Advertise on Bikeforums.net



User Tag List

Results 1 to 20 of 20
  1. #1
    half man - half sheep Doggus's Avatar
    Join Date
    Apr 2005
    Location
    Allen (Dallas), TX
    Posts
    2,452
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Cracked Co-Motion frame!!!

    We did it!!! We cracked our frame without going down in a firey crash. She's just barely a year old and we managed to crack her. Why so excited? Cause the whole bike shop where we bought it had to stop business and everyone came to see the Co-Motion with a DEFECTIVE crack in the frame!!! No one has ever seen a cracked Co-Motion frame without being in a crash.

    Glad we have a Co-Motion with a lifetime warranty. This shouldn't cost me a dime to fix, we'll see how that warranty holds up.

    On several past rides, I've noticed a little 'grease' running down the side of the stoker seat tube. First time I saw I thought maybe I had spilled something on it while servicing the bike. Cleaned it up and moved on. Then I saw the same marking again a couple weeks later. Thought to myself...what the hell am I doing to this bike. It seemed like I would spotted it after I would service the bike (I always wash it at that point too). Then this weekend, we were sitting at the feeding trough after the ride and I spotted the tale-tale lube running down the seat tube. So me and one other rider inspect it and low and behold and crack running horizontal across the seat tubing, across the weld and into the top tube. The crack is about .5" long. You can barely see it but we can tell it's all the way through since there is stuff seeping out of the crack. No one seems to know what the black is coming out other than it might be the seat post grease.

    Not sure what Co-Motion is going to do to fix this. I'm assuming they'll be cutting and rewelding in some new tubing. Our LBS told us we could probably get the paint job we always wanted now since they're gonna have to repaint the bike anyway. Not sure if they'll just replace the frame. I'm no bike maker.

    They're going to take photos this morning and I'll hopefully get hold of the images and post them here.

    We we're signed up to ride our local tandem club's two-day overnight ride this weekend too. It was supposed to be a really cool ride
    Last edited by Doggus; 10-23-06 at 08:57 AM.
    "The cycling community is so small that it is nearly inbred." - Steve Tilford

  2. #2
    Senior Member transam's Avatar
    Join Date
    Jan 2004
    Location
    Sebring, FL
    My Bikes
    Cannondale RT1000; Santana Sovereign; Co Motion Supremo
    Posts
    145
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Co-Motion should replace the frame instead of doing a fix like you're talking about. Can you imagine going down a long grade at 45mph on a bike that had a cracked frame and was scabbed back together? Scary!!!

    Looking forward to seeing before and after pics. Hope you get that custom paint job.
    Just remember, once you're over the hill you begin to pick up speed.

  3. #3
    Senior Member bockwho's Avatar
    Join Date
    Apr 2005
    Posts
    93
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    scab patch it and let me see some booger welds .. ill ride it..... the ablitly to weld is a art that I do not have ... as long as its done right it will be safe. ever flown on a airplane ... your trusting someones welding
    Kelsey Bockmuller


    06 lightspeed teramo
    06 lemond etape (wife's ride)
    06 cannondale tandem
    odds and ends.
    96 gt backwoods
    01 Trek 2300
    3spd fugi on a 333 hub
    4 or 5 other frames waiting to become something.
    6 and 7 just added.

  4. #4
    Senior Member
    Join Date
    Dec 2005
    Location
    London, UK
    My Bikes
    Trek T200 plus enough others to fill a large shed
    Posts
    562
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes you are trusting welding when you fly. What you're not doing is trusting something which has been modified or repaired without thought using unproven techniques. Normally modifications to original designs only take place with very careful though and testing by people who are expert in aircraft design. This is why people who want to design and build their 'plane either have to get inspected by the CAA and build it to the original design, or build it under a 'experimental' category, i.e. you're on your own when it comes to safety.

    I wouldn't be very happy to fly in a jetliner registered under the 'experimental' category and wouldn't ride a commercially produced tandem on that basis either.

  5. #5
    Senior Member zonatandem's Avatar
    Join Date
    Dec 2003
    Location
    Tucson, AZ
    My Bikes
    ariZona carbon fiber tandem & single
    Posts
    9,832
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    We've put 57,000 miles on our Co-Motion custom tandem. No problems.
    If you are the original owner of the Co-Mo, it will be fixed.
    In our 31+ years of tandeming, we've broken two tandem frames and one fork (not Co-Mo) and all were fixed gratis by the builder(s).
    Sometimes stuff happens . . .

  6. #6
    Junior Member
    Join Date
    Jul 2012
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hey,

    we've developed a crack in our Co-Motion Speedster exactly like one you describe -- across the stoker seat tube, through the weld into the top tube. Ours is about 1" long, kind of squiggly.

    Ours has not gone through the tube, yet. I thought it was a scratch at first, but on closer inspection, it's pretty obvious to be a hairline crack.

    Question, what was the end result for your bike with Co-Mo?

    I've dropped off the rear triangle of the frameset with our tandem dealer (College Park Bicycles, Md.) for inspection by the manager. We have couplers so I wonder if they'd try to remanufacture just that end of the bike.

    thanks,
    Ed

  7. #7
    Senior Member
    Join Date
    Oct 2008
    Location
    Ottawa
    My Bikes
    Too few
    Posts
    73
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dailyrandonneur View Post
    I've dropped off the rear triangle of the frameset with our tandem dealer (College Park Bicycles, Md.) for inspection by the manager. We have couplers so I wonder if they'd try to remanufacture just that end of the bike.
    We had cracked our S&S'ed steel frame around the captain's seatpost clamp. Send it back to my builder. He replaced the whole frame. As he explained to me, a coupled frame is built by first building a regular frame and then cutting the built frame to install the couplers.

    Good luck.

  8. #8
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,143
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by scycheng View Post
    As he explained to me, a coupled frame is built by first building a regular frame and then cutting the built frame to install the couplers.
    Some do it that way, but not all. Co-Motion, for example, incorporates the couplers into the raw tubes during the frame fabrication and lay-up process, before welding the frame's joints.

    More info: http://www.co-motion.com/index.php/i...to_my_old_bike

  9. #9
    Senior Member
    Join Date
    Jan 2007
    Location
    Texas
    My Bikes
    Trek T-1000 tandem, Specialized Allez Elite, Dolce,
    Posts
    103
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Just curious if you bought your tandem from Richardson Bike Mart? We did. Did not know of another tandem dealer in Dallas at that time.

  10. #10
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by moonwalker View Post
    Just curious if you bought your tandem from Richardson Bike Mart? We did. Did not know of another tandem dealer in Dallas at that time.
    We bought our CoMotion from Plano Cycling and Fitness in 2006. At that time we looked at Richardson Bike Mart and they only handled Santanas and not CoMotion.

  11. #11
    Junior Member
    Join Date
    Jul 2012
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Update on our ailing 2006 Speedster -- the frame definitely cracked at the stoker seattube/top tube junction. On close inspection, our shop found a crack inside the seat tube running away from the hole into the top tube, left-right. That's in addition to the crack on the exterior drive side. We've been hearing a ticking sound back there on and off for the last year or so but without any other evidence chalked it up to the seatpost & Brooks Flyer S combination.

    Co-Motion has told our dealer to send in the entire frameset and they will fix it, but we don't know what all they plan to do.

    Ed

  12. #12
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If done well, it is perfectly safe to replace a tube on a TIG welded frame. If they choose to do so you will not be able to tell it from a new frame. One thing to consider if they fix the frame consider asking if you can change the color of the frame when they repaint it.

  13. #13
    Junior Member
    Join Date
    Jul 2012
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The question will be that the frame is coupled. Expect they will have to replace everything from the captain seat tube rearward. At that point, is it practical for them to cut and reweld, and will it come out straight? I'm interested in what they did for the original poster in this thread and how their repair turned out.

  14. #14
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,143
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Co-Motion will do what ever's the most prudent approach to making the repair.... it's what they do. That the frame is steel makes it a bit less complicated vs. aluminum, but steel, titanium and composite frames really do lend themselves nicely to rework by skilled frame builders. But, we've seen a couple aluminum frames that have been reworked by Ventana for customers and you absolutely can't tell the frames have been reworked.

    The key here IS being the original owner to whom the lifetime frame warranties apply, or with some builders subsequent owners who have re-registered the frames with the builder where they have "second life" warranties, e.g., Calfee offers a Second Life Warranty

    Anyway, the key for original frame owners who have a program is to do exactly what our friend, the OP, did here. Contact their dealers who, in turn, will work with the manufacturer to establish if the observed condition falls within warranty coverage (that is to say, it was not caused by a crash or other external factors) and if so, how best to remedy the condition.

  15. #15
    half man - half sheep Doggus's Avatar
    Join Date
    Apr 2005
    Location
    Allen (Dallas), TX
    Posts
    2,452
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Co-motion replaced our frame under warranty. It took well over 6 months because we ordered a custom paint job on the new frame that they continually kept screwing up. I started riding my single, I got fast, got a power meter, started racing, my daughter started riding, she got really fast, she was asked to join the junior development squad of Exergy TWENTY12 (you've heard of them, Kristin Armstrong, Olympic gold medal in London), all we do now is travel to her races. Oh, the tandem, if I could light it on fire, I would. We are pretty much ex-tandem riders.
    "The cycling community is so small that it is nearly inbred." - Steve Tilford

  16. #16
    Senior Member waynesulak's Avatar
    Join Date
    Jan 2008
    Location
    Ft Worth, TX
    My Bikes
    650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport, Trek TX700,
    Posts
    1,576
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Doggus View Post
    Co-motion replaced our frame under warranty. It took well over 6 months because we ordered a custom paint job on the new frame that they continually kept screwing up. I started riding my single, I got fast, got a power meter, started racing, my daughter started riding, she got really fast, she was asked to join the junior development squad of Exergy TWENTY12 (you've heard of them, Kristin Armstrong, Olympic gold medal in London), all we do now is travel to her races. Oh, the tandem, if I could light it on fire, I would. We are pretty much ex-tandem riders.
    Sorry to hear that but at least you are both still riding. If you can get together you should be able to do some damage with your power on the tandem.

    I am glad we have a backup tandem.

  17. #17
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,143
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Doggus View Post
    Oh, the tandem, if I could light it on fire, I would. We are pretty much ex-tandem riders.
    Why not sell the tandem instead of keeping as a reminder of what is apparently an unpleasant memory?

  18. #18
    Junior Member
    Join Date
    Jul 2012
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Co-motion has our tandem and is ready to repair it for free under warranty. There were some welds from that year, 2006, that have not held up, they say.

    We're also being offered a very low price for a full replacement, which we are considering. The Java 29er is our preference because we found our Speedster a little flexy when we stand up and way too flexy with four panniers.

    It has a very long rear top tube. We'd also like more tire clearance.

    Dwan says the Java will be stiffer than the Speedster even without a lateral, but we may add the lateral anyway. He says it will make the bike stiffer still. Thinking as a sport touring setup, do we get the lateral? This is a coupled tandem so we'd save a fair amount of money by leaving out two couplers with no lateral.

  19. #19
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,143
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dailyrandonneur View Post
    Co-motion has our tandem ...
    There's no bad option in there that I can see.... Got with your gut!

  20. #20
    Senior Member
    Join Date
    Aug 2012
    Posts
    138
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mrfish View Post
    ... This is why people who want to design and build their 'plane either have to get inspected by the CAA and build it to the original design, or build it under a 'experimental' category, i.e. you're on your own when it comes to safety.
    I wouldn't be very happy to fly in a jetliner registered under the 'experimental' category and wouldn't ride a commercially produced tandem on that basis either.
    We've put over 10,000 miles on an "experimental" Co-Motion tandem.... it was the first triplet they ever built!
    Then again I've been a member of the EAA for well over two decades now.
    I affixed not only an FAA data plate to the boom tube just for kicks, but a "solo from front seat only" placard as well.
    The company's tech folks were very easy to deal with during the design process, and since it has run flawlessly ever since we have had no further contact.
    I'm sure they will make you better than whole again.

Posting Permissions

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