Close

Postby Thathertz » February 20th, 2008, 6:08 pm


Thathertz
step two
step two
 
Posts: 51
Joined: June 3rd, 2005, 6:01 pm
Location: BC
Isn't carbon fiber technology just over hyped paper mache with fancy materials?
check out this post on bicycle design blog and you'll see what I mean. http://bicycledesign.blogspot.com/2006/ ... -fork.html

Time RTM Technique

Postby mikep » February 23rd, 2008, 2:54 am


mikep
 
Posts: 2
Joined: February 6th, 2008, 1:48 pm
Location: Vancouver, Canada
I took a look at the Time marketing blurb. They actually say " Unidirectionnal braids offers excellent flex characteristics." I agree, but you might as well use black fibreglass or Kevlar which is far more flexible! Moreover a braid is always bi-directional.

As I mentioned in my initial message, woven materials are not desirable in stiffness-critical structures.

The resin/fibre ratio with RTM is lower than prepregs. This means they are heavier.

Parlee

Postby moderator » June 30th, 2008, 1:03 am


moderator
step three
step three
 
Posts: 183
Joined: January 17th, 2006, 2:56 pm
Location: golden
Most industry people consider Bob Parlee's frames the best carbon fiber bikes made in the US.

Outside the US, a tremendous number of frames are made to very high standards.

Basically, it comes down to how much marketing do you want to believe. I 100% guarantee, your local bike shop has been fed a large amount of aerospace "blah blah". It is your choice to believe it or not.

The bike industry is incredibly small, If you are an inseder, you will hear hundreds of stories. " did you hear the _____ bikes are made in the same factory as the _____" Yes it is true.
Good design does not have borders

Re: Time RTM Technique

Postby Supernaut » June 30th, 2008, 12:04 pm


Supernaut
step three
step three
 
Posts: 141
Joined: July 8th, 2005, 9:26 am
Location: Tipping Cows in Fields Elysian
mikep wrote:I took a look at the Time marketing blurb. They actually say " Unidirectionnal braids offers excellent flex characteristics." I agree, but you might as well use black fibreglass or Kevlar which is far more flexible! Moreover a braid is always bi-directional.

As I mentioned in my initial message, woven materials are not desirable in stiffness-critical structures.

The resin/fibre ratio with RTM is lower than prepregs. This means they are heavier.


being a materials engineer, aside from the marketing hooey. is Time's RTM lay up "better" than a normal cloth with a higher resin fiber ratio?

I have heard that it is and typically lasts longer before it goes dead...

I ask in all sincerity as someone who is looking for new frame but not interested in "lightweight and stiff" for racing but "compliant, strong and efficient" for longer distance riding and longer life of the frame.

My preference would be Titanium, custom by Tom Kellog, but I have an eye on a certain pre-owned ride...
Occam's Razor makes the cutting clean

Postby NURB » June 30th, 2008, 12:15 pm

User avatar

NURB
Moderator
Moderator
 
Posts: 4619
Joined: November 10th, 2005, 1:31 pm
Location: MPLS
I've ridden many of Trek's carbon frames, and the new Madone is pretty spectacular. Especially considering I ride a 62cm frame. I've heard their sales pitch countless times (working at a dealer) and I've heard many others from the likes of Scott, BMC, Titec, Look, and Colnago. None so far have matched the ride quality as Trek in my opinion. Believe me, the last thing I want to do is ride a Trek because everyone has one, but they ride way too nice to ignore.

Here's a small blurb on their process. Its much more in depth than this though.

http://www.trekbikes.com/us/en/company/technology/oclv/

techniques for laying fiber

Postby moderator » June 30th, 2008, 12:51 pm


moderator
step three
step three
 
Posts: 183
Joined: January 17th, 2006, 2:56 pm
Location: golden
Supernaut - Time makes a great frame - years ago the sales reps would bring 3" sections of each tube to show the internal geometry

I think the constructiopn techniques are starting to trump the materials.

It is easy to make a tube, but it is tough to make a joint.

I have sold hundreds of carbon bikes back in the day- I started to key in on proprietary techniques that would slip out of the technical guys at hte trade shows.

For example a carbon rimed wheel manufacturer was using a freezer to store his special carbon sheets - he claimed to have only 8 minutes to remove tha packaging around the frozen sheet and get it layed up in the mold. after eight minutes the material would degrade by percentages per minute

He aslo claimed to have the highest mold pressures for removing air between the sheets and stiffest bladder materials.

Again claims, but interesting non marketing blah blah from a guy who actually had worked the fiber with his own hands.
Good design does not have borders


abbaa1234
 
Posts: 1
Joined: March 23rd, 2016, 1:24 am
What you have to offer a lot more useful.
เกมสล็อตออนไลน์

Previous

Return to materials and processes