Gluing Chuck's Frame

Below is a series of photos showing how I glued Chuck's frame together.  I use 3M DP 420 epoxy for all the joints.  First is two photos showing the bonding of a titanium BB shell into a carbon BB tube.  I made sure that there was always glue being pushed at the leading and trailing edge when inserted.  I managed not to get any in the threads which was a miracle.

The next two photos show the amount of glue used on the seat tube joint.  I's a small bead on the end of the tube that, when placed in the jig forms a small fillet and seals the joint completely.

When all the joints are set and the dropouts bonded in it's time to let it cure overnight. I used flash breaker tape on the seat and chain stays as well as the dropouts this time to make clean up much easier post cure.

Finished Guide and New Carbon

Today I finished the titanium brake cable guide tube flush with the top tube.  Careful grinding to avoid heat build up then finish filing and sanding left me with this.

Which looks like this with some casing installed.

I also received a new batch of carbon fiber prepreg.  It's all being stored in a small chest freezer at -20C.

Here is the 2x2 twill weave prepreg I'll be using some of to help bulk up the joints rather than using all uni-directional.

I did a very quick drapability test on an old test joint.  The 2x2 twill conforms well to the tough contours at the BB so it should not be any problem using this in the other joints.

 Here is some of the equipment being used.  There is a late 1970's First Mill, a Standard Modern 11" Lathe, a Garvin Horizontal Mill from 1910(ish) which needs some work and a King 7" bandsaw.

Internal Top Tube Cable Guide

I decided to try making the next few frames with internal cable guides for the rear brake.  I decided to use some titanium tubing to guide the brake casing the entire length for ease of insertion etc.  I chose titanium because it's light and has a similar coefficient of thermal expansion to carbon composite.

Here is the rather cobbled fixture I used to cut the 20deg entrance holes.  That's a carbide burr to cut through the tubing cleanly (and not get dull).  Once I have my little Garvin horizontal mill set up this will be much easier and less nerve-wracking.

I ended up bending the 1/4" titanium tubing around my 6" rotary table diameter by hand.  A parallel filled the gap nicely and I bent the tube with some cable casing inside.  There was no collapsing of the walls at this bend radius.

It's hard to see but the tube fit quite nicely down the center.  Next time I'll cut the holes 1/2" closer to the ends of the tubes so I can actually reach in with my fingers.  Fishing it through was interesting but running casing through helped guide the tube into place.

When ground and sanded flush the casing should exit at a good angle for the rear brake.

The tube was quite snug as is but a little 3M DP 420 on the outside and some on the inside should hold everything in place. 

I'll let this dry, finish it smooth with the OD of the top tube then everything is ready to bond in the jig.

Chuck's Frame in the Jig

I've cut and mitered all the tubes for Chuck's new road frame.  They're all fit in the jig and ready to glue once I put in the water bottle bosses and glue the titanium brake cable tube in the top tube.
First we have the new ENVE custom head tube in place.

Next we have the seat cluster area with the ENVE standard seat stay component.  It's quite wide at the top and should blend well with the top tube.

Here is the BB joint.  It's a 68mm shell with bonded in titanium threaded shell and an ENVE chain stay component.  I'm pretty happy with the ENVE parts except for a seam along the tool parting line visible here.  It will take extra work to fill and sand that until it's cosmetically acceptable.

I purchased a few sets of aluminum dropouts from Nick Crumpton http://www.crumptoncycles.com/
I had them anodized black.

Here is an interior view of the titanium brake cable guide tube test fit inside the top tube. 

An another showing it exit the carbon tube at a 20deg angle.  Once glued in place I'll trim the titanium flush with the carbon.  I think it should look quite clean when finished.

I'll need to finish the top tube cable guide but after that the frame can be cleaned and glued in it's final form.

Two New Road Frames

It's been too long since I updated the blog, my appologies.  I've had over 10,000 page views from 34 countries so far.  Apparently the interest in carbon frame building is larger than I thought when I started posting to keep a friend updated on his frame build.

I received a box full of ENVE Composites ( http://www.enve.com/ ) tubing and frame components today so it seemed like a good time to start posting again.  I have two new road frames to build over the coming weeks.  Check back and see the build process changes I have planned.

To start off we have the tubes and rear end parts for the first build.

Here is a close up of the in-molded chain stay cable stop that ENVE offers.

Included in the tube order was some custom spec 44mm ID head tube and 41mm ID tubing for use with BB86 press fit bottom brackets.  There are a number of 90deg layers used to tolerate the press fit forces.

Here is something new for me, a 0.25" titanium tube that I'll be bending and using to route the rear brake cable through the top tube.  

Here is a close up detail for the ENVE seat stay brake mount.  The first frame will use this while the next one will use individual stay tubes and a custom brake bridge.

 I design each frame using 3D CAD software.  From here I can generate dimensions for cutting each tube and how to set up the frame jig.

That's it for now.  Dropouts are on the way and I'll be ordering some 300g/m^2 uni-directional and some 10.7oz/y^2 8HS carbon prepreg shortly for the joint construction.

Frame #2 Four Months of Testing

It's been far too long since I last posted.  In the mean time I completed frame #2 about three weeks after the first one and I've been test riding it ever since.  It has about 2700 km on it on mostly paved roads, rollers, some gravel roads and some less than gravel twin track roads in the Appalachians of North Carolina near West Jefferson.

I built the bike with an EDGE 2.0 fork, Shimano Dura-Ace Di2 groupo, Ritchey WCS stem and post, a Pro carbon bar and Shimano 7900-C24-CL wheels. 

It has internal Di2 wiring and an under down tube battery mount.  The frame has a "lugged" look to the joints rather than the smother finish on the first frame.  The finish on this is spray can automotive clear coat.  I have an interesting finish idea for the next frame and it will have the proper logos etc (now that I know the frames work).

It's been ridden hard and has held up well.  No frame related issues of any kind.  At first I though the back end was a bit too harsh but I think that was just in contrast to the True Temper S3 frame I'd been riding for years.  I used the BB86 or press fit Shimano standard for the BB.

I'm planning the next version of this frame with a lighter chain stay assembly and thinner individual seat stays.  This should bring the weight down from the current 1060g for a 58.5cm frame.  I'd like to do internal rear brake cable as well as Di2 wiring.

Finished Carbon Frame #1

Neil's frame is finally finished.  It's the first full carbon frame and it turned out well.  Still need to work on the cosmetic finish etc and see how test riding goes.  Without further ado here it is with integrated seat post, PF30 BB, ChrisKing 44mm Inset compatible head tube and a final weight of 990g.

Frame Load Test

I took the first trial frame and loaded it to failure.  It took a lot of force to get it to fail.  In most cases it took almost double the load I've applied in the past to cold set OX Platinum frames and accidentally destroy an S3 frame.  For example, the side load test where the head tube is supported, I was suspending my full body weight on the end of a 4' bar and bouncing slightly.  Is the frame "strong enough"?  It's hard to say yet but this does give me confidence.

More Cable Guides

I finished the cable guide through the chain stay yoke of Neil's frame.  It turned out well, see for yourself.

A little more finish work and it should be ready to clear coat.  Here are the down tube mounted derailleur guides.  I'm going to work on carbon versions that bond on to avoid the drilled holes in future frames.

Next up, a real treat (here is a hint).

Cable Guides

The next and approaching final step was to position the cable guides and drill the holes.  Here is the frame with the derailleur and one brake cable guide in place.

 I put a modified 1/2 cable guide on the chain stay next.

The next step was tricky.  I had to position and drill a hole through the frame behind the BB for the front derailleur cable.  After placing a Shimano BB guide on the frame I marked the entrance hole on the bottom.

After drilling through the far side guided roughly by eye I glued in a 1/8" dia brass tube.

I'll trim and sand the ends flush once the glue cures.  Here is another photo for Neil, the weight prior to cable guides.

I have to modify my rivet gun to reach down into the cable guide pockets.  Once that's done the guides will be glued and riveted in place.