Rans tailwind gearing/shifting

Discussion in 'Recumbent bicycles' started by Lacustral, Jul 30, 2003.

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  1. Lacustral

    Lacustral Guest

    i have a '99 Rans Tailwind, 62-52-39 crankset and 11-12-14-16-18-21-24-28 cassette. The shifter it
    came with was a grip shifter, SRAM 7.0 ESP. I liked the rapid fire shifters on my mountain bike so
    i asked the bike shop if they could put some on the tailwind. Fine, they said. But, the front
    shifter doesn't work. I can shift onto the largest front chainring OK but it will hardly go onto
    the smallest at all. Even with the bike shops best efforts at adjusting the derailleur it still
    doesn't work.

    Is the original front grip shifter the best shifter for those front chainrings? I don't know how
    well it will shift because it got out of adjustment quickly. I didn't need the smallest chainring.
    Now I'm living in a very hilly area and i do want the smallest chainring.

    They said there is a rapid fire shifter now that is meant for road derailleurs, like i have, the
    Shimano R440. Would that work ok on the large front chainrings?

    Also, the lowest gear on this bike isn't low enough for the steeper hills. i really need to go about
    walking speed on the really steep hills. I like the highest gear -- can i get a lower low gear
    without sacrificing the high gear?

    thanks Laura
     
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  2. R2D2

    R2D2 New Member

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    You are in luck.

    All Shimano and SRAM front shifters move exactly the same amount of cable (between gears, and overall). The shifters and derailleurs are also completely interchangeable between the two manufacturers, and between mountain and road groups.

    I rode a Tailwind for a couple of years and the shifting was always right on (don't let the LBS tell you it's because of the big gears). The LBS mechanic should be able to tune the shifting perfectly, as long as the parts are installed properly and functioning normally.

    If the shifters, cable, cable housing, alignment, limit screws, adjustment knob, derailleur height, chain, and crankset are all working perfectly, then that only leaves a couple of possibilities.

    One is that the derailleur cage might be bent. Both plates should be exactly parallel with the chain (when chain is in the middle gear both front and back). I've accidentally kicked mine a couple of times (one time bending it slightly out of place). The mechanic should be able to see this.

    Another possibility is that the bottom bracket axle is too short (it may have been swapped out at some time?). A couple of other less likely problems (though neither will cause as severe a problem as you describe) could be related to chain type and wear, or chainring style (HG/IG).

    I think the solution is actually presented in the second part of your question. Replacing the crankset with something like the Shimano Ultegra Triple (30-42-52) will give you a better "granny" gear for those tough hills. Of course you lose the big 62 tooth gear for the other side of the hill! But that is the compromise of course.

    The LBS will also have to replace the bottom bracket. If this is getting too expensive, then the 105 group is very worthy too.

    Good Luck, and hope this helps some!
    R2
     
  3. Cletus Lee

    Cletus Lee Guest

    In article <[email protected]>, [email protected] says...
    > You are in luck.
    >
    > All Shimano and SRAM front shifters move exactly the same amount of cable (between gears, and
    > overall). The shifters and derailleurs are also completely interchangeable between the two
    > manufacturers, and between mountain and road groups.
    >
    >
    And you are 'Blowing smoke'.

    SRAM ESP Rear Derailleurs have a 1:1 Actuation Ratio while Shimano Rear Derailleurs have a 2:1
    Actuation Ratio. SRAM Makes Shimano Compatible shifters. These are the 'Named' models like 'Rocket'
    and 'Attack' The SRAM models are the 'n.0' series. Shimano only makes Shimano Compatible shifters.

    BTW Guess how I found this out? :-(
    --

    Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
    - Bellaire, TX USA -
     
  4. Cletus Lee wrote:

    > And you are 'Blowing smoke'.

    > SRAM ESP Rear Derailleurs have a 1:1 Actuation Ratio while Shimano Rear Derailleurs have a 2:1
    > Actuation Ratio. SRAM Makes Shimano Compatible shifters. These are the 'Named' models like
    > 'Rocket' and 'Attack' The SRAM models are the 'n.0' series. Shimano only makes Shimano Compatible
    > shifters.

    All true enough, but we're talking about /front/ shifters here. Do SRAM front grip shifters pull the
    same amount of cable as Rabidfires? IIRC the R440 front mech is /supposed/ to work with a
    combination of "Flat-bar" (i.e. Rabidfire) shifters and "road" sized chainrings.

    Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  5. La

    La Guest

    That was a beautiful reply. Nice job Lon

    R2D2 wrote:

    > You are in luck.
    >
    > All Shimano and SRAM front shifters move exactly the same amount of cable (between gears, and
    > overall). The shifters and derailleurs are also completely interchangeable between the two
    > manufacturers, and between mountain and road groups.
    >
    > I rode a Tailwind for a couple of years and the shifting was always right on (don't let the LBS
    > tell you it's because of the big gears). The LBS mechanic should be able to tune the shifting
    > perfectly, as long as the parts are installed properly and functioning normally.
    >
    > If the shifters, cable, cable housing, alignment, limit screws, adjustment knob, derailleur
    > height, chain, and crankset are all working perfectly, then that only leaves a couple of
    > possibilities.
    >
    > One is that the derailleur cage might be bent. Both plates should be exactly parallel with the
    > chain (when chain is in the middle gear both front and back). I've accidentally kicked mine a
    > couple of times (one time bending it slightly out of place). The mechanic should be able to
    > see this.
    >
    > Another possibility is that the bottom bracket axle is too short (it may have been swapped out at
    > some time?). A couple of other less likely problems (though neither will cause as severe a problem
    > as you describe) could be related to chain type and wear, or chainring style (HG/IG).
    >
    > I think the solution is actually presented in the second part of your question. Replacing the
    > crankset with something like the Shimano Ultegra Triple (30-42-52) will give you a better "granny"
    > gear for those tough hills. Of course you lose the big 62 tooth gear for the other side of the
    > hill! But that is the compromise of course.
    >
    > The LBS will also have to replace the bottom bracket. If this is getting too expensive, then the
    > 105 group is very worthy too.
    >
    > Good Luck, and hope this helps some! R2
    >
    > --
    > >--------------------------<
    > Posted via cyclingforums.com http://www.cyclingforums.com
     
  6. Lacustral

    Lacustral Guest

    well, i think I will get my old grip shifter put back on. It has 3 clicks per chainring so that you
    can adjust it so the chain won't rub against the front derailleur and will also shift OK.

    I would like to get lower gears though, without sacrificing the highest gear. Would it work to
    change the smallest chainring to something smaller? Or to change the rear cluster to something with
    a larger largest gear?

    thanks
     
  7. Cletus Lee

    Cletus Lee Guest

    In article <[email protected]>,
    [email protected] says...
    > well, i think I will get my old grip shifter put back on. It has 3 clicks per chainring so that
    > you can adjust it so the chain won't rub against the front derailleur and will also shift OK.
    >
    > I would like to get lower gears though, without sacrificing the highest gear. Would it work to
    > change the smallest chainring to something smaller? Or to change the rear cluster to something
    > with a larger largest gear?
    >
    > thanks
    >
    >
    Your present set up (62-52-39 crankset and 11-12-14-16-18-21-24-28 cassette) can be modified as
    follows: You can drop the granny on the fron to 36T or 38T and use the existing fron Derailleur. On
    the rear, You can replace the 11-28 with a 11-34. However, the capacity (largest cog) of the rear
    derailleur needs to be 34T. What you have for a rear derailleur may or may not have the capacity for
    the larger cogs. If it does not, you will need a new rear derailleur. At that time you can match the
    new rapid-fire shifters if you like.

    If you make these changes, you will not lose any of the high gears and gain a lot on the low gears.
    --

    Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
    - Bellaire, TX USA -
     
  8. On 31 Jul 2003 22:31:15 +0950, R2D2 <[email protected]> wrote:
    >
    >All Shimano and SRAM front shifters move exactly the same amount of cable (between gears, and
    >overall). The shifters and derailleurs are also completely interchangeable between the two
    >manufacturers, and between mountain and road groups.

    That's not what I was told when I asked about it here recently. According to Sheldon Brown:

    "While rear indexing is the same for all recent shifters/derailers, Shimano fronts use a different
    amount of cable pull for drop bar vs straight bar controls. This makes it difficult if you want to
    use a "road" crankset, with full-sized chainrings (52, 53 top) with straight handlebars, or if you
    want to use a "mountain" crankset (44-48 tooth top) with drop bar STI shifters. "

    Source: http://www.sheldonbrown.com/harris/derailers.html#front

    However Shimano does make road bike front derailleurs compatible with flat handlebar controls: the
    R440 (double chainring) and R443 (triple).

    Ken Kobayashi [email protected] http://solarwww.mtk.nao.ac.jp/kobayashi/personal/
     
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