Advertise on Bikeforums.net



User Tag List

Results 1 to 18 of 18
  1. #1
    Senior Member
    Join Date
    Nov 2004
    Posts
    293
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Un-Synchronized Tandem?

    Hi,

    I'm entirely new to tandem cycling though not to cycling.

    Someone told me about a new (?) type of tandem where the stoker and the captain don't have to synchronize their pedal stroke. What's the term I'm looking for? (I did a quick search of the forum but didn't find anything)

    Has anyone tried such a bicycle? What are the disadvantages/advantages of such a system? Who is best suited of this type of riding?

    Thanks for all replies!

    Cheers

  2. #2
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,151
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Independent Coasting System (ICS) by www.daVincitandems.com

    Do a search of the archives using the terms ' daVinci tandem ' and you'll find several threads.

    There are also a few other systems like this on the market, e.g., ATP Independent Pedalling System (IPS) which first appeared on Vision Recumbents tandems. Produced and marketed under license to someone else following ATP / Vision's demise a few years back. There's also a cruiser bike on the market with a jackshaft for ICS/IPS like crank action.
    Last edited by TandemGeek; 10-31-07 at 09:50 PM.

  3. #3
    Senior Member
    Join Date
    Nov 2004
    Posts
    293
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Fantastic! Thanks!

  4. #4
    Senior Member zonatandem's Avatar
    Join Date
    Dec 2003
    Location
    Tucson, AZ
    My Bikes
    ariZona carbon fiber tandem & single
    Posts
    9,968
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Advantages:
    Each rider pedals/coast as desired. Especially great for newer tandem duos.
    A great conversations starter!
    Confuses the heck out of folks behind you who want to count your cadence!


    Disadvantages:
    By not being constant in or out-of-phase, it can create tandem sway, especially when stomping/climbing. If leaning hard into a corner 'could' cause a pedal to scrape, but most tandems (unless really racing) do not lean into corners that hard.
    If you want to pedal in phase, or out-of-phase, with an ICS tandem, stoker has to visually check captain's foot position and then co-ordinate her pedal stroke (or disable the ICS system).
    More expensive and complex than standard pedaling system.
    Has 3 bottom brackets instead of 2.
    A bit heavier (if weight is a concern).

    Test ride both systems and then decide TWOgether!

    Yes, have ridden ICS equipped tandem. No, do not own one.

  5. #5
    Senior Member
    Join Date
    Jul 2006
    Location
    Buenos Aires, Argentina
    My Bikes
    Co-Motion Mocha, Trek T100, Schwinn Fastback Comp, Specialized Stumpjumper
    Posts
    378
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Do keep in mind that Independent Coasting does not permit differing cadences between riders, only the choice to spin or not to spin, once you are spinning you cannot deliver power to the pedals at different rpm.

    In some rare Independent Pedaling recumbents, as TG pointed out, each rider has his own transmission to his own wheel, so each can choose his cadence.

    I have not tried either one.

  6. #6
    Senior Member zonatandem's Avatar
    Join Date
    Dec 2003
    Location
    Tucson, AZ
    My Bikes
    ariZona carbon fiber tandem & single
    Posts
    9,968
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    As Xanti Andia pointed out some systems are able to do different/individual cadences + independent coasting, but that usually involves a 3rd derailleur.
    And yes, rode of of those too.

  7. #7
    Senior Member Leigh_caines's Avatar
    Join Date
    Sep 2007
    Location
    Woolgoolga NSW Australia
    My Bikes
    Long Recumbent, Short recombent, racing bike, MTB, beach bike,Tandem,Fixy.2 twentys and a folding bike
    Posts
    275
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I made my own...
    I mean I addapted a cheap tandem by putting "freewheels" on both cranks
    The ' daVinci tandem ' is way out of my price range.

    >>Has 3 bottom brackets instead of 2.<<
    Can be but dosen't have to be [our one is 2]

    My lady stoker loves it... and now so do I
    See Thread "New One" for pic

    You can change the "cadences between riders" if you want [if one rider is a lot faster spiner then the other] by having less teeth on one crank [I've done this as my lady is somewhat disabled and needs to spin slower]

    There are lots of ways to go... just keep thinking outside the square

  8. #8
    Senior Member Leigh_caines's Avatar
    Join Date
    Sep 2007
    Location
    Woolgoolga NSW Australia
    My Bikes
    Long Recumbent, Short recombent, racing bike, MTB, beach bike,Tandem,Fixy.2 twentys and a folding bike
    Posts
    275
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    O... cost was $100 Aust for 2 freewheeling cranks off e-bay

  9. #9
    Senior Member
    Join Date
    Nov 2004
    Posts
    293
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks all. Much appreciated.

    I'll be traveling to Taiwan so I'll probably pick up one of the cheaper DaVinci knockoffs over there.

    Basically, my gf is an adequate athlete so I consider myself pretty lucky already. I don't want to make her work too hard to get into the cycling/touring thing, otherwise it would put her off for good. It pretty much boils down to either she gets on the bike with me or be left behind for weeks/months at a time.

    Thanks again all.

  10. #10
    Senior Member
    Join Date
    Jul 2006
    Location
    Buenos Aires, Argentina
    My Bikes
    Co-Motion Mocha, Trek T100, Schwinn Fastback Comp, Specialized Stumpjumper
    Posts
    378
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Mooncricket, before you go into all the trouble of installing an Independent Coasting mechanism, you ought to try riding a regular tandem for a while. Many teams (including ours) have the differences in ability which you describe, and manage fine without it. It is a matter of compromise on the cadence, and communication. You will need compromise and communication in any case, so why not apply it to the crank? The actual power delivered to the pedals is always independent.

    Independent coasting looses a communication link which is the sych chain, you might be surprised how much is carried between the riders by this simple chain, once you have settled into your team habbits. I hardly call the bumps for example, my stoker knows that if I stop pedaling and I raise my butt, a bump is likely coming, a form of dancing. Independent Coasting also adds weight and complexity to the bike. Though there are riders who swear by it is a small minority of the tandem population, it might look like a good idea, but why not find out first if its a good idea for your team?.

  11. #11
    Senior Member PlanetU's Avatar
    Join Date
    Jun 2007
    Location
    Washington, UT
    Posts
    541
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Xanti Andia View Post
    Mooncricket, before you go into all the trouble of installing an Independent Coasting mechanism, you ought to try riding a regular tandem for a while. Many teams (including ours) have the differences in ability which you describe, and manage fine without it. It is a matter of compromise on the cadence, and communication. You will need compromise and communication in any case, so why not apply it to the crank? The actual power delivered to the pedals is always independent.

    Independent coasting looses a communication link which is the sych chain, you might be surprised how much is carried between the riders by this simple chain, once you have settled into your team habbits. I hardly call the bumps for example, my stoker knows that if I stop pedaling and I raise my butt, a bump is likely coming, a form of dancing. Independent Coasting also adds weight and complexity to the bike. Though there are riders who swear by it is a small minority of the tandem population, it might look like a good idea, but why not find out first if its a good idea for your team?.
    I agree, wholeheartedly. We tried a DaVinci at the Outdoor Demo and, frankly, we hated being out-of-sync. From the stoker's standpoint (me) the bike felt jerky and unstable. We went out of our way to peddle at different tempos to see how it felt; and after a few miles, we wound up back in sync anyway, because it felt so horrible not to be.

    My Husband/Captain is a much, much stronger and faster rider than I am - but we've learned to compensate; and have done very well on centuries, double centuries, and touring. And we both agree that standard tandem cranks are way, way better! We'd NEVER switch.

    Good luck!

    Deb

  12. #12
    Senior Member Leigh_caines's Avatar
    Join Date
    Sep 2007
    Location
    Woolgoolga NSW Australia
    My Bikes
    Long Recumbent, Short recombent, racing bike, MTB, beach bike,Tandem,Fixy.2 twentys and a folding bike
    Posts
    275
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    >we hated being out-of-sync.<

    No that is not what happens...
    we have only been ride as a pair for two months...
    but within a few days we rode "in-sync"
    My lady can see my legs go around and she likes to get in time.
    The huge advantages are [for us]...
    Starting off [remembering my lady is disabled] is very smooth [no delay while I clip my feet in]
    I never jerk her by going backwards [even a little bit dose jerk]
    And the big one is... she can rest while I keep going [in our case this is half the rideing time] she get out of the house and goes farther then she ever could before. We go places she couldn't go on her own.
    So for us having freewheeling is the best thing ever!!

  13. #13
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,151
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Leigh_caines View Post
    ...but within a few days we rode "in-sync"
    This is also what most of the teams whom we've ridden with or know who ride daVinci tandems report. Riding out-of-sync is something that seems to occur under just a couple of different scenarios:

    1. Intentionally on long seated climbs
    2. When one rider decides to coast or soft pedal for a break
    3. When one rider becomes fatigued and unitentionally soft pedals**
    4. When a kid-back is riding and does what ever it is that kids do on the back of tandem when not required to stay-in-sync.**
    5. When riding technical single track off-road and negotiating hazards.

    **This is a blessing in disguise to captains who might otherwise find themselves pushing their stoker's feet around.

  14. #14
    Senior Member Leigh_caines's Avatar
    Join Date
    Sep 2007
    Location
    Woolgoolga NSW Australia
    My Bikes
    Long Recumbent, Short recombent, racing bike, MTB, beach bike,Tandem,Fixy.2 twentys and a folding bike
    Posts
    275
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    1- yes
    2- since I always pedal and she cuts in in time.. not a prob
    3- hasn't happened
    4- have to wait for my grandaughter to visit
    5- hope my lady get to this stage

  15. #15
    Senior Member
    Join Date
    Oct 2005
    Posts
    1,735
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Xanti Andia View Post
    Do keep in mind that Independent Coasting does not permit differing cadences between riders, only the choice to spin or not to spin, once you are spinning you cannot deliver power to the pedals at different rpm.

    In some rare Independent Pedaling recumbents, as TG pointed out, each rider has his own transmission to his own wheel, so each can choose his cadence.
    Not quite true regarding cadence for the ICS system. Since each crank has it's own chainring that drives the "jack gear", by varying the captain or stoker chainring, you can change the relative cadence. I.e. put a larger drive chainring on the stoker crank and the stoker will have a lower cadence than the captain. Much the same as Leigh Canes stated for his 2 BB system.

    Quote Originally Posted by Tandemgeek
    This is also what most of the teams whom we've ridden with or know who ride daVinci tandems report. Riding out-of-sync is something that seems to occur under just a couple of different scenarios:

    1. Intentionally on long seated climbs
    2. When one rider decides to coast or soft pedal for a break
    3. When one rider becomes fatigued and unitentionally soft pedals**
    4. When a kid-back is riding and does what ever it is that kids do on the back of tandem when not required to stay-in-sync.**
    5. When riding technical single track off-road and negotiating hazards.

    **This is a blessing in disguise to captains who might otherwise find themselves pushing their stoker's feet around.
    +1 to Tandemgeeks scenarios. I would only modify #2 and 3 to indicate a broader spectrum of intentional and unintentional soft pedaling (tired, distracted, perturbed, adjusting, drinking, etc.).

    Just as PlanetU would not switch to ICS we currently would not want to switch from it. It has its advantages and drawbacks.

  16. #16
    Senior Member adamlaw's Avatar
    Join Date
    Apr 2006
    Location
    Ithaca, NY
    My Bikes
    1980 Mercian Olympic, 2004 Spectrum Ti custom, 2007 Bob Brown fully lugged steel tandem with S and S coupling and DaVinci ICS
    Posts
    53
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have been riding a Bob Brown tandem with a DaVinci Independent Coasting system as a newbie to tandem riding. It has been great. My 10 and 12 year old stokers have taken to it easily. They automatically end up in phase without any conscious effort. We haven't practiced out of phase - that is likely more difficult. It makes starting very easy. Also, it provides a huge range of gears with 4 chain rings on the front and 10 on the back!

  17. #17
    Junior Member
    Join Date
    May 2006
    Location
    Portland, OR
    My Bikes
    Bianchi crossbike; LeMond Victoire; Trek 820; Burley Duet
    Posts
    13
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Mooncricket,
    Not to infer ignorance on your part (or maybe I misunderstood your question), but I've heard some people express the notion that tandem riding is really hard because you have to learn to pedal together. Not true. With a normal tandem, the chain connecting the front and rear cranks forces you to pedal together, whether in or out of phase. So there is no problem in "having to synchronize their pedal stroke." My wife and I have vastly different fitness levels; on her own she'd probably ride at 12-13 mph, while I cruise at 17-18. But we are a fine tandem team. You'll find the compromise through good communication (remembering that anything wrong is not the stoker's fault). Maybe you'll need to ride less aggressively than you would on your own, but that's a small price to pay for companionship. And she might find that as she gets stronger she can ride faster than she thought.

  18. #18
    Senior Member zonatandem's Avatar
    Join Date
    Dec 2003
    Location
    Tucson, AZ
    My Bikes
    ariZona carbon fiber tandem & single
    Posts
    9,968
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Mooncricket ;

    Issuing utlimatum of 'she gets on the bike with me or get left behind for weeks, monhs at the time' . . .?!
    It takes 2 people to make a good tandem 'team'.
    If you two are not willing/able to compromise a bit, then why bother riding TWOgether?

Posting Permissions

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