Myths Debunked: Titanium is Lighter than Steel, but…

Myths Debunked: Titanium is Lighter than Steel, but…

In part 2 of our series ‘Myths in Cycling,’ we’ll look at why titanium isn’t always lighter than steel. I can hear you saying, “What? Everybody knows that titanium has half the density of steel.”

That much is true: The same part made from titanium will weigh half as much as the equivalent from steel. But titanium has only half the stiffness, so the part will be half as stiff. To make the parts of the same stiffness, you need to use twice as much material with titanium, and the weight will be equal. The same applies to aluminum, which is one-third as heavy and one-third as stiff. (These numbers are for the high-strength alloys; raw aluminum, titanium and iron are not strong enough for cycling applications.)

For example, if you made a titanium rack, it would weigh the same as a steel rack with the same load capacity. That is why the best racks are made from steel: Other materials don’t offer any advantages.

So why do people use titanium at all? There are other considerations than stiffness. Frame tubes are a good example. The larger the diameter of a tube, the greater its stiffness-to-weight ratio. However, with steel tubes, you run into limits, because a frame tube cannot be made with walls much thinner than 0.4 mm. Otherwise, it becomes too easy to dent, and braze-ons will just rip out of the ultra-thin tube.

A way around that problem is to use titanium. With half the density of steel, if you double the wall thickness, you get a tube with the same stiffness and weight as a steel tube. But you don’t need the walls to be that thick, so you can use larger-diameter tubes. Many titanium frames are both a little lighter and a little more flexible than steel frames. Especially smaller frames can be too stiff for their riders, and using titanium can make for a better-performing frame.

The advantage of titanium frame tubes turns into a liability where you cannot increase the tubing diameter: at the chainstays. Chainstays have to fit the narrow space between the tire and the cranks. Because of this, making titanium chainstays as stiff as their steel equivalents is difficult, especially on a bike with wide tires.

My Firefly (above) uses super-beefy chainstays that probably contribute to its excellent performance, but as a result, standard road cranks don’t fit. The photo above shows it with its original CNC-machined cranks, which resulted in a wide Q factor and cross-chaining in the gears I use most. Since then, I installed forged Rene Herse cranks and filed the ends of the cranks, so I can use a shorter BB spindle. That improved the chainline and (almost) eliminated the cross-chaining. Now the Q factor is acceptable, too. Everything had to be optimized very carefully to make it work to my satisfaction, because it is such a tight fit.

Will a titanium frame provide superior performance for you? My Firefly (above) feels very similar to my steel bikes, and the small weight advantage of the frame is lost amongst other factors, such as the added weight of the disc brakes. I love the bike, but a similar one made from steel would perform similarly. It may be a different matter for small riders: Even a lightweight steel frame may be too stiff (small frames inherently are stiffer than larger ones). A carefully designed titanium frame may offer more flex in the right places and thus ‘plane’ better…

What about titanium bolts and other small parts? If you just replace a steel part, say a bolt or a bottom bracket spindle, with a titanium one, it’ll be far less strong. That is what Campagnolo found out when they introduced their Super Record bottom bracket – many of these broke. Of course, all parts have a margin of safety built in, and sometimes, you can reduce that margin without failure. A smoother-than-average rider probably can ride a titanium bottom bracket without failure.

The same applies to titanium bolts – if tightened carefully, they can work OK. But then you wonder why you don’t redesign the part with smaller steel bolts. They have the same strength, but go into a smaller hole, which allows you to make the mating part smaller, saving further weight… It’s one example where a well-designed part with steel bolts actually is lighter than one using titanium hardware.

There are a few places where titanium bolts make sense. The eyebolts that hold the brake pads of our brakes (upper bolt in the photo above) are large because the post of the brake pad needs to fit through the head. They don’t need to be this big to be strong enough. This means that a titanium eyebolt weighs half as much, yet has sufficient strength. And that is why we offer them as an option to reduce the weight of our brakes to just 75 g per wheel. That is lighter than any currently made brake, and yet we don’t give up any strength.

That eyebolt is an exception. Most bolts are dimensioned for the loads they need to withstand, like the bolt that attaches the brake to the pivot (lower bolt in the photo). We won’t offer a titanium version of that bolt because it might break, with disastrous consequences.


Titanium’s stiffness-to-weight ratio is the same as steel’s. Titanium’s density is lower, which can be an advantage when you need or want to make large parts (oversize frame tubes, eyebolts), or a disadvantage when space is limited (chainstays, bottom bracket spindles). Titanium’s lower density saves weight only in places where the dimensions of steel parts are constrained by other factors.

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Comments (60)

  • Christian Bratina

    There are two other reasons to use titanium in a frame. You don’t have to paint it or worry about chipping the paint off. Ever drop a wrench or allen key on a steel frame and chip the paint? And because it does not rust or corrode, it can last forever. We have had wonderful steel frames rust through from the inside of the tubing due to corrosion.

    January 9, 2018 at 2:39 am
  • Scot Koehler

    As a rider of both steel and titanium bikes regularly and love the ride of both. One more advantage of titanium is it’s resistance to corrosion. When I raced my steel bike it required new paint every 3 years from corrosive perspiration while after riding titanium for 25 years it still looks like new. Your mileage my vary, since I quit racing, steel paint is holding up well. Both bikes have over 100,000 Miles on them.

    January 9, 2018 at 3:27 am
  • JOnah Jones

    Jan, one consideration for using titanium over steel, is that it won’t rust. regards Jonah (here in salty Bermuda.)

    January 9, 2018 at 3:54 am
    • Jan Heine, Editor, Bicycle Quarterly

      I’ve had zero issues with rust on frames. A little car wax protects the frame, and if you sweat a lot, wiping down the top tube after a ride with a wet rag helps, too. In the past, I’ve had bolts rust, but there, car wax (applied with a toothbrush) works great for protection, too. I wash my bikes on average once a year and apply wax at the same time…

      January 9, 2018 at 4:30 am
    • teamdarb

      Those who do not live in the southeast, will never understand the struggle. I know your pain Jonah.

      January 13, 2018 at 7:58 pm
  • Christian Bratina

    In a humid environment or when riding wet roads, most of the corrosion comes from inside the tubes. Even using Weigle Framesaver, it is hard to protect the inside of seat stays, chainstays and forks.

    January 9, 2018 at 4:39 am
    • Jan Heine, Editor, Bicycle Quarterly

      Seattle and Paris, where the oldest bikes I’ve ridden spent most of their lives, are both places known for their rainy weather. I do use Weigle’s Framesaver when I build up a bike, but I’ve found that on a bike with fenders, there isn’t much water entering the frame. Most water seems to be spray from the rear wheel that runs down the seatpost into the frame – and you eliminate that with fenders. If your frame has vent holes (many builders close them after brazing to seal the tubes), then you can plug them with beeswax to seal the tubes.
      I’ve ridden bikes that were 70+ years old and didn’t have anything beyond surface rust. When I overhauled the bottom brackets, there wasn’t any rust inside, either. Unless you live in an area that gets salty fog or ride on wintry roads covered in salty slush, rust isn’t as big of an issue as many cyclists fear.

      January 9, 2018 at 5:05 am
      • prt

        Jan, you’re succumbing to survivorship bias here. 70 year old frames are those which – by definition – have not experienced the conditions that led to others rusting out. The condition of surviving frames doesn’t tell us anything about what happened to the frames that didn’t make it.

        January 10, 2018 at 5:26 am
        • Jan Heine, Editor, Bicycle Quarterly

          Interesting idea. However, rust isn’t a random process, but a continuous one, so it’s not like a bike suddenly fails, while another remains intact. Among the BQ Team, we have more than a dozen frames that are more than 20 years old, and none have rusted through… and while I’ve seen plenty of broken frames, I haven’t seen many rusted ones… all indicate that rusted-through frames are far less common than broken frames.

          January 10, 2018 at 5:33 am
      • morlamweb

        Owner of a 30-year-old rigid-framed steel mountain bike here. I’ve ridden this bike daily for transportation, in New England, for 5 years, and there’s only a small bit of surface rust on the handlebars. I’ve ridden in through 5 winters, at least as many blizzards, countless rainstorms, and hail; it’s seen it all. The bike has not turned into a pile of rust, despite the naysayers. That’s due to it’s largely intact OEM paint and the full-coverage fenders + mudflaps on both wheels (and the fact that I keep it inside as much as possible). So yes, steel can rust, but it’s a problem that is easily prevented.

        January 10, 2018 at 10:50 am
      • Waldo

        We are discussing steel frames, some of which have rusted and some that have not. I am yet to hear of a rusted titanium frame.

        January 11, 2018 at 6:58 pm
    • Conrad

      Rust is s funny thing. I have seen a steel bike that rusted out at the bottom bracket. It wasn’t mine and I suspect it had some pretty serious neglect. My regular commuter is a bianchi volpe that sees about 5000 rainy Seattle miles a year. No frame treatment or special maintenance and very minimal rust. It seems to have a primer coat of some sort. It’s funny that even compared to my fancier bikes it has better paint by far. My serotta Colorado 2 has some rust issues on the top tube with a hidden brake cable. Sweat drips right into it. Other bikes paint has orange peel or chips off much more easily than on the volpe.

      January 10, 2018 at 10:18 am
  • wqlava1

    What diameter front triangle tubes and size rear stays were used for your Firefly? Do you know if they were butted at all?
    Did you ask the people at Firefly why they chose a steel rather than Ti fork? Is Ti too flexy without vast weight? I appreciate that there are no carbon low trail/ disk/ rack forks currently available.

    January 9, 2018 at 5:16 am
    • Jan Heine, Editor, Bicycle Quarterly

      I don’t know the tube diameters of the Firefly. I don’t think the tubes are butted.
      As to forks, there are very few titanium forks. It’s another place where you run into the problem of constrained dimensions. To save weight and still be sufficiently stiff, a titanium fork and steerer would have to be very large. There are other issues that make steel forks the best option. Carbon forks are easier to mass-produce, so they are less expensive than quality steel forks, but they also can’t easily be adapted to different geometries, etc.

      January 9, 2018 at 5:41 am
      • Christian Bratina

        Kevin Wolfson told me that Jan’s Firefly had:
        Top Tube 35 x 0.028″ straight gauge
        Down Tube 38 x 0.028″ straight gauge
        Seat Tube 31.8
        Chainstay 22 x 9 mm
        Seat Stay 19 x 0.9 mm, larger diameter and thicker due to the disc brakes
        When having Mike DeSalvo build my Ti dirt road bike, the thinnest butted Ti tube center wall I could find was 0.028″, with thicker ends. The thinnest straight gauge tube was also 0.028″. Good frame builders only need the heavier, butted tubing for the seat tube due to the additional heat applied. I went with 31.8 mm top tube, oval 29/17 mm chainstays tapered to 16 mm, and 16 x 0.7 mm seat stays with center pull brakes

        January 9, 2018 at 6:30 am
        • Jan Heine, Editor, Bicycle Quarterly

          Thank you for getting the tubing specs. I wasn’t sure whether they were a ‘trade secret’…
          Interestingly, when you calculate the stiffness of the main tubes, they are significantly stiffer than those of the ‘Superlight’ steel frames I usually ride, yet the Firefly feels and performs very similarly to those bikes. There is a lot to making bikes, and whatever the spec, Firefly clearly understands how to make a bike perform great.

          January 9, 2018 at 4:23 pm
      • Matthew J

        Jan – Have you had a chance to ride a bicycle with a titanium truss fork such as the one Jeff Jones’ offers? The limits for rack and other braze ons notwithstanding, always been curious how they ride.

        January 9, 2018 at 9:12 am
        • Jan Heine, Editor, Bicycle Quarterly

          We tested a Jeff Jones in BQ 51. The Jones truss fork is an interesting design that reduces the loads on the steerer tube by attaching the fork at the top and the bottom, thus getting around the problem you’d run into with conventional forks made from titanium.

          January 9, 2018 at 3:51 pm
  • Gert

    On your J.P Weigle for Concour de Machine you had a titanium bottom bracket. Is that no good?
    I had intended to go for one for my next bike.
    Should I reconsider. It is 40 grams ( 4 times as much as drilling holes in the chainrings)

    January 9, 2018 at 5:41 am
    • Jan Heine, Editor, Bicycle Quarterly

      I am a rider who rarely breaks parts, so the Concours bike’s titanium bottom bracket is probably fine. Nonetheless, I plan to replace it every 10,000 km or so – a broken spindle almost always causes a crash, which isn’t worth the risk for me. Even when new, the BB did creak a bit when I pedaled hard. Whether a titanium bottom bracket is a good choice really depends on your riding style, your mileage and your expected lifespan of the component.

      January 9, 2018 at 5:52 am
      • Gert

        I will try it then

        January 9, 2018 at 5:59 am
    • mike w.

      Since the BB spindle is a non-rotating mass (as opposed to pedals and rims,) there really is no great advantage to the weight savings over a steel spindle. My personal opinion is that one should opt for sturdier components -choose reliability and durability over a few grams of weight saved. Remember that a broken component could do you an injury or leave you stranded miles from assistance.

      January 9, 2018 at 6:29 am
      • Jan Heine, Editor, Bicycle Quarterly

        The BB spindle does rotate, but it’s rotational inertia is very small. In general, the importance of rotating mass is often overestimated. The old adage “an ounce on the wheels is worth a pound on the frame” isn’t true in our experience (nor if you apply pure physics). I agree that if it’s not to win a prize for lightweight, I’d prefer a bottom bracket spindle that I don’t need to worry about.

        January 9, 2018 at 6:42 am
  • Grant

    My lemond has plenty of titanium bolts, and even a couple of aluminum bolts: the water bottle cages and seat clamp bolt are m6 alloy. So far, no issues, but I set them once and haven’t touched them since. There are even people who use nylon bolts for the cages.

    January 9, 2018 at 5:59 am
    • Jan Heine, Editor, Bicycle Quarterly

      The problems really occur when you remove the bolts and then replace them, etc. Also, at speed on rough roads, I suspect eventually, the heads of the aluminum bottle cage bolts will shear off – I doubt they’d survive something like the Oregon Outback…

      January 9, 2018 at 6:40 am
  • Tyler Evans

    Hey All,
    Just so you know, we are addressing the tire/crank arm/chainring clearance issues on titanium All-Road framesets. In the very near future, you will be able to fit 48mm tires on 700c rims, Dura-Ace cranks with 53-39t, and a chainstay length of 420mm. Our solution will also considerably stiffen the drivetrain.
    You’re welcome 😉
    Tyler Evans
    Firefly Bicycles

    January 9, 2018 at 7:17 am
    • Jan Heine, Editor, Bicycle Quarterly

      Tyler, thank you for weighing in. I look forward to the new solution. By the way, I didn’t intend this post to cast any doubt on your bikes. I love mine, and I think it’s as good as any bike I’ve ridden. I just wanted to point out some of the limitations of titanium as a material – just like all other materials have limitations, and every bike and component is a compromise that tries to optimize the bike in the face of these limitations.

      January 9, 2018 at 3:55 pm
      • Tyler Evans

        Understood. Clearance is an issue we are constantly up against. Narrow Q-Factor, larger tires and shorter chainstays doesn’t leave a lot of room for chainstays. Especially when making custom bikes. Every one is different, so there is no off the shelf solution or design that can be easily implemented across the board. I guess the real the trick is to not be afraid to evolve, embrace new technologies, and to be able to discern the difference between a trend and a fad.

        January 10, 2018 at 7:50 am
  • Dr J

    “But titanium has only half the stiffness”
    Stiffness is not really a measure of material properties since it depends on geometry. Titanium alloys have roughly half the Young’s modulus and tensile strength of steel, but tubes made out of titanium can have the similar stiffness if made in larger diameter.
    Basically, steel frames can be made from small diameter, thin wall tubes thanks to higher Young’s modulus and tensile strength and therefore remain lightweight, while Ti frames require larger diameter tubing to reach the same stiffness.

    January 9, 2018 at 7:51 am
    • Jan Heine, Editor, Bicycle Quarterly

      When I drafted the blog at first, I planned to talk about the lower tensile strength of titanium, but there are so many alloys that it gets quite confusing. In the end, the message is the same: Titanium parts need to be larger than steel ones to offer similar performance and strength – which can be an advantage or a disadvantage, depending on the part.

      January 9, 2018 at 4:12 pm
    • Stefan

      Tensile stresses of titan alloys can be in the same range as common steel alloys for bicycles (up to 1000 MPa).

      January 10, 2018 at 7:55 am
  • Paul

    Any material, other than steel, which is routinely flexed is going to break. Nothing can change that. If you look for super-light Ti or Alu bikes ridden by pro racers in the late 1990’s they are extremely hard to find unbroken. Marshall Major Taylor’s bicycles weighed 12lbs in 1895 and those all broke, too.
    I would most certainly opt for polished lugs and beautiful paint and craftsmanship over industrial-looking Ti if the costs were not too far apart. However, I don’t ask as much from my bike as you Hammerheads do.

    January 9, 2018 at 9:18 am
    • Jan Heine, Editor, Bicycle Quarterly

      Steel frames have an excellent reliability record. I raced my Marinoni for 10 years, more than 60,000 miles, many crashes… and it held up great. No significant rust, either, not even now, almost 20 years after it’s been retired from everyday duties.

      January 9, 2018 at 4:13 pm
    • Volsung

      Steel will break if you flex it too much of too often too. I’ve never met a paperclip that can handle my boredom.

      January 9, 2018 at 10:53 pm
      • Jan Heine, Editor, Bicycle Quarterly

        As you say, all materials eventually break, but paperclips don’t break because you bend them (going beyond the yield limit), rather than flex them below the yield limit. One of the reasons we use alloyed steels for bikes and not for paperclips is that they have a higher yield strength and thus can flex without bending.

        January 10, 2018 at 12:09 am
  • Han-Lin

    Another new material to keep an eye on is magnesium infused with ceramic silicon carbide nanoparticles. It has a high stiffness to weight ratio.

    January 9, 2018 at 9:23 am
  • Keith Gaunt

    In my way of seeing how cantilever brakes mount, doesn’t the stud that the brake mounts on take virtually all of the stress and forces of braking? ((Other than the rim of course) The bolt simply keeps the brake from loosening. A titanium bolt should be adequate for the job. Correct me if I am missing something here.

    January 9, 2018 at 9:44 am
    • Jan Heine, Editor, Bicycle Quarterly

      On the front, the brake is pulled forward quite strongly as the pad contacts the rim. I’ve seen brake bolts loosen, and I’d be wary of using a titanium bolt there. It’s a different matter for the rear brake, where the brake force pushes the brake further onto the canti post. There, you could use an aluminum bolt – in fact, I did that on my René Herse to save a little weight.

      January 9, 2018 at 3:47 pm
  • Virgil Lynskey Walker

    Thinking about the problem of tyre clearance (and to some extent durability) I’ve wondered about constructing a frame with a combination of steel and titanium. Couldn’t this be done by using the Ritchey Breakaway system; steel chain stays, seat stays & post; and titanium front end (top tube, down tube, and head tube)? You’d have a demountable frame for easy transport in a box & a great conversation starter. I also wonder whether steel and titanium could be bonded with modern glues, or joined via carbon fibre “lugs”.

    January 9, 2018 at 4:06 pm
    • Virgil Lynskey Walker

      In addition, whether or not you use different types of tubing, the Breakaway system offers the possibility of using slightly different front- or rear ends with existing parts of the bike, eg., a longer chainstay version for more rear loaded touring; or a front end with different head angle & fork. Just a thought.

      January 9, 2018 at 5:04 pm
  • Stuart Fogg

    I have a Lynskey Backroads titanium frame which differs in concept from the Firefly. The Backroads uses large-diameter tubing, making it somewhat heavy and very stiff. The weight doesn’t bother me and I like the stiffness with the long 108cm wheelbase. The rear triangle includes a solid plate on the drive side so it will accommodate a 48-622 tire with a normal road double crankset.
    Having corroded previous steel and even aluminum frames from copious perspiration I appreciate the saltwater resistance of titanium. I’ve also rusted out countless Campagnolo chromed-steel bolts so I now use only stainless steel fasteners.
    One advantage both steel and titanium have over aluminum and carbon is the availability of custom sizing.
    How come nobody has extolled the virtues of beryllium?

    January 10, 2018 at 2:07 am
  • tzeng

    How about stainless steel bike? Another better choice?

    January 10, 2018 at 6:33 am
    • Jan Heine, Editor, Bicycle Quarterly

      Stainless steel is an appealing material at first. Unfortunately, most stainless steels are more brittle than CrMo. Whether it’s stainless steel bolts or stainless steel frames, they break more easily than their CrMo counterparts. Modern stainless frame tubing seems to be better than in the past, but if you want to ride your bike hard and keep it a long time, CrMo probably is a better choice. The higher strength in real-world applications is also the reason why the bolts on our brakes are not stainless. We simply couldn’t make our brakes as strong and as light with stainless hardware.

      January 10, 2018 at 5:14 pm
  • Mark

    There’s a bigger myth here, one that is rarely mentioned, that is; that frames are built from titanium purely to save weight. While the goal of a lighter frame is one of the original reasons to build in titanium, over the years it’s become clear that titanium offers far more advantages than just weight over steel.
    Steel’s primary advantage over titanium is cost and ease of fabrication. Imagine if titanium were as inexpensive and easy to fabricate as steel. Would anyone ever bother building another steel frame? Mostly, no. Even with the higher cost and careful fabrication required of titanium, builders and riders embrace it. Why? It’s a better material for a bicycle frame than any other material. Incidentally, titanium frames are typically lighter than a comparable steel frame.
    The comment of titanium being a liability in close quarters such as the chainstays pictured is a stretch. This is not a limitation of titanium, but rather a limitation of the builder’s ability to make the required clearance. This is not a slam on Firefly, it’s been a challenge for titanium builders since the beginning. Looking at the photo, it is easy to see that if the S bend in the chainstay was more pronounced, there would be far more room for the crank arm. The bigger issue is getting enough clearance for chainrings. Q factor and chainline will always get compromised in a tight situation. Of all the design factors in the crank/BB/chainstay area, Q factor and chainline are the least important. If a modern chain can handle a 12 speed cassette, it can easily accommodate a few millimeters of tolerance on the chainline.
    Clearance in this area is not a problem with some good fabrication techniques. Bingham, Engin and others use 1″ chainstays with no clearance issues. The use of a machined yoke can completely eliminate these problems, and I imagine this is what Tyler at Firefly is alluding to when he commented, “In the very near future, you will be able to fit 48mm tires on 700c rims, Dura-Ace cranks with 53-39t, and a chainstay length of 420mm. Our solution will also considerably stiffen the drivetrain.” A machined yoke covers all these points, although there is a trade off with cost. Not sure if a stiff drivetrain is a good thing, some oil might help.
    Finally, bicycles cannot plane. To say they can is to misunderstand the meaning of the word and the physics of the action.

    January 10, 2018 at 11:24 am
    • Jan Heine, Editor, Bicycle Quarterly

      Mark, thank you for your interesting comments. You mention that “titanium offers far more advantages than just weight over steel” and “it’s a better material for a bicycle frame than any other material,” but you don’t mention any of those advantages. I can think of a few reasons to choose titanium (aesthetics being the most important one for me), but I don’t think your comment “Would anyone ever bother building another steel frame? Mostly, no.” is correct. Just witness the thousands of Keirin racers in Japan who order new steel frames every year. In fact, today, more steel bikes are being raced professionally than titanium ones. The point is that great bicycles can be made from many materials, and it’s silly to argue that one is vastly superior.
      As to the clearance issues, there are ways around it, but it’s not as easy as you make it sound. Fitting wide tires between narrow road cranks, while leaving enough room for sufficiently stiff chainstays, is a problem that bedevils all builders of allroad bikes – witness the dropped chainstay of the (carbon) Open and 3T bikes. Steel has the greatest stiffness-to-volume ratio, which is an undeniable advantage here. A machined yoke adds weight, especially if you want to get the same stiffness as you get with a tubular stay.
      With regards to ‘planing,’ it’s not a description of the physics, but of the observation. I don’t think anybody knows exactly what is going on when a bike frame gets in sync with the rider. We know it does, we can measure the extra power the rider can put out when it happens, but we can only guess at the physics behind it. Thus, a term that pretends to describe the physics would be misleading, so we chose a term that is purely an analogy. Arguing over semantics obscures the bigger issue we face: How do we design bikes that get in sync with their riders, when riders’ weight, power, pedal stroke, etc. are so variable?

      January 10, 2018 at 4:53 pm
      • Rick Thompson

        Jan – You’ve done a lot for cycling and got me back on my bike, but as a long time human powered boater I’m not getting the use of “planing” for bicycles. Human powered boats are almost always displacement designs, and get their speed from elegant design principles such as long aspect ratio, low drag hulls. The connection to the human and power transfer involves proper design of the flex characteristics of oars and paddles, the same kind of impedance matching I think you mean for bicycles.
        Planing boat designs use big motors and lots of horsepower to push the boat above displacement speeds, not at all elegant. They are faster, but less efficient per mile covered than a good displacement design. The transition from displacement to planing makes a huge ruckus and disturbs everyone around. Bikes don’t do any of that.
        BTW – A company I used to work for was a beryllium superfund site, not on my bike!

        January 10, 2018 at 5:53 pm
        • Jan Heine, Editor, Bicycle Quarterly

          Let’s not argue about semantics… Whether it’s ‘Q factor’ or the ‘entree’ you order as the main course at a restaurant, words are just symbols. What is important is what they describe. And for ‘planing’ bike frames, that is something very different from the ‘static’ (for lack of a better word) design elements of boats such as aspect ratio and low drag.
          Speaking of boats, Mark Vande Kamp wrote a piece in BQ 10, way back when we first started discussing ‘planing.’ He talked about the baidarkas, the Aleutian kayaks that were designed to be ‘light, fast, and flexible.’ The exploits of these kayaks have often been discredited in modern times as myths, but some suspect that the flex of the baidarkas was key to their performance.

          January 10, 2018 at 6:32 pm
      • Mark

        Jan, addressing your comments/questions from the top:
        Titanium’s advantages over steel are longevity, corrosion resistance,
        cosmetics and ride quality. Admittedly, the last two are subjective,
        but there is a lot of agreement from riders about these two, including
        you. Steel cannot begin to compare with the first two. I didn’t
        originally mention these qualities because I felt that other commenters
        had brought them up. Based on these qualities, I stand by my statement
        that, “it’s a better material for a bicycle frame than any other material”.
        Regarding race bikes, and particularly Keirin, you’re off topic. I made
        my comments with the assumption that the subject was custom built,
        consumer level recreational bicycles. One of the requirements of Keirin
        is that the frames are made of steel. There is no option for a Keirin
        builder to make a titanium frame. On the subject of race frames, they
        tend to be built lighter than a consumer frame, with a corresponding
        shorter lifetime. This may be why there are thousands of new Keirin
        frames made every year. I don’t feel that racing bicycles have a place
        in this discussion.
        I never said clearance was easy. As a matter of fact, I described it as
        a challenge. Steel does have an advantage over titanium in this
        particular area, but with the penalty of having to build a frame from
        steel. Clever builders have solved these clearance problems in
        titanium, and ultimately have built frames far better than their steel
        counterparts. A machined titanium yoke is slightly heavier that the same
        assembly fabricated from tubing, but is still lighter than the same
        assembly in steel, tubular or machined. Weight and cost may be more,
        but riders who are buying custom built titanium frames have the resources to pay the cost. This discussion concerns frames at very high price levels. Little of this applies to less expensive bicycles.
        I agree that a bicycle frame can be made from many materials. Among
        those materials, titanium has enough excellent qualities to qualify it
        as the best for custom built, consumer level recreational bicycles.
        “With regards to ‘planing,’ it’s not a description of the physics, but
        of the observation.” You’re searching for a word that describes a
        condition unknown to me. Boats plane, they’re called Hydroplanes.
        Aircraft plane, they’re called Airplanes. There is no surface vehicle
        known as a Terraplane, except for a defunct automobile brand. This is
        because surface vehicles do not plane. Semantics have to be part of the discussion regarding the proper use of a clearly defined word.
        Words may be symbols, but symbols have a specific meaning. You’ve
        appropriated the symbol for planing and made it into something else.
        This is the same as taking the symbol for zero, and unilaterally
        declaring that this symbol now has a new, undefined meaning, known only
        to you. As you say, “What is important is what they describe”. Zero or
        Planing both describe very specific things.
        Try using the word “harmony” as a description of this condition. Or, if
        you feel that “static” is the opposite of planing, maybe “dynamic” is a
        better word choice.
        Rick Thompson did a great job expressing his thoughts about planing.
        You got off topic again on baidarkas. Whatever the properties of
        this craft may be, they have nothing to do with the current discussion.
        If you do feel that a harmonic or dynamic condition exists, what you call planing, here’s a challenge:
        Using objective methods, 1)prove that it exists, 2)figure out
        the optimum parameters for such a condition, 3)come up with a description that doesn’t confuse people. If you can do this, you can go down in history as the person who revolutionized bicycles. Good luck!

        January 11, 2018 at 3:45 pm
        • Jan Heine, Editor, Bicycle Quarterly

          Mark, thank you for elaborating on the qualities of titanium. You mention four, so let’s look at them individually:
          – Longevity: With titanium, we don’t yet know how long a frame will last. Many of the early titanium frames broke, but let’s not hold that against the material. Presumably, we now know more about how to make a titanium frame. On the other hand, steel frames commonly last 70 years and more, even lightweight ones that are ridden hard. I raced for 10 years and 70,000 miles on a steel frame, including many crashes, some which rippled the paint, but the steel tubes and joints are fine. Conclusion: Steel frames last for decades; titanium ones – we don’t know yet.
          – Corrosion resistance: Titanium is more resistant to corrosion, but corrosion in steel is rarely an issue. So unless you ride through salt spray daily, I’d say this is a moot point – few steel frames suffer from corrosion (see also ‘longevity’ above).
          – Cosmetics: If you like raw welds, then titanium is nice, but I don’t think it matches the appeal of a finely crafted lugged joint. And if you paint titanium frames, as I see more and more, the paint seems to chip off more easily than on steel.
          – Ride quality: I must admit that I have never been able to feel the ‘magic ride’ of titanium. In my experience, other parts, especially tires and the fork (which is either steel or carbon), have a greater effect on the ride quality than the frame material. I suggest that the proponents of the ‘magic ride of ti’ do a double-blind test of a steel and a ti frame – same geometry, same frame stiffness, same components – and see whether the riders who think they notice a difference can replicate that under carefully controlled conditions. We did that with ‘planing’ because people were skeptical, and we were able to show that it’s real. Now it’s your turn! This would make a great Bicycle Quarterly article – let’s work together and make it happen!
          So if we are keeping score, I’d say that longevity probably goes to steel, corrosion resistance is a moot point, cosmetics and ride quality are a draw. It doesn’t look like titanium is a ‘far better material’ than steel.
          On the plus side of steel is the advantage of easier fabrication (as you mentioned in your original comment): racks, fenders, integrated lighting, etc., can be done relatively easily with steel, but I haven’t seen them done well yet in titanium. I wrote about that in this post.
          Once again, this post was not meant to deny the appeal of titanium bikes. I love my titanium bike, but I also love my steel bikes and my aluminum bike. It seems silly to say categorically that one material is better than the other. They are different, and depending on the type of bike you want, you have different choices. Each material has advantages and disadvantages, and which one you choose depends on what you want from your bike, and what appeals to you.

          January 12, 2018 at 6:11 am
    • Conrad

      As an alternative to planing: I think about the flex characteristics of a frame like those of skis. When you bend a ski in a turn, it flexes. At the end of a turn, the ski rebounds and returns some of that energy. Depending on your size, strength, and the way you turn- some will do better with stiff skis, some with comparatively soft skis. But that energy rebound is definitely happening!

      January 10, 2018 at 7:44 pm
      • Rick Thompson

        Last comment from me on this: BQ readers understand the planing term. Trying to explain to other cyclists and spread the word is awkward. Non-boaters don’t understand, you try to say it is a boating term applied to bikes. Boaters understand planing but know it is not the same meaning. I have stopped using the term in conversation, just too confusing.
        I will shut up now and go for a ride on my new Fitz steel rando with Snoqualmie Pass ultralights, which really does synchronize with my pedal strokes better than any previous bike!

        January 12, 2018 at 8:13 am
        • Jan Heine, Editor, Bicycle Quarterly

          I think the bigger issue isn’t the semantics, but the whole idea that a stiffer frame isn’t always better. It goes against a century of accepted knowledge in cycling, and yet more and more people in the industry are coming around to the idea that some frame flex is actually beneficial.

          January 14, 2018 at 12:16 pm
  • albrechtbeck

    Beryllium is toxic and carcinogen. Not just the ideal material to work with.

    January 10, 2018 at 1:34 pm
  • Matt Sallman

    Beryllium was used for cantilevers in high end phono cartridges, but the safety risks have stopped manufacture of them. Something as large as a bicycle would be many times the risk of a tiny cantilever.

    January 10, 2018 at 3:02 pm
  • Dan Eldredge

    Informative post and excellent discussion as usual. Is there a threat of galvanic corrosion between titanium and steel interfaces on titanium bikes? I may be wrong, but I assume dropouts are steel and threads (if titanium) will be used with steel bolts as you discussed for brake bosses. If the bosses or threads are steel, they are still connected to a titanium frame so there are dissimilar metals in contact. Much thanks, Dan

    January 10, 2018 at 5:33 pm
    • Jan Heine, Editor, Bicycle Quarterly

      Galvanic corrosion occurs when dissimilar metals touch, because a current flows from one metal to the other. Water makes it worse, because it improves the conductivity between the parts. It’s an issue with aluminum seatposts in steel frames, which tend to corrode in place, especially if the bike doesn’t have fenders.
      Titanium bikes have titanium dropouts, so that isn’t an issue. As to steel bolts in titanium braze-ons, I suspect that is why there are products like ‘Titanium Anti-Seize.’ I haven’t encountered problems, but I usually lubricate the bolts with beeswax or grease. I know that some car restorers don’t use stainless steel bolts, because they tend to suffer from galvanic corrosion when threaded into non-stainless parts.

      January 10, 2018 at 5:45 pm
  • Owen

    Slightly off topic, but I’m curious about each metal’s flex characteristics as they relate to shock absorption, particularly in “cockpit” components such as handlebars and seatposts. I’ve heard anecdotes of old MTB riders claiming their CroMo Bullmoose bars were great at shock absorption, and the current gravel crowd seems keen on titanium seat posts for the same reason. Do steel and ti have advantages to aluminium in these applications?

    January 10, 2018 at 5:33 pm
    • Jan Heine, Editor, Bicycle Quarterly

      Absolutely. The difference in stiffness is easiest to feel in saddles, because the rails are cantilevered and thus easy to flex. Anybody who’s ever ridden one of the classic Idéale saddles with tall aluminum rails knows that they feel stiff, and the difference between a Gilles Berthoud saddle with steel and the same model with titanium rails is noticeable, too.
      With seatposts, the difference is smaller, since they are more vertical, and how long the seatpost extends probably makes the biggest difference. Another question is how much flex you want – especially on a seatpost that will also flex laterally to the detriment of the bike’s handling. I’ve seen this especially on tandem with a very small rear compartment and a huge seatpost – the flex made it hard to keep the tandem going in a straight line.

      January 10, 2018 at 5:55 pm
  • B. Carfree

    I don’t know much about materials science, maybe even negative knowledge. I’d like to hear what folks who do know this stuff think about this piece on titanium vs steel written by a local bike shop/frame builder, particularly the part about reliability.

    January 12, 2018 at 10:57 pm
    • Jan Heine, Editor, Bicycle Quarterly

      That is an interesting analysis by R&E bicycles. Much of it mirrors what I wrote in the post above. I am not sure about their claim that steel frames are lighter – the idea that a titanium frame of the same weight will be more flexible isn’t borne out by simple physics.

      January 16, 2018 at 8:44 am

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