Crack carbon fiber bike frame
09-16-16, 10:28 AM
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Crack carbon fiber bike frame
Hi all,
I have a cracked carbon fiber seat stays. I was checking a few places online bike shops particular that actually repairs cracked carbon frame. I sent them pics and they confirmed with me that the crack on my bike frame is repairable and gave me a price estimate. It was pretty pricey.
After doing some research, I was able to find some carbon fiber repair bike kit online. I just need someone's opinion on what they think of the three I found. Which one is best? Do you think these are made differently or equal especially when they're different in price. are all resin and hardener made the same?
which one would u recommend? do you have any repair kit you recommended if not any of these?
do you think the one sold by predator cycling is the same exact one as the one sold by ebay for 27 buxs with the exception of them adding their company logo and providing extra tools to make them sell it at a higher price?
https://www.amazon.com/Carbon-Repair.../dp/B00UMATXWY
cost a lot but comes with every thing you need and to prepare you for repair your cracked frame....
Godzilla Carbonworks Carbon Fiber Repair Kit Car Body Trim Free SHIP | eBay
a bit more pricey.
Real Carbon Fiber Uni Repair Kit for Added Stiffness Uni and Epoxy Resin | eBay
cheapest but i'm wondering if this will do the job?
I have a cracked carbon fiber seat stays. I was checking a few places online bike shops particular that actually repairs cracked carbon frame. I sent them pics and they confirmed with me that the crack on my bike frame is repairable and gave me a price estimate. It was pretty pricey.
After doing some research, I was able to find some carbon fiber repair bike kit online. I just need someone's opinion on what they think of the three I found. Which one is best? Do you think these are made differently or equal especially when they're different in price. are all resin and hardener made the same?
which one would u recommend? do you have any repair kit you recommended if not any of these?do you think the one sold by predator cycling is the same exact one as the one sold by ebay for 27 buxs with the exception of them adding their company logo and providing extra tools to make them sell it at a higher price?
https://www.amazon.com/Carbon-Repair.../dp/B00UMATXWY
cost a lot but comes with every thing you need and to prepare you for repair your cracked frame....
Godzilla Carbonworks Carbon Fiber Repair Kit Car Body Trim Free SHIP | eBay
a bit more pricey.
Real Carbon Fiber Uni Repair Kit for Added Stiffness Uni and Epoxy Resin | eBay
cheapest but i'm wondering if this will do the job?
Last edited by BrooklynQueens; 09-17-16 at 01:20 PM.
09-16-16, 11:04 AM
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Without researching the actual kit's materials and bonding specs I can't say much about their comparisons. I can say that there are many different "epoxy" blends as well as the carbon tows/ribbons/cloths and how they are/aren't initially prepared with said bonding agents.
I can give a few insights further though. The first is that a repair done by an experienced hand will usually look far better then a first time job. Like many jobs the preparation is equally important as the application of the repair materials. Knowing the curing specs is also important as dry to the touch doesn't speak to the chemical reactions that are happening in the bonding compounds. Adding heat can be both helpful and hazardous to the job. Some form of compaction is usually needed. These types of repairs tend to be like roof repairs. The crack might only be, say, 1" in length but by the time all is said and done you have a 6"+ area that's been effected.
If you want both a strong and well done repair as well as a good looking one I would strongly consider the pro path. Of course if one has experience in composite fiber work and frame finishing (as in paint and such) then go for it. (Although with that kind of experience I doubt you'd be asking here). Andy.
I can give a few insights further though. The first is that a repair done by an experienced hand will usually look far better then a first time job. Like many jobs the preparation is equally important as the application of the repair materials. Knowing the curing specs is also important as dry to the touch doesn't speak to the chemical reactions that are happening in the bonding compounds. Adding heat can be both helpful and hazardous to the job. Some form of compaction is usually needed. These types of repairs tend to be like roof repairs. The crack might only be, say, 1" in length but by the time all is said and done you have a 6"+ area that's been effected.
If you want both a strong and well done repair as well as a good looking one I would strongly consider the pro path. Of course if one has experience in composite fiber work and frame finishing (as in paint and such) then go for it. (Although with that kind of experience I doubt you'd be asking here). Andy.
09-16-16, 11:26 AM
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I guess my first question is was the frame damaged from an impact or from use/fatigue? It the crack structural or mainly cosmetic? Do you care if it looks good after the repair? Notice the kits are for small cracks and blemishes.
If it is structural, you may find that you have to way overbuild the repair and while it should hold if done right, it will look like it has been repaired. If cosmetic and the bike is not an easy color or just weave, it will still look repaired and potential sale down the road would be very difficult.
I guess if you are going to keep it and ride it, and you trust that it will be repaired safely by you, any kit will do. If not, I would spend the time and any money to just replace the frame. If it's something special, I would hang it on the wall. I am also in agreement that you would somehow need to compact the repair to infuse the epoxy throughout. Otherwise, the repair will be full of air and gaps and not really strong.
If it is structural, you may find that you have to way overbuild the repair and while it should hold if done right, it will look like it has been repaired. If cosmetic and the bike is not an easy color or just weave, it will still look repaired and potential sale down the road would be very difficult.
I guess if you are going to keep it and ride it, and you trust that it will be repaired safely by you, any kit will do. If not, I would spend the time and any money to just replace the frame. If it's something special, I would hang it on the wall. I am also in agreement that you would somehow need to compact the repair to infuse the epoxy throughout. Otherwise, the repair will be full of air and gaps and not really strong.
Last edited by Number400; 09-16-16 at 11:35 AM.
09-17-16, 12:48 AM
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here's the pic of the crack...i dont want to buy a new frame if i replace frame i might as well get a new bike or a new bike. cause i wont know if the frame i'm getting will fit the component i have on this bike if i decide to swap..i don't care if the repair dont look as good n ugly but as long as i can ride this bike again i'll be happy..i found a few vid on youtube where people have repair their crack frame but i dont know what repair kit they use so i just found a few and hoping someone might have done it and recommend one or help out on picking out of the three i have chose but can't decide.... this bike is about a 2 k total cost with tax so i need to know which kit i should get....
sorry here's the link it was showing up as blank square where when u right-click and hit copy link. but now it isn't here i have reposted the link.
https://www.dropbox.com/s/ll4oe51v04...45217.jpg?dl=0
https://www.dropbox.com/s/3yfu26a30b...45254.jpg?dl=0
https://www.dropbox.com/s/7tinupnu3x...45446.jpg?dl=0
https://www.dropbox.com/s/6vyjm91l57...45538.jpg?dl=0
sorry here's the link it was showing up as blank square where when u right-click and hit copy link. but now it isn't here i have reposted the link.
https://www.dropbox.com/s/ll4oe51v04...45217.jpg?dl=0
https://www.dropbox.com/s/3yfu26a30b...45254.jpg?dl=0
https://www.dropbox.com/s/7tinupnu3x...45446.jpg?dl=0
https://www.dropbox.com/s/6vyjm91l57...45538.jpg?dl=0
Last edited by BrooklynQueens; 09-17-16 at 01:19 PM.
09-17-16, 08:00 AM
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No pics for me either.
I upload to Photobucket, then post links.
I upload to Photobucket, then post links.
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09-17-16, 10:37 AM
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Third (cheapest) kit looks to be most appropriate in terms of narrow CF tape supplied which is more adaptable to tubing repair than a large swathe of CF that you have to cut. FWIW the cut CF fibers are considered 'hazardous',
as are the epoxy resins supplied. Youtube can help a great deal in the mechanics of doing the repairs. The more
expensive kits give increasingly complex directions about prep and technique and $0.50 worth of mixing cups and
brushes etc. If I were considering doing this I might invest in a roll of fibreglass tape and small amount of suitable
epoxy and practice on a junk frame, which could be steel, AL or whatever, just to see how the mechanics of wrapping
smoothing and dealing with the epoxy are before jumping in with the CF kit. Here is one: https://www.amazon.com/3M-Fiberglass.../dp/B000BO9NOO
just cut the fibreglass to an inch or so wide tape and practice away til you feel comfy then do the CF. Dealing with ripples and folds in the CF and getting good impregnation
with the epoxy is the biggest problem along with smoothing everything out before it hardens up.
Prep is the most important: removing the overcoat on the existing CF and cleaning it and proper use of the epoxy.
as are the epoxy resins supplied. Youtube can help a great deal in the mechanics of doing the repairs. The more
expensive kits give increasingly complex directions about prep and technique and $0.50 worth of mixing cups and
brushes etc. If I were considering doing this I might invest in a roll of fibreglass tape and small amount of suitable
epoxy and practice on a junk frame, which could be steel, AL or whatever, just to see how the mechanics of wrapping
smoothing and dealing with the epoxy are before jumping in with the CF kit. Here is one: https://www.amazon.com/3M-Fiberglass.../dp/B000BO9NOO
just cut the fibreglass to an inch or so wide tape and practice away til you feel comfy then do the CF. Dealing with ripples and folds in the CF and getting good impregnation
with the epoxy is the biggest problem along with smoothing everything out before it hardens up.
Prep is the most important: removing the overcoat on the existing CF and cleaning it and proper use of the epoxy.
Last edited by sch; 09-17-16 at 10:42 AM.
09-17-16, 01:26 PM
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yea i heard the mixing of the resin and hardener needs to be well mixed and the one u recommend that is for car repairs i could use it for the carbon bike frame? its actually my seat stay that got cracked...
what is FWIW? the third link for kit on ebay u said it was hazardous when i cut the carbon fiber cloth is okay when i'll be wearing gloves??
what is FWIW? the third link for kit on ebay u said it was hazardous when i cut the carbon fiber cloth is okay when i'll be wearing gloves??
09-17-16, 01:29 PM
#11
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Made anything in Fiber glass or CF before ?.. cloth is different You could Use Epoxy Resin with glass cloth.
works in Boat repairs .. wet layup is resin saturated cloth and the catalyst in both Polyester and epoxy resins causes a chemical reaction that is irreversible.
see Vacuum Bagging Vacuum Bagging Basics
the vacuum causes the outside air pressure to push down and that gets the bubbles out of the resin.
Adding more to the outside is all you may be able to do, patch wont blend in invisible.
./.
works in Boat repairs .. wet layup is resin saturated cloth and the catalyst in both Polyester and epoxy resins causes a chemical reaction that is irreversible.
see Vacuum Bagging Vacuum Bagging Basics
the vacuum causes the outside air pressure to push down and that gets the bubbles out of the resin.
Adding more to the outside is all you may be able to do, patch wont blend in invisible.
./.
09-17-16, 01:35 PM
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Hope this helps: https://en.wikipedia.org/wiki/Kludge
09-17-16, 02:11 PM
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not sure if its really a CF cloth the one they sell in ebay link 3... but watching some youtube video of someone who brought some kit from youtube it looks like the same one they used in link 3...so i should be looking for a glass cloth which will be stronger after applying resin and hardner onto the cloth and letting it dry for the cf bike frame...??
09-17-16, 02:37 PM
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I agree the cheapo kit you list is unidirectional CF, no weave. Most likely it would be adequate but better is available and cheaper. Googling around I found this: ACP Composites- Epoxy Resins
Carbon Woven Tape, Carbon Fiber Braided Sleeves - Composite Materials
This stuff would be better as it has a selvage edge and 1" tape 1 yd long would be more than enough. Fibreglass was suggested
only as a practice material, but the ACP stuff is cheap enough and your application on chain stay has simple geometry
so that you could likely do it with only a little practice.
ACP has a 'how to" make your own pre-impregnated CF here: ACP Composites - Large Stock of Ready to Use Composite Plate, Tube, Sheet, Fabrics and Core Materials.
Did not look at order site for limitations on minimums or who they sell to but there is a start.
"hazard' of CF is mostly inhalational, as is the epoxy but the epoxy can be an ingestion hazard. No big deal, especially with the selveged tape. You can google handling procedures.
Carbon Woven Tape, Carbon Fiber Braided Sleeves - Composite Materials
This stuff would be better as it has a selvage edge and 1" tape 1 yd long would be more than enough. Fibreglass was suggested
only as a practice material, but the ACP stuff is cheap enough and your application on chain stay has simple geometry
so that you could likely do it with only a little practice.
ACP has a 'how to" make your own pre-impregnated CF here: ACP Composites - Large Stock of Ready to Use Composite Plate, Tube, Sheet, Fabrics and Core Materials.
Did not look at order site for limitations on minimums or who they sell to but there is a start.
"hazard' of CF is mostly inhalational, as is the epoxy but the epoxy can be an ingestion hazard. No big deal, especially with the selveged tape. You can google handling procedures.
Last edited by sch; 09-17-16 at 02:40 PM.
09-17-16, 03:45 PM
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That is a serious structural damage best left to a pro and I suspect he will tell you the frame is junk or no promise that it will hold... Way beyond cosmetic damage as the whole tube is compromised. Roger
09-17-16, 05:23 PM
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My buddy cracked a seat stay, & Ruckus Composites in Portland repaired it
for $300, not including shipping. I happened to be there to pick it up, & talked to them
& saw their operation. The repair was hard to spot, & they said that while not necessarily cost effective,
they could repair any damage to a bike frame. There were about a dozen high end frames hanging,
ready to be shipped back.
09-17-16, 05:36 PM
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the frame is a nice one they was the site i asked but they gave me an estimate of 325 and recommended if i didnt want to let them repair to buy a new frame or a new bike but i dont want to do either those two other options...sorry for the title it is actually my seat stay that is carbon that got cracked they recommend i can also try repair it myself by following the video on their site...but i would have to wrap a carbon cloth around the damage area with 3 full wraps and then use the resin and hardener....which they said is hard and will do the job....i'm guessing now i should go for the ebay kit or the other few kits u guys recommend? now which carbon cloth do u guys recommend? fiber cloth? can yall post a link?? i found a few on ebay also..
09-18-16, 05:13 AM
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If you do decide to repair it yourself, which I think is a great idea, please document it. Then post it here as a step by step. I think it would be highly educational for others to see. Good luck with your repair.
09-18-16, 08:23 PM
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so do u think the repair kit on ebay 3rd link would be good enough?? its hazardous but i'll do everything i could to make sure i'll be safe...
09-18-16, 11:43 PM
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some more opinion or suggestions please i plan to make a decision by end of this week..on which repair kit u guys recommend or choose out of the three link i posted...
09-19-16, 01:11 PM
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the frame is a nice one they was the site i asked but they gave me an estimate of 325 and recommended if i didnt want to let them repair to buy a new frame or a new bike but i dont want to do either those two other options...sorry for the title it is actually my seat stay that is carbon that got cracked they recommend i can also try repair it myself by following the video on their site...but i would have to wrap a carbon cloth around the damage area with 3 full wraps and then use the resin and hardener....which they said is hard and will do the job....i'm guessing now i should go for the ebay kit or the other few kits u guys recommend? now which carbon cloth do u guys recommend? fiber cloth? can yall post a link?? i found a few on ebay also..
Options are get fixed professionally, scrap it, or self fix and hope that it doesn't fail when your are riding, which could cost a lot more than a pro fix or a new frame.
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Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
09-19-16, 03:26 PM
#23
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To be bluntly honest, there's no good home method of doing this. Dealing with carbon fiber requires a moderate amount of specialized equipment.
The easiest methods for using carbon fiber utilize "prepreg" material which carbon fiber cloth+resin. The problem is that you need a oven to cure to cure it (~250F), and you have bike frame, which is significantly larger than most ovens.
Since I'm assuming you don't have an oven large enough for a bike frame, the next option is the mix it yourself option. That requires a vacuum bagging solution to minimize voids, and is tricky at best.
If you want to do a home fix there's basically one good approach.
1) Cut out the damaged portion (~2cm).
2) Insert a carbon fiber tube, making sure it's a very snug fit on both ends. Epoxy in place. You'll need a jig to maintain frame alignment while this is performed.
3) Over wrap with carbon fiber and resin, vaccuum bag and wait for it to cure.
4) Hope it works, and doesn't crack/creak at the joint.
The easiest methods for using carbon fiber utilize "prepreg" material which carbon fiber cloth+resin. The problem is that you need a oven to cure to cure it (~250F), and you have bike frame, which is significantly larger than most ovens.
Since I'm assuming you don't have an oven large enough for a bike frame, the next option is the mix it yourself option. That requires a vacuum bagging solution to minimize voids, and is tricky at best.
If you want to do a home fix there's basically one good approach.
1) Cut out the damaged portion (~2cm).
2) Insert a carbon fiber tube, making sure it's a very snug fit on both ends. Epoxy in place. You'll need a jig to maintain frame alignment while this is performed.
3) Over wrap with carbon fiber and resin, vaccuum bag and wait for it to cure.
4) Hope it works, and doesn't crack/creak at the joint.
09-19-16, 06:09 PM
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Is this a case of "don't ride a bike you cannot afford to replace?"
carbon fiber was never the most durable material and unless you are a racer that gets access to free replacement bikes i am not sure it is worth it to replace the frame or fork every time the carbon gets scratched.
carbon fiber was never the most durable material and unless you are a racer that gets access to free replacement bikes i am not sure it is worth it to replace the frame or fork every time the carbon gets scratched.
09-19-16, 08:58 PM
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the pro didnt say my frame was a junk frame they actually said its a good frame...i just need suggestion on picking out which repair kit to buy as i made my decision to repair it on my own if it fails after i repair it or i get hurt its my fault...just not to confused u guys its my seat stay that is carbon that is damaged and not the top part of my carbon bike frame...i'm a light rider and was told i need some carbon fiber wrap/cloth wrap it around two-three times then apply the resin and hardener well mixed throughly and then let it dry...thanks for the sugguestions. keep them more coming. i need suggestion for the carbon fiber cloth to purchase??