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  1. #1
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    Rear shock on Ventana ECDM

    I posted this over on mtbr.com's tandem forum but thought I'd post here as well -- seems to have a bit more activity & some very knowledgeable folks.

    I recently purchased a used ECDM and had the LBS give it a once-over since I'm a poor bike mechanic. The only issue found was the rear shock (Fox DHX Air 5.0) isn't rebounding properly. Their recommendation was to have it rebuilt - about a $130 task. I'm wondering if that shock is worth the investment or if I'd be better off purchasing something new. If a new shock is the best route - any advice on which one?

    Does anyone have input or advice on this? It's not an issue of trying to minimize cost - I would just like to have a good shock back there and want to make an educated decision.

    Thank you!

  2. #2
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    Update: I rec'd some good advice on mtbr.com.

  3. #3
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    Buying new may not be quite so simple...

    Shocks are, or should be, matched up the spring rate. Thus I would expect a spring/shock combination for a tandem to be quite different from one on a half-bike. True that adjustment on shock might compensate, at least somewhat.

    Thus the question is if the OEM shock you have has been tweaked for the tandem application or did they just throw standard parts together and call it close enough?

  4. #4
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    Good point.

    It's my understanding it's a stock unit & tweaked / adjusted for use on the tandem.

  5. #5
    PMK
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    I replied to you on MTBR. Hope it helped.

    For us, I the Fox DHX 5.0 air has internal shim stacks very close for the ECDM, and I changed no shims during rebuilds. The clickers have a wide range and easily dial in and as I explained we adjust on the fly almost every ride.

    The 5.0 air early style is a very good design.

    PK
    2006 Co-Motion Roadster, flat bars, discs and carbon fibre fork, size 22 / 19
    2006 Ventana ECDM full suspension mountain tandem
    Some single bikes and a couple of KTM's
    And most important, someone special that enjoys them with me (except the KTM's)

  6. #6
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    Just curious.......... did you consider getting in touch with the builder(Ventana) and asking them what they would recommend?

  7. #7
    Senior Member
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    Call Sherwood at Ventana he is very responsive and helpful.

  8. #8
    PMK
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    During AORTA 1 a few years ago, I talked with Sherwood about rear shocks on the ECDM. In simple terms, he mentioned the design of the frame and linkage rates / ratios were based on the current style of airshox. This was important since my main concern was having a new frame built and obtaining proper rising rate for a coil spring Ohlins style shock.

    Ultimately, the ECDM we purchased used to strip parts off of, became our full suspension off-road tandem.

    When we purchased it the machine had a Fox RP series installed on it. I did open the shock and revalve the shimstacks to a better setting. In the end though, once I installed the non tandem rated Fox 40 Kashima fork, the RP shock could n longer keep up. I then went shopping and have settled on the Fox DHX 5.0 air series. These have a ton of available adjustments both in compression and rebond along with a variable volume rezzy to dial in riding rate.

    The OP posted also on MTBR, I responded there explaining that I would not make a change in the shock, but rather ensure the the unit has a minimum of 100 psi in the rezzy but 125 would be better and see if it cures the knocking rebound, which it should. He was quoted 130 for a rebuild, and honestly, that is a fair price if done by a quality suspension tuner.

    PK
    2006 Co-Motion Roadster, flat bars, discs and carbon fibre fork, size 22 / 19
    2006 Ventana ECDM full suspension mountain tandem
    Some single bikes and a couple of KTM's
    And most important, someone special that enjoys them with me (except the KTM's)

  9. #9
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    Paul
    i wish I had your suspension knowledge as I'm sure our Ventana and singles would really benefit from your expertise and ride a whole lot better.
    Mark

  10. #10
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    Quote Originally Posted by Tookool View Post
    Just curious.......... did you consider getting in touch with the builder(Ventana) and asking them what they would recommend?
    Well... as intelligent as that suggestions seems... No, I did not.

    I've been lurking on the various tandem forums for a while (here & on mtbr), figured there was plenty of real world experience, and just was looking for input on if the current shock was worthy. PMK has a big track record of shock advice, so as soon as he gave a thumbs up on the shock I figured I'd send it in for a rebuild. Going up to DirtLabs in Boulder today and I'll pick it up later this week. Will also be using them for their 'suspension setup service'.

    With a big investment like this I feel comfortable spending some money up front to make sure everything is working as best as it can.

  11. #11
    PMK
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    Quote Originally Posted by akexpress View Post
    Paul
    i wish I had your suspension knowledge as I'm sure our Ventana and singles would really benefit from your expertise and ride a whole lot better.
    Mark
    akexpress, honestly, I wish I could afford to spend some quality months riding in AK, and the winters here. I'm sure you and Rick would show us the best trails, or road rides. Plus we would not need lights.

    As far as suspension and things that go along with it, I have been intrigued and passionate about it since the mid 70's. I enjoy helping friends but came to not like it so much as a business. Far easier to fix airplanes and feed the family than do shocks. Maybe you can come to AORTA 2 and we can get you dialed in for sag and clickers.Rebuilds or revalves would be tougher...bring your single also. See you in Asheville?

    PK
    2006 Co-Motion Roadster, flat bars, discs and carbon fibre fork, size 22 / 19
    2006 Ventana ECDM full suspension mountain tandem
    Some single bikes and a couple of KTM's
    And most important, someone special that enjoys them with me (except the KTM's)

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