Snapped stem on first ride

Discussion in 'Recumbent bicycles' started by Nick Keenan, Jun 1, 2003.

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  1. Nick Keenan

    Nick Keenan Guest

    On Friday I took delivery of a brand new RANS Vivo. After a brief test ride I noticed that the stem
    was a little loose, in that I could twist the handlebars independently of the front wheel. So I
    tightened the two stem bolts, and all seemed well.

    Today I took it for my first real ride. After a few miles, I went over a bump, and the handlebars
    were twisted again. Lucily I had a 5mm Allen wrench with me, so I tightened the stem bolts again. A
    few miles later it happened again, so I cursed and tightened the stem bolts again.

    A few miles later, the stem snapped as I was pulling away from an intersection. It had vertical
    cracks on each side of the steering column. If the stem bolts are 6 o'clock, then the cracks were at
    3 and 9 o'clock.

    So now I have to fix it. There isn't a RANS dealer who is convenient to me, so the most practical
    thing is for me to order the part and either fix it myself, or have my LBS install it for me.

    Now here's the question: Did I screw this up, or was the part defective? I can't shake the suspicion
    that I just overtightened those stem bolts. My experience with working on bikes is that there is
    almost nothing on a bike you really want to torque down tight. However, I couldn't figure out any
    other way to keep the handle bars from twisting. There are two practical ramifications to this
    question. The first is I have to decide whether to make a warranty claim; if I'm responsible I
    won't. The second is that I don't want to just order the part, replace it, and then make the same
    mistake again.

    What say ye, members of the jury?

    Thanks, Nick Keenan
     
    Tags:


  2. Vol

    Vol Guest

    You could, of course, say nothing about the loose stem and your tightening and just make the
    warrenty claim as if it had broken without any user intervention.

    Since you are asking the question, though, I suspect you have a sense of ethics. IMHO, living up to
    your personal standards is much more important than a cracked stem, even on a new ride.

    Contact RANS, tell them the whole story, and ask for both a new stem and some instructions on
    keeping it firmly in place.

    George
     
  3. My suspicion is there is something else causing the original problem. Yes you probably caused the
    stem to crack, but something else caused the stem to be loose. I'd call Rans explain the travel
    situation and see if they would cover a visit to a local repair shop. Ideally the shop who assembled
    the bike should be given a shot at the repair. Denny in Sayre, Pa "Bent but not Broken" "Vol"
    <[email protected]> wrote in message news:[email protected]...
    > You could, of course, say nothing about the loose stem and your tightening and just make the
    > warrenty claim as if it had broken without any user intervention.
    >
    > Since you are asking the question, though, I suspect you have a sense of ethics. IMHO, living up
    > to your personal standards is much more important than a cracked stem, even on a new ride.
    >
    > Contact RANS, tell them the whole story, and ask for both a new stem and some instructions on
    > keeping it firmly in place.
    >
    > George
     
  4. John Riley

    John Riley Guest

    I'm guessing there are at least two pieces that could twist. There is the lower piece that goes into
    the top of the fork, right? Then there is the upper piece that goes over that and to which the
    handlebars are attached. It sounds like you were tightening the upper part. Are you sure it wasn't
    the lower part that was twisting?

    johnriley1 (at) rogers.com
     
  5. John Riley

    John Riley Guest

    Whoops, I guess there would be a flip-it in there somewhere. So you are saying that the upper part
    was twisting relative to the flip-it?

    JR
     
  6. JR, I left this alone last night. However, here is a thought. Is Murphy at work here? The locking
    collar that connects the stem to the flipit installed upside down? There is a small ridge at one end
    of this collar its where the stem is SUPPOSED to butt against when properly installed. It is
    possible with a little work to install it upside down. What happens after this is done is....the
    ridge cuts a groove in the stem and it will (a) never tighten up and (b) eventually fatigue the area
    enough to cause a clean snap. I really can't think of another cause. Its just a guess "Almost
    nothing is Murphyproof"
    --
    Jude....///Bacchetta AERO St. Michaels and Tilghman Island.. Maryland Wheel Doctor Cycle and Sports,
    Inc 1-800-586-6645 "john riley" <[email protected]> wrote in message
    news:[email protected]...
    > Whoops, I guess there would be a flip-it in there somewhere. So you are saying that the upper part
    > was twisting relative to the flip-it?
    >
    > JR
     
  7. If the lower stem piece isn't tight, then no matter how tight you make the upper piece, it will
    still twist crooked when some force is put on the wheel and handlebars.

    Steve McDonald
     
  8. good point John!
     
  9. Seth Jayson

    Seth Jayson Guest

    Could it be that there was not enough length of tube riser coming off the flipit inside the bottom
    of the bar tube? you're supposed to have three inches. I could imagine that not having much in there
    could cause a situation similar to that described...

    Sj
     
  10. Nick Keenan

    Nick Keenan Guest

    [email protected] (john riley) wrote in message
    news:<[email protected]>...
    > Whoops, I guess there would be a flip-it in there somewhere. So you are saying that the upper part
    > was twisting relative to the flip-it?
    >
    > JR

    As soon as I posted I realized there would be a problem with nomenclature. The part that cracked was
    where the flip-it attaches to the top of the fork -- i.e., the very bottom of the flip-it. It was
    definitely the spot that was twisting as well.
     
  11. Nick Keenan

    Nick Keenan Guest

    "Denny Voorhees" <[email protected]> wrote in message
    news:<[email protected]>...
    > My suspicion is there is something else causing the original problem. Yes you probably caused the
    > stem to crack, but something else caused the stem to be loose.

    That's along the lines of what I was thinking. I was hoping that by throwing the question out I
    might get some insight into what "something else" could be, perhaps someone else who has had the
    same problem. Or that maybe there is a special technique for attaching the lift-it on a RANS.

    My bet is that if I replace the lift-it, then make sure the mating surfaces are clean, the stem
    bolts are at the proper torque (70 inch pounds?), and the headset is properly adjusted I'll be OK.
    If it still slips I will try fitting a shim. If I hadn't been so impatient to try out my new toy
    this is what I would have done.

    I noticed that Hostel Shoppe has an upgrade to the flip-it called the TerraCycle. Does anyone have
    experience with it? Is is worthwhile as an upgrade?

    Thanks, Nick Keenan
     
  12. Jeff Wills

    Jeff Wills Guest

    [email protected] (Nick Keenan) wrote in message
    news:<[email protected]>...
    >
    > I noticed that Hostel Shoppe has an upgrade to the flip-it called the TerraCycle. Does anyone have
    > experience with it? Is is worthwhile as an upgrade?
    >

    That would be a Glideflex stem, made by Terracycle: http://www.terracycle.com/ .

    I don't have any experience with the RANS Flip-It, so I can't make a direct comparison. However, my
    Lightning now has a Glideflex stem on board- it's a very well made, precise unit. Of course, I'm
    prejudiced: Terracycle's Pat Franz is a friend who has done a ton of work for me and has supported
    the Portland Human Power Challenge for the last several years.

    Jeff
     
  13. Gary

    Gary Guest

    > I noticed that Hostel Shoppe has an upgrade to the flip-it called the TerraCycle. Does anyone have
    > experience with it? Is is worthwhile as an upgrade?
    >
    > Thanks, Nick Keenan

    There's been some talk on Bent Rider Online and Yahoo Vision Owners about these stems' clamping
    mechanism failing, causing loss of steering and a resulting crash. May want to "steer clear" (sorry)
    for a bit until things get sorted out. They are using these on the new Visions and they are really
    nice set-ups but like I say...
     
  14. Pat Franz

    Pat Franz Guest

    [email protected] (Gary) wrote in message news:<[email protected]>...
    > > I noticed that Hostel Shoppe has an upgrade to the flip-it called the TerraCycle. Does anyone
    > > have experience with it? Is is worthwhile as an upgrade?
    > >
    > > Thanks, Nick Keenan
    >
    > There's been some talk on Bent Rider Online and Yahoo Vision Owners about these stems' clamping
    > mechanism failing, causing loss of steering and a resulting crash. May want to "steer clear"
    > (sorry) for a bit until things get sorted out. They are using these on the new Visions and they
    > are really nice set-ups but like I say...

    We recently received reports that 3 people have had problems with folding stems coming loose from
    the fork adapter, resulting in a loss of steering. We have analyzed and solved one instance, are
    working on the second, and are trying to contact the owner in the third instance.

    In the one instance we have analyzed so far, the threaded to threadless fork adapter had been
    shortened for aesthetic/testing purposes before it went to a bike show. After the show, the bike was
    sold before the modified adapter was removed. The design of the adapter has a taper from the 1" stem
    clamping part of the adapter to the 7/8" fork insertion part of the adapter. The shortened adapter
    put the folding stem's clamp on the tapered area, where it was unable to hold adequately. In use,
    the stem would rock down the taper and eventually loosen. Upon hearing of the problem, we
    immediately replaced both the adapter and the stem, and the owner reports the problem solved.

    The situation appears to be isolated, but the possible loss of steering on even one bike is serious,
    and we need to find out if others are experiencing this. If you, or anyone you know, has experienced
    a TerraCycle GlideFlex folding stem coming loose from the fork adapter on a 2002 Vision recumbent
    with Above Seat Steering, please contact us immediately.

    Thank You,

    Ricky Comar, Vision 1-425-673-2448 [email protected] Pat Franz, TerraCycle 1-800-371-5871
    [email protected]
     
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