I hate carbon

[Streddaz]

"Repair kits"
oh how easy, we've got repair kits.

But lets face it, those are little better that wrapping some tape around and over the area and allowing it , or the epoxy to harden.

Frames are built and use vacuum moulds to form and apply a great deal of pressure to force out any trapped air bubbles. So jsut wrapping a bit of tape around not dissimilar to an elastoplast isnt really,truly doing much. Its strengthening the area to some degree, but if you were to do it properly, you would need to form a vacuum around the 'patch' and lets face it the vast majority don't have access to one of those(Though I do, but im not the lending type )

Carbon frame repair really depends what's getting repaired. Will it be as strong as it originally was? Maybe, but is it still serviceable? That's a case by case call but it certainly can be done, and has been done for years.
With a 6061 aluminium frame, you technically can weld it, but due to the heat treatment process required to bring the heat affected area back up to T6 specifications it will be a lot weaker than before and likely to fail again.
If you want something easy to repair steel and titanium is the way to go, but you have the drawbacks of weight, cost (in the case of titanium) the lack of the ability to easily form the tubes (do you want to house the battery in an attractive looking downtube) are examples that come into play.
The gain from carbon fibre is the ability to make the frame stronger in the area that it needs to be in any area of the frame. A good FEA analysis (which all manufacturers would be using these days) will find where this is needed. It's not as easy with an alloy frame as you are limited to the cross sectional area of the tubing. Hydroforming can aid this but it's always a compromise.

 

[Binhill1]

"Repair kits"
oh how easy, we've got repair kits.

But lets face it, those are little better that wrapping some tape around and over the area and allowing it , or the epoxy to harden.

Frames are built and use vacuum moulds to form and apply a great deal of pressure to force out any trapped air bubbles. So jsut wrapping a bit of tape around not dissimilar to an elastoplast isnt really,truly doing much. Its strengthening the area to some degree, but if you were to do it properly, you would need to form a vacuum around the 'patch' and lets face it the vast majority dont have access to one of those(Though I do, but im not the lending type )

Someone near me makes stuff out of carbon. He quoted me 140 to repair a split one part of a split carbon paddle. Got another guy said he would fettle about with it and it cost a tenner he reckons the bit repaired is the strongest bit of the paddle now. I know nothing about carbon i can't even remember why I bought a carbon Levo probably not that much lighter ?

 

[Mikerb]

"Repair kits"
oh how easy, we've got repair kits.

But lets face it, those are little better that wrapping some tape around and over the area and allowing it , or the epoxy to harden.

Frames are built and use vacuum moulds to form and apply a great deal of pressure to force out any trapped air bubbles. So jsut wrapping a bit of tape around not dissimilar to an elastoplast isnt really,truly doing much. Its strengthening the area to some degree, but if you were to do it properly, you would need to form a vacuum around the 'patch' and lets face it the vast majority dont have access to one of those(Though I do, but im not the lending type )

vaccum packing?!! Thats a wet layup process to remove as much resin as possible.....................I would hope the majority of bike carbon composite frames are fabricated using pre preg and heated in an autoclave.

 

[2WheelsNot4]

I would hope the majority of bike carbon composite frames are fabricated using pre preg and heated in an autoclave.

Yes, but this isnt about initial manufacture, more to do with wrapping the broken bit and hoping it bonds to the area. You must have pressure for that to happen.

 

[Plummet]

"Repair kits"
oh how easy, we've got repair kits.

But lets face it, those are little better that wrapping some tape around and over the area and allowing it , or the epoxy to harden.

Frames are built and use vacuum moulds to form and apply a great deal of pressure to force out any trapped air bubbles. So jsut wrapping a bit of tape around not dissimilar to an elastoplast isnt really,truly doing much. Its strengthening the area to some degree, but if you were to do it properly, you would need to form a vacuum around the 'patch' and lets face it the vast majority dont have access to one of those(Though I do, but im not the lending type )

You don't need to vacuum bag or use prepreg to do carbion repairs. A traditional wet layup with compression wrap works fine. With the correct layup you can make the area stronger than original. Ok you add a bit more weight, But not much!

Check out my carbon repair of my slayer done in 2019 here.

https://www.mtbr.com/threads/carbon-frame-repair.1101743/#post-14059353

4 years later. Still sending this bike over sizable stuff. Here's a 12 ft step down. I have not treated this bike lightly since the repair. Quite the opposite. This is now my send it saturday bike. I full trust that the repair is stronger than original. I'm hitting features that would send me to hospital if it failed......

Check my boy sending the whole line of the nuts trail here.

 

[Ark]

Carbon-ara not Sayōnara
I'm not sure I'd trust a repair without xray or whatever it is the pros use to check a frame over.

 

[Plummet]

Carbon-ara not Sayōnara
I'm not sure I'd trust a repair without xray or whatever it is the pros use to check a frame over.

Just smash more carbon on... boom. Easy peasy to make it way more stronger than original. You dont need to xray to know that.

With that said. Not any old schmo can repair carbon frames. I can.... so its not a problem for me.

 

[maynard]

I told my girlfriend I had to get the expensive carbon 1 cos the cheaper alu ones will rust .

 

[steve_sordy]

linky link?

It is right there in post#3, but in case the gremlins have struck your access, here it is again.

Santa Cruz Bicycles - Test Lab - Pinkbike

Pinkbike documents what has until now been securely under wraps; the Santa Cruz destructive testing facility. A place where they coolly go about destroying the aluminum and carbon frames they love to create.

www.pinkbike.com

 

[Binhill1]

Most folk that dont like carbon for whatever reason dont like carbon full stop and probably never will . I never ate Salmon till a year ago love it now.

 

[RiderOnTheStorm]

I'm using both carbon frame and alu frame on different ebikes l, and I love them both for different reasons But the only carbon parts I would not use on my heavy e-bikes are carbon rims... May be I need to eat more salmon!!

 

[Binhill1]

Broke two alloy frames doing nothing serious . Feart to say I never broke carbon one . Broke a carbon paddle though.

 

[Shjay]

Have to carbon framed bikes. Never broken a frame but have snapped couple of carbon windsurf boards

 

[Plummet]

I think its fair to say that these days a carbon bike is stronger and is unlikely to break unless there is a design or manufacturing fault or you do something very silly that would also have destroyed your alloy frame.

Back in the early days they went too light weight with carbon layup to save too much weight. Now the bikes are optimised to their application and though they make the frames a little bit lighter than an alloy equivilent, they stronger.