Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 12-05-09, 03:27 AM   #1
stryper
I just wanna ride
Thread Starter
 
stryper's Avatar
 
Join Date: Oct 2008
Location: Chico Califo
Bikes: 2013 BMC Impec
Posts: 1,153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
carbon fiber build

I am going to attempt to build my own carbon fiber bike frame once I get some money together, which will likely be after the new year, but I need as much information as I can get to ensure I will do it right. I have read these guides thus far but am looking for more:

http://www.bmeres.com/carbonframe1.htm

http://www.sheldonbrown.com/rinard/carbon_fiber.htm

http://rqriley.hostcentric.com/xr2.htm

Those sources and various othesr do not provide nearly enough information to completely grasp the "how to" aspect of this. I still don't understand:
•how to best bond the bb, st, and ht to the frame.
•how to wrap the carbon fiber. Do i cut a shape to precisely fit the tube based on what direction the layup is?
•can there be overlap of the carbon fiber in a single layer?

Those things along with other I am sure I have not thought of, all need to be understood before I even proceed to buy any product. Any help, link to websites, or just talk from experience would be much appreciated.
stryper is offline   Reply With Quote
Old 12-05-09, 08:20 AM   #2
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I am also planning on building a carbon frame in the near future. Are you gonna make your own tubes? I had a customer who has made a couple of frames and he has been giving me lots of tips. First off, apparently there is a good book(maybe several) from Aircraft Spruce that will help a lot. He said when he made his tubes that he did not overlap them, one end wrapped right up to the next, then on the next layer he just rotated it a quarter turn to cover the seam and so forth depending on the layers. There are a couple of guys on Utube building a carbon frame using the vacuum bag method that is pretty interesting as well as people making other carbon products. Are you gonna build a complete frame out of carbon fiber, with the exception of the BB shell? Carl from Edge Composites has given me a lot of info, they sell all the tubes, wishbone chain/seatstays, etc., most everyone I have talked to has been really helpful and whatever problems you have someone has already encountered it and can tell you how to fix it. Good luck with it.
meech151 is offline   Reply With Quote
Old 12-05-09, 08:56 PM   #3
stryper
I just wanna ride
Thread Starter
 
stryper's Avatar
 
Join Date: Oct 2008
Location: Chico Califo
Bikes: 2013 BMC Impec
Posts: 1,153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I don't plan on making tubes for it, but instead having it more or less a 1 piece frame. Creating a foam core and wrapping the fiber over that. There will be nothing pre-made on the bike except bb, ht, st, and maybe dropouts. But I am thinking about having those custom cut locally. There is a pretty nice water jet company here.
stryper is offline   Reply With Quote
Old 12-16-09, 03:08 AM   #4
stryper
I just wanna ride
Thread Starter
 
stryper's Avatar
 
Join Date: Oct 2008
Location: Chico Califo
Bikes: 2013 BMC Impec
Posts: 1,153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
bump for more help
stryper is offline   Reply With Quote
Old 12-16-09, 08:56 AM   #5
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Here are a few resources:

Quote:
Originally Posted by AllenG View Post

This link has a fairly decent primmer on vacuum bagging.

For materials look through this link.
Order this pamphlet, it's well worth the five bucks.
When you are ready to start working with composites order this practice kit and a roll of carbon cloth or TOW line.
You will also need some couplers, hoses, vacuum generator, and stuff from this page

YouTube- West SystemŽ Vacuum Bag Demonstration
West Systems has some good videos on composite basics.
Quote:
Originally Posted by AllenG View Post
http://link.brightcove.com/services/...id=29739780001

^^^
Two good primers on composite lay-ups.

http://www.cycle-frames.com/bicycle-...ng/COMPONENTS/
^^^
Nova has Columbus premade rear ends


If you don't want to make a monocoque frame Aircraft Spruce sells carbon tubing.
Aircraft Spruce also sells the epoxies and resins you'll need.

I would recommend 3M Scotch Weld for attaching the bottom bracket shell and head tube.

If you are willing to use a BB30 bottom bracket look at Paragon Machine Works' aluminum shell. It's pre scored to give the epoxy a physical surface to adhere. Also score the outside of your headtube for the epoxy.


Yes you may have some overlap with your carbon.
Use a piece of paper and wrap it around your frame and trim it to fit. Use that as a template to cut your carbon. Cut the carbon after you make the saran wrap pre-preg sandwich (the ends of the carbon cloth will fray badly and be a PITA--you'll see what I'm talking about).


And most importantly, make some smaller test pieces first to learn your material.

Good luck.
Allen is offline   Reply With Quote
Old 12-16-09, 10:11 PM   #6
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Nessism View Post
Read on the Framebuilders List where some pros use JB Weld to attach carbon rear triangles to the main frame. I'd give it a go after you check for corrosion and possible cracks in the carbon.
Nessism posted this in another thread. Good to know and Framebuilders List is another good resource for info.
Allen is offline   Reply With Quote
Old 12-17-09, 01:36 AM   #7
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Bikes:
Posts: 14,529
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
AllenG, can't a super moderator fix a title?
unterhausen is offline   Reply With Quote
Old 12-17-09, 06:09 AM   #8
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
An observent one could.

Got it now though.
Allen is offline   Reply With Quote
Old 12-17-09, 08:19 AM   #9
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Is JB Weld good enough for permanent use? I have always heard about it but never used it for fear of it just being a temporary thing. Once, I cut a fork crown down to too small a diameter and a bicycle mechanic said to build it up with JB Weld and when I got to the automotive store the owner talked me out of it. He basically said, "...you can use JB Weld but its not the right way to do it." In the end I just brazed a little silver on it.
meech151 is offline   Reply With Quote
Old 12-17-09, 08:26 AM   #10
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Epoxies such as the Scotch Weld can be a little runny. I can see how JB Weld being a putty could alleviate that issue, but I have no idea about it permanence.
Allen is offline   Reply With Quote
Old 12-17-09, 11:30 AM   #11
cs1
Senior Member
 
cs1's Avatar
 
Join Date: Feb 2004
Location: Clev Oh
Bikes: Specialized, Schwinn
Posts: 6,651
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Great links, what about using CF tubes glued into AL or some other meatal lugs? Seems easier and the results might be just as good.
cs1 is offline   Reply With Quote
Old 12-17-09, 01:50 PM   #12
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Trouble there is finding the lugs. No one make any the right size you need for carbon tubes that I know.

Last edited by Allen; 12-17-09 at 02:38 PM. Reason: grammar
Allen is offline   Reply With Quote
Old 12-17-09, 01:51 PM   #13
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Building up the lugs is not overly difficult.
Full disclosure--I've not used carbon tubes only bamboo.
Allen is offline   Reply With Quote
Old 12-17-09, 02:41 PM   #14
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Check with Carl from Edge Composites. I spoke with him about a month ago when I first got curious about a carbon fiber build, they have standard carbon tube sizes but he also acted like they would make tubes to fit your need, the price might be a little more but he didn't act like it would be too much more than their standard tubes.
meech151 is offline   Reply With Quote
Old 12-21-09, 05:19 PM   #15
stryper
I just wanna ride
Thread Starter
 
stryper's Avatar
 
Join Date: Oct 2008
Location: Chico Califo
Bikes: 2013 BMC Impec
Posts: 1,153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thanks for the additional info. Buying pre-peg tubes isn't the kind of things I'm into. I know it would work just fine and I still would have made the bike, but I like the idea of building it from scratch. It'll have more of that, you know, value beyond monetary cost, personal meaning, I seriously can't think of the word, tried a thesaurus and google but couldn't find it.

And i've used jb weld on skateboard parts before and it's okay, but I wouldn't use it on a bike frame. I found it was overall pretty fragile when it came to things that have a lot of pressure and banging on.

And i will definitely be doing some test runs on small things. Might make a front fender first just to get my hands wet in dealing with the materials. I don't want to mess up on a 3-4 hundred dollar frame lol. I don't have that kind of disposable cash.
stryper is offline   Reply With Quote
Old 12-21-09, 05:42 PM   #16
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
For doing something like fenders you may wish to check out something like this hand pump vacuum kit used in woodworking lamination.

Tip: build your mold so the finished side of your fender is next to the mold and not on the plastic bag side. All you will need to do is trim the flashing and you won't have to sand the bag marks off of of the top side of the fender.
Allen is offline   Reply With Quote
Old 12-21-09, 09:47 PM   #17
Allen
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 4,752
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
These are interesting:



Actually all of his videos are worth looking over.

They are building this:


Last edited by Allen; 12-21-09 at 09:51 PM.
Allen is offline   Reply With Quote
Old 01-03-10, 08:41 AM   #18
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quick question. In regards to reaming the head tube to accommodate the head set, I'm sure the tool will cut the carbon fiber since it will cut steel but I am wondering if it would damage the head tube in a manner that would compromise the strength or longevity of it. I know when cutting carbon tubes it is best to wrap them with a little masking tape to keep it from fraying but I was wondering what is the best way to go about this head tube thing. Can you use a standard headset or would you need to go to an integrated style?
meech151 is offline   Reply With Quote
Old 01-03-10, 09:34 AM   #19
hotbike
Senior Member
 
hotbike's Avatar
 
Join Date: Dec 2006
Location: Long Island, New York
Bikes: a lowrider BMX, a mountain bike, a faired recumbent, and a loaded touring bike
Posts: 2,851
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Okay, I'm glad I came across this thread. I have some experience with composites. I was an Aircraft Mechanic in the US Navy, aboard an Aircraft Carrier. I learned to overlap the Fiber about a half inch.

Also I built the Fiberglass Ladies Bicycle which my Daughter designed. I would like to say a few words about fiberglass: Fiberglass is worked by the same method as Carbon Fiber. There aren't many Fiberglass bicycles out there, just this one and the Bowden Spacelander. My theory is that the Fiberglass Bicycle should be perfected *before* any more Carbon Fiber bicycles are built. Keeping in mind the nature of Fiber Composites, a Composite material should have very large diameter tubes, and in fact should be cast in one piece, rather than connecting smaller tubes.

Let me dig up some pictures and video:

http://www.youtube.com/watch?v=GjyS_lXE6F0

http://www.youtube.com/watch?v=X0akAccfjv4

http://www.youtube.com/watch?v=eaVxN...eature=related

What I'm getting at is , a CF bicycle should NOT try to look like a chrome/Mo steel bike. Take advantage of the unique properties of the Composite material.
The Fiberglass Ladies Bicycle pictured is a semi-recumbent and has a fairing molded in- one piece with the frame. The oversize tube (4"x6"nominal), allows a ladies bike to be built with the same strength as a mens bike ( I like the unencumbered dismounting).


A few notes before you begin building-
1) This bike was built using polyester resin over a plaster mold- never mind that, you can go ahead and use epoxy over a foam core.

2) I side-stepped the issue of the BB and HT by burying an entire 24" ladies MTB frame in the fiberglass casting. There are ten layers of 'glass throughout, and there are liberal internal braces to hold the 'glass shell to the steel tubes. The internal brackets are like the shape of the greek letter "Omega" which I don't have on my keyboard, but think of the shape- the 'glass wraps around the tube, comes together, and flares out against the inside of the shell.
Omega:
http://en.wikipedia.org/wiki/Omega
(the upper case)

3) I used a tray, a plastic "paint-roller" tray to mix the resin in. The roller tray saves a lot of difficulty when dipping the fiber cloth in the resin. ( a bucket requires contorting your hands while dipping the cloth).
hotbike is offline   Reply With Quote
Old 01-03-10, 09:49 AM   #20
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Interesting build. I think I would stuff that front fairing with a pillow in case she goes over the bars though, or better yet design an airbag system.
meech151 is offline   Reply With Quote
Old 01-03-10, 10:50 AM   #21
Canaboo
Senior Member
 
Join Date: Dec 2009
Bikes:
Posts: 321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would recommend a high quality foam as a core for a first effort. A good core limits how much material you need on the outside.
A good choice is Core-Cell and balsa wood makes good core material for seat and chainstays.
Core-cell is expensive but it shapes well and you can let your imagination run a bit wild with your frame design. If you buy a big piece you can make the entire frame from a single piece. It is thick enough to split into the rear triangle and you can heat form it to spread it.
You can get Core-Cell from marine stores such as Jamestown distributors.
Canaboo is offline   Reply With Quote
Old 01-03-10, 02:09 PM   #22
meech151 
meech151
 
Join Date: Apr 2009
Location: Mountain Home, AR
Bikes: MEECH road & cross bike
Posts: 206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Do you remove them after the product is cured or leave them inside and how do you go about removing them? How do professional carbon tube makers make theirs?
meech151 is offline   Reply With Quote
Old 01-03-10, 02:44 PM   #23
Canaboo
Senior Member
 
Join Date: Dec 2009
Bikes:
Posts: 321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
People making their own monocoque frames and using cheap styrofoam generally melt the foam with Acetone and drain it out.
The foam I am talking about has tremendous structural strength on its own, is very light weight and doesn't soak up resin. You would leave it in since it's adding strength and impact resistance. In fact it's designed to absorb impact so it would make a carbon bike far less crash sensitive since it can't collapse.
The added weight of it is nothing but good.
Professional tube makers form their tubes around a mandrel and then remove it or they use a latex bladder and a mold. Picture wrapping carbon around a waxed piece of tubing and sliding it out after cure or covering a balloon with carbon and then letting the air out of the balloon. You're just left with the shell. That's the roughest description of the process of course.
You can google Core-Cell for the specs. It's good stuff and used in a lot of demanding circumstances (except bike frames it seems) Frame makers probably consider their processes more advanced but for a homebuilder looking to experiment and wanting a less fragile bike, it's the way to go.
Canaboo is offline   Reply With Quote
Old 01-04-10, 10:09 AM   #24
hotbike
Senior Member
 
hotbike's Avatar
 
Join Date: Dec 2006
Location: Long Island, New York
Bikes: a lowrider BMX, a mountain bike, a faired recumbent, and a loaded touring bike
Posts: 2,851
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by meech151 View Post
Interesting build. I think I would stuff that front fairing with a pillow in case she goes over the bars though, or better yet design an airbag system.
The top, rear edge of the fairing is closed cell foam. Yes, there is a possibility of installing an airbag - I think an experiment could be done with a large plastic bag full of styrofoam peanuts, in place of an airbag.

I want to remind people that a fairing is, first and foremost, a Protective Shield, and aerodynamic advantage is a secondary consideration.
hotbike is offline   Reply With Quote
Old 01-04-10, 10:21 AM   #25
hotbike
Senior Member
 
hotbike's Avatar
 
Join Date: Dec 2006
Location: Long Island, New York
Bikes: a lowrider BMX, a mountain bike, a faired recumbent, and a loaded touring bike
Posts: 2,851
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by meech151 View Post
Do you remove them after the product is cured or leave them inside and how do you go about removing them? How do professional carbon tube makers make theirs?
I have heard that some builders leave the styrofoam in- This makes it possible to use a lighter , thinner carbon fiber tube wall, and reduce the chance of the frame tube being crushed by accident. I'm speaking of recumbents, of course.

Again, I will state, that it might be a good idea to build a fiberglass bike or two for for "practice", before building a carbon fiber bike. Carbon costs seventy times what fiberglass costs, so a mistake would cost a lot less, if one uses fiberglass. Call it "trial and error", if you will.
Also, although carbon fiber has a tensile (pulling) strength much higher than that of fiberglass, the compression (pushing) strength is about the same. It might be possible to use some extra fiberglass in a carbon fiber bike in areas of compression (i.e.- around the Bottom Bracket that you were discussing).
hotbike is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 02:04 AM.