Chain slap/noise over rough ground

kenan
kenan Posts: 952
edited October 2010 in MTB workshop & tech
When I'm riding my Marin Wolf Ridge over rough ground I can hear the chain clunking away. This happens in gears like say middle ring up front and 3/4th on the back or smaller. However if I run the same steps in the same rear gear but use my top ring up front there is no noise.


The chain is set-up for biggest front and rear + 1 link as per most the guides I can find. Now is there a problem or should I just shorten then chain?

Comments

  • neiltb
    neiltb Posts: 332
    normal, on top ring you have more tension on the chain and by virtue of where it is it's farter from the stays.

    shorten chain and risk not being able to use some gears.
    FCN 12
  • Or just but a chainstay protector......
  • chedabob
    chedabob Posts: 1,133
    I've found mine clatters off the teeth on the chainrings (I've got a chainstay protector). 99% sure it's the derailleur arm moving just enough to put some slack in the chain.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    The better the rear mech generally the less slap you get....

    Like neil says - use bigger rings to help give the chain more tension and move futher away from the stays.

    And as cheddar and herbie say use a protector - 8 quid, less noise and paint chips....
  • kenan
    kenan Posts: 952
    To be honest I don't think it's hitting the frame, this is why I'm a little baffled by it. Riding the bike later today so will stick some foam on the chainstay to eliminate it.

    I'm very specific with my gears using as follows:
    Rear Front
    1-4 Small ring
    3-7 Middle Ring
    6-9 Big Ring - Rarely used.

    So based on this I could shorten the chain a link at a time till I lose the noise.

    Would a chain tensioner like the blackspire resolve the issue?
  • Koiler
    Koiler Posts: 513
    kenan wrote:
    Would a chain tensioner like the blackspire resolve the issue?

    assuming you mean the stinger? its purpose is to hold the chain on the front rings, its more of a retention device than a tensioner.

    if you're sure the chain isn't hitting the frame, then as said above, its likely to be the chain going slack as the rear mech jumps up and down.

    a different mech with a stiffer spring might help, it did on my bike when i upgraded to an SLX.

    by removing links from the chain, you run the risk of having it too short and ripping the mech off if you accidentally try and shift to a larger rear cog than the capacity of the chain/ mech can handle.
  • Anonymous
    Anonymous Posts: 79,667
    Or just but a chainstay protector......
    He has no chainstays.
  • chedabob
    chedabob Posts: 1,133
    Don't touch the chain. Either ignore it, or get a stronger mech. I just ignore it and accept it as one of the noises the bike makes during normal use.
  • Assuming you have full suspension - as you are going over bumps etc the wheelbase is expanding and contracting as the suspension does its job. This can make the chain go quite loose especially if you are in lower gears at the time and the RD can have a job keeping up with taking in the slack - hence the rattling noise - if you video yourself going over a small jump and then play it back slo-mo you can see the chain actually droop. If you are in a really low gear at times it will almost touch the floor! Best to keep it in as high a sgear as you can to reduce the whipback from this action. :D
  • kenan
    kenan Posts: 952
    Thanks for the advice, I have a plan.

    I'm going to take off my front outer ring and fit a bash guard I have. This way I can reduce the chain length?

    Mech has seen a fair bit of action, but if the wife sees any more parts turn up the chain will be the last of my problems :)
  • Make sure that the chain is not hitting the underside of the swing arm. You will be able to tell as the paint will be chipped off. My Rift zone(2006) developed a crack in the swing arm across the weld on the underside of the swing arm which could have been related to the chain repeatedly hitting it.
    I would recommend a chainstay protector or helicopter tape.
    BTW yeehaamcgee, if a tube connects the rear axle to the main part of the bike and is essentially horizontal, is it not reasonable to describe it as a chainstay?
  • Anonymous
    Anonymous Posts: 79,667
    BTW yeehaamcgee, if a tube connects the rear axle to the main part of the bike and is essentially horizontal, is it not reasonable to describe it as a chainstay?
    Does a motorcycle have a chainstay?
  • W00DENT0P
    W00DENT0P Posts: 211
    Does a motorcycle have a chainstay?

    I'm sure some do, can't see what relevance this has to his Marin tho ?
  • BTW yeehaamcgee, if a tube connects the rear axle to the main part of the bike and is essentially horizontal, is it not reasonable to describe it as a chainstay?
    Does a motorcycle have a chainstay?

    Motorcycles have swingarms, which are a different concept to a chainstay on a bike.
  • nicklouse
    nicklouse Posts: 50,675
    the chain will be hitting the underside of the swing arm.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Anonymous
    Anonymous Posts: 79,667
    Motorcycles have swingarms, which are a different concept to a chainstay on a bike.
    That's what I was getting at.
  • Northwind
    Northwind Posts: 14,675
    Well thank god we cleared that up!

    It's a wolf ridge, throw away the big ring, lose some chain links, it'll make less noise due to the improved tension in the gears you have left, and give you back some ground clearance.
    Uncompromising extremist