Results 1 to 18 of 18
  1. #1
    D_K
    D_K is offline
    mtbr member
    Reputation:
    Join Date
    Dec 2010
    Posts
    64

    New question here. Bronson 2x10 ppl - need your help

    I have an issue that I am hoping one you Bronson 2x10 people can help with. My Bronson originally started life as the "cheap" RAM kit (3x10). I had an XT 2x crank sitting around with a 36/24 combo, so I bought the needed derailleur and converted the thing over. But now the bike is driving me insane on rocky descents. The problem is if I am in the granny gear to crest a peak and leave it there as I go flying down the other side, the chain machine guns off the bottom plate of the derailleur as I bounce down the rocks. The noise is pissing me off. You can see see the spacing in the below pics. I have setup a ton of front derailleurs before and I don't recall ever running into this. The derailleur definitely can't be mounted any lower. The LBS where is it at right now (already getting the Fox fork rebuilt) didn't have any solutions, so I am hoping that someone here might have an idea or two??

    Bronson 2x10 ppl - need your help-chainspacing2.jpg

    Bronson 2x10 ppl - need your help-chainspacing1.jpg

  2. #2
    mtbr member
    Reputation: jgutz71's Avatar
    Join Date
    May 2012
    Posts
    162
    I have the same issue and mine cannot be adjusted any further down. The noise though is actually coming from the bottom of the chain stay where that metal part is (I think). Funny though as when it is in the big chain ring the bike is quiet as heck...
    Stumpy FSR Comp 29er
    SC Bronson C

  3. #3
    D_K
    D_K is offline
    mtbr member
    Reputation:
    Join Date
    Dec 2010
    Posts
    64
    I never thought about that metal plate... hmmm. Dumb things like this just annoy me on things so expensive. Like why do high dollar XT brakes clank on engagement or why does a brand new Fox fork feel worse than my beat to hell and never serviced 8 year old Marzocchi?

    But on the plus side, it's fun taking this bike into the LBS. Santa Cruz bikes are very rare around here so everyone flocked to the thing like a super model just walked in the door!

  4. #4
    mtbr member
    Reputation: Irregular's Avatar
    Join Date
    Apr 2013
    Posts
    20
    You can try a large zip tie around the bottom part (and top) of the cage for that racer/ghetto mod look. That may help the noise some. Also check your chain length. You may be able to take a link or two since you gave up the triple. And a switch to the med. cage rear der. would help chain management as well, which you can do with the double crank.

    Oh, and make sure the clutch is doing its thang.

  5. #5
    rox
    rox is offline
    mtbr member
    Reputation:
    Join Date
    Aug 2008
    Posts
    958
    I have the same problem. I think its the seat tube angle. I have heard of others putting a small piece of garden hose or similar rubber material around the bottom horizontal part of the derailleur. personally I really try not to descent in the little ring so it doesnt bother me that much

  6. #6
    D_K
    D_K is offline
    mtbr member
    Reputation:
    Join Date
    Dec 2010
    Posts
    64
    I forgot to mention that I already did take a couple of links out of the chain. It is still on the loose side on the smallest rings but taking another set out would make it too tight. I was wondering if swapping the rear derailleur would help. Might have to order up one of those next. But the zip tie / garden hose ideas are awesome and cheap!

    As for why I descend in the granny gear. I tend to worry more about body position and avoiding pedal strikes than pedaling on the way down. Once I get near the bottom is when I worry about shifting up.

  7. #7
    Illuminati
    Reputation: scant's Avatar
    Join Date
    Jan 2004
    Posts
    1,593
    Quote Originally Posted by D_K View Post
    .. started life as the "cheap" RAM kit (3x10). I had an XT 2x crank sitting around with a 36/24 combo, so I bought the needed derailleur and converted the thing over. But now the bike is driving me insane on rocky descents. The problem is if I am in the granny gear to crest a peak and leave it there as I go flying down the other side, the chain machine guns off the bottom plate of the derailleur as I bounce down the rocks. ... I have setup a ton of front derailleurs before and I don't recall ever running into this. The derailleur definitely can't be mounted any lower.

    Click image for larger version. 

Name:	ChainSpacing2.jpg 
Views:	300 
Size:	202.5 KB 
ID:	812158

    Click image for larger version. 

Name:	ChainSpacing1.jpg 
Views:	268 
Size:	189.1 KB 
ID:	812157
    2 points.
    -the double front derailleur is considerably shorter than the triple front derailleur, which is where the noise will come from, rubbing/bouncing on the horizontal section.
    -as you crest over the peak shift up into the larger chainring. I wouldnt ever recommend extended descending in the inner chainring, as even with a clutch rear derailleur the amount of excess chain will always hit the front derailleur & at worst could go into the spokes.

  8. #8
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    23
    Another cheap solution to try.

    Not the same bike, but a similar issue on my Nomad was fixed with a small piece of adhesive velcro stuck on the derailleur - the furry part.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Dec 2006
    Posts
    40
    Rubber/Silicone bump stop used on cabinet doors

  10. #10
    No Clue Crew
    Reputation:
    Join Date
    Apr 2005
    Posts
    4,025
    You could run a 2x setup with the stock XT front der. I am. Is the rear der. clutch on? And the chain is properly shortened? Descending in granny is always gonna cause more noise. Do the Velcro trick mentioned above.

  11. #11
    mtbr member
    Reputation: jgutz71's Avatar
    Join Date
    May 2012
    Posts
    162
    I like the Velcro idea, I'm going to give that a try...
    Stumpy FSR Comp 29er
    SC Bronson C

  12. #12
    D_K
    D_K is offline
    mtbr member
    Reputation:
    Join Date
    Dec 2010
    Posts
    64
    Quote Originally Posted by scant View Post
    -the double front derailleur is considerably shorter than the triple front derailleur, which is where the noise will come from, rubbing/bouncing on the horizontal section.
    Yep, but I can't say that I understand the engineering logic of the stumpy cage. They don't do that on their road line. And as someone else said, SC's steeper seat tube angle rotates it around and compounds the issue.

    Quote Originally Posted by scant View Post
    -as you crest over the peak shift up into the larger chainring. I wouldnt ever recommend extended descending in the inner chainring, as even with a clutch rear derailleur the amount of excess chain will always hit the front derailleur & at worst could go into the spokes.
    I can think of plenty of scenarios where I can be bouncing through rock gardens and in a gear combination that leaves the chain as loose as descending in the granny. Those just don't make the noise because the top of the chain run is under tension. So if chain slack on the bottom of the run was going to take out my spokes, I would have to eliminate more than just descending in the granny. Just for clarification, I live in a glacial region. The longest section of smooth trail that we have is about 10 feet.

    Quote Originally Posted by Blatant View Post
    You could run a 2x setup with the stock XT front der. I am. Is the rear der. clutch on? And the chain is properly shortened? Descending in granny is always gonna cause more noise. Do the Velcro trick mentioned above.
    Part of my issue is this is the first time I have used the "proper" combination of parts to do a 2x10. So I guess I can chalk some of this up to inexperience with Shimano's odd design. But the chain is shortened and the rear clutch is on and seems to be doing it's job.

    I really like the velcro idea though! When I get the bike back, I'm definitely going to try that!!

  13. #13
    Old school BMXer
    Reputation: Blaster1200's Avatar
    Join Date
    Feb 2004
    Posts
    2,678
    For the photos above, what gear on the cassette is the chain on?
    There's no reason to be in the bottom 3-4 cogs on the cassette when in the small ring, and I'm not sure why you're going down rocky descents in the small ring.

    I think you said it's a 2X front derailleur, but the arc of the cage sure looks like a 3X.
    May the air be filled with tires!

  14. #14
    D_K
    D_K is offline
    mtbr member
    Reputation:
    Join Date
    Dec 2010
    Posts
    64
    It's a 2x derailleur. It I left the 3x on there I wouldn't be having the issue because its cage is so much longer.

    For those pics the chain was on the middle of the cassette.

  15. #15
    Illuminati
    Reputation: scant's Avatar
    Join Date
    Jan 2004
    Posts
    1,593
    Quote Originally Posted by D_K View Post
    It's a 2x derailleur. It I left the 3x on there I wouldn't be having the issue because its cage is so much longer.
    thats exactly my point. I've run a double crankset with a triple front derailleur with no issues.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    164
    The seat angle is a little steeper than other bikes, that should help explain why the rear of the front derailleur cage is higher than usual.

  17. #17
    mtbr member
    Reputation:
    Join Date
    Nov 2008
    Posts
    42

    回覆: Bronson 2x10 ppl - need your help


    Im run 32/22T with 10speeds no problems at all!

  18. #18
    mtbr member
    Reputation: CrozCountry's Avatar
    Join Date
    Mar 2011
    Posts
    715
    The Bionicon C guide is good at keeping the chain from bouncing and hitting things. After I installed mine, its the first time I could hear the tires rolling on the ground. Before that I always heard the chain.

    Little pricy for such a small piece, but it does work.

Similar Threads

  1. Bronson C SPX AM 2x10 build and first ride thoughts
    By DrewBird in forum Santa Cruz
    Replies: 10
    Last Post: 07-13-2013, 11:10 AM
  2. SRAM 2x10 crank with Shimano 2x10 system
    By Vhom in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 5
    Last Post: 07-10-2013, 01:42 PM
  3. 2x10 FD-m785 work on 3x10 FC-m660 converted to 2x10?
    By govertime in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 2
    Last Post: 12-03-2012, 07:17 AM
  4. WTB Bronson 29 vs. WTB Bronson 29 Race
    By teachndad in forum 29er Components
    Replies: 3
    Last Post: 08-13-2012, 10:28 AM
  5. XT 2x10 Crankset Compatible with SRAM 2x10 Drive Terrain??
    By sbchisholm in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 2
    Last Post: 12-01-2011, 07:30 PM

Posting Permissions

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