kooby

I'm an am amateur to framebuilding (but learning fast!), currently riding my first carbon frame, building my second, and designing my third.
I'm wondering if there are any other, more experienced carbon frame builders on this forum willing to share some information and experience. I'm especially curious about preferences when it comes to bottom brackets, dropouts, and bottle bosses, as well as monocoque vs bonded tube constructions.

unterhausen

I don't think we have anyone that posts here regularly that works with carbon. I always wanted to build carbon frames. I even took a class on composite materials back in 1981. That was a mistake, the professor talked me out of building frames.

Andrew R Stewart 

Over on Velocipede Salon there's a few that do. Or there's a few who in the past have posted. None that I remember ever talked about teaching though. Andy

Canaboo

What are you building your first with? Tube to tube carbon is not rocket science. Neither is monocoque if you are using a foam core.

guy153

I've made a steel frame with a carbon TT and DT going into "lugs" that I welded up. I don't think there's much benefit to this over just using steel (actually I prefer steel) but it's what the friend I was making it for wanted. But this probably isn't relevant to what you're trying to do.

But if you want to post about it I will be interested to read it!

Kontact

On Velocipede there was a tutorial posted by a guy who made tube to tube carbon frames commercially. He showed how he used sanded filler to blend the joints and then over-wrapped them with carbon. Lot's of good detail. I forget the brand.

For a more basic technique, there are lots of pics out there of Calfee's method using carbon tow for building customs like tandems or working with bamboo. The joint is a big knot of tow that is ground smooth after it has cured.

I've always wanted to try doing it with carbon socks, like how fork crowns used to be made.

georges1

Serotta did it back then ,now I don't know who does carbon custom frames.

unterhausen

I thought about mentioning that too, but I'm pretty sure there are no pictures any more. And I also forget his name. Also, they reorganized again and the thread is hidden in history

It was Nick Crumpton

Canaboo

It was Crumpton. The whole process actually is quite simple. There's a limited number of ways you can wrap carbon around a lug
Even with all the theory on how to do it you still need to actually be able to execute the idea yourself.
You'll see a lot of carbon work done by people who know what needs to be done but struggle to actually execute the process.

Kontact

Found the thread, but the pics are, indeed, gone.
https://www.velocipedesalon.com/foru...ing-18058.html

Andrew R Stewart 

One could say the same about a lot of endeavors. In my mind I am a great singer but I've learned to keep my mouth shut when the music starts. Andy

Canaboo

Yes but poor work by an otherwise knowledgeable person can be easily passed off as proper work to those who don't know better.

smontanaro 

There is a single Wayback Machine capture that seems to have some photos:
​​​​​​https://web.archive.org/web/20220627...ng-18058.html?

smontanaro 

Also, Tim Massengill does (or did) custom carbon fiber frames. He's good friends with Doug Fattic who can probably put you in touch.

Canaboo

Here's an article that shows a lot of the process used by Crumpton. https://pezcyclingnews.com/technspec...rbon-crumpton/

To me the joints could be made to look a lot neater.

ETA. This is an old article and I will say his bikes do look much neater on the lug joints now. I believe he no longer uses woven carbon on them The build along that disappeared showed unidirectional.

kooby

Thanks for the responses everyone

My first frame was monocoque using a 3d printed core instead of a foam one. My result was not the best aesthetically, but was rideable (its still my daily rider today). I would have liked to had done a tube+lug construction but at the time (pandemic + college student budget) it came out cheaper to buy all the carbon and do it monocoque.

Recently I've gotten back into carbon fiber as I'm working on a carbon cargo bike build and experimenting with some other carbon fiber component projects. And I've discovered a lot of interesting people doing interesting things with carbon fiber out here in eastern europe.

smontanaro 

3D printed core? Got pix?

kooby

Sorry for the long wait


Here is the top tube being printed.

Here are all the core parts glued together and mounted in my low-tech jig. The HT, BB, and seat cluster were printed from plastic mixed with carbon fiber for some added strength.

Here's the final result. It doesn't look great, but it rides pretty well and was a great learning experience
A lot of the lessons I learned building this bike have helped me with deigning and working on my current project I'm working on.

Doug Fattic 

kooby, nice frame work! You will want to get in contact with Tim Massengill. I'll send you his contact information by PM. He is also an amateur carbon framebuilder and painter in Texas. He has been doing that for a long time. He learned steel framebuilding from me when he was nearby in college and graduate school many years ago. He has been involved with our Ukraine charity bicycle project for over 20 years. Between 2001 and 2008 we used to do these week long bike rides somewhere in the boonies of Ukraine. He went to the bicycle show in Kieice, Poland in 2016. He spent 3 months in Bucha, Ukraine in 2018 making some of our steel fillet brazed frames. Twice he has repaired and repainted our former president George W. Bush's Trek carbon frames. He has designed and made a take apart carbon travel bike too. I think Tim has done some 3D printing as well. I'm sure you two have some things in common you will want to discuss. If any of us can get back into Ukraine to continue working on our bicycle project, we will probably have to fly into Poland and drive to Ukraine. Because of the Russian invasion (which started at the airport a stone's throw from our workshop in Bucha), we have focused this year on general humanitarian aid including getting generators and wood burning stoves to some of the areas hardest hit by the Russians. The Ukrainian company that makes my laser cut stainless steel fixtures is also the one making the heaters. The Russians did break into and steal general tools in our workshop but left all the fixtures fortunately.

squirtdad

maybe check out some facebook groups....I see people popping up on framebuilders that do carbon