For the cycling geeks out there

This video is already a few years old, but still cool.

Point of order, I do have carbon fiber bikes personally, and I have a few frames available for sale. I am not 100% sold on carbon fiber as a frame material. Why? Because of catastrophic failure of carbon tubes. It’s not pretty. The bike become instantly unsafe to ride. It’s difficult to repair properly. The frames themselves once they’re toast, are not recyclable as of now, breaking down the epoxy to extract the carbon is cost ineffective right now. That may change in the future, but right now not worth the time.

That all said, carbon fiber is an amazing material. You can do so much with it.

Aluminum is making a comeback right now. That’s good. It’s biggest drawback is once an Al tube is damaged, it’s not reparable. Reheating the tube to replace it messes with the crystalline matrix of the Al alloy, making it very, very brittle.

Steel and Titanium, both can be fixed if damaged. The Ti frame requires some specialized knowledge of welding it. Steel, anyone who can braze copper pipes can essentially repair a damaged steel frame, so your friendly neighborhood plumber could make your bike rideable again.

Back to why I’m posting this. The video from GCN (Global Cycling Network) did a bit of work on a graphene impregnated carbon fiber frame. It has the possibility of being a better version of the current carbon fiber technology, also a bunch more expensive. Watch the video. I found it interesting, I hope you do too.

I was in the same boat as you regarding carbon frames and catastrophic failures but it seems like manufacturers have finally dialed in their process so the frames don’t fail like the early bikes did.

This video finally made me realize they could make a carbon frame that should be better than aluminum.

I’m with on on steel and titanium road frames and hardtail mountain bikes but mountain bike manufacturers, who aren’t worried about a few extra ounces, now have warranties that are several years, or even lifetime. I have a carbon mountain bike and have no worries that the frame will fail.

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My main concern about carbon (aside from recycling) is when/if it starts to delaminate, then it becomes a question when it fails, not if. Delamination usually happens when an outside force creates pressure against the weave of the carbon. Example: a crit I officiated last year. A guy with a cervelo S3 or 5, crashed and his seattube hit the curb. His seattube was visibly damaged. It was an odd situation, but illustrates my concern with carbon. Now with graphene impregnating the carbon weave and the epoxy it may become a moot point down the road, except the recycling part.

I have seen the video that you linked sometime in the past. It’s rather interesting to say the least.

I’m with you on carbon, for the most part. There was a stage in the TdF that Armstrong’s handlebar was snagged on a spectator’s handbag. He was pedaling uphill but it still pulled him over. That little spill broke the chain stay on his frame. That’s back when they were making road frames so light they were pretty much disposable, at least at that level.

I have a carbon mountain bike and am confident it will last as long as I will, at least that’s what the warranty leads me to believe.

I still prefer steel on road bikes. To me that is the best all around material. That material they are adding sure looks interesting though. That video is over three years old. Do you know if it is being used more?

I haven’t done any research on graphene since I found the video. So, it’s possible that it’s being used more, I just don’t know.

I found that video looking something else up, and found it fun and interesting. I was actually looking up some videos on a Schwalbe tire that i’m having a bear of time getting onto a rim, both are tubeless so it’s been maddening to get them to play nice.

I’ll dig into the graphene question you had, and update later, hopefully with more videos.

Sadly, the most recent article on graphene bikes is a little over a year old.

If you’ve been watching the cycling industry you’ve probably seen graphene laced tires, and the new absoluteblack graphene chain lube (awfully pricey but looks interesting).

I tried to get to but it keeps coming up suspended in 3 different browsers, so I don’t know about that.

So, at least temporarily graphene bikes seems to be a dead end. That is probably due to the cost of creating the graphene, as opposed to how to apply it in the epoxy.

FWIW I did find one for sale. Not sure it’s worth the cost right now, but still it’s pretty cool.

This is an interesting application for graphene. It is $31 per ounce. But it is supposed to be good for over 1000 miles, and reduce friction enough to effectively add 5 watts. Lots of interesting info about it on this page.

D’oh! CCU already mentioned this, but still interesting for anyone that hasn’t seen it.

I can’t even keep up with the high-level nerdism of this thread, but I love the fact that you guys are in fact, so knowledgeable.
@Carolina_Cycling_Ute: It’s amazing that you have the technical ability/artistry to craft these beautiful bikes and take the risk of the business venture, these concerns and inevitable, well, biking.

I freely admit, I’m a bike geek. I’m still working on technical ability. I think artistry will come with technical ability. Just my opinion.

Sometimes I wonder if I have just enough knowledge to get into trouble, but maybe not enough to get out of trouble. I suppose it helps that Mrs. CCU is extremely supportive of my passion, that allows for mistakes to be made and learned from.

I could go into my philosophy on bikes considerably more, but it’d probably bore the snot out of most of you. Suffice it to say, without the support of my wife, it’d all just be a “what if” dream.

A Someone once said “We all marry up”
I’m happy your wife is also a friend who has found ways to support you even though it is not without risks and costs.
I have similar experience and most grateful.

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Continuing the discussion from For the cycling geeks out there:

Part 1 of 2
Well now you’ve done it. You’ve waded into an area I know a little about from my professional career and with one of my favorite hobbies in retirement. I used to manage the R&D Engineering for the composite structures when I was a working stiff, so black string and glue was something I needed to understand.
So, where to start . . .? How about graphene? Fascinating material but the technical and manufacturing maturity levels aren’t really there yet with bikes. The promise of them providing very robust composite materials is great, but near as I can tell it’s still cost prohibitive. It’s cheaper than true carbon nano tubes, but some of the processing complexities of nano tubes are there also in graphene. It’s a ways out.
As far as composite bikes, there’s a few things I want to say. First off, right now there’s no way you will beat carbon/epoxy frames for cost effective weight reduction against any metal frame. The standard rule of thumb that we got really close to time after time was carbon fiber composites were 30% lighter than the analogous aluminum part. We hit 35% on an interstage design once and 30% of its mass was the metallic attach hardware. The costs of fiber are going down and the knowledge base to make them is going up. The process they use to make them is pretty standard – lay-up unidirectional cloth around a rubber bladder, put it in a mold, pressurize the bladder, and heat to cure. The costly part is the tooling investment.
As for composites fragility, I spent six years on a mission to convince NASA they were a lot less sensitive to impact than they believed. We actually had one NASA manager telling us if you just rapped your knuckles on them you had to throw them away. A demo we did with a thick-walled graphite/epoxy pressure vessel, admittedly a much different animal than a structure, showed them otherwise when we had them actually whack it with a sledge hammer then burst it and it broke somewhere else. With modern, toughened resins (nylon or rubber reinforcement) you can get them to be pretty tough and robust. You’re right that delams are an issue for integrity, but you need a lot of flex to cause them and that can be designed for to optimize stiffness in the right spots.
An old boss of mine has made a good chunk of money as a consultant for people suing bike makers over failed forks. He has some good points. Most forks and frames are being manufactured overseas (primarily China) and one has to wonder about manufacturing discipline and inspection protocols. In late 2017 just before I retired I went to one of his technical papers on this work. Like I said, he’s not all wrong, but when you dug into it he was poking at a total of six catastrophic failures in forks on Trek bikes. How many forks that could have failed are out there? Millions! That would make the reliability of those forks better than what we expect for human space flight. A guy I was talking to at the conference told me Felt had increased their in-person oversight for their frames from China. I suspect, but don’t know, that someone like TIME in Lyon, France is probably more careful.


Part 2 of 2

In 2016 I was at a composites trade show in Paris and they had a bike there where the frame was designed using software from Collier Research in Hampton, VA (I know the principal guy there) called HyperSizer. The thing was feather light. (After I picked it up I noticed the sign asking us not to pick it up. Oh, well.) That shows the beauty of using a composite material where you actually design the response you want into the part and can optimize the weight as a result. You simply cannot do that with isotropic materials (i.e. the same properties in every direction) like metal. Another part of this is how you can design damping into the composite frames to smooth out the ride. I’m more familiar with Trek’s system (I ride a Domane SL7) that they call, “Isospeed De-coupling.” I understand Specialized has a similar system and I’m sure others do too. By designing the layup right you can give the frame varying stiffness by direction, allowing you to create natural shock absorption and ride smoothing. (We did something similar in working a proposed design for a structure for NASA to help damp out vibration and smooth out the ride for the astronauts.) I switched to my bike two years ago and it’s a ton smoother ride than my old Al frame/Carbon fork bike.
That wound up being a lot longer than I first thought it would be, but what can I say? I hope I provided some insight from the technical perspective on the material.


This was quite interesting. I know that carbon has come a long way since LeMond first used it way back in the 80s or so with his Look frames with La Vie Claire. To today’s ultralight aero frames.

I’ve known the basics on layup and whatnot for sometime. I also knew that that the epoxy used played a huge role in durability.

Like you mentioned about Chinese frames, I’m a bit leery about the small manufacturers from China, but the larger one, who do contract work for some of the BIG known brands are pretty good. I know that Trek, and Colnago do their top frames in house at their facilities in the US or Italy. I think Bianchi does too, but I don’t know for certain with them.

It’s an interesting discussion that has gone round and round in the bike industry for years. There are niche framebuilders using all the prime materials. Steel has fallen out of favor with the big guys due to weight (primarily), Ti has fallen out due to cost. Aluminum is making a comeback for mid level bikes, especially in gravel frames. FWIW the US National Road Champion for 2017 won Nats on an Al Specialized frame. I thought that was good, because it shows that it’s more the rider than the bike.

Thank you for giving your insights. I’ll reread again later, there was that much to digest.

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