Interesting read on carbon fiber control arm manufacturing.

[registered user]

I also have to think that the stresses put on bars on a mountain bike vs a 300 pound quad are way different.

I would think so for sure. was it the same guy that used mnt bike brakes on a quad ? hahaha

 

I think cf parts can work well on qauds and cars but it has to be well thought out , not slapping on hodge podge schwinn mnt bike bars. a professional attempt at making successful cf parts would require placing some stress sensors on the original steel parts and examine the data. then you would have a idea what cf material and design would be needed.

[rubberneck]

I have zero info except for what i read on facebook.  The debate over which materials/how light things should be could go on forever.  I just have to think at some point you have to say, man is my life worth saving a pound of weight on a bike?  Thats my .02 which after inflation is really worth nothing.

[registered user]

i think the problem is people don't put much thought into what theyre doing and cut corners. cf can be very strong but you cant just glue a few sticks of it together in the garage and expect it to be of sound design. im sure those mustang wheels took a shit load of computer and real world testing before they were put on that car and sold to the public. not to mention the special coating that was needed to deal with brake heat and salt water. the reason i think you don't see much cf stuff for atvs , motorcycles etc, is only because cost is far to high for the majority of us. no way im paying a few hundred buck for damn handlebars. its not so much the cost of material but to make any cf parts for a structural application would require professional engineers and that wont be cheap. this is pretty good info on cf testing http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1038&context=mesp

[trickedcarbine]

http://www.materialstoday.com/composite-applications/features/motorcycle-swingarm-redesigned-in-carbon-composite/

[ClaudeMachining]

i think the problem is people don't put much thought into what theyre doing and cut corners. cf can be very strong but you cant just glue a few sticks of it together in the garage and expect it to be of sound design. im sure those mustang wheels took a shit load of computer and real world testing before they were put on that car and sold to the public. not to mention the special coating that was needed to deal with brake heat and salt water. the reason i think you don't see much cf stuff for atvs , motorcycles etc, is only because cost is far to high for the majority of us. no way im paying a few hundred buck for damn handlebars. its not so much the cost of material but to make any cf parts for a structural application would require professional engineers and that wont be cheap. this is pretty good info on cf testing http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1038&context=mesp

I have no problem doing r&d, 3d model, fea/cfd. That's my day to day job.

 

But I have about zero knowledge about 'making' carbon fiber parts.

 

I can put a couple of layers together, I even had a small vacuum baging unit for my rc airplanes wings.

 

But I cant go further than that.

 

The good new is that Tricked found a good suplier for carbon block, but they are $$$ to play with.

 

Envoyé de mon GT-P5113 en utilisant Tapatalk

[sheerider11]

i think the problem is people don't put much thought into what theyre doing and cut corners. cf can be very strong but you cant just glue a few sticks of it together in the garage and expect it to be of sound design. im sure those mustang wheels took a shit load of computer and real world testing before they were put on that car and sold to the public. not to mention the special coating that was needed to deal with brake heat and salt water. the reason i think you don't see much cf stuff for atvs , motorcycles etc, is only because cost is far to high for the majority of us. no way im paying a few hundred buck for damn handlebars. its not so much the cost of material but to make any cf parts for a structural application would require professional engineers and that wont be cheap. this is pretty good info on cf testing http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1038&context=mesp

I paid a few hundred for handle bars.

My flexx bars aren't cheap.

I have carbon fiber rims on my quad.

[trickedcarbine]

The rims IMO are kind of a backward step. They are sweet in concept and look great, but weigh a ton. The only reason I wanna do any carbon fiber is weight. If something needs enough material to be structural, that it out weighs a metal part it's not worth the effort. I am thinking of making a few pieces from the carbon billit to see what the weight difference is between carbon and aluminum for CNC stuff. I also have my eye on that Dremel 3D printer for $999.00. I'm thinking parts like front master covers can be made from light plastic.

[JTmachining]

The rims IMO are kind of a backward step. They are sweet in concept and look great, but weigh a ton. The only reason I wanna do any carbon fiber is weight. If something needs enough material to be structural, that it out weighs a metal part it's not worth the effort. I am thinking of making a few pieces from the carbon billit to see what the weight difference is between carbon and aluminum for CNC stuff. I also have my eye on that Dremel 3D printer for $999.00. I'm thinking parts like front master covers can be made from light plastic.

Start a build thread. Don't be like RU

[trickedcarbine]

Start a build thread. Don't be like RU

It's just a room full of boxes. I need to get my priorities in order, lol.

[trickedcarbine]

I'd never run cf arms.

 

 

What if you hit a tree or have a roll over and the carbon fiber splinters or gets a hairline crack that you can't see?

Then you are riding around on a death trap.

We're not talking about trail bikes.

[ClaudeMachining]

I'd never run cf arms.

 

 

What if you hit a tree or have a roll over and the carbon fiber splinters or gets a hairline crack that you can't see?

Then you are riding around on a death trap.

It's even easier to see if cf is damaged than aluminium, it crack and/or delaminate... Pretty easy to see.

[rubberneck]

What concerns me on CF suspension parts is how they are most likely to fail if they do as compared to a metal component.  If any of you are fisherman you have most likely overloaded and broken a rod.  Most every modern rod is a carbon fiber or carbon blend. Everybody refers to them as graphite rods but i assure you its nothing more than a long cone shaped carbon fiber part.  When they break they explode, its not uncommon to end up with 3 or 4 pieces because once they let go all hell breaks loose. I built rods for about 8 years and always test loaded the blanks  to make sure there were no flaws before going through the work of building them out. I can promise you when they go, you know it.  With a chromoly or mild steel part i think its more likely to bend or twist on a hard impact than break into pieces.  Look at how the carbon fiber axles they were pushing a few years ago to the drag guys were breaking.  Im sure it has happened but im thinking you are far more likely to bend a JJA than to shear it clean off.  Same with the handlebars in the post mentioned above.  the dang things just broke clean off.  I bet if they were aluminum they may have collapsed and at least he would have had something to hang on to.  May have still crashed, who knows.

[ClaudeMachining]

What concerns me on CF suspension parts is how they are most likely to fail if they do as compared to a metal component. If any of you are fisherman you have most likely overloaded and broken a rod. Most every modern rod is a carbon fiber or carbon blend. Everybody refers to them as graphite rods but i assure you its nothing more than a long cone shaped carbon fiber part. When they break they explode, its not uncommon to end up with 3 or 4 pieces because once they let go all hell breaks loose. I built rods for about 8 years and always test loaded the blanks to make sure there were no flaws before going through the work of building them out. I can promise you when they go, you know it. With a chromoly or mild steel part i think its more likely to bend or twist on a hard impact than break into pieces. Look at how the carbon fiber axles they were pushing a few years ago to the drag guys were breaking. Im sure it has happened but im thinking you are far more likely to bend a JJA than to shear it clean off. Same with the handlebars in the post mentioned above. the dang things just broke clean off. I bet if they were aluminum they may have collapsed and at least he would have had something to hang on to. May have still crashed, who knows.

You are right. At the same time, in many tops racing machine, there is a lot of carbon fiber or titanium parts. There is a lot of brains and r&d on those machines.

 

The banshee world cant afford that and the old school mentality is not helping either.

 

I know some people will not like that, but they need lots of engineering to go next step imho, not just 'experience'

[JTmachining]

F1 peeps are the only ones I'd let make me a CF a arm

I don't see a good reason to use CF on a Banshee with suspension posted

I haven't seen a CF wheel lighter than a DWT used on a Banshee

CF wheels break. Aluminum bends. I know top MX/etc racers use DWT more than any other wheel option and for good reasons

Because I can't afford the F1 level of CF parts it would take for me to use CF on a suspended bike. Have you even weighed same components made from diff material to see the weight diff? I know when comparing CF to aluminum or titanium the weight diff on most components aren't much

I was going to post a pic of that but nah. Anything can break. Component to application choice and quality are super important

Hmm

[ClaudeMachining]

Issue is using inferior parts, material, and/or manufacturing processes. Those CF axles were not great. Look at driveshaft. CF driveshaft shown to be 3x stronger before failing (4728n-m verus 1346n-m), offer greater rigidity (4.5* at 1.3Kn-m verus 23* at 1.3Kn-m) and is lighter.

Carbon fiber based parts are used in higher stress applications than a drag banshee would ever see.

 

Sure, remeber when i was talking about stifness to weight ratio?? That was exactly what i was talking about. Carbon fiber have a way higher ratio than Ti or Aluminium.

 

But i have zero knowledge about making carbon fiber parts.