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  1. #1
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    Got my downtube Novas today -- Bent Derailleur?

    Ordered two downtube novas last week and they arrived today. White setting them up, I noticed one of them had a really noisy derailleur.

    After trying to adjust the high and low limits and cable tension to no avail, I started comparing the two bikes, and noticed the derailleur on one of them was a little crooked.







    I've emailed Yan about this, and am waiting for his response, but I wanted to see if anyone has any suggestions.

    Note: It *will* shift into all of the gears, but the bent one is significantly more noisy than the other one--there is a periodic sound like it's getting ready to shift gears, but doesn't. Is it going to damage anything if I ride it like this?

  2. #2
    Hooligan Abneycat's Avatar
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    The hanger on the white bike is clearly bent in those photos, but whether or not the derailleur itself is, I cannot discern.

    It shouldn't damage anything if you ride it like that, so long as the derailleur is not going to end up in the spokes with its crooked position. Make sure the limit stops are well set to prevent such things happening.

    There are specialty tools designed to straighten bent derailleur hangers, a good bike shop should have both the equipment and the expertise to set things right in that regard. And while it wouldn't hurt to get a replacement from Downtube if you can (I would try as a new derailleur hanger is always good), that hanger should be repairable, and the hanger itself is a low stress item - there isn't a lot of force on it normally, and they can typically be straightened several times before becoming too fatigued.

  3. #3
    Senior Member JosephLMonti's Avatar
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    +1

  4. #4
    Nobody mconlonx's Avatar
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    Quote Originally Posted by Abneycat View Post
    The hanger on the white bike is clearly bent ...

    There are specialty tools designed to straighten bent derailleur hangers, a good bike shop should have both the equipment and the expertise to set things right in that regard. And while it wouldn't hurt to get a replacement from Downtube if you can (I would try as a new derailleur hanger is always good), that hanger should be repairable, and the hanger itself is a low stress item - there isn't a lot of force on it normally, and they can typically be straightened several times before becoming too fatigued.
    Maybe DownTube will send you a new derailleur hanger, which is a simple bolt-on fix; otherwise, bring it to a bike shop--straightening bent derailleur hangers is an almost daily task and shouldn't cost that much, maybe $20. There's a specific too for it, Park Tools calls it a D(erailleur) A(lignment) G(auge).

    If you're in touch with DownTube and you have a local shop you like and trust, maybe suggest having the hanger straightened there with DT reimbursing you for the labor charge?
    I know next to nothing. I am frequently wrong.

  5. #5
    Pedaling fool ShinyBiker's Avatar
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  6. #6
    coprolite fietsbob's Avatar
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    if it's shipping damage , there is a replaceable dropout, it appears, have DT send another one .

    may be a PIA to get shipper to reimburse you, but you can try.

  7. #7
    Senior Member kamtsa's Avatar
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    Quote Originally Posted by ShinyBiker View Post
    Step #6 is different from instructions I read in other places.

    1. You need to turn the tool. If you turn the wheel and leave the tool stationary the measurement is meaningless.

    2. To avoid measurement skew due to a non trued wheel, measure the distance to the smae wheel point (e.g. the valve). That is, turn both the tool and the wheel.

    As for two points defining a line and three points defining a plane, this is true of course only if the points are different and not collinear. I am sure that Dr Yan already knows that though ;-)

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    Dr. Yan's response: "Sounds like one needs the dérailleur hanger twisted by hand."

    Sigh.. what a bummer. Seems barbaric, but w/o the specialty tool, looks like i'm outta luck. Called an LBS, and they said it would take 3 days to get my bike back.

    Trying to decide if I should:

    1. Try to bend it back by hand (is this safe? Where exactly do I grab to bend? The hanger seems like it's pretty thick metal...)
    2. Take it to the LBS and wait 3 days
    3. Find a place to buy an alignment tool (this is $50-$70? Is this worth owning? How often would I use this thing?)

  9. #9
    Senior Member coolio's Avatar
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    Quote Originally Posted by lighto View Post
    Dr. Yan's response: "Sounds like one needs the dérailleur hanger twisted by hand."
    So much for Dr. Downtube's much vaunted customer service, lol.

  10. #10
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    Well, just got back from a community bike garage (http://bikeoven.com/) and while the guy helping me didn't use derailleur alignment tool (I don't think they had one in the shop), he straightened the hanger out fairly decently by taking it off and putting it into a bench vise. That being said, after he reinstalled it and adjusted the derailleur, the top and bottom gears were still making strange periodic clicking noises. After messing with it for a long time, looking closely to see if any cog teeth were damaged, and checking the chain links, he couldn't find anything wrong with those components and said he thinks the derailleur arm/assembly is bent.

    Anyhow, while doing this, he also checked the rear wheel and said the (hub nuts?) were too tight and not allowing wheel to spin freely and adjusted that for me too.

    He asked me how much I paid for it, and when I told him, said I should have just paid a little more for a Dahon. I really wanted to like this bike, but I'm getting a little frustrated with this thing, and starting to think maybe he's right.

    I asked Dr. Yan if he would send me a replacement hanger, but so far have not received any response. Even if he agrees to send me another one (which I think he should, but doubt he will), now I have reason to believe that the derailleur itself is damaged. I have to say, the disinterest of his last response is pretty disappointing.

    Well, on the bright side, my orange nova appears to be ok, although I have not taken it for any long rides because I've been busy trying to fix the white nova. Maybe the lesson here is to always buy the orange one...

  11. #11
    The Legitimiser Sammyboy's Avatar
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    Yan will replace derailleur hangers, but there's an issue. The ones that come on the bike are malleable, and can be bent back into shape many times. The ones he has as spares cannot. Everyone is better off if you just get a pair of slip-joint pliers, grab the hanger, and bend it straight.

  12. #12
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    dr. yan used you be active on this forum and quite frankly very responsive but that was years ago. now that there's not much bikes on his site except for the Nova, and customer service is not that good anymore (judging from the above response) i wonder if there's any problem with downtube right now ?

  13. #13
    The Legitimiser Sammyboy's Avatar
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    As an insider, no, there isn't. Yan has posted here recently with pictures of the about-to-be-released new range, and of course, he's been running down inventory first on older machines. The Nova will continue as is, I believe. He and I both have been hit very hard by the recession and the rising prices of Eastern made goods, but he's financially fine, and life continues. The above response is actually a typical Yan response; he hasn't said quite enough for someone to understand. As I mentioned, the replacement hangers that he has are not as good as the ones on the bikes from the factory, and since on a folder particularly, bent derailleur hangers are pretty common, having one that can easily be bent back is a benefit.

  14. #14
    jur
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    I wonder if I may be of help here...

    Derailers especially ones with the 2:1 pull ratio (Shimano, Microshift) require really high accuracy to match up the derailer with the shifter. Along the way there are a few places where things can go wrong.

    So, if you are experiencing clicking in top and bottom gears but it seems OK elsewhere, well the conclusion is fairly straightforward that the pull ratio is a bit off. Either it pulls too little or too much, resulting in the behaviour you see. It matches up with most gears but the extremes are out.

    How to fix this: The trick is to reposition the derailer cable under the pinch bolt. Loosen the pinch bolt holding the cable and reposition the cable either further way from the bolt shaft or right up against it. Putting the cable right against the bolt will increase pull, and moving it a bit to the edge decreases pull.

    To find out which case is yours, shift to and fro between top and the next gear next to it. In one direction it will be hesitant and the other direction it will be quick. If it is hesitant to go to top gear, it needs more pull - move the cable right up against the pinch bolt. If it is hesitant to move out of top gear, it needs less pull, so move the cable away from the bolt shaft.

    I hope this is clear enough.

    One final thing to keep in mind - Novas come with absolute bottom of the range equipment. To expect perfect performance from less-than-entry-level equipment is unrealistic.
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  15. #15
    Pedaling fool ShinyBiker's Avatar
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    Quote Originally Posted by vmaniqui View Post
    dr. yan used you be active on this forum and quite frankly very responsive but that was years ago. now that there's not much bikes on his site except for the Nova, and customer service is not that good anymore (judging from the above response) i wonder if there's any problem with downtube right now ?
    You may be on to something here. I've owned 3 downtubes and been satified with them. However, I do my own maintenance and am able to take care of problems as they arise. We all know the quirks that come with new DT bikes. Since I frequent these boards I kinda know what they are. But someone new may not be familiar with them and gets (understandably) upset when bikes are not "ready to roll" right out of the box.

    I remember that there was a poster that had a problem with a new DT bike she bought and she posted all her messages in All Caps. I do admit she was a little loopy. I think that thread was deleted. Anyway, the OP is doing the right thing in posting here since it seems that this results in negative publicity for DT and causes Yan to pay attention.

  16. #16
    Nobody mconlonx's Avatar
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    Quote Originally Posted by lighto View Post
    Well, just got back from a community bike garage (http://bikeoven.com/) and while the guy helping me didn't use derailleur alignment tool (I don't think they had one in the shop), he straightened the hanger out fairly decently by taking it off and putting it into a bench vise. That being said, after he reinstalled it and adjusted the derailleur, the top and bottom gears were still making strange periodic clicking noises. After messing with it for a long time, looking closely to see if any cog teeth were damaged, and checking the chain links, he couldn't find anything wrong with those components and said he thinks the derailleur arm/assembly is bent.

    Anyhow, while doing this, he also checked the rear wheel and said the (hub nuts?) were too tight and not allowing wheel to spin freely and adjusted that for me too.

    He asked me how much I paid for it, and when I told him, said I should have just paid a little more for a Dahon. I really wanted to like this bike, but I'm getting a little frustrated with this thing, and starting to think maybe he's right.

    I asked Dr. Yan if he would send me a replacement hanger, but so far have not received any response. Even if he agrees to send me another one (which I think he should, but doubt he will), now I have reason to believe that the derailleur itself is damaged. I have to say, the disinterest of his last response is pretty disappointing.

    Well, on the bright side, my orange nova appears to be ok, although I have not taken it for any long rides because I've been busy trying to fix the white nova. Maybe the lesson here is to always buy the orange one...
    If the hanger is bent and it appears the derailleur cage is too, this is either a manufacturing/assembly defect, perhaps when packing the bike for shipping, or damage in transit.

    How did the shipping box look when it arrived? If it was damaged, hope you saved the box so you can make a shipping claim with the shipper. If box was solid, this is a manufacturing defect and should be corrected by DownTube. Bent derailleur either covered by DownTube or the der mfg.

    Again, a difference between buying at a shop v. online -- now you have to track all this down yourself, instead of just bringing it back to the shop and saying "fix it." ...And leaving them to take the time to deal with the warranty or shipping issues. If everything is well with a bike and/or you know what you're doing, buying online or mail order is a great way to go; when things go wrong, you find out where a portion of the online vs. brick and mortar store pricing difference goes: overhead for time dealing with repairs or warranty issues on new, out of the box bikes.

    But I have a concern about merely straightening the hanger in a vice--the shallow part of the hanger, where it sits flush with frame once you bolt it on would not get fixed that way since there's no double-sided support to keep the step-down cut area in the hanger even with the rest of it. Without measuring with a Derailleur Alignment Gauge, the hanger could still be bent. Bring it to a shop with the DAG and pay the minimal fee to have them check it out before assuming the derailleur is bent.
    I know next to nothing. I am frequently wrong.

  17. #17
    Senior Member kamtsa's Avatar
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    Quote Originally Posted by lighto View Post
    2. Take it to the LBS and wait 3 days
    Waiting 3 days does not sound that bad if it will result in enjoyable bike for years.

    The question is can they fix it and for what cost.

  18. #18
    Senior Member JosephLMonti's Avatar
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    I believe that the Downtube website, or instructions that come with the bike, recommends that all customers take their new bike to a LBS for inspection/set-up. So in fairness to Downtube, the company is being up-front that you will come out-of-pocket more than the $300 + shipping that is listed on their website.

  19. #19
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    Well, just to tie up a couple loose ends:

    Despite what some have said, Dr. Yan will not replace the hanger: "Bent hangers are not defective. They are easily bent into place. You may want a tech to it if you are not comfortable"

    Anyway, I took both bikes out for a couple mile ride around the neighborhood, and comparing the two, yeah.. the orange one is pretty much silent on all gears, while the white one makes the noises in the two gears mentioned, but does seem to work fine (didn't get any skipping or anything.. just mildly annoying).

    I'll ride them for awhile and see how much it bothers me and take it from there. Thanks for all the adjustment suggestions everyone. Looking on the bright side, I have learned quite a bit about derailleurs and derailleur-related components from this... (although apparently, not enough to get rid of a clicking sound on my white nova )

  20. #20
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    Oh yeah, I forgot to mention. For those who suggested filing a claim against the shipping... well, the ironic thing is, when they arrived the orange bike's box had a big hole in it (looks like there's a pre-cut slot for handling and somebody's hand went through it too rough and ripped part of the box), but the orange bike turned out to be fine. The white bike's box was in perfect shape and is the one with the damage--go figure.

    Anyhow, I don't know for sure, but these boxes look like they came straight from China to the downtube warehouse where they were shipped out (I found cardboard with chinese text on it inside the box). So, one can only guess where the damage took place: in the assembly plant, in shipping container, at Downtube's warehouse, or in the hands of UPS. In any case, looks a steep uphill battle...

  21. #21
    jur
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    Quote Originally Posted by lighto View Post
    . (although apparently, not enough to get rid of a clicking sound on my white nova )
    Did you read post #14 on how to fix the clicking isue?
    My folding bike photo essays www.dekter.net/

  22. #22
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    Yes, the bikes most likely come in their boxes all loaded/stacked into a shipping container. They don't get shipped individually otherwise you would be paying $200 for shipping alone. Proving shipping damage without a damaged box & without pointing this out before signing for the package will be extremely difficult.

    Regarding the hanger, either buy the Park Tool for bent hangers or check to see if there are bicycle coops by you where you can drop in & get this fixed.

  23. #23
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    Quote Originally Posted by jur View Post
    Did you read post #14 on how to fix the clicking isue?
    I just followed the instructions from the parktool website for the derailleur adjustment: (http://www.parktool.com/repair/readhowto.asp?id=64) (high, low, b-screw, and cable tension)

    Jur, if I'm understanding you correctly, you're essentially describing adjusting cable tension for the index setting, but manually, instead of using the barrel adjuster?

  24. #24
    jur
    jur is offline
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    No, what I am referring to you won't find on any website. It is a trick to get past production tolerances of lower quality shifters and derailers. The closest thing I am describing, would perhaps be here:

    http://sheldonbrown.com/derailer-adjustment.html
    Scroll to the bottom to the heading, Cable Attachment (rear) and the one immediately following it Alternate Cable Routing.

    What I am trying to describe is changing the amount of derailer movement that a certain amount of cable pull causes. The photos show the extreme example, to get an 8sp shifter to work with 9sp gears or vice versa. Basically what that accomplishes, is to change the amount of derailer pull for each click in the shifter.

    Quote Originally Posted by Sheldon Brown
    One area that commonly causes problems is the attachment of the inner cable end to the derailer's anchor bolt. If this comes in at the wrong angle, it can change the geometry of the parallelogram and make it impossible to get the derailer to index properly across its range.
    Last edited by jur; 09-23-10 at 10:10 PM.
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  25. #25
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    Quote Originally Posted by jur View Post
    What I am trying to describe is changing the amount of derailer movement that a certain amount of cable pull causes. The photos show the extreme example, to get an 8sp shifter to work with 9sp gears or vice versa. Basically what that accomplishes, is to change the amount of derailer pull for each click in the shifter.
    Ok, I think I understand now--the position of the cable on the pinch bolt affects the distance the derailleur moves when shifting.

    I'm not sure this explains the noises on the high gear though--with no cable tension (shift cable unbolted), and just by moving the guide cog with the H screw, there's no position achievable where the noise goes away...

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