Bicycle frame and component technology appears to be advancing rapidly. We've had steel frames for more than a century, but in the last few decades we've seen aluminum, titanium and carbon fiber added to the mix... giving frame and component designers options that were never dreamed of thirty years ago.

Is anyone aware of new materials or technologies currently under development that will advance bike designs even farther than what we have today? Or... are we nearing the practical limit of bicycle design technology?

Also, if you could radically improve any bike component or system, what would you change?

Carbon nanotube

It started as Bucky ball(think of soccer ball) in early 1980s. Some made it in a tube form(still much thinner than others so callled "fibers") in early 1990s, then layered. It seems like this can be grown into any shape, any size. Said to be much stronger than carbon fiber. I don't know exactly how it is going to be used in bicycle material but its prperty is way beyond just light and strong. People will experiment next 100 or 200 years just to find out what this material can do.

One use of this material I have heard of is that connect a satellite to a station on the ground with a ribbon made of carbon nanotube, use it as a rope to bring the elevator up and down between them instead of using rocket to go back and forth. Believe it or not, it's a serious project.

I listened to a three-part documentary about nanotech on BBC radio last month. One of the things that caught my ear was the ability to design programmable nano-machines.

For instance, a bicycle frame could be designed to shift its stiffness back and forth depending on the forces acting upon it from the rider. Imagine sprinting on a bike that can respond to the rider's left-right weight shift at a molecular level. This part of nanotech is not theoretical... it's already been done.

Read a similar article. Fascinating stuff. It would be about a meter wide and solar powered robots would climb it at 220mph. It was estimated this could become reality in 20-30 years.

Derailleurs seem crude and old-fashioned. How about a computer-controlled continuously variable transmission. Tell the computer what cadence and power level you want to ride at. Let's say you want to ride at 88 crank revs per minute and you want to put out 150 watts. The computer would continuously change the gear ratio depending on hills and wind. An indicator would tell you to pedal slower or faster to hit your cadence target.

Interesting concept. Of course, we already have bike computers that simply report operational information back to us, but you're talking about a computer that that takes an active role in the performance of the bike.

How "electronic" do we want bikes to be? Do we really want a bike that has to be programmed before it can be ridden? (Automobiles already do this rather succcessfully.)

Also, how much electronic control will racing organizations allow. Would they allow a biuke that could continuously compensate for the vibration and weight-shifting caused by Roubaix's cobblestones... or what about a bike that constantly re-calibrated itself to maximize energy on a hillclimb, thus giving the rider a clear advantage?

Nanotube CF is already being used in the bicycling industry. Check out Easton's 2005 line of handlebars, forks and seatposts. Currently they are using multiwall nanotubes but as the manufacturing process evolves single-wall nanotubes will hit the scene.

People have always thought that we'd reached the edge of technology. It'll never happen.

I think that the next big change in bicycles will be thermal plastics. I can foresee injected molded frames that might only take a couple of minutes to make. Course, the right material hasn't been invented yet but I expect it will be during my lifetime. It'll kill the small frame builders.

Steel... all the way.

Uh - Which one of us is supposed to be the retro grouch?

However, K2 was losing its shirt making these frames. It was simply labour intensive. The production run only lasted two years before they dismissed it as not being cost effective. In all honesty, this is the thermoplastic CF bike I really lusted after.

Mantis Screaming V

GT used to make thermoplastic frames, threading a nylon/carbon tube through a set of Al lugs. It looked quite neat.
PBO is the latest wonder fibre, stronger than carbo or kevlar. It's used in some spokes.
A lot of bike design is limited by tradition, the UCI and component availability. Why are axles supprted on both sides? Why are frames symetrical when the transmission is only on one side? Why do we use large hollow axle BB spindles with tiny bearings squished into a BBshell designed over 100 years ago.

Yep. The GT STS/LTS was the first production thermoplastic CF bike. Mantis actually worked with GT on the design. The Screaming V was the result of joint technological development. GT then produced a second generation thermoplastic CF bike called the XCR2000.

My thermoplastic CF MTB is a K2 Oz-M. It's made by K2 and Easton (subcontracted). The main triangle is produced by K2 and is a 3-piece monocoque structure with two halves bonded to an internal reinforcement spine all made out of CF. This construction is similar to what Cannondale used for their CF bike except that Cannondale used an aluminum and then later magnesium internal spine. The K2's main triangle was produced in Vashon, WA but I'm not sure where the swingarm and fork legs, which were produced by Easton, were made. The bike was made for only two years. It was offered in two main trim levels and a superlight version. In 1998, it retained the Pro-Flex name and was called the Pro-Flex 4500C and the Pro-Flex 5500C. In 1999, there were some minor improvements, a slightly different subdued finish and the names were changed to the Oz-X and Oz-M respectively. An Oz-M Superlight (Oz-ML) was also added which had all the fasteners and coils replaced with titanium equivalents. My bike is a modified Oz-M. The stock rear shock on the Oz-M is a Noleen NR-2. I replaced it with the NR-5 SmartShock to match the front shock in the CrossLink-CS fork and changed the rear spring to same titanium one used in the Oz-ML's NR-2 shock to give it a smoother feel.

Not many companies produced thermoplastic CF bikes. Most CF bikes (road and mountain) are made using thermosets. Mantis and GT worked on a joint project to create the earliest thermoplastic bike I believe with the Mantis Screaming V. This is the bike I really wanted but very few were ever produced before Mantis closed up shop and they were/are quite rare and expensive. GT itself took the technology to produce a limited number of CF-based STS/LTSes back in 1995 which was a CF version of their XCR. They later followed up with a second generation thermoplastic bike called the XCR 2000.

K2/Pro-Flex started sticking CF swingarms and forks on their aluminum Evo frames around 1996 and then produced a full CF frame based on the Evo geometry for 1998. While they performed well, the cost and labour involved to produce these things were so high that they discontinued them after only a two year run.

While many people in the roadbike community were surprised to see Cannondale come out with a full-CF road frame, it should be noted that Cannondale had been using CF in some of their MTBs for a while and they introduced the thermoplastic Raven back around the same time as K2 introduced the Pro-Flex 4500C/5500C in the 1998 model year I believe. Cannondale actually stuck with the Raven longer. I think they terminated production of that frame in 2001 or 2002. Neither the GT nor Cannondale bikes were full thermoplastic CF though. They all used aluminum rear triangles and swingarms. To my knowledge, only Mantis and K2 ever made full thermoplastic CF bikes. You can find out more about the K2/Pro-Flex CF bikes on the K2/Pro-Flex Riders Group webpage.

And this is what I believe severely handicaps or rather oppresses the full utilisation of CF technology. The real strength in CF lies not necessarily in it's lightweight properties and physical strength but in its ability to be employed to form shapes which are difficult to impossible with other materials. The advent of nanotube CF allows engineers to build and essentially design the bike frame from the molecular level up. In order to fully realise all the potentials, some traditional thinking needs to be sacrificed but of course the purist, retrogrouches and traditionalists will scoff. And there are plenty of those in the UCI. Roadbikes will probably not benefit to as large a degree as other types of bikes where frame shapes are not constricted by tradition. That said, CF can still highly benefit the traditional diamond frame since a designer can structurally tune the frame while still conforming to the look and shape which the UCI has used to deem a bicycle a bicycle.

If you look at MTB designs, you'll notice that many of these "outdated concepts" have already been challenged. Cannondale has the Lefty Fork and there have been expiriments with rear axles being only supported on one side. Many MTB frames use assymetrical chainstays. Outboard bearing design is prevalent in the latest generation of crankset/BB designs (Shimano, FSA, TruVativ, RaceFace) and was pioneered in the MTB world with the Bullseye cranks back in the early/mid-1990s.

I'm not entirely certain but I'm fairly sure these points were what you were hinting at?

That immediately came to mind. I got a good look at the Cannondale last week. It's an eyecatcher for sure. In fact, the first thing that went through my mind was that the for was not traditional... therefore not right.

I think our brains want to see symmetry because we think it is naturally better than asymmetry. My non-cyclist buddy who went with me to the LBS took one look at the C'dale and said, "Awesome!" Now that I've had time to ponder the issue, I think he's probably right.

Well... I'm going to play devil's advocate against myself and say, don't be so quick.

The Cannondale Lefty has a fairly checkered history. The concept is sound but the execution leaves a bit to be desired. There have been reliability problems and quite a number of fork failures. That said, single-sided axle mounts have been used in motorcycles with a fair bit of success. I still think it's an avenue worth persuing... it's just that I don't think the Cannondale design has quite arrived yet.

One of the promising aspects of nanotech is that the nano-machine construction is programmable. Perfect copies of the tiny gadgets can be grown again and again. Some of the nanotech scientists believe that (eventually) larger machines -- like bike frames -- can be grown as well. If they can jump the mass-production hurdle, they may be able to produce unimaginably high-grade, ultralight frames in large numbers. (See khuon's table of material strength comparisons.)

Imagine the stiffest, strongest road frame you've ever seen... and it weighs less than a pound. Even better, it continually restructures itself according to the way you ride it. Fantasy... perhaps, but I remember paying $100 for a four-function calculator when I was in school... and thinking I was getting a great deal.

Point taken. It just occurred to me that my non-cyclist buddy rides a motorcycle all day.

Problem with any sort of automatic transmission (and that goes for cars as well as bicycles) is that they can't see what is coming up on the road. Are you pedalling harder becauce you want to enjoy the downhill, or because you want to get up speed before hitting that killer hill. If your automatic gearing shifts to maximum just as you hit the hill, it really will be a killer. Although I suppose the ideal computer will think faster than the human rider can shift and automatically give you the perfect performance, just in time for you to switch it again for the next hill. My tuppence worth would be to keep bikes mechanical and not electronic. Use the super materials for weight, or flexibility, or whatever else, and leave the rider to get the performance.

Of course if bikes become so light and efficient that everyone is capable of riding at 40mph over sustained periods you'd better watch the accident rate very carefully.

Sure, there will always be newer types of materials to build anything out of but for
bicycles Steel is the material of choice with folk's who don't race, care for the earth,
want a truly simple bicycle, the "gee-whiz" factor means nothing, perfers just to
get on and ride.

Steel can be-recycled endlessly where other materials can not. Steel "rings" which
which means that for weight by volumn it will yield a better ride with less material
without the need for other means of shock absorbtion for the non-race applications.
Steel people understand due to it's long proven track record for mass production
uses. Steel simply is realfor the masses who ride bicycles as means of transportion
and utility uses.

For racing or other uses then any material can be used as the sky's the limit for any
racing materials. The truly sad part of this whole subject is that bicycle makers will
continue to shove this new tech down the average riders throat in their never ending
quest for "market share" instead of building steel bicycles that are dependable,simple
to operate and maintain, cost effective to buy by the very masses of buyers they seek
to tempt. If this is not understood by the big makers soon then many will perish without
at least one steel framed bicycle for the true "user" of bicycles. Until that time small
custom makers still using steel will flourish as will the used bicycle market for steel
framed bicycles.

I think design is about 90% of our gains.

Pity roadies are so picky about this....

I could imagine seeing a bike simlar to the 8.somthing lb trek posted here ages ago...that bike was sex....well it needed drops, but it was still sex. Something about the frame shape just screams "come and break me racer boy, cmon TRY IT PUNK!!!!!"

The designs are being challenged because the originators of mountain bikes pull technology from road bikes (I am sure not expecting mountain bikes to go into some of the realms they have gone into)...we are fortunate to be destroying the road base parts left, right and centre requiring new ideas to appear.

I won't say much about the lefty, it has its place, just not on any of my bikes. The 1 side rear wheel axle, interesting, mountain bikes are starting to pull more from bmx and mx, I wonder if anything like that would come to fruition. I wonder how the multi sided torque of someone pedalling would affect it over a mx drive train.

I guess the same outdated argument could be said for drive train (I know this is about materials), not for roadies, but the drive train is pretty outdated and imo not very functional for some aspects of mountain biking. Shimano and sram keep coming up with lateral changes to the drive train. Thats my personal rant, I hate deraileurs and deraileur hangers

Also, the recycled steels tend to be of higher quality and purer grade than it's non-recycled predecessors. The extra refinement seems to burn off the impurities and there will be different grades of molten steel at various layers of the vat. Kind of like beer!!! ... a subject I can really appreciate! But I don't recommend drinking recycled beer though.

I wish CVT's would be made for consumer level sometime...I don't like the deraileur setup on my bike either...it gets clogged up with crud in less than an hour...and yes, I love rolling my bike in the mud like a summer pig