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Bicycle Tech Drivetrain Advances Showcased 412

Posted by simoniker
from the penny-farthing dept.
whoda writes "For many years, bicycles have had very few advancements in drivetrain technology. This is finally changing. The newly formed g-Boxx Standard has been incorporated into the new Nicolai Nucleon TFR bicycle frame. This bike uses an internally geared 14 speed planetary gear system, mounted in the center of the bicycle, to drive the rear wheel using a conventional chain. The design allows the chain to run inside of the frame. This removes many fragile components from the bicycle, and allows a more rigid frame structure to be made. Evil Bikes have also shown a protoype Evil 2013i hardtail which also incorporates this new standard - I've found the toy I want for the holidays."
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Bicycle Tech Drivetrain Advances Showcased

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  • Internally Geared (Score:3, Informative)

    by Anonymous Coward on Saturday November 15, 2003 @08:07PM (#7483812)
    Internal gearing in bicycles is not, new, it just never catches on.
    • you are correct, they are nothing new at all. They have only seen use in plane jane bike like you rent at the beach and so forth. The design is heavy and not very versital. Same as bikes with automatic gearboxes, they just arn't going to take off
  • I don't know... (Score:4, Insightful)

    by Anonymous Coward on Saturday November 15, 2003 @08:09PM (#7483825)
    This just means now that if something breaks down, it would be hard as heck to get at it. Parts inside the frame? Kind of hard to do trailside maintainence on that! (Especially since it's not from a well known component manufacturer.

    I'll wait until I see it on the World Cup circuit before trying it myself...
    • Re:I don't know... (Score:5, Informative)

      by Gudlyf (544445) <`moc.ketsilaer' `ta' `fyldug'> on Saturday November 15, 2003 @08:36PM (#7483945) Homepage Journal
      Well, according to the site, the maintenance should be limited. Specifically for the EVIL transmission bike without primary drive and open secondary drive:

      Benefits

      • low maintenance transmission
      • low unsprung weight
      • freedom to design specific front and rear sections of the frame
      • light weight
      • use of simple rear hub possible
      • good wheel travel
      • changing of gears is possible without pedaling (my favorite)
      • platform compatible

      Limitations

      • need for chain tension device
      • secondary drive chain is open to outside influences
      • small amount of chain growth
    • All bicycle innovation is welcome, but...
      It usually is absurd, pointless, and only of interest to either professional racers or the people who will spend for a bicycle than a used car.

      What we bike riders really need is:

      1) Tires that don't go flat! Or, rather, I should say... tires that don't go flat and only cost two or three minimum wage units. $15 US. Yes there are Kevlar tires that are as thin as your thumb and cost $200, hold 100 PSI air pressure, and rarely go flat, but they don't count.

      2)
      • Snow is generally softer than the front of an oncoming bus, and the probability of being sideswiped by two tons of barely-controlled 4x4 is considerably lower on the piste than it is on busy roads during rush-hour.
      • by legLess (127550) on Saturday November 15, 2003 @10:28PM (#7484383) Journal
        In fact, I HATE bicycle helmets. Their sole purpose is to show all the people driving around that the person on the bike is middle class, [snip]

        I've ridden 10s of thousands of miles and I'm here to say that a bicycle helmet is an absolute necessity, period. I've completely destroyed two helmets and scraped several more. I once scraped right through the plastic cover of a helmet and well into the insulation. If I hadn't been wearing it my scalp, hair, and a decent chunk of skull would have been left behind on the road.

        "But," the yuppies tell me, "you NEED a helmet for safety!

        Yes, you do. It's a matter of when, not if. Every cyclist wrecks, and some wrecks you land on your head. Why would you not want to protect your head?

        It should be illegal to ride without one."

        On this we agree: the government should stay the fuck out of decisions that affect only my own health. Anyone above the age of consent should be able to ride anything with as much or as little safety equipment as they desire, as long as no one else is at risk of harm. Mandatory helmet laws are like anything else the government does "for your own good:" dangerous.

        • I've had a similar skull saving from a helmet. As a mountain biker I'd have to say I'm as much or more concerned about the helmet protecting me from things above head height than just protecting my head from the ground.

          I remember riding some single track once, where someone had sawed off a overhanging tree branch - only they didn't go quite far enough back - so a nice cleanly cut 4 inch branch was hanging right at head height. Unfortunately for me it was just above the level where my visor blocked it fro

        • There is an old adage in the motorcycle industry that goes, "if you have a cheap head, wear a cheap helmet." I think that speaks volumes about people who don't want to wear helmets...
        • by Anonymous Coward
          Sorry to pick on you but the fact that you are chronically destroying helmets may be a good argument for you to wear a helmet but is not enough to prescribe a universal need. People both inside and outside the US (the Europeans sometimes call helmets the "American Obsession") have been riding bicycles to get where they are going for over 100 years and they have not been dropping like flies, regardless of what the fear mongers would have us all believe.

          Despite common knowledge to the contrary, cycling prop
          • ...Yet nobody even remotely considers wearing a helmet before crossing the street or climbing in the car

            Hey, I'm all for it
            Driving helmets for soccer moms!

            It'd be of absolutely no practical use whatsoever, especially as they're usually the ones who come out safe after they kill 20 people driving through a parking lot while on the phone and getting the baby's bottle, but who cares, it'd make them look ridiculous.

            Maybe the helmets could be "Beware! Fucking idiot!" in big letters on the front or something.
        • maybe if you actually pay yourself for all the expenses that come(through insurance and whatnot) when you get hospitalised after you wreck your head into coma it should be legal to ride without a helmet.

          but when the state pays for majority of expenses in the case you get injured and disabled for the rest of your life the state can except you to take good care of yourself(and wear seatbelts, and wear helmets).

          mandatory helmet laws are like mandatory seatbelt laws, for your own good AND to safe the govermen
      • 1) Tires that don't go flat! Or, rather, I should say... tires that don't go flat and only cost two or three minimum wage units. $15 US. Yes there are Kevlar tires that are as thin as your thumb and cost $200, hold 100 PSI air pressure, and rarely go flat, but they don't count.

        Firstly, those $200 tires go flat just as easily as cheap tires on pavement (i.e. a piece of glass or nail). They are $200 because they're light (by way of having a high thread per inch count) and they're grippy (fancy rubbers and

      • 2) Something to keep the rain and road dirt from putting a big skunk stripe up our backs when riding in wet climates. There are fenders, but they don't work well.

        I don't know what you're talking about. A full set of wrap-around fenders is a solid barrier between the wheel and you, and the bike. They protect your back and butt from the rain thrown up by the wheels, and protect the bike quite a bit as well. I bike year round and know this from experience. I'm partial to the SKS fenders myself, but other bra
      • This year, you may (or may not have noticed) that every rider in the Tour de France was wearing a helmet. They're only allowed to take off their helmets for the last 5km or so of a race when the finish is uphill. Why?

        Well, earlier in the year, a nice young rider with a 2 month old son went over his handlebars in a low speed crash. He bumped his head on the ground, and never woke up. From all accounts, Andrei Kivilev was a nice guy just trying to make it as a pro.

        He was apparently the last straw. Finally, the UCI has instituted mandatory helmet laws for all riders. It's not because it's flashy, it's because they CAN save lives. It's not a guarantee, but neither is a seatbelt.

        The bike that you're asking for is constantly being aimed for, not by bike companies, but by people that try to develop cheap bikes for third world countries, where they're actually a fantastically important asset. Hopefully, they'll also make bikes domestically. I think that something like what you're suggesting could bring cycling back to our overly sedentary society. What we need are cheap, effective helmets and cheap effective bikes. In that, you're totally right.
        • ..What we need are cheap, effective helmets and cheap effective bikes. In that, you're totally right.

          And a community designed where a bike is the most transportation a person needs to own. Much safer ride withou the cars... human-scaled cities.

        • This year, you may (or may not have noticed) that every rider in the Tour de France was wearing a helmet.

          And every driver in NASCAR/F1/USAC also wears a helmet.

          The TdF has as much to do with most normal, everyday riding as NASCAR has to do with driving to work.

          Appropriate equipment for the situation. If I'm tooling a mile down to the store, the helmet is pretty unecessary. If I'm in a 40mph pack on a fast downhill...that's a completely different situation.
      • In fact, I HATE bicycle helmets. Their sole purpose is to show all the people driving around that the person on the bike is middle class, has a car at home, can afford a $100 helmet, and is seriously concerned about saving the environment to the point of actually going out into the public on a bicycle. The guys who don't speak English and ride a bicycle because they make $7 an hour and have four kids aren't wearing helmets.

        When you crash and go quadrapalegic, everyone else's insurance dollars will have to
      • I wear a helmet because if i hit my head with a helmets it hurts less.

        See, all your indulgent masterbatory pseudo intellectual drivel asside, it comes down to; Helmets are good, They make your head hurt less. All other nonsense is crap.

      • I live in Holland, where everybody and his dog has one and a half bikes and ride the complete one. People laugh at bike helmets for a good reason. we just made sure we don't need them(if your doing 50 km on a small inroad it might be a different matter, most people use bikes in and around the city). We just made sure that there are good bikelanes or bikepaths with clear crossings. on top of that the law was changed to make motirized drivers responsible for all damage if they have an accident with a bike (or
  • Still using chains? (Score:5, Informative)

    by Anonymous Coward on Saturday November 15, 2003 @08:10PM (#7483830)
    How about shaft drive [chainless.com]?
    • by Anonymous Coward
      No. Sorry shaftdrives are fundamenatally less efficient than chains. Its to do with translating the energy from one plane to another. And it has to happen twice in a shaft drive. Motor bikes use them a fair bit, but efficiency is less important here. And you will never ever find a grand prix bike with a shaft drive. So, serious (distance covering) bikes will never have them.
    • Cycling geeks are fanatical about weight. The worry and fret about every gram. I don't think shaft drives will catch on anytime soon.

      It's hard to imagine any system being simpler to make and maintain then a chain drive. Maybe using belts would be some help (no lubing) but you'd still lose the ability to repair your chain on the road.

      The only reason to pay more for a heavier bike is a recumbent. They are much more comfortable to ride all day even if you can't keep up with the wedgies.
      • by drinkypoo (153816)
        Ever heard of carbon fiber tube? It's inexpensive, and if you need to make it stronger than the preformed tubes provide, you can wrap it in a "sock" of tubular-woven carbon fiber, stretch it tight, and put resin over it.

        Calfee is now working on carbon fiber recumbents, which are being designed by fast freddy, who formerly had the bicycle land speed record on an Easy Racers gold rush with a fiberglass shell.

        Maybe you can repair your chain on the road (if you have some links, and a chain tool) but chains

        • " Ever heard of carbon fiber tube?"

          Yes. But I don't see the relavance here? Are you talking about a carbon fiber shaft drive system? I certainly don't see that happening anytime soon. maybe you can encase the shaft in carbon fiber but the gears would have to be made out of metal.

          "Calfee is now working on carbon fiber recumbents"

          Great. But the fact is that a recumbent will still be heavier then a equivalent wedgie. A CF recumbent may be lighter then a steel road bike but it won't be lighter then a CF road
          • I am talking about a carbon fiber drive shaft system. You can make most of the gears in it (except the outer part where the teeth are) out of carbon fiber if necessary, but you're better off with aluminum, with steel teeth attached to that, if you are really concerned about weight.

            There are lots of cars out there with carbon fiber drive shafts on them. We're talking vehicles with several hundred foot-pounds of torque, here. The tiny amount of power applied to a bicycle drive system would be trivially sent

  • Muckety muck. (Score:5, Insightful)

    by Anonymous Coward on Saturday November 15, 2003 @08:12PM (#7483836)
    Look at that photo carefully. Notice that part of the chain is exposed. Now just were do you think all the road dirt and other muck is going to end up?
    • "Look at that photo carefully. Notice that part of the chain is exposed. Now just were do you think all the road dirt and other muck is going to end up?"

      Um, perhaps on the frame encasing the majority of the chain? Man, is that a minor pesimistic gripe.

    • were do you think all the road dirt and other muck is going to end up?

      On the plastic cover that was removed for the photo? If there is none, it would not be hard to make. Considering the 40 lb curb weight of this anchor, you might as well make the cover out of cast iron. Now that's durable!

  • good idea but (Score:5, Insightful)

    by zymano (581466) on Saturday November 15, 2003 @08:13PM (#7483843)
    Sounds good for mountain bikes that need to protect the chain and sprockets but might add some unnecessary weight to roadbikes.
    • Re:good idea but (Score:3, Informative)

      by kidlinux (2550)
      That was my thought immediatly upon seeing a picture of one of the bikes. Looks like it adds a ton of weight. The only thing I could see this being used in is a downhill bike, because weight isn't as much of an issue. But no one riding on the road or riding cross country will ride one of those things.

      I ride and race a lot of road and x-country, and I for one would not use one of these for either of those.

      I think the intention is for downhill though. Stronger frames, less exposed parts, the pictures I
  • by Beryllium Sphere(tm) (193358) on Saturday November 15, 2003 @08:14PM (#7483852) Homepage Journal
    >16-19kg (35-40lbs) for a complete bike

    Comment would be superfluous.
  • Stoopid (Score:5, Insightful)

    by Anonymous Coward on Saturday November 15, 2003 @08:17PM (#7483864)
    The Q looks horrific, the weight is high, the chain is still exposed, there's no easy way to clean the frame out when it gets filled with the muck and water that the chain will inevitably drag in, the lanetary gearing is less efficient than a pure chain drive. Yeah, I can really see why you'd want that setup: to look like an idiot with a fat wallet and a small brain. Oh, and prepare to be savaged by rec.bicycles.tech, where the posters actually know a bit about the technical issues.
    • That brings back memories of my Bridgestone MB-1...ahh, those were the days. I still hadn't caught on to computers, and bicycles were my great love. To tell the truth, I do live in Italy now, and ride a sweet custom Morello steel ride with campy parts, although I spend too much time with the computers and not enough out riding...

      Bridgestones were nice bikes. High quality, low on buzzword crap. Light, fast, strong. I miss the days befor suspension and "gnarly d00dz extreme sportz" got ahold of mountain
  • by earthforce_1 (454968) <earthforce_1 @ y a h o o . c om> on Saturday November 15, 2003 @08:24PM (#7483896) Journal
    Driven through a continuously variable transmission, like those used in many motorcycles. They are more reliable, less prone to breakage than a chain.

    I remember seeing bikes with elliptical gears in an old popular mechanics they claimed match the power transfer curve of the human body, that would lower the gear ratio at the point you have less energy to push. They said it was about 20% more efficient or something like that, but I never saw it catch on much. Maybe the patent fees were too high.
    • by voodoo1man (594237) on Saturday November 15, 2003 @08:28PM (#7483912)
      I believe those were introduced by Shimano as the "Biospace" (or at least Bio-something) brand chainrings. Didn't catch on much because most people found the pedalling to feel jerky, or so I heard. I've also heard that they're still sold.
      • You're thinking of Shimano BioPace chainrings. I still have a set on an old mountain/messenger bike and they rock for high RPM grinding on the pedals up the steeps, but you do notice them on the street. But then they weren't designed for street AFAIK.

      • by dan_b (982)
        Biopace. Some people liked it, others didn't. These days everyone's using clipless pedals anyway, making for much smoother power transmission all the way around and elliptical chainrings yet less sensible.

      • Close - Biopace. Now thing about your deraileurs - the back is moving back and forth keeping tension, and the front has to be setup to clear the high spots, but still work on the low...
  • by whoda (569082) * on Saturday November 15, 2003 @08:24PM (#7483897) Homepage
    They are raced on some of the most demanding downhill courses in the world.
    They are strong and have an excellent reputation by hardcore mountain bikers.And 40 pounds for a complete bike of this type is fairly light to be honest.

    There are videos available from the main Nicolai Home Page [nicolai.net]
    • So are they UCI approved? I know there is a lower limit on weight for road cycling (6.5kg I think) but giving the UCI's penchant for making weird rules they might not allow rad drivetrains and all. IIRC, the derailleur was illegal until 1977 on the Tour (Tour rules didn't allow them). Also, downhilling is the domain of people who would be considered suicidal if no such thing existed.
    • And 40 pounds for a complete bike of this type is fairly light to be honest.
      40 pounds??? my fully xtr equipped bike is just slightly over half that! (~23 pounds) '99 specialized FSR fully upgraded
  • Pure fun (Score:3, Funny)

    by Dr. Spork (142693) on Saturday November 15, 2003 @08:29PM (#7483916)
    According to the article [rohloff.de]: "Pure fun is guaranteed."

    For how many days, I wonder? What if after 20 days, the pure fun just goes away for me? Do you take it in for a free repair?

  • want to try fixing that with the tools in your underseat bag on the side of a singletrack about ten miles from your car?

    I don't think so.
  • by avi33 (116048) on Saturday November 15, 2003 @08:32PM (#7483926) Homepage
    You could simply ride fifteen pounds of funk [usrnull.com].

    One gear -> stronger legs, more distributed workout, less to maintain, fewer parts to fail, just mo' fun

    Every once in a while someone spends a crapload of money trying to change the fundamentals of the bicycle, but really, other than the derailleur, not much has changed in over 100 years.
  • by Rosco P. Coltrane (209368) on Saturday November 15, 2003 @08:36PM (#7483939)
    Okay, I admit the chain-inside-the-frame thing is cool : less crap on the legs, cleaner, well lubed chain, etc... But somehow, there has been a notion that current bike drivetrains (i.e. chain+derailleur) are inadequats. There are continuously people who dream of making CVTs for bikes, or non-rotating drivetrains or whatever, to replace the "old" chain-and-derailleur. Well here are some facts :

    - A chain/derailleur system is the only system that offers that many speeds under 2Kg

    - Bicyclists don't need Continuously Variable Transmissions : human legs are incredibly efficient over a range of speeds from 0 to 13/140 RPM

    - A bicycle is virtually the only vehicle where a chain drive is useful and needed, because the "engine" (you) is slower than the wheel, which is unique amongst all vehicles. This is also why any other kind of transmission will fail miserably compared to a chain drive in terms of efficiency (a chain drive routinely gets over 97% efficiency, and you need that with the 75W-100W power you get out of an average rider).

    - A cyclist who's moderately used to shifting well will *not* feel impaired by derailleur actions.

    - A chain + derailleur system is maintainable on the road. Just try to service a geared hub on the road ...

    - Geared hubs are great for compacity and easy maintaining. However, their efficiency sucks. For example, a 7-speed Sachs hub can go down to 90% efficiency. That's a lot of power loss with under 100W of input power.

    For more bicycling myth debunking, read the rec.bicycles.tech newsgroup and the Bicycle Science list.

    I do over 10000Km/year and, apart from chain cleaning and re-lubing, I think the derailleur system is very adequate.
    • by taj (32429)
      "- Bicyclists don't need Continuously Variable Transmissions : human legs are incredibly efficient over a range of speeds from 0 to 13/140 RPM"

      As a retro biker that does it smart going on 40 I suggest you rethink this.

      Hold on their young one. Any 17 year old can do 0-140 rpm but as the joints get older, you need to keep the rpms higher and the impact lower. 90rpm would be about right for all times.

      You can crank for 30 years at 5 rpm but I'd rather let the gears do the work and sleep at night without ar
      • Hold on their young one. Any 17 year old can do 0-140 rpm but as the joints get older, you need to keep the rpms higher and the impact lower. 90rpm would be about right for all times.

        I never said you should ride at 5rpm or 120rpm all the time, I said human legs can provide torque or speed with (almost) equal efficiency even when you force them to pedal way outside their "preferred" cadence.

        Of course, when you're not accelerating or climbing something steep, you use the gears to find that comfortable cade
    • I think the main reason is for those hard core mountain bikers. As an avid cyclist myself, I always lub up the chain before bicycling, and clean it after every 5 rides.
    • Right on. Internal speedhubs are really only used on downhill bikes, due to their inefficiency and weight.

      I doubt we'll ever see anything like this in the Tour de France...so road bikes will be safe from this rather bizarre looking maintenance nightmare.
    • nice post but... (Score:5, Informative)

      by MarcoAtWork (28889) on Saturday November 15, 2003 @09:37PM (#7484166)
      100W? are you kidding me? I am not a fast cyclist by any stretch of the imagination (I just do triathlons, any cat4 cyclist can kill me easily) and I can do 200W sustained over fairly long (1h+) periods of time, Armstrong IIRC can do 400-500W sustained, and sprinters (Pantani) can generate up to 2000W for short periods of time.

      Also the most efficient cadence (in terms of power generation) is more like between 90 and 110rpm (of course you have to train to have a 'round' pedal stroke, 'mashers' tend to pedal around 70rpm) and the range of maximal power generation is not that wide (in terms of rpm), that's why the latest geartrains have 10 cogs at the back (and 2 or sometimes 3 at the front). If human legs were =incredibly= efficient we'd all be riding single speed bikes :)

      Agreed about the rest, internal drivetrains are a fad that doesn't seem to want to go away: the only application where IMHO they make some sense is pure downhill, where hitting your derailleur on a rock can put you out of the race and where pedaling power doesn't really matter that much...
      • How about a two wheel drive system for mountain bikers. The power could be transferred via a shaft through the frame. A chain could then transfer power to the front wheel.

        Front wheel power would be especially valuable while going uphill.

      • by noewun (591275)
        and sprinters (Pantani)

        Marco Pantani ain't no sprinter. You're thinking of Cippolini, or, even better, Nothstein.

      • by kma (2898)
        Dude? Pantani's a climber. Or he was one, before he got all depressed and started hitting the canollis hard.

        Cippollini, Petacchi, McEwen, and Zabel are the current cream of the sprinting crop. And you're indeed right that Cipo puts out over 1 horsepower in full flight.
    • They wear out and provide a terrifying ride. Check Dr. Sharp's 100 year old compendium and see for yourself. It also helps to check motorcycle history because motocycle development took right off of bike tech at the turn of the century. You will find that complicated sprung frames generally have problems. There's a reason most bikes are made in diamond frame sytle.

      That said, the current generation of sprung frame mountian bikes do provice considerable advantages over rigid frames. You will pay for th

    • I think a whole lot of point missing is going on.

      I've been interested in this project for some time and have been exchanging email with Karl Nicolai about it. Yes, OK, a gearbox is not going to be a win on a road racing bike for a number of reasons, but not all bikes are road-racing bikes. On any mountain bike (I'm particularly interested in cross country bikes, where weight does matter) this is a potential win.

      It's true that in perfect conditions a deraileur system is more efficient than a gearbox. Bu

  • by Anonymous Coward on Saturday November 15, 2003 @08:37PM (#7483948)
    Reading these comments, it looks like 99% of the detractors of this concept fail to understand that the biggest plague of the downhill racer is the rear derailleur - it hangs in a VERY exposed position and is extremely easy to rip off. When you lose your rear derailleur in a DH race, your chances of making the podium are slim. Believe me, it happens a LOT, and it gets expensive and very annoying.

    Another thing people fail to realize is that this concept is about DH bikes, not about cross-country bikes. It may weigh a lot, but a 40-pound DH bike is pretty light.

    Too many opinions, not enough brain power to go around, if you ask me. If you ride a 23 pound XC-racer, you might as well comment on the suitability of an 8" travel, 12 pound, dual crown suspension fork for your riding style.
    • When you lose your rear derailleur in a DH race, your chances of making the podium are slim. Believe me, it happens a LOT, and it gets expensive and very annoying.

      All the good downhillers I know in my neck of the wood have short-tail road derailleurs that don't hang down as much, a big bash-plate around the derailleur and chainstay, and anti-derailling/chainslap/chainsuck rollers on top and bottom of the chainwheel. None of them seem to lose derailleurs a lot ...
    • the biggest plague of the downhill racer is the rear derailleur - it hangs in a VERY exposed position and is extremely easy to rip off.

      Maybe somebody should invent a derailleur cage or something to protect the mechanism from getting ripped off by rocks/stumps/whatever.

      I think a previous poster said something about a chain driven bike being 97% efficient. Hard to beat that, so why not just protect the already super-efficient mechanism?
    • Reading these comments, it looks like 99% of the detractors of this concept fail to understand that the biggest plague of the downhill racer is the rear derailleur - it hangs in a VERY exposed position and is extremely easy to rip off.

      Reading your comment, I don't see how ordinary readers of the article or the links given are supposed to know that this design is only to be used for downhill racing, a very small niche application for bicycles. So it's not lack of "brain power" (nice ad hom), but a poorl

    • I have a question, tho many probably know the answer. As a disclaimer, I AM NOT A CYCLIST!! (ianac?).

      that said, wouldn't be possible to mount the derailleur ABOVE the gears so that it is not so prone to snag on rocks, etc? I would think that would help a lot.

      Let me know.
      • wouldn't it be possible to mount the derailleur ABOVE the gears

        The derailleur has to shift the chain to the right position before it reaches the cluster so that it feeds onto the correct sprocket. Since the chain is going up and behind the cluster at that time, the derailleur has to be on the bottom. On the front chainrings, the derailleur is on top and wouldn't work on the bottom.

      • wouldn't be possible to mount the derailleur ABOVE the gears so that it is not so prone to snag on rocks, etc?

        Uh, no. Unless you prefer looking at the scenery through your ass. You'd be going backwards.

        The derailleur is on the bottom because that's the direction the chain travels. Clockwise, viewed from the right side. The derailleur is the chain tensioner, and it also moves the chain from one sprocket to another to change ratios. If it was on the top, the action of pedaling would stretch it out, lose the

      • This has sort of been tried. Back in the 30s to 50s all sorts of derailleur designs were tried, and some did sit above the sprockets. The problem is, to change gear in this location you have to shove around a section of chain that's under tension because it's between teh chainring and sprockets.

        This mean, among other things, that shifting gets harder when you are putting a grater load through the chain... which is often when you most want to change gear!

        Nevertheless, this is how front derailleurs work - t

  • by Joao (155665) on Saturday November 15, 2003 @08:40PM (#7483964) Homepage
    I spend a lot of time on high-performance Human Powered Vehicles (HPVs), and efficiency is a big thing among high-speed bikes. The main problem with these internally geared drivetrains is that they are not very efficient at all. They rob you one heck of a lot more power than chains and derailers. The regular chain and derailer design is something in the neighborhood of 97-98% efficient, while these geared drivetrains are about 70% or less.

    The main advantage of the internal gears is for downhill mountain bikes. Drivetrain efficiency is not as much of an issue since gravity is doing most of the work, and there is no risk of losing your chain in mid air at 40mph.

    Joao "member of far too many HPV and bicycle clubs and associations" de Souza
  • by Jack Auf (323064) on Saturday November 15, 2003 @08:45PM (#7483979) Homepage
    The three top priorities for racing bikes are weight, weight and weight. Speaking as a lifelong rider, racer and former messenger, stuff like this never works out too well in practice. Anyone tried the electronic shifting systems? They (mostly) suck.

    There have been may refinements, but as the article post says "few advancements in drivetrain technology" because what we have currently is very lightweight, works extremely well, is very reliable, and is easy to service.

  • The design allows the chain to run inside of the frame. This removes many fragile components from the bicycle, and allows a more rigid frame structure to be made.

    Where was this 25 years ago when I needed it? I was always getting my bell-bottoms caught in the chain of my bicycle!

    (in my defense: I was 9 at the time, so I wore what mom bought me, and she was not alone (by any stretch of the imagination) in thinking that bell-bottoms were cool. I didn't really care, but I did hate how they always got

  • by euxneks (516538) on Saturday November 15, 2003 @08:55PM (#7484025)
    Great. The Bike was just released and we already broke it. =D
  • A scooter that looks and rides like a real motorbike :-)

    DNA's are fantastic :-) [motobykz.co.uk]

    Simon.
    Escaping the tyranny of London Underground :-)))
  • While the internal gearing may have advantages (though changing the ratios won't be so easy I suspect), I actually consider the intenal chain to be a bad idea since it provides for less access when (not if, but when) problems occur - it's a maintenance nightmare waiting to happen.

    I've been racing bikes since I was ten, (mumble) years ago, and know that no matter how good the chain is, how well it's tensioned, geared and aligned it can still cause grief. Sure, this design may reduce the frequency of some pr

    • Looking at the pictures there IS no externally exposed part of the chain; sealed-for-life?

      Jon

      • Try opening your eyes a little! Check the inside of [pinkbike.com] link - there is very clearly a good ten inches or more of chain visible around the rear wheel cog and leading into and out of the frame.
  • 503 comments: "It sux."

    (Further proving the axiom that all hype no substance, and the low attention span caused by television commercials makes everyone believe that anything new sux, unless presented in a movie trailer, then it only sux after it's paid for)

    10 comments: "That's pretty cool. Too bad it costs money."

    2 comments: "Does it run Linux?"

  • 9 speeds? (Score:3, Interesting)

    by The Ape With No Name (213531) on Saturday November 15, 2003 @09:56PM (#7484217) Homepage
    From the G-boxx site:


    The aft system contains a rear hub which houses the cassette assembly, providing up to 9 different gearing ratios


    My Airborne [airborne.net] Zeppelin is all Campy and a 10-speed on the rear sprocket. Combined with a triple up front this is 30 effective gears (and ratios). Shimano is not the only thing on the planet and certainly not the best.


    IANAMTBR (I am not a mountain biker) but those I-drive bottom bracket systems are pieces of shite. Sure they are very adjustible, yada, yada, but when you are 30 miles from fuck-all and it gives up the ghost you'll wish you had a tough-as-nails XTR bottom bracket. Simple is beautiful on a bicycle. That's why I like them. I hope it is light! If it isn't then you are not going to sell this stuff, ever.


    Personally, I am waiting for the Campy/Shimano electric shifts to get cheap enough.

  • by trick-knee (645386) on Saturday November 15, 2003 @10:49PM (#7484564) Homepage
    sorry if I sound like a troll, but I've been a serious cyclist for over 20 years now, done competition at the USA national level (okay, I got waxed, but I was there!), worked in the industry (local shop, major retailer, manufacturer), and have read way too much hype about new stuff. reading the comments here reminds me of a bunch of bike guys sitting around talking about how cool Windows ME was when it came out.

    okay, okay, we're just off our usual topic set here. but someone tell me why this story is on /. anyway. there are several posters here that seem to be actual riders, but the great majority don't seem to be very discerning cyclists.

    first, this supposedly new and supposedly cool design is, as others have already pointed out, just recycled concepts, the main function of which is to separate the consumer from his/her cash.

    these concepts have all been relatively stillborn over the years mainly because they are more expensive, less reliable and heavier than existing designs. plus, internally geared hubs are fine for the grandpa and grandma riding around the retirement community, but they are notoriously inefficient for someone trying to actually go fast.

    reasonable cost is important because stuff breaks. always. even the unbreakable stuff.

    reliability is important because we'd all like to ride home, not walk. plus it keeps us from having to pay for more stuff. this looks like stuff designed for freestyle use, and that stuff gets thrashed.

    light weight is important if you ever have to (a) accelerate the bike (including changing its direction, or (b) go uphill. maybe also (c) put the damn thing on top of your car.

    anyway, these bikes look like expensive pigs using minimally tested technology. we should all be sneering at this.

    I mean, shit, if you don't want your shoelaces to get caught in the chainrings, double tie them. put a fucking rubber band around your pants cuff.

  • This is ridiculous. (Score:4, Informative)

    by Pig Hogger (10379) <pig.hogger@NoSpaM.gmail.com> on Saturday November 15, 2003 @11:57PM (#7485062) Journal
    Planetary-gear transmission for bicycles?

    Comeon. Let's be serious.

    Bikes with drailleurs have the most efficient transmission possible. Because a chain, unlike gears, has no inherent inefficiency caused by the gear teeth engaging and disengaging themselves. With a pair of gears, the distance of point of contact between teeth and the axis varies as each gear teerh engage and disengages the opposing gear teeth.

    The result: non-constant velocity at the output of the geartrain. This induces vibration and is a source of drag.

    On a chain, the distance of the point of contact of the chain link with the teeth remains constant WHERE THE POWER IS APPLIED TO THE CHAIN. Of course, the distance varies when the link engages the teeth, but as it happens for a very small percentage of the time the links are around the wheel, the gear teeth can be cut in a shape that does not allow any teeth to contact the chain until it is firmly seated against the gear.

    A chain transmission will therefore offer the most efficient power transmission possible.

    This is why race bicycles have chain drives. They cannot afford to lose the slightest erg of effort!!! This is why many motorcycles have chain drives, too. And the drailleur offers the best solution: variable diameter sprocket gears! The number of intermediate points between the cyclist leg and the pavement is kept to a minimum. How many inner gears and clutches does that 14-speed planetary gearcase have???

    And a planetary gear change is not the most efficient design around. Ford-Ts had planetary gear transmissions. Cars have evolved a little bit since then, in case you haven't noticed.

  • I submit a simple thesis: all (well, most) bicycle inovation is driven by professional racing (like many sports). Though you will find occasional things that make it into wide- or semi-wide adoption (say, recumbants), it it is not used by top amatures or pros, it won't get serious attention to develop or migrate to lower price points in a quality fashion.

    So, for a planetary gear to be developed and become widely used, it would first have to prove value to professionals beyond the cost (i.e. better perform

  • Bikes with shaft drive have been built, but the shaft was too heavy. That idea might be worth a try again. It wiil never be as light as a chain, but with newer materials, it would be better than the 1940s steel shaft drive bikes. It could be useful for riding through brush and grass, where chains jam.

    As for transmission bikes, the old three-speed bikes had that decades ago. There was even a Borg-Warner 2-speed automatic tranmission for bikes.

    Berg makes flexible plastic chain, and at one time they tri

  • A german company Rohloff, has been making an internally geared 14 speed transmission for bikes for few years now. The gearing range on it is equivalent to a standard Shimano 27 speed triple chainring system. The only problems with these things is maintenance issues and the cost. I beleive if you had any problems with the Rohloff system, it had to go back to Germany for repair, apparently these things are pretty complicated. The other drawback is price, I believ the Rohloff rear hub/transmission was alot hea

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