Bicycle Design

How light is too light?

In keeping with the weight theme from the last two posts, I want to pose a question; how much lighter can bikes get? Scott’s 6 kg (13 pound) Addict road bike received a lot of attention at Interbike last year. The Storck Fascenario, which Posh Bikes claims to be the lightest bike in the world, is built up with carefully selected parts to make a 4 kg (sub 9 pound) complete bike. The custom fixie Crumpton that I posted the other day weighs less than 3.5 kilograms. Wow, that certainly seems like the lower limit to me.

I love modern lightweight bikes, but as a rider, I don’t have much interest in testing the limits of weight versus durability. My 8+ kilogram road bike, which I consider light, might seem heavy by weight weenie standards. Call it heavy if you want too, but I wouldn’t feel comfortable on a 50 mph decent with some of the ultra light parts that I have seen on the market in recent years. Some of the new products that I see bring to mind the component drilling craze of the 70s and 80s. Some parts broke then because people modified them to a point below the limit. I just wonder if some of the new factory parts out there are pushing that same limit. Any thoughts?

Vintage drilled Campy shifter photo from Velo Retro

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James

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13 responses to “How light is too light?”

  1. Anonymous Avatar
    Anonymous

    the top quality parts out there are trustworthy, but when you look at immitation price piont knok off parts, then yeah its sketchy on the 100kmph downhill.

    Reply
  2. Tim Jackson- Masi Guy Avatar
    Tim Jackson- Masi Guy

    My bikes are not the lightest on the market and I doubt they ever will be.

    For a reason; ride quality. I have yet to find an ultra light bike that has a good road feel or feels steady and reliable on a quick decent/ fast corner. Light bikes, really light bikes, are really only good for a season or two and then you buy a new really light bike. Look at the new European testing standards; products are about to get heavier because the ultra light parts are failing. Now products will get a bit more reliable. I think it is a good thing, personally. But then again, at over 200 pounds and a track sprinter, I break really light stuff. So a little heavier gives me a chance to ride a few more cool tidbits.

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  3. Edu&Nano Avatar
    Edu&Nano

    Maybe the key is in the design actions, Are there any standard actions design rule for bycicles? I guess this just remain on the engineering deparment of bycicle builder. May Masiguy could answer that.

    Making lighter bikes, makes stresses going up and as wisely point Masiguy, reduce the lifetime for a bike. the increasing in stresses, reduce the comfort, good working, and safety, because the design criteria(actions) are not quite clear, and some manufacturers could go further than reasonably(even wihtout knowing) and fails are more usual than desirable.
    More tensions-less stiffer is anohter point to involved.

    The lightweight pursuit is quite interesting as a concept for improve the rest as an exercise to have good ideas for more reliable parts. Remember UCI has limited the minimum weight for a race road bike, I guess for stopping this before a realiability limit was reach.

    Edu

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  4. James Avatar
    James

    Tim, I agree with you. It’s time for the weight/durability pendulum to start swinging the other way a bit. For pros, bikes are disposable, but that is simply not the case for the average consumer. I will say again that I do love lightweight bikes, but some of the current lightweight craze is probably driven more by marketing than by true engineering and materials advances. That is pretty scary to me. In 20 years of riding and racing, I have seen a few catastrophic part failures that resulted in serious injuries. For anyone who has not seen it first hand, trust me, you don’t want to break a handlebar or seatpost during an all out sprint. Manufacturers need to remember that he average rider puts a lot of faith in his or her equipment. In most cases, that trust is warranted, but unfortunately, sometimes it is not.

    Edu, you mentioned the UCI weight restriction. Those restrictions have little to do with safety; they are supposedly about leveling the playing field. I am not at all a fan of any of the UCI restrictions, but I don’t believe that we would see a bunch of pro teams riding on 4kg bikes if the 6.8kg weight restriction were suddenly dropped. Sure they might use ultralight bikes for climbing (probably with a bike switch at the top) but I seriously doubt that they would use them for most road races and stages. Of course, I could be wrong (note to UCI president Pat McQuaid: Why don’t you drop the weight restriction so we can see what happens in the peloton).

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  5. Edu&Nano Avatar
    Edu&Nano

    James: My main worry on that is engineering is the big forgotten on this weight crazy. All we know that the kind of stress involved in bicycle riding(dinamyc)drives to a brittle fracture, this should be enough to scare all those weight freaks. I think if Pat MQ drop this restriction we will see more catastrophic failure parts in race. You are right this restriction maybe is more for fair play, but as an indirect effect we have stopped this weight crazy on Pros, safety of the pros is the hidden benefit of this measure. I have see some failures on race but Hincapie´s on Paris Roubaix is the most scariest for me. I don´t know anything about the causes of that. As a secondary effect for that is the negative marketing image given.
    Masiguy you don´t know that for Masi.

    As a conclusion I am agree with you, there´s not enough engineering behing this marketing crazy.

    Edu

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  6. robodobo Avatar
    robodobo

    I disagree. People have used this “ultra light bikes don’t handle well” excuse for ages. When 20 lb bikes were the norm, people said that about 18 lb bikes.Yet, the pros’ bikes, bikes they trust their lives to on a daily basis, are routinely at the UCI minimum of 14.7 lbs. This weight was unheard of just a few years ago, but today can barely even be considered ultralight. The pros still use ultralight frames and parts, but since they must now meet the arbitrary weight limit imposed by the UCI, things like SRMs and deeper section aero wheels are used to round out the weight. Other companies, like Cervelo have chosen to hone the aerodynamics of an ultralight frame. It has become quite common for the club racer, not restricted for the UCI, to have a lighter machine than the world’s top cyclists are allowed to use.
    I have been involved in the sport for well over 20 years and believe me, my 15 lb Scott CR-1 and Giant TCR Advanced bikes in XL size are stiffer, more compliant over bumps, lighter, more durable and just plain faster than any bikes I have ever ridden. I have had top end steel, aluminum, titanium and carbon bikes and refuse to ride parts that are finicky, disposable or questionable in any way. When they sport carbon race wheels, both of these bikes are easliy UCI illegal.
    Tim, perhaps Masi bikes will never be the lightest because Masi is no longer a true innovator and has lost its spot at the top of the food chain. The Masi of old pushed the envelope. People thought that the wall thickness on the original 3V was impossibly thin. Masi now seems content to just capitalize on what was once a great name, offering great bang for the buck and the somewhat tarnished image as one the the great brands of the 80s and 90s. I am sometimes saddened to see the mystique disappear in brands after a buyout or change of ownership, like Motobecane, GT, Syncros and Schwinn. Masi was once held in the same high regard as Pinerallo, DeRosa and others. Now, even the price of the vintage Masis on Ebay has been negatively affected by the new breed of Masis.
    The top companies push the envelope not only with design, but with engineering to back up that design. The Scotts and Cervelos ridden by pros have held up to very impressive failure testing. Hincapie was using an aluminum steerer tube that failed. It was hardly a cutting edge part, when the majority of pros have used carbon steerers for years.
    James, you state that for pros the bikes are used for a season and then retired. This has always been the case and thse pros give the bikes more abuse over that year than most of us could give them in a lifetime. There are plenty of weak parts out there, but parts like Ritchey 4Axis stems, Easton posts, bars and forks and SLR saddles are pretty well proven as both light and strong.
    Having said all that, aerodynamics still plays a much larger role on the average bike than does weight. The rule still makes no sense and is not for the safety of the riders. It would have made far more sense for the bike to have been limited to a certain percentage of a riders body weight, like maybe 8%. Certainly a 115 lb rider should not be limited to the same weight bike as a 210 lb rider. Should he?
    I don’t mean to unfairly criticize what the Masi of today is either. Clearly, they are very nice bikes at a price that is more than fair. However, I see little evidence of a pendulum swing away from light weight. The Scott Addict is a lighter versin of what already was one of the world’s lightest bikes. The new Lew wheels are 800 grams per pair.

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  7. Tim Jackson- Masi Guy Avatar
    Tim Jackson- Masi Guy

    Robodobo- Masi is decidedly a different breed of bike now. Believe me, if we had the resources to fund more design and development, we would- have to walk before you run. I can assure you that we are not “content to just capitalize on what was once a great name”. We really believe in what we are doing and that we are making every effort to remain true to the wonderful heritage. We sweat the details like you wouldn’t believe for a company that amounts to less than 1% of the road bike market in the US. It’s totally disproportionate to our size. I am lucky that Haro (my parent company) continues to fund the brand. Without it, it would no longer exist- other than as a faint memory.

    As for bringing down the value of the vintage bikes… I think that is debatable. Other than once the brand is no longer being made (hopefully long after my death), the value will increase for all bikes with the Masi name- simply because there will be no more made.

    As for the weight argument of bikes and parts… I agree and disagree. Some parts are holding up just fine at super low weights. Others are not. I’ve seen lots of scary failures of parts over the past few years- failures that I never saw in years past. Does that mean the new parts and technology are flawed or bad? No, not at all. It just means that the average consumer, one who frequently overtightens his/ her stem bolts is walking on a fine line between safe and unsafe. One that could possibly kill a person. Carbon parts require way more scrutiny than aluminum or steel- same for frames and forks- but most average consumers don’t spend the time to check these things out or know how to quantify what is safe or unsafe. Hell, many shop rats can’t tell either. That is what personally concerns me.

    I race a carbon frame with carbon fork with carbon steerer tube, carbon stem, carbon bars, etc, etc. I am 210 pounds and a track sprinter. I break lots of stuff. BUT… I have access to replacement parts on a frequent basis and “retire” stuff often. And yes, now and again I have those scary thoughts of “what if” when I’m flying down a hill at close to 60mph. That said- I did the same thing when I raced steel bikes in the early 80’s.

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  8. James Avatar
    James

    Robo, I have been riding road bikes for as long as you, and I agree, bikes now are better than ever. You are also correct that “lightweight” is very much a relative term. What was considered light in the 80s is considered heavy now because of advances in materials and processes (and that is a good thing). I can say with certainty that I would feel much safer flying down a steep descent on your 15 pound Scott Addict than on an old 18 pound “ultra-light” lugged SLX bike with swiss cheese drilled Campy components. For the record, I don’t think the Addict is a scary light bike (If anyone at Scott wants to give me one, I’ll gladly ride it) The Fascenario weighs over 33% less that your Scott. I have no idea what it feels like to ride a 9-pound bike, so I am not going to guess. I also don’t know if that is the lower limit based on current material options, but it sounds like it is approaching scary light to me. That is why I posed the question. You have to admit that there IS a finite limit to what is a safe weight for bikes made from any given material. For carbon that safe weight is going to be lower than steel because of the material properties, but the limit still exists. For example, you could make a steel frame that weighs 1.75 pounds like your Addict, but that doesn’t mean it would be safe to ride. Engineering advances that make bikes lighter should be just that, engineering advances. I think that Scott, Cervelo, Giant and the other companies that you mentioned have the resources to make sure that they are releasing safe, well designed products. I get nervous when I see ultra light products from the some of the smaller companies without those resources. I am afraid that some of those parts are not thoroughly tested until they land on the bikes of consumers. Tempting as it may be, marketing people should NEVER make the decision to shave a few grams of a part to compete in a weight obsessed market, those decisions should be made strictly from a engineering perspective. That is really the point of this post.

    On the subject of vintage Masis, I saw an early 80s Prestige with Super Record go for around 1400 bucks on ebay last week; pretty good for an old heavy steel bike. It seems to me that those bikes are just as collectible as ever.

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  9. James Avatar
    James

    Oops, I meant to say CR1 when referring to your bike Robo. You would have to put a powermeter on the Addict to get it up to 15 pounds.

    Reply
  10. robodobo Avatar
    robodobo

    I’m not so sure that Haro is so interested in keeping the Masi name alive and its heritage as much as simply trying to capitalize on its name recognition and trying to go downmarket.While Masi may still produce a pro level bike, I’d guess sales figures are pretty low for that model. Masi is now perceived as more of a value oriented company. Has Masi remained in continous production, or did Haro just buy the name and revive production with new models using the long established model names?
    I’m happy to see that you sweat the details. I particularly like the stainless steel dropout inserts on your aluminum track frame. Track axles and nuts chew aluminum pretty quickly. I wish Masi well and am always happy to have another choice of bikes at buying time.
    I concur that today’s bikes require different care than the bikes we rode in the 80s. My old Campy Super Record friction shifting didn’t require much fiddling. On the other hand, today I don’t have to unwrap the bars and take off the brake levers to try a different length stem.You win some and lose some. Today, torque wrenches are a must, but so are lots of other tools. My Cannondale Scalpel mountain bike has hydraulic brakes, tubeless tires, front and rear air sprung, oil damped suspension systems that all take special tools, techniques and parts.
    Bikes have become very specialized and people often disregard the intended purpose of parts and see tragic consequences. How often do we see the biggest weight weenie is often the fat bellied and fat walleted guy. 210 lb guys don’t need to train on Zipp 202s on rough roads. To most of us, that is common sense.
    There is an old saying about bike parts. Light, Strong, Cheap: Pick Two. This old addage has a lot of truth. Strong, lightweight parts are often expensive. Even price is no guarantee of strength so beware when you buy.

    Reply
  11. Edu&Nano Avatar
    Edu&Nano

    Well, so quite interesting comments,

    Prestige and Bussiness: Many brands in the world keep a glory days legend, but this cannot leave the Engineering forgotten. Look at Campy and Suntour in the end of 80´s and beggining of the 90´s. Two brands with big problems due to Shimano and take different strategies, with the result that we see. Main worried on the top world brands of one who wants to see it should be engineering. The prestige of the brands is supported of that. The biggest value on parts and bikes is the reliability than the riders put on them.

    Testing Ligwth parts: I believe only a few brands do enough tests on this components. This a direct consecuence of the balance engineering-marketing, these deparments are often divorced in the brands. Engineers want to test more and go further, Market guys want to drop the product on the market. In this competitive market only brands with a real compromise in his reliability image, his prestige and his engineering department cand hold that at a reasonable point.

    Small brands: Small companys are basically under my opinion in two types. Those who are ambitious and they are whising to grow and others who are focused on doing-well-things. All we know many examples on both. The dangerous ones are the first for the reasons that James has exposed ( less resources-more risk assumed). So take care what are you buying.

    Capytalize brands: I guess robo is refering sad examples that we have Schwwin is one of the saddest for me, the people on this bussiness should know all the emotional charge put a rider in his bike, and when this a brand is over and refund, they should keep all the things that had make this brand big in the past, keep the past, and change the present to make a big future. In other case the past buyer of this brand should be disappointed with the present and he´ll be in the future.

    What is Masi doing?: Well, I don´t know the brand,(I´m European)but the future will place in where it should be, Where is this. Afortunately that depends on what Masi do in the present and in the future. The legeng is writting everyday. The way to bankrupt too. Remember really big mistakes ussually are so obvious and are well known for all the people in the company, It important to be aware of critics and try to find what remains in the bottom of them. We should listen to everyone,and do according with your own.

    Edu

    Reply
  12. Edu&Nano Avatar
    Edu&Nano

    I´d like to add some additional comment, about the fatal fails that Masiguy comment are more often in recent times.

    Steel and Titanium has a two fanstastic properties to help mechanichal engineers, these are isoptropy and ductility, those keep many unknownlegde and mistakes hidden and give really quality and durable rides, and both are fantastically weldable, wiht relative “easy-to-make” procedures.

    Aluminium has a ductility, fatigue, and weldability difficults not passed by all the manufacturers

    Composites (Carbon, etc)are really crazy materials, the should be specially calculated and engineered, because they are anysotropy and really low ductility. This drives to a really castastrophic fails when knowledge of the material, engineering or testing is not really good and carefully made. Additionally composites fracture mechanism are brittle.

    In recent times we´ve really new an fantastic materials, but we´ve less experience on them and we´re more hurried on engineering, maybe due to tools for engineers are more advanced (FEM analysis, etc, but testing is the same boring an long stuff, and it´s essential in engineering for check that the hypothesis are working fine, you cannot go over of enough test procedures.

    Sorry for this freaking long comment.

    Edu

    Reply
  13. Anonymous Avatar
    Anonymous

    the road bike rider newsletter that just came out today talked about the danger of ultra light parts if they are not replaced regularly . I don’t think they have a link on the website yet though.

    Reply

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