Results 1 to 14 of 14
  1. #1
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,365

    Idea! Do you do drops on your 6-Pack? In the granny ring? Don't...

    I was just messing around with my 6-Pack checking stuff. I deflated my DHX Air and compressed the suspension and noticed that the front derailleur just barely had breathing room above the swing arm. That was in the middle ring. When I let the f der drop to the granny it overlapped with the compressed swingarm. If I did a drop while in the granny and bottomed the suspension, the swingarm would bind on the front der.

    I set the front der up based on the clearance needed to shift properly to a 44t ring, as the standard protocol. It is an XT der and has a bit of a bulge in the cage which I could grind down to give me more clearance, though I never do drops in the granny. Here is a pic with a line drawn in the rough area that would provide ample clearance. And yes, my poor bike spends a lot of time wet and steel parts rust...

    My video techniques can be found in this thread.

  2. #2
    on a routine expedition
    Reputation: Marshall Willanholly's Avatar
    Join Date
    Jan 2004
    Posts
    1,558
    I noticed the same thing with a SRAM front derailleur. There's a small dent in my chainstay where it met the derailleur. I ended up setting the front derailleur height so it just clears the chainstay when the suspension is fully compressed.

  3. #3
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,365
    I also have paid attention to f der clearance, but invariably I did it in the middle ring and didn't give much thought to the granny. I don't think it has had a functional difference so far since I don't do drops in the granny (and there are no marks on the swingarm), but it's food for thought. I did space out a little when setting up the BarnyMobile and did mount the f der low, and realized it when I saw a ding on her Spot's swingarm.

    A compounding issue is that I am running a 5-Spot seat stay which is shorter than the stock Pack stay. This raises the relative height of the swingarm at any point in travel, so it will give me a little less f der clearance. The complications of the FrankenTurner.
    My video techniques can be found in this thread.

  4. #4
    Lay off the Levers
    Reputation: Bikezilla's Avatar
    Join Date
    Dec 2003
    Posts
    10,130
    Good info to be aware of. I'm not likely to drop in the Granny but now I know to be mindful of it.

    Tnx.
    Faster is better, even when it's not.

  5. #5
    banned
    Reputation: Jerk_Chicken's Avatar
    Join Date
    Oct 2005
    Posts
    16,480
    I routinely do 6 footers on my Four Pack, also known as my Flux and I have not seen clearance issues.

    [SIZE="1"]Calm down people, I'm only kidding. My Four Pack is strictly a flatlander rig[/SIZE]

  6. #6
    Team Sanchez
    Reputation: El Chingon's Avatar
    Join Date
    Nov 2004
    Posts
    4,363
    I've got little tiny indentations on my swingarm from the front derailleur hitting. I am always in the middle ring when doing the big stuff, but I suppose out at goose I have hit a 2 footer or so in the granny ring.

  7. #7
    Just another FOCer
    Reputation: Winston's Avatar
    Join Date
    Apr 2004
    Posts
    1,376
    This is what the Dremel was invented for. Shaving material off the back of the FD so it doesn't strike the frame.
    "I hope your gravity droppers all seize up....BASTIDS." - Aquaholic

    [SIZE="1"]NLZ
    The Path Bike Shop
    Winston presents - Socal Videos[/SIZE]

  8. #8
    mtbr member
    Reputation:
    Join Date
    Aug 2004
    Posts
    319
    I noticed front derailleur issues on my older RFX with the longer stroke (2.25") shock when set up in the middle chainring. After having the front derailleur set up so it would clear the chainstay at full compression, I found there were hardly any usable gears in the granny without some FD grinding. I think I'm just going to remove the front derailleur and throw on a chainguide for a single ring front set up.

  9. #9
    fried stuff with cheese
    Reputation: Locotiki's Avatar
    Join Date
    Feb 2005
    Posts
    1,269
    I've had this issue on my Spot. I've now got the der so it just clears the swing arm by maybe 2mm.
    Egg

  10. #10
    SASQUATCH!
    Reputation: big_olly's Avatar
    Join Date
    Jan 2006
    Posts
    138
    Ah, serendipity.

    During my recent shakedown ride on my new 5 spot, I encountered an odd problem with my chain (seemingly) catching on "something" while pedaling uphill in my granny. I have an Xgen front der.

    I couldn't reproduce the problem when I got off the bike and shifted and I wasn't eager to try to make it happen again too often since it felt bad (like, I'm-about-to-do-some-serious-damage-to-my-drivetrain bad) so I just finished up in the middle ring and racked the bike to look at it later.
    Thinking about it today at work, I figured it probably had something to do with the suspension/sag while on the bike, since that's the only variable and would be more pronounced when pointed uphill.

    Not two hours later, I see this post. Gotta go home and check it out, but this just reinforces my suspicion.

    And yes, the spot is awesome; feels great. It's my first FS and I'm really pretty amazed at how brilliantly it climbs.

  11. #11
    It's a Turner!
    Reputation: sirbikesalot's Avatar
    Join Date
    Jan 2005
    Posts
    513
    Just wrap something around the chainstay, as such...
    Attached Images Attached Images
    I didn't just drink the koolaid, I stuck my head in the punchbowl.

  12. #12
    Bodhisattva
    Reputation: The Squeaky Wheel's Avatar
    Join Date
    Dec 2003
    Posts
    9,573
    Nothing new here.
    I reported the same thing back in October '05
    http://forums.mtbr.com/showthread.ph...74608#poststop
    Life....the original terminal illness

  13. #13
    fried stuff with cheese
    Reputation: Locotiki's Avatar
    Join Date
    Feb 2005
    Posts
    1,269
    This was from November while I was having issues. (bike vs. my normal mental issues)

    Help please... 5-spot and XT 761 Front Derailleur hitting swingarm

    I am still running two spacers, even though everyone said not to. It was the only way we could get it to work.

    Also, before someone picks up on it and gets pissed, yes that is by buddy Louis asking the question, the same kid who not too long ago got everyone riled up with his useless x-post on here and the Ellsworth just to get people stirred up. Ok, now I'm getting off topic.
    Egg

  14. #14
    mtbr member
    Reputation:
    Join Date
    Jul 2005
    Posts
    893
    Quote Originally Posted by tscheezy
    I was just messing around with my 6-Pack checking stuff. I deflated my DHX Air and compressed the suspension and noticed that the front derailleur just barely had breathing room above the swing arm. That was in the middle ring. When I let the f der drop to the granny it overlapped with the compressed swingarm. If I did a drop while in the granny and bottomed the suspension, the swingarm would bind on the front der.

    I set the front der up based on the clearance needed to shift properly to a 44t ring, as the standard protocol. It is an XT der and has a bit of a bulge in the cage which I could grind down to give me more clearance, though I never do drops in the granny. Here is a pic with a line drawn in the rough area that would provide ample clearance. And yes, my poor bike spends a lot of time wet and steel parts rust...

    Same thing on my 5-spot. I brought the FD over to my bench grinder and ground down along where your red line is. You've probably thought about that already I'm sure. I just wanted to say that there are no shifting issues by doing so.

Posting Permissions

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