Why We Still Ride Aluminum

Why We Still Ride Aluminum

Aluminum has an interesting history in cycling. Without it, we’d never have developed lightweight wheels, brakes, derailleurs, cranks, bars, stems and seatposts. So while our current crop of road bikes wouldn’t have been possible without the material as used in components, as a frame material, its history is far less distinguished.

In the modern era, we can look back to the Vitus, Alans and Guerciottis as interesting explorations of aluminum. Because they used the same tube diameters as steel frames, they traded stiffness for weight savings. They weren’t a lot lighter—generally a few ounces per given size, though more with the largest sizes—but for those concerned with performance, they were a decided step backward because the handling was compromised due to how flexible the frames were. Just don’t mention that to Sean Kelly; he rode a Vitus on mountain descents at speeds high enough to make my palms sweat.

How we got from that to the Cannondale CAAD10 is evolution on a more-than-industrial scale.

IMG_1641A classic mark of a Cannondale is the dynafiled welds. They look better and smoothing the welds makes the bike last longer.

Beer can tubes
By the time the industry was ready to take a fresh look at aluminum, it was thanks to Gary Klein and Cannondale. Those early oversize-diameter frames succeeded in reducing weight in a way the small-tubed aluminum bikes hadn’t, but they took ride quality and fed it to a den of alligators.

The issue wasn’t the diameter of the tubing, as people have often thought. The issue was that the tubes were straight gauge. It’s this simple fact that led to the reputation that aluminum frames have a harsh ride. Straight gauge tubing, whether aluminum, steel, titanium or carbon fiber, will transmit more vibration than butted tubing. I learned this first-hand when I went for a short ride on a frame made with Aermet tubing. The steel alloy was hard as calculus and could only be drawn with a .51mm wall thickness—no butting. It was all the rage for a few short years because it got rid of the .8mm butted ends of most tubes, thereby reducing weight. But the material was almost impossible to cold set and it rode was harsh as the taste of cough syrup.

So while oversize aluminum tubes reduced weight and increased stiffness, especially stiffness under power, most of the bikes out there used straight-gauge tubing. All of those Italian and French frames being used in the late 1990s used straight-gauge tubing. The moment bike companies began offering carbon fiber bikes that could match the weight of the aluminum ones, even though they gave up some stiffness, because they had a better ride riders will willing to move to them.

IMG_1643The tubes may be big, but they’ve been shaped to offer stiffness without beating you like a drumhead.

Now what?
With fifteen years of product development behind us, not to mention an influx of good mechanical engineers into the bike industry, a few different things have taken place. The first is that bikes have gotten much more expensive, expensive beyond just what economic inflation can account for. The second is that very few bikes are so stiff as to give you back pain on a 100km ride. The third is that the engineers have figured out how to reduce road vibration and jarring while also holding weight low and maintaining stiffness under power. Just one problem: the majority of the bike world has stopped talking about aluminum.

I see aluminum bikes on the road less often than I see titanium ones. And I see ti bikes less often than I see steel ones.

Specialized may have made a somewhat splashy return to aluminum with its Smartweld, and Trek and Felt have continued to offer more budget-oriented aluminum bikes, but it is Cannondale that has faithfully continued to pursue aluminum as a valid frame material, pouring significant resources into their CAAD series of frames.

It stands for …
Cannondale introduced the CAAD series of frames in 1997, with the CAAD3. It stands for Cannondale Advanced Aluminum Design, a development ethos that has kept the monicker fresh for nearly 20 years. The heart of the CAAD frames is 6061 aluminum, a material often derided for not being particularly advanced for aluminum, because it requires heat treating following welding. Heat treating thin-walled tubing without a loss of alignment isn’t easy, but Cannondale figured this out back in the 1990s and it’s a trick of the trade that has truly given the company a competitive edge.

So while one-man shops that work in aluminum will favor 7000-series because they can weld it and be done, 6061, once heat-treated, will offer a stronger, longer-lasting frame. And because it’s stronger, you can use thinner-walled tubing, which will improve ride quality.

Compared to Cannondale’s 2.8 and 3.0 frames that immediately preceded the CAAD3, that first-generation of CAAD improved the ride quality of aluminum significantly, without giving up any of the drivetrain stiffness, at least, not in any appreciable way.

It’s worth noting that in the ’90s as aluminum was evolving into more forgiving designs, steel was undergoing a transformation into larger diameter tubes to better approximate the stiffness found in aluminum. They didn’t quite meet in the middle, but Cannondale’s ongoing work with CAAD means that today many riders could be blindfolded and wouldn’t be able to distinguish the difference between a steel frame and an aluminum one from Cannondale.

IMG_1644_2A fork must work in concert with the frame. If the frame is stiffer than the fork, you’ll notice it.

Marital bliss
We hear complaints and criticism about how expensive many of the bikes are that we review. There’s no question that $5k represents a significant investment. And $10k, well it’s hard to advocate that anyone spend that, but it does remain the price point where some of the most exciting work in cycling is being done. That said, constraints like marriage and rent can render retail ambitions irrelevant.

As much as I love some of the cutting-edge carbon fiber work being done, were I actively racing, especially if I was racing crits, I don’t think I’d have the stomach to toe the line with a carbon fiber rig that cost five biggies. Crit racing and crashing are intimate bedfellows and racing crits at the back because you want to avoid the carnage really negates the point of being out there. It’s this reality that makes the CAAD10 a bike worth more than you might think at first glance.

The CAAD10 employs every trick in the book used in aluminum. Tubes are hydroformed, butted, and in some cases tapered. Welds are dynafiled smooth to eliminate stress risers and then, as previously mentioned, the frames are heat treated to offer the best possible strength and longevity.

The CAAD10 Force is a sub-$3000 ride ($2820 retail) with SRAM Force (and Cannondale Hollowgram SI crank) and a carbon fiber fork. Force is probably the most underrated group on the planet; when riding the group, I can’t tell a difference between it and Red, except under acceleration. Same number of gears, same brake and shift performance (provided the Gore cables are used), same lever shape, just more weight, and a lot less cash.

IMG_1645I appreciate the way Cannondale included a number of spacers to allow a rider to get a great fit.

Expensive lessons
When Cannondale introduced the SuperSix EVO, even at 20 paces you could tell it apart from its predecessors, thanks to the flattened chainstays, which improved ride comfort at the saddle. You see a similar, though more subtle, flattening of the chainsays, something Cannondale is calling micro-suspension. What’s more is that all this ride quality comes without many of the traditional setbacks. While I didn’t have a chance to disassemble my test bike, Cannondale says that an anodized 56cm frame weighs a scant 1150 grams. There are plenty of carbon fiber frames that weigh that, or more. Of course, Cannondale would likely never have pushed carbon fiber to such lengths had carbon fiber not made such a pursuit so necessary.

One of my favorite features of the CAAD10 is that it comes in a whopping eight sizes: 48, 50, 52, 54, 56, 58, 60 and 63cm. There was a time when such a size run wasn’t an oddity; this isn’t the time for that conversation, but Cannondale needs to be praised for offering such a broad range of sizes at this price point.

My second ride on the CAAD10 was at the Palm Springs Century, and many of the roads there are rough to the point of making riders rethink their tire pressure. On early generations of the CAAD frames, I’d have been in pain by the end of the day with tires pumped to 100 psi. The bike was surprisingly smooth, and I write that as someone who expected a good experience; I just hadn’t ridden a Cannondale aluminum bike since the CAAD5.

What I noticed on hills on my favorite roads was how responsive the bike was out of the saddle, and how crisp the handling was. It’s a great example of why you don’t run across bad bike reviews. There’s a team of people at Cannondale who love bikes and are dedicated to offering the best bike they can at a price point. I’ve looked at a number of bikes in the $2500 to $3000 price range; very few of them come close to offering a bike that feels this good on the road at this price. What usually suffers is ride quality; carbon fiber frames in this price range usually have a pretty wooden ride due to the amount of lower-cost carbon fiber that has to be used to make the frame stiff enough to perform.

It’s funny, but this bike gave me the sense that something pleasantly devious had been committed under my nose. Aluminum has been hiding in plain sight all this time, but it’s been easy to focus our attention on carbon fiber; it gets almost all the press releases. The CAAD10 is evidence that first-rate performance can be had without spending $5000 or more.

Final thought: smart money, race performance

15 comments

  1. Gus C

    Wait till you ride a Caad12. it’ll blow the top of your head off. Thing is amazing. I own a Caad10 (winter bike) and a locally made Aluminum rig. The locally made rides nicer, but mostly because it has an ISP and better parts. But if i were to get a racing machine *today*, it’d be a no brainer: cannondale aluminum all the way. They really have figured it out.

  2. Pat O'Brien

    I had a Cannondale 2002 Road Warrior 2000. Very nice all Ultegra bike, and I put many miles on it. But the bike transmitted every road vibration to the bars and saddle. Even with the carbon Slice fork and 700×25 tires. When I retired, I bought a 2005 Trek Pilot 5.2 as a gift to myself. It was a Wisconsin made OCLV carbon frame. The geometry of the two bikes was virtually identical. And I ran the same wheels and tires on the two bikes. The difference in ride quality was stark. I sold the Cannondale immediately.

  3. ChrisC

    Great write-up, and I can’t disagree.

    However, there is one absolutely inescapable metallurgical quality of aluminum that makes it – for me anyway – a “racers only” option. Fatigue limit, or more specifically, aluminum’s lack thereof. I have cracked headtubes on two aluminum frames over the years (one Specialized, one Cannondale) from nothing more than long-term use and tens of thousands of stress cycles. Aluminum. Will. Break. It’s inherent in the metal and no amount of engineering will ever change that.

    True, the longevity is good – excellent really – for the price, but anyone who might be considering a bike to have “forever” needs to be aware of this fact.

  4. Dan

    Two of my favorite frames were the Vitus 979 and 992. They were light, responsive, comfortable and inexpensive compared to the high-end steel of the day. Aluminum is a great frame material you just can’t over build it like Cannondale did early on and you need to replace your frame every few years due to fatigue limits. If Vitus was importing an endurance style frame to the US I would buy one in a heartbeat. The Trek Emonda ALR looks temping, if I didn’t already love my Roubaix I might try one.

  5. Chuckles

    You speak of crits as suited for aluminum…more so cyclocross. Giant’s hydrodormed TCX line is light and bombproof.

  6. Walter Nash

    I had a Cannondale in the old days (early 80’s). Tooth jarring ride. A couple of years ago I picked up a used Spooky Skeletor that was part of the new generation of alu bikes (like the current Cannondales). Stiff where it needed to be, not a bad ride at all, and very light. Sold it only because the size turned out to be a bit off for me.

  7. David

    I remember riding my purple Vitus 979 and looking back at my rear tire many times, thinking it was going flat the ride was so soft – until the downtube pulled out of the head tube’s “glued and screwed” joint. Then my C’dale 2.8 – with the cantilevered rear dropouts, was the direct opposite, beating me up on the Farm-to-Market chip seal of Central Texas, until I cracked the downtube just behind the head tube. Now I ride titanium.

  8. Andy Grimaud

    I remember my good friend having one of the first Cannondale Aluminum frames, what a brick. I have an aluminum Tommasini that has a carbon fork and seat stays, one of my favorite rides still. I like aluminum a lot still and continue to ride them. Good ride and really is a distinct different flavor compared to my steel and carpet fiber bikes. Great article.

  9. Les.B.

    A downside of the thin-wall aluminum frame, as I understand, is that they cannot be repaired. Even carbon fiber frames can be repaired, depending on the break in question.


    1. Author
      Padraig

      That’s true, but often they are a good deal less expensive to replace. Cannondale has often had a crash replacement program over the years that made stacking your bike into another ride in the last corner of a crit a bit more affordable. Given the expense of repairing a minor crack in a carbon frame, it’s less expensive, provided C’dale still does that.

  10. CowtownCyclist

    I’ve been riding a Devinci aluminum frame for around eight years and it is getting close to the end of its life. It is not a particularly light frame, but it is quite stiff and I can’t say I have ever found the ride overly harsh, even with 23mm tires. It is externally and internally butted in every conceivable place and looks quite fancy. When the time comes though, I think I will replace it with a carbon frame.

    I had a Cannodale CADD something in late 90s that cracked near a weld in the BB after a little less than 2 years. Given the reputation their mountain bikes had for catastrophic failures around Vancouver at that time, when I got the frame back from warranty I sold it and moved on.

  11. Karl

    I raced steel frames for years: they all cracked within two years or so; to date, none of my aluminum frames has ever cracked after 10 plus years of racing (the frames are: Co-motion Ristretto, a Quattro Assi, and a 1988 Klein Quattro). I just don’t believe that Aluminum frames fail earlier than steel; it just ain’t that simple fatigue limits notwithstanding. There are many other variables that determine the life of a metal frame. Also, I am 6’6″ tall and 190 lbs: hard on frames! I no longer compete, but drive my Klein hard 8+ hours per week and it still looks like new.


    1. Author
      Padraig

      Workmanship can and will affect a frame’s longevity every bit as much as the material selection, sometimes more. However, in an all-things-being-equal world, a properly made frame, with tubing appropriate to the rider, steel will last longer. It will simply last more fatigue cycles. None of that is to say that an aluminum bike can’t last, though. Even without knowing which steel frames you killed, I can say that if a builder constructed a frameset from Columbus Max for you, it would last to the end of your cycling days.

Leave a Reply

Your email address will not be published. Required fields are marked *