's human nature. Everyone would want a new frame rather than a repaired one.

 

10 years back, I was hit by a car. My Specialized Tarmac was only 6 months old. Only the frame and saddle was damaged. New bike back then was R18k, new frame plus parts swop was R14k. Sanatam replaced the entire bike with a new one. Times have changed.

Edited by Longbarn Killer

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