Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 28
  1. #1
    Member
    Join Date
    Jan 2004
    Location
    Texas, US
    Posts
    45
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Opinions on chainless drives

    Anyone have any opinions on chainless drives? You know the shaft type drives? I found the article and would like to know what you all think...

    Chainless bicycle.(Brief Article)
    Whole Earth, Winter, 2002

    I've renounced chains on bikes now that I've fallen in love with the chainless bicycle. Drive shafts for bikes were invented at least a hundred years ago; what's new are their new low cost, clever shifting, and improved efficiency. A chain can be more energy efficient if--big if--it is kept well lubricated, aligned precisely, and fine-tuned with constant attention. But a modern sealed drive shaft beats the efficiency of the average neglected crusty chain--like my old ones. Getting rid of a chain removes the least stable part of a bike, the item most likely to need adjustment or fail, and the dirtiest component. Shifting is a breeze on these drive shafts; just click into discrete gears. I don't mind tossing the bike into a car (no grease) and I can ride with long pants (no pinched trousers).

    There are three of four high-end custom versions of the chainless bike, but as far as I can tell they use the same patented drive shaft as the inexpensive model I've been riding. This make is a slightly clunky Taiwan-made weekend bike. Get the maximum seven-speed version. It uses a Shimano Nexus non-cog gear hub, but it's not as fancy as the German fourteen speedhub reviewed right. For serious trail blazing, I'd prefer the combo of the speedhub and drive shaft (if they made a bike like that), but this bike has gotten me everywhere I've wanted to go--without the hassles of a chain.

    --KK

  2. #2
    Bike Junkie
    Join Date
    Nov 2003
    Posts
    238
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I imagine a driveshaft might be of use on a bike that get's no maintenance. For my purposes a chain drive bike works fine. My chains do not rust and are easy to adjust because I do the easy routine maintenance. I'm not willing to pay the weight, efficiency or complication penalty of a shaft drive when it offers no benefits over a well maintained chain drive.

    -s

  3. #3
    Pat
    Pat is offline
    Senior Member
    Join Date
    Jan 2002
    Location
    Orlando, FL
    My Bikes
    litespeed, cannondale
    Posts
    2,795
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by slider
    I imagine a driveshaft might be of use on a bike that get's no maintenance. For my purposes a chain drive bike works fine. My chains do not rust and are easy to adjust because I do the easy routine maintenance. I'm not willing to pay the weight, efficiency or complication penalty of a shaft drive when it offers no benefits over a well maintained chain drive.

    -s
    I can not agree more on this one. Keeping a chain cleaned and lubed is no big deal.

    Also a chain system means that you can readily choose the gearing you find most appropriate. You can even adjust the gearing a bit by changing out your rear cluster.

    So why would anyone want to go to a heavier, less flexible and less efficient system then the chain system unless of course they are so careless as to do no maintenance at all?

  4. #4
    Member
    Join Date
    Jan 2004
    Location
    Texas, US
    Posts
    45
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the assumption. I'm make sure my questions aren't so newbish for this place.

  5. #5
    Senior Member
    Join Date
    Sep 2002
    Location
    NC
    Posts
    3,411
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    no biggie, man. in future, you might want to do a search of the site before posting on the site. We get a few recurring threads, and no offense, but this is one of them, along with the questions about the landrider bike.

    IMHO, I think that the driveshaft would work for a city type of commuter bike, like what is popular in europe, but not for a roadie bike. in order to make the driveshaft stiff enough to take the power of a sprinting racer, you'd have to make it fairly heavy, and that would defeat the purpose. a chain, for all of its faults, is fairly light.

  6. #6
    Wood Licker Maelstrom's Avatar
    Join Date
    Apr 2002
    Location
    Whistler,BC
    My Bikes
    Transition Dirtbag, Kona Roast 2002 and specialized BMX
    Posts
    16,888
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I think if they could make is strong and efficient enough it would be a good system for mtb's. Our bane right now is deraileurs as they tend to break easily and or go out of whack. Any ideas to remove / improve the drive train by eliminating the deraileur is a good one to me. Biggest concern would be weight...and of course I would want a dually which would make the drive shaft difficult to make.

    I still think the internally geared hub is a better idea for eliminating the crappy deraileur but in both case the big 2 will not invest enough money into that area. And to be honest the chain itself, to me, is not the weakness of the deraileur drive train

  7. #7
    Wood Licker Maelstrom's Avatar
    Join Date
    Apr 2002
    Location
    Whistler,BC
    My Bikes
    Transition Dirtbag, Kona Roast 2002 and specialized BMX
    Posts
    16,888
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The thing about starting 'new' threads about old stuff is potentially more people seeing it and giving opinions. If threads weren't repeated there would be no need for this site (or others) as you could simply search through the newgroup archives and find all the same info.

  8. #8
    Senior Member DieselDan's Avatar
    Join Date
    Mar 2003
    Location
    Beaufort, South Carolina, USA and surrounding islands.
    My Bikes
    Cannondale R500, Motobecane Messenger
    Posts
    8,522
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'd like to have shaft drive crusiers for my rental fleet, but the cost is way too high. Sand gets into the chains too easily here, but that has more to do with the beach riding and the extra-fine sand here.
    Bikes use brakes to stop.

    If your bike has breaks, don't ride it.

  9. #9
    Senior Member
    Join Date
    Jul 2002
    Posts
    727
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Jericho Cycles has a belt-drive system for their singlespeeds called the Red October. it's supposed to work flawlessly, never had a chance to see it with my own eyes though.
    i ride bikes.

  10. #10
    Crank Crushing Redneck SamDaBikinMan's Avatar
    Join Date
    Nov 2002
    Location
    A van down by the river.
    My Bikes
    Bikes are environmentally damaging
    Posts
    2,600
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'm sorry but a gear drive shaft setup will not come close to a chain drive in efficiency related to power transfer. the typical 90 degree gear type setups are around 85% efficient and you won't find them on a bike. Consider you will end up with two 90 degree gear setups, crank to drive shaft and drive shaft to hub. And you might as well count on 20-25% power loss.

    Trust me. If this were such a great idea and superior to chain drive systems it would be the mainstay for bikes worldwide and Lance and his buddies would be riding them in the tour.
    [SIGPIC][/SIGPIC]

  11. #11
    Senior Member
    Join Date
    Dec 2001
    Location
    New Jersey
    Posts
    6,296
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by SamDaBikinMan
    I'm sorry but a gear drive shaft setup will not come close to a chain drive in efficiency related to power transfer. the typical 90 degree gear type setups are around 85% efficient and you won't find them on a bike. Consider you will end up with two 90 degree gear setups, crank to drive shaft and drive shaft to hub. And you might as well count on 20-25% power loss.
    .
    Bingo. You stole my thunder. I've seen the "Chainless" bicycle and shaft is heavy and you won't find the weight of the device because it's probably 5 pounds! The Nexus 7 hub maybe durable but I've discovered that a cassette is more efficient than any internal gear bike out there. I've been able to climb most hills with my Nexus 7 bike but I can certainly see a need for more gears.

    The Chainless bicycle would be good for a junk commuter that stays outside in the rain, snows and mud. It would be good for a town bike or a beach cruiser where you're more than willing to make compromises in efficiencies for bike that can withstand punishment.

    The Chainless bicycle would not be good for Tandams, Road bikes, Cross, recumbents, MTBs and Touring bikes. The Nexus 7 does not have enough gears and was not designed for MTBs

    The author also mentions about the $1,000.00 German Speedhub as an alternative to the Nexus 7. First, you can never leave that hub on a junk commuter that will stay out in the snow, rain and mud as it will get damaged or stolen. Second, the Speedhub is large and heavy which is why it should not go on a light weight roadbike or cyclocross. Third, the Speedhub does not have enough gears for a recumbent or Touring bike. Fourth, the Speedhub was not designed for the kind of punishment that an MTB requires or you'll break the internals. So what kind of bike do you use the $1,000.00 dollar German Speedhub??

    Good question. I've been trying to find out that answer myself. It guess you would put it on a town bike for commuting purposes but the Nexus 7 or Sram Spectro 7 work just fine for that kind of cycling. Heck! Even a Sturmey Archer 3 speed works OK as a town bike.

    Folks. The German Speedhub are for those folks who want to show everyone they have money to burn.

  12. #12
    Senior Member
    Join Date
    Jul 2002
    Posts
    727
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    steve, you really should do some research before posting, it'll save you a bit of confusion in the future.

    that "german speedhub" is the rohloff speedhub. here's some nice information about it.

    A) it's plenty durable. nicolai, evil bikes, and rohloff are developing a standard for downhill/freeride bikes called the G-Boxx around that very hub. if it can handle the stresses of those, it can handle the stresses someone commuting back and forth to work will put on it.

    B) once you take into account the overlap found on standard 3x9 derailler systems, the rohloff has basically the same gear range as any off-the-shelf mountain bike. i reckon that should cover the needs of most tourists.
    i ride bikes.

  13. #13
    Formerly Known as Newbie Juha's Avatar
    Join Date
    Mar 2002
    Location
    Helsinki, Finland
    Posts
    5,854
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Steve, search for Rohloff in the Forums and you will find a thread where its pros and cons are thoroughly discussed. Price and weight seem to be its weak points, but certainly not durability or gear ratio.

    --J
    To err is human. To moo is bovine.

    Who is this General Failure anyway, and why is he reading my drive?


    Become a Registered Member in Bike Forums
    Community guidelines

  14. #14
    Senior Member
    Join Date
    Dec 2001
    Location
    New Jersey
    Posts
    6,296
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fore
    steve, you really should do some research before posting, it'll save you a bit of confusion in the future.

    that "german speedhub" is the rohloff speedhub. here's some nice information about it.

    A) it's plenty durable. nicolai, evil bikes, and rohloff are developing a standard for downhill/freeride bikes called the G-Boxx around that very hub. if it can handle the stresses of those, it can handle the stresses someone commuting back and forth to work will put on it.
    .
    I've done enough research on the Rohloff speedhub before posting on this subject. Would you really want to put that heavy hub on a Cannondale 1000 or LightSpeed? Would you really want to put that heavy hub on a Tandam? Come on!

    The hubs internals are not designed for that kind of punishment. All those dozens of moving parts inside that hub and you're going to do freestyle?? Good luck! Furthermore, it's way too expensive and I'll take a 3X9 system that's more efficient and can be repaired at any bike shop. This is something you can't do with a damaged Rohloff speedhub in the middle of a tour.

    They're starting to experiment the Rohloff with some downhill bikes but the jury is still out. I would hate to damage that $1,000.00 dollar hub and have to send it back to Germany for repairs.

  15. #15
    Senior Member
    Join Date
    Jul 2002
    Posts
    727
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i didn't say it was the best hub for all situations, but there are plenty of cases where i think it'd be a perfectly viable option.

    by the time one removes the extra chainrings, deraillers, cassette, etc, part of the extra weight of the hub is offset.

    i still maintain that if that hub can be used successfully on something like a downhill bike it'll handle just about anything else just fine. the ability to shift while stopped would appeal towards a lot of people.

    if a system like the g-boxx was developed for cross-country bikes i'd consider getting one. g-boxx solves the rotational weight issue by building the hub into the frame, so the rear wheel is pretty much a standard wheel. i'd feel a lot more comfortable in the tight singletrack we have around here with that sort of setup than i would with deraillers which love to get caught on things.
    i ride bikes.

  16. #16
    Formerly Known as Newbie Juha's Avatar
    Join Date
    Mar 2002
    Location
    Helsinki, Finland
    Posts
    5,854
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Sheesh. All right, I searched it for you. Here.

    The thread opens with a rather shameless plug-in by a happy user, but what follows is a thorough conversation where all the points mentioned here are discussed and then some. Once more, according to testimonies in that thread durability or efficiency or gear ratio are not real problems with Rohloff. Weight and price are.

    --J
    To err is human. To moo is bovine.

    Who is this General Failure anyway, and why is he reading my drive?


    Become a Registered Member in Bike Forums
    Community guidelines

  17. #17
    Banned.
    Join Date
    Aug 2001
    Posts
    616
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Shaft drives aren't *that* inefficient. With the best turn of the 20th century machining, they were about 92% efficient. Engineers could do better today.

    Major Taylor broke more than one record riding a shaft drive.

    Chains, when maintained adequately, are almost 99% efficient, however.

    The most important disadvantages of a shaft drive are its much greater weight, and its greater cost. It's much more expensive to machine to the tolerances required by a shaft than a chain.

  18. #18
    cycle-powered nathank's Avatar
    Join Date
    Mar 2002
    Location
    Munich Germany (formerly Portland OR, Texas)
    My Bikes
    '02 Specialized FSR, '03 RM Slayer, '99 Raleigh R700, '97 Norco hartail, '89 Stumpjumper
    Posts
    1,848
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i agree with all of the counter-posts regarding the Rohloff Speedhub...

    i have considered it myself and will probably put it on the next bike i buy.

    i have heard ZERO reports of durability being a problem. actually one of the big reasons many buy it is durability -- the other is you only need one front chain-ring so you can use a strong double-bash guard AND with a straight chain-line you don't loose a chain and rarely break a chain... it's getting very popular in the downhill and Freeride scene although you obviously won't see it on the low-end bikes.

    weight is a factor, but if i remember right, on a MTB the Rohloff system weighs less than an XT setup although less than XTR... although i don't run XTR on my bikes as it is expensive and XT is usually more durable.

    the 2 major complaints from the mountain bike crowd:
    1) weight DISTRIBUTION: you have more weight on the rear than a typical 3X9 setup so it changes the handling - guys often say they have to "relearn" to bunny-hop
    2) INITIAL cost -- almost everyone i know who has Rohloff says they SAVE money compared to an XT or XTR system as the maintenance/durability is so high --- for example, i replace almost the entire drivetrain once per year -- cassette, front chainrings (with my chaingaurd the big ring lasts 2 years), chain multiple times -- and i break a rear deraileur about once a year and front every 1 1/2 years... --- this means in year 2, 3 and so on a high-mileage/heavy abuse rider like myself probably SAVES money compared to a mid- to top-of-the-line deraileur system. (unfortunately most pre-built bikes come with Deraileur systems so you get a discount and have to upgrade or build your own Rohloff system)

    as to the initial topic: shaft-drive if it could be made cheaply might be good for "cruisers" and commuters, but for high-performance stuff the chain seems to offer more advantages b/c of efficiency.
    why drive when you can ride?
    now a fully certified German MTB Guide! (DAV)

  19. #19
    Senior Member
    Join Date
    Dec 2001
    Location
    New Jersey
    Posts
    6,296
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by nathank
    i have heard ZERO reports of durability being a problem.

    2) INITIAL cost -- almost everyone i know who has Rohloff says they SAVE money compared to an XT or XTR system as the maintenance/durability is so high --- for example, i replace almost the entire drivetrain once per year -- cassette, front chainrings (with my chaingaurd the big ring lasts 2 years), chain multiple times -- and i break a rear deraileur about once a year and front every 1 1/2 years... --- this means in year 2, 3 and so on a high-mileage/heavy abuse rider like myself probably SAVES money compared to a mid- to top-of-the-line deraileur system. (unfortunately most pre-built bikes come with Deraileur systems so you get a discount and have to upgrade or build your own Rohloff system)
    .
    The fact that there are ZERO reports worries me. Everthing mechanical has problems and this hub is not the exception. There are tons of people who think this hub will never have any problems. It's a mistake. I haven't met anyone who had a problem with the Sram Spectro 7 but they're out there. Trust me.

    Here's a good exercise. Call the company and tell them your Rohloff hub just broke. These are danger signs that you will have problems when service is needed.

    1. Long waiting times on the phone and poor communications between the service department.
    2. Cannot give an estimate on repairs
    3. Require you to buy new internals (expensive)
    4. Cannot give you a date when the product will return
    5. Rude or abrupt treatment over the phone

    If you want my opinion, I would think twice about buying this hub. Why? It's obvious you're very hard on the bikes. I don't have anywhere near the amount of part replacement you have and suspect most don't either. If you go to the web site, the German hub is marketed for "touring" purposes and not for extreame riders like yourself. Did you notice all the riders are moving slowly while carrying loads? Why don't you think they have pictures of people jumping cliffs with this hub? Hummmmmmmm? (These are all clues folks)

    The initial costs is only one aspect that worries me. Service and durability are critical as you cannot take this device to the local bike shop. I don't know anyone who is brave enough to take this monster apart and those that will are suspect. If you crack a 3/9, buy a used one on Ebay and your problems are over. If you crack this hub, you're out a cool $1,000.00 USD and your problems are over.

  20. #20
    I drink your MILKSHAKE Raiyn's Avatar
    Join Date
    Jul 2002
    Location
    St. Petersburg, FL
    My Bikes
    2003 Specialized Rockhopper FSR Comp, 1999 Specialized Hardrock Comp FS, 1971 Schwinn Varsity
    Posts
    15,071
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Poor Steve. I think it's time to put down the crack pipe.
    TECHNICAL


    Every new development undergoes a critical examination. Only once our downhill-, our dirt-, our mountain-, and our everyday-riders are happy with the product, will we put it into production.

    The high quality of all Rohloff products is ensured by the special commitment and enthusiasm of our staff. Experience gained over time allows us to improve bicycle technic, solve known problems but also the joy of development and the courage to explore new territory will ensure that in the future Rohloff will broaden the market with interesting new developments.
    http://www.rohloff.de/index.php?p=TECHNIK
    What I always wanted to know about working efficiency, but never trusted myself to ask!


    Wherever power is transmitted, friction is produced within the mechanical system.In general this firction is lost as heat and is refered to as power loss.

    When observing gear systems, two different kinds of power losses can occur. These are power dependent and power independent losses. Power independen losses are e.g. the friction within the seals. Whether the bike is being pushed, ridden down a hill or ridden with extreme force upon the pedals up a hill, the friction force within the seals remains the same. Here the friction losses vary according to the condition of the seals (smooth or rough surfaces) and depending on the speed are very small producing between 1W and 3W of power loss. This small power loss is enough that it can bring a free spinning wheel to a halt after just a few rotations, or make the cranks rotate whilst the bike is being pushed.

    The power dependent losses work completely differently. Whilst pedaling the friction loss is produced between the tooth flanks of the gears and all bearing in use. Every different gear system produces a different percentage of power loss depending upon the mechanical construction. When the working efficiency of a gear system lies at e.g. 95%, that means that the 5% of the transmitted power is lost through friction. So, when a rider is pedaling with 100W of input power, the rear wheel will only transmit 95W of output power onto the road because of the 5W power loss. When the input power is increased to 300W, the power loss will be increased to 15W.

    Should the rider increase his tempo to a fast, high blood pressure sprint with 1000W of input power, 50W of will be lost through friction reducing the output power conciderably. This example shows clearly how important a good workig efficiency is. The input power given by the rider defines the amount of power loss. In the examples this could be 5W, 15W or 50W. Through special constructive developments like an increased number of teeth per gear and the choice of using roller bearings for the planetary gears, running the gearbox within an oil bath and extremely rigid construction of the overall gearbox, the working efficiency of the Rohloff SPEEDHUB 500/14 is brought up to 96% (for gears #1 to #7) and 98% (for gears #8 to #14).

    This working efficiency is comparable to a derailleur gear system. Common seven speed gear hubs reach a working efficiency of approx. 90% (gear #1) and 98% (direct drive gear). Again we observe our test rider, now pedaling up a hill with 200W of input power. When using the Rohloff SPEEDHUB 500/14 or a derailleur gear system, he will loose approx. 4% of output power (when riding in gear #4 as this is comparable to the first gear of a seven speed gear hub) which is 8W. With the same input power but using a seven speed gear hub, our test rider will loose approx. 20W of output power. Adding approx. 2W of power loss caused by the seals for the Rohloff SPEEDHUB 500/14 would bring the overall loss of power with the Rohloff SPEEDHUB 500/14 upto 10W against 20W with the common seven speed gear hub. Conclusion: Power independant losses like the friction of the seals, will have the same effect as a lightly rubbing brake block. This brings a free spinning wheel to a halt but are barely noticable whilst riding.

    This is easy to recognise on a bicycle repair stand. In contrary, power dependant losses mean that a particular percentage of the transferred power is lost, this is not so easy to detect on a bicycle repair stand, the measurement can only really be attempted with the bicycle being riden with the appropriate measuring aids. The Rohloff SPEEDHUB 500/14 has an extra fact to take into concideration: When the pedals are rotated backwards, the gearbox is activated, This means that the sprocket is rotated backwards and therefore the planetary gear system is run in reverse.

    The sun gears, that are always fixed in position on the axle (when the wheel is being pedaled forwards), then rotate with a ratchet function against the planetary gears when pedals are rotated backwards, this in turn causes more friction. When the rear wheel is freewheeling forwards, the sun gears rotate with the planetary gears around the axle creating no excess friction. Now it is easy to see why the working efficiency of a derailleur and a hub gear system can not so easily be compared, so, away with the theory and back to the drawing board.

    There are many Rohloff SPEEDHUB 500/14 equipped bikes in operation in special MTB marathon races and the results show that the riders are either equally as fast or even faster as the derailleur gear system riders. This shows quite plainly that there is hardly any difference between the two gear systems as far as working efficiecy goes. The faster times are results of the fact that the SPEEDHUB 500/14 riders have less stress over the shifting because the system is quicker and more positive to find the correct gear. Next to the working efficiency of the gearbox, the working efficiency of the human body is just as important.

    Every rider knows that when you ride in the correct gear (the right pedaling frequence and force upon the pedals for the optimum riding situation) then everything goes forwards and you stay in a good mood. Approx. 25% of the breakfasts calories get burnt up in action through the muscles. If the gear selected is not correct, then the rider must increase the force applied upon the pedals (as if the rider has lead in the legs so that the burning of those calories is no longer at the optimal level) or increase the speed at which the cranks are being rotated (which will cause the pulse to rise and the blood circulation to rise up into the red area).

    The working efficiency of the human body sinks to under 10%. Lots of sweat but very little action will be produced and the mood of the rider will sink along side. Alongside the good working efficiency of the mechanical parts is the use of the correct gear for the riding resistance (which is also just as important), so quick gear changes and a large choice of different gears. Only with these factors; overall working efficiency, breakfast, human body, bicycle and speed is the posibility of success and fun achieved.

    This is the reason that the SPEEDHUB 500/14 was constructed.
    http://www.rohloff.de/index.php?p=SPONSORING/MTB
    Sponsoring - MTB


    Rider: Christiane Rumpf
    Discipline: Downhill

    Successes:

    Being the current female German Downhill Champion and that of Hessen, too, she meanwhile rides her 4th season in competitions with her Rohloff SPEEDHUB 500/14. To all who won't believe this: It's her 4th year with the same single hub!
    In 2002 there were also German and Austrian competitions to win, as many on her timer as in the years before. The aim of this young teacher will still be riding about the „stockerl“ (wildernis) even if her job meanwhile takes more and more time off her.
    Last edited by Raiyn; 02-05-04 at 03:26 PM.

  21. #21
    Rider in the Storm
    Join Date
    Mar 2003
    Location
    Portland, Oregon
    My Bikes
    LeMond Zurich, KHS Fiero (Fixed), Centurion Ironman Expert
    Posts
    736
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I really couldn't care much less about this argument, but the evidence to "contrary" in the post above all comes from the Rohloff website. Anything reported there cannot necessarily be construed as unbiased truth or reality.

    Check out www.landrider.com and let me know their "truth."

  22. #22
    Senior Member
    Join Date
    Dec 2001
    Location
    New Jersey
    Posts
    6,296
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    >>>>>>Through special constructive developments like an increased number of teeth per gear and the choice of using roller bearings for the planetary gears, running the gearbox within an oil bath and extremely rigid construction of the overall gearbox, the working efficiency of the Rohloff SPEEDHUB 500/14 is brought up to 96% (for gears #1 to #7) and 98% (for gears #8 to #14).

    This working efficiency is comparable to a derailleur gear system. Common seven speed gear hubs reach a working efficiency of approx. 90% (gear #1) and 98% (direct drive gear). Again we observe our test rider, now pedaling up a hill with 200W of input power. When using the Rohloff SPEEDHUB 500/14 or a derailleur gear system, he will loose approx. 4% of output power (when riding in gear #4 as this is comparable to the first gear of a seven speed gear hub) which is 8W.<<<<<

    I find this hard to believe. Nexus made similar claims about their 7 speed hub and I believed it hook, line and sinker. They claim the new Nexus 8 is even more efficient but I doupt this is a fact. I have ridden planetary gear bikes from Sturmey Archer, Sram and Shimano and ALL suffer from friction losses. There is no oil bath out there that will eliminate friction completely. A hub with many gears by default generates more friction than one with less gears because there are more moving parts.

    The author talks about less stress when shifting which is a valid point. What he did not state is that your rear wheel is VERY HEAVY thus causing you to exert more energy than one using a cassette. Some road bikers can help me with the math here but for every ounce of weight you reduce on the wheels creates a significant performance gain. That Rohloff wheel is heavier than the Nexus 7 which feels like I have a water bottle attached to the rear wheel! It's not bad if you're making a commuter bike but is a significant consideration if performance is an issue. The most expensive wheel sets in production are the lightest and a big heavy hub in the back defeats this purpose. The Ultegra 9 speed hub weights a little over 400g and the Rohloff is how many pounds?? Whatever efficiencies gained in shifting will be wasted in moving that rear wheel. Trust me.

    Hey... I like the Rohloff. If I were rich, I'd buy one tomorrow. Lets be honest. It's not the greatest thing in the world. Keep the 9 speed folks.

  23. #23
    Formerly Known as Newbie Juha's Avatar
    Join Date
    Mar 2002
    Location
    Helsinki, Finland
    Posts
    5,854
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Dahon.Steve

    (details about Rohloff's stated relative efficiency deleted)

    I find this hard to believe. Nexus made similar claims about their 7 speed hub and I believed it hook, line and sinker. They claim the new Nexus 8 is even more efficient but I doupt this is a fact. I have ridden planetary gear bikes from Sturmey Archer, Sram and Shimano and ALL suffer from friction losses. There is no oil bath out there that will eliminate friction completely. A hub with many gears by default generates more friction than one with less gears because there are more moving parts.
    You have a very complicated way to say that you actually have no data or first-hand experiences to support your doubts about Rohloff's claims.

    Quote Originally Posted by Dahon.Steve
    Hey... I like the Rohloff. If I were rich, I'd buy one tomorrow. Lets be honest. It's not the greatest thing in the world. Keep the 9 speed folks.
    I do not understand. You "like the Rohloff" and yet you spend several posts bashing it, expressing your subjective concerns about various issues, most of which have already been discussed elsewhere in the Forums. Based on these you are even ready to say everyone should give it a pass. And you have not even tried the thing once, fer crying out loud!

    Let's be honest: if you're interested in it, take a look at these Forums and other sources as well, talk to owners, try to get to test ride one if possible. If you're not happy, THEN keep the 9 speed (or whatever) folks. But don't forget it just because Steve (and I) don't have it. Trust me, what does not work for us may well work for you.

    --J
    To err is human. To moo is bovine.

    Who is this General Failure anyway, and why is he reading my drive?


    Become a Registered Member in Bike Forums
    Community guidelines

  24. #24
    Senior Member
    Join Date
    Dec 2001
    Location
    New Jersey
    Posts
    6,296
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Juha
    You have a very complicated way to say that you actually have no data or first-hand experiences to support your doubts about Rohloff's claims.

    I do not understand. You "like the Rohloff" and yet you spend several posts bashing it, expressing your subjective concerns about various issues, most of which have already been discussed elsewhere in the Forums. Based on these you are even ready to say everyone should give it a pass. And you have not even tried the thing once, fer crying out loud!

    Let's be honest: if you're interested in it, take a look at these Forums and other sources as well, talk to owners, try to get to test ride one if possible. If you're not happy, THEN keep the 9 speed (or whatever) folks. But don't forget it just because Steve (and I) don't have it. Trust me, what does not work for us may well work for you.
    --J
    You're correct in stating that I don't have any real experience with the Rohloff hub. My statements come from experience in riding with other hub gears. Unless this German company made some scientific breakthrough, I don't see how they're going to develope a hub significantly better than Shimano, Sram or Sturmey Archer when it comes to friction losses. As I said before, Shimano made similar claims on performance gains and left me disapointed. There is no way I'm going to risk $1,000.00 dollars when the current offering works fine for commuting purposes.

    This summer I intend to get my first road bike. There is no way I want a heavy hub gear from ANY manufacturer on the back of that rear wheel. If you have the money, buy the Rohloff hub and take it to the hills and race with it if you like. Experience has shown me that an internal hub with all those moving parts was NOT designed for this activity. I can tell you stories from personal experience if you like about what happens when you abuse Sturmey Archer hubs or race with the Nexus 7.

    I've looked at the information on this forum and found lots of misinformation concerning hub gears. I'm going to write to Sram, Sun Race and Shimano and find out what they think about this hub and why I should buy from them. It might be interesting to see how the competition view this product. I'll post any responses on this thread.

  25. #25
    Formerly Known as Newbie Juha's Avatar
    Join Date
    Mar 2002
    Location
    Helsinki, Finland
    Posts
    5,854
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Dahon.Steve
    Unless this German company made some scientific breakthrough, I don't see how they're going to develope a hub significantly better than Shimano, Sram or Sturmey Archer when it comes to friction losses. As I said before, Shimano made similar claims on performance gains and left me disapointed.
    If you think that Shimano's products (and others mentioned) represent the absolute top in mechanical engineering, think again. Just look at how another German company, Schmidt, builds their dynohubs, compared e.g. to Shimano's similar products.

    What Shimano claims (and in your case apparently failed to deliver) has got nothing to do with Rohloff. Claiming that is like testing one disappointing halogen light and then claiming all halogens are sh** because they are all based on same technology.

    I think it is evident Rohloff choose to do better job with their product than most internal gear manufacturers. I also think it is evident a Speedhub offers significant advantages over "normal" 3x7/8/9 setup. It is also evident there are disadvantages, most importantly weight and price.

    So whether this hub is good for you is entirely subjective (for my riding it probably would be). Whether it is worth the extra expense is also entirely subjective (for me it is not). I just don't think you can categorically state "keep the 9 speeds folks" here.

    --J
    To err is human. To moo is bovine.

    Who is this General Failure anyway, and why is he reading my drive?


    Become a Registered Member in Bike Forums
    Community guidelines

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •