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  1. #1
    the commutor / tourer mcavana's Avatar
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    my double wireless cateye computer almost killed me today!

    I was going down "the wonderwood" today (a locally popular bridge for riding... pretty steep, and long... it is close to the ocean so the winds can really turn it into quite a ride) I had a nice tailwind and was going down it at 37, 38, then 39, then POP... POP, POP!!! I thought to myself "This is it! I am dead!" Thank god I was able to quickly and safely slow down. (keep in mind the fastest i have ever gone before was 38 on this same bridge... weighing in at 265 takes a little time to slow down... think of a train..) I thought I had survived a double blow out... but then after taking a moment to pull myself together, I realized that my tires were fine... but my computer was gone! That 140 dollar little bastard came off!!! I guess that the first pop was it hitting my from tire on the way down and that threw it forward, then both of my tires ran it over (700X23 tires on a Giant TCR2)

    I always thought that the computer did not connect very tightly... well now it is even worse, so i put a wire tie around it to hold it on. One thing, the dam thing did survive a 40mph fall, then being crushed by 265 pounds!

    Questions:
    *Has anyone experienced this problem with this computer?
    *Is Cat Eye going to help me out here, or are they going to say it was user error? (the computer itself pretty much needs to be replaced... the fall did make the mount even worse
    *When I get up to those speeds I am off the saddle, with my hands on the drops, as low as I can be... over about 35 or so the bike really starts to shake. My wheels are true... Is it just my weight, or should is something maybe out of wack on the bike? I am sure this shaking helped the computer to wiggle off... it is pretty bad.

    Thanks,

    Mike
    "Ready to retire, just can't afford it yet!"

  2. #2
    Klaatu barada nikto cascade168's Avatar
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    Quote Originally Posted by Mike Cavanaugh

    Questions:
    *Has anyone experienced this problem with this computer?
    *Is Cat Eye going to help me out here, or are they going to say it was user error? (the computer itself pretty much needs to be replaced... the fall did make the mount even worse
    *When I get up to those speeds I am off the saddle, with my hands on the drops, as low as I can be... over about 35 or so the bike really starts to shake. My wheels are true... Is it just my weight, or should is something maybe out of wack on the bike? I am sure this shaking helped the computer to wiggle off... it is pretty bad.
    Thank goodness you did not crash. I went off the road at 35 once and it was very scary.

    I have a couple of Cateye's (but not the double sensor), and several other types of cyclocomputers and they all have a positive feedback lock (i.e. it clicks into place when you seat it in the cradle). I'd be kind of surprised if this is not the case with yours. Maybe you have some bit of plastic molding that did not get trimmed. You should send the cradle and computer head to Cateye. See how they seat after you get them off the handlebar and make sure it was not some problem with the mounting.

    Cateye has a good rep for customer service. Give them a call: Toll Free: 800-5-CatEye (in the US)

    Wheels shaking at high speed can be a function of fork stiffness. Assuming your wheels are strong, and that your headset and hubs are adjusted properly, you may need a stiffer fork. Especially, since you are in the heavyweight class. CF forks are a common solution for this, but I would recommend you discuss this with your local LBS. See if they concur.
    "Work is the curse of the drinking class."
    - Oscar Wilde

  3. #3
    Fattest Thin Man Az B's Avatar
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    I would suggest not going that fast until you figure out why your bike is shaking.

    There's basically two kinds of shaking, a weave and a wobble. A weave generally originates from the rear of the bike and makes it move down the road like a porpoise. Some common causes are rear wheel out of true, rear wheel drastically out of alignment, rear axle bent, and frame bent or out of alignment.

    A wobble is more common and feels more like the handlebars are coming to life as they snap back and forth. This is very dangerous as it get worse and worse it can easily lead to a complete loss of control. Since it almost always happens at higher speeds, this means painful crashing and burning. A wobble is commonly caused by front wheel issues, (bearings, axle, true) frame issues, (severely bent or even broken frame) or steering head bearing issues. If the bike has been customized in the front end, the modifications may have caused unwanted changes in the bikes geometry.

    Oh, and I think you're out of luck on the speedo.

    Good luck.

    Az

  4. #4
    the commutor / tourer mcavana's Avatar
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    Quote Originally Posted by cascade168
    Thank goodness you did not crash. I went off the road at 35 once and it was very scary.

    I have a couple of Cateye's (but not the double sensor), and several other types of cyclocomputers and they all have a positive feedback lock (i.e. it clicks into place when you seat it in the cradle). I'd be kind of surprised if this is not the case with yours. Maybe you have some bit of plastic molding that did not get trimmed. You should send the cradle and computer head to Cateye. See how they seat after you get them off the handlebar and make sure it was not some problem with the mounting.

    Cateye has a good rep for customer service. Give them a call: Toll Free: 800-5-CatEye (in the US)

    Wheels shaking at high speed can be a function of fork stiffness. Assuming your wheels are strong, and that your headset and hubs are adjusted properly, you may need a stiffer fork. Especially, since you are in the heavyweight class. CF forks are a common solution for this, but I would recommend you discuss this with your local LBS. See if they concur.
    the bike is a giant TCR2 (it is all carbon) and the wheels are mavic kysirium elite... if it is a weight problem... then that is cool... I will weigh allot less very soon... i will slow down until then.
    Last edited by Mike Cavanaugh; 01-17-06 at 03:09 PM.
    "Ready to retire, just can't afford it yet!"

  5. #5
    the commutor / tourer mcavana's Avatar
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    Quote Originally Posted by Az B
    I would suggest not going that fast until you figure out why your bike is shaking.

    There's basically two kinds of shaking, a weave and a wobble. A weave generally originates from the rear of the bike and makes it move down the road like a porpoise. Some common causes are rear wheel out of true, rear wheel drastically out of alignment, rear axle bent, and frame bent or out of alignment.

    A wobble is more common and feels more like the handlebars are coming to life as they snap back and forth. This is very dangerous as it get worse and worse it can easily lead to a complete loss of control. Since it almost always happens at higher speeds, this means painful crashing and burning. A wobble is commonly caused by front wheel issues, (bearings, axle, true) frame issues, (severely bent or even broken frame) or steering head bearing issues. If the bike has been customized in the front end, the modifications may have caused unwanted changes in the bikes geometry.

    Oh, and I think you're out of luck on the speedo.

    Good luck.

    Az
    Thank you for that explanation.. it is certainly a "wobble" all the shaking is in the handle bars. The wheels I have (mavik kysirium elite) have adjustable hubs that have never been adjusted... If that might be it I will swing by the local bike shop so they can show me the ropes on how tight they should be. do you think this could be the problem?>
    "Ready to retire, just can't afford it yet!"

  6. #6
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    My bike once started shimmying. A friend behind me could not believe it. Braking only made it oscillate worse. I was barrelling down a hill. I did manage to get it under control using both lanes of the road by intermittantly braking and letting loose, slowly bringing down the speed.

    I've since read that you may be able to regain by hugging the top tube with your thighs to kind of dampen the harmonics. It was a awful feeling.

  7. #7
    Senior Member Deanster04's Avatar
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    most of the computers have a positive lock. Sometimes I have had the problem of not having the side seated properly and it feels loose. Usually backing out and feeding it back in until I get the positive locking click. Sounds like there was a problem with the cradle. I agree with the person who says CatEye has excellent customer service. Call them and talk to customer service...and be nice.

  8. #8
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    "My...computer almost killed me today!"

    You know, the title to this thread makes it sound like you're blaming your computer for your shimmying problems.

    In reality, it sounds like the bike's vibration caused the computer to hit your wheel. I can't see how the computer caused the vibration in the first place.

    There can be many causes for high-speed wobble on a bike, including:

    1. bent frame
    2. loose/bent axles
    3. wheels not properly installed in dropouts
    4. bent fork
    5. wheels not true
    6. loose headset
    7. seat too far forward/backward
    8. stem too long/short
    9. poorly fitting bike (wrong size bike)
    10. poorly fitted bike (right size bike, but not properly fitted to you)
    11. operator error (poor weight distribution, stiff arms, nervous shaking, etc.)

    Many times a bike that seems to handle well at slow speeds will wobble at higher speeds, typically while coasting downhill, so you don't even realize the problem exists until things are almost out of control.

    I would take the bike in to a trusted LBS and have them check it out completely to try to isolate the cause. If they can't find anything wrong with the bike and if they can't replicate the shimmy, it would point to operator error.

    Bob

  9. #9
    Isaias NoRacer's Avatar
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    The double wireless doesn't have a cradle per se, unlike many of the other CatEye line of computers. The HB mount has a mounting area similar to what you find for headlights that are removable, except that the mounting area is parallel to the horizon instead of vertical. The locking mechanism on the bottom of the receiver is composed of three spring-loaded locking 'bearings' and a small projection that forms a sideways 'u' that slips into the HB mount from the left. The only thing keeping the computer in place is the lip of the HB mount that captures the projection around the bottom of the receiver and the three spring-loaded 'bearings' that keep it from backing out of the mount leftwise.

    If the lip on the HB mount is compromised or the computer is not mounted with both of the projections under the lip of the HB mount, the computer will fall off with a jolt. Also, it may be that with a decent jolt the projections can unseat themselves and the computer falls off. This can happen because the receiver is mounted horizontal to the horizon, unlike how headlights are seated in their mounts (i.e., vertical).

    With a wobble--I've had this happen once or twice on my TCR C2 as well, during a decent--if the oscillation is violent enough and the locking bearings underneath the receiver is sprung (i.e., no longer locks as well as it should) the receiver could go flying.

    I haven't had any of this happen with my double wireless--yet (fingers crossed). I haven't had it very long, but I can see the potential.
    Last edited by NoRacer; 01-18-06 at 07:39 AM.
    2009 mileage = 14,738 miles; 2010 mileage = 15,234 miles; 2011 mileage = 17,344 miles; 2012 mileage = 11,414 miles; 2013 = 12,169

  10. #10
    Isaias NoRacer's Avatar
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    Quote Originally Posted by Bobby Lex
    There can be many causes for high-speed wobble on a bike, including:

    1. bent frame
    2. loose/bent axles
    3. wheels not properly installed in dropouts
    4. bent fork
    5. wheels not true
    6. loose headset
    7. seat too far forward/backward
    8. stem too long/short
    9. poorly fitting bike (wrong size bike)
    10. poorly fitted bike (right size bike, but not properly fitted to you)
    11. operator error (poor weight distribution, stiff arms, nervous shaking, etc.)

    Many times a bike that seems to handle well at slow speeds will wobble at higher speeds, typically while coasting downhill, so you don't even realize the problem exists until things are almost out of control.

    I would take the bike in to a trusted LBS and have them check it out completely to try to isolate the cause. If they can't find anything wrong with the bike and if they can't replicate the shimmy, it would point to operator error.

    Bob

    Another cause can be that the aero-fork found on the TCR C2 can exacerbate this:

    http://www.sheldonbrown.com/brandt/shimmy.html

    This was reported in at least one of the roadbikereview.com owner reviews for the Giant TCR C2.

    .
    Last edited by NoRacer; 01-18-06 at 07:40 AM.
    2009 mileage = 14,738 miles; 2010 mileage = 15,234 miles; 2011 mileage = 17,344 miles; 2012 mileage = 11,414 miles; 2013 = 12,169

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