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Bash guards & chain guides

JimboMJimboM Posts: 380
edited April 2012 in MTB workshop & tech
I'm fed up with the chain slap I'm getting on the downhill runs on my Canyon Nerve AM and as I've never used the big ring I've decided to go for a 2 ring setup wih chain guide.

I'll probably get a Stinger or possibly the Superstar equivalent, but not sure how the bash guards work. Do I need one of the size of the chain ring I'm removing (ie 43T) or should it be the size of what as the middle chain ring (32T)

Also what , if anything, do I need to do to the derailler?

Thanks

Jim
Cannondale Synapse 105
Giant FCR3
GT Avalanche 3.0
Canyon Nerve AM 6.0

Posts

  • gtd.gtd. Posts: 626
    Bash guard should be big enough to protect the chain and middle ring so if 32 then 32 or bigger.

    Just screw in the H limit/stop screw on the mech, so that the cage of the mech wont shift the chain up off the middle ring.

    See Front Derailleur- Adjusting H-screw
    The outward travel of the front derailleur is stopped by the H-screw. When viewing the H-limit adjustment, make sure there is enough tension on the inner wire by either keeping extra pressure on the lever, or by pulling the exposed inner wire taut by hand. Use a rag to protect your hand if pulling the inner wire. After the H-screw is adjusted the inner wire should be re-tensioned to assure proper shifting.

    Shift to outermost sprocket in rear and outermost front chainring. Inspect derailleur for mark indicating H-screw.
    Pull inner wire with hand to increase tension to insure derailleur is against H-screw.
    Maintain full pressure on inner wire and check gap between chain and outer cage plate. Only a small gap should be visible, about 1/16" or 1mm. Pedal bike slowly and continue to sight gap. Set clearance at tightest point in chainring rotation.


    A. If chain is rubbing cage, loosen H-screw 1/8 turn and pull fully on inner wire. Check gap again.
    B. If chain is not rubbing, tighten H-screw repeatedly until chain is 1mm

    Test shift to the large ring. Shift derailleur from next to largest to largest ring using hand pressure on inner wire rather than shift lever. If shifting is slow, loosen H-limit screw slightly and repeat test. If chain shifts off the outside of the large chainring, the outer-limit is set too loose. Tighten H-screw limit and test shift again.
    Then you will just have 1 and 2 on the shifter as it wont shift up to 3.

    You'll need to shorten the chain

    See Chain Sizing - Largest Cog and Largest Chainring Method
    An alternative method for determining chain length for new chains is to use the largest size sprockets on the bike. It is easiest to size the chain without threading it through the derailleur.

    Remove the old chain.
    Shift the front derailleur over the largest chainring, and the rear derailleur on the smallest cog.
    Thread the new chain through the front derailleur. It is not necessary to thread the chain through the rear derailleur at this point. Simply wrap the chain around the largest front chainring, through the chain device and around the largest rear cog.
    Pull the chain tight, and note the closest rivet where the two could be joined. Keep in mind a chain can only be joined by mating inner and outer plates.
    From the closet rivet, lengthen the chain by counting over an additional two rivets (two links), which is a distance of one-inch. Cut the chain at this point.
    Remove the chain from the bike and thread it through both derailleurs and join the ends.

    MASTERLINK NOTE: If the bike chain uses a "master link", it is necessary to account for the link. Install one-half of the master link on one side of the chain. Size the chain by cutting the other end of the chain.
    Mountain: Orange Patriot FR, SubZero & Evo2LE.
    Road: Tifosi Race Custom.
    Do it all bike: Surly Disc Trucker 700c/29er
  • JimboMJimboM Posts: 380
    Great info, thanks for your help

    Jim
    Cannondale Synapse 105
    Giant FCR3
    GT Avalanche 3.0
    Canyon Nerve AM 6.0
  • JimboMJimboM Posts: 380
    Sorry, one more question

    Do I have to remove the large ring? Could I leave it on (so that it acts like a bash guard itself) and just adjust the limit screws to keep the chain on the first 2 rings

    Thanks
    Cannondale Synapse 105
    Giant FCR3
    GT Avalanche 3.0
    Canyon Nerve AM 6.0
  • oxocube1oxocube1 Posts: 651
    Yea you could do that but it would either be an idle outer ring or the bashguard. I'm sure there would not be enough room on the chainset to have both.
  • bennett_346bennett_346 Posts: 5,029
    JimboM wrote:
    Sorry, one more question

    Do I have to remove the large ring? Could I leave it on (so that it acts like a bash guard itself) and just adjust the limit screws to keep the chain on the first 2 rings

    Thanks
    You could but... why? If you're going to do that you aren't benefitting from lost weight, increased clearance or the strength of a proper bash. Plus adjusting the limit screws to render the outer ring useless is the biggest waste of time i've ever heard. You may as well use it as an outer ring when you need it if you're going to leave it there. Adjusting the stops will not benefit you at all.
  • gtd.gtd. Posts: 626
    You could use the outer ring as a bash although it wont slide over logs and obstacles like a bash would. You could just use shorter chain ring bots and do without a bash ring / outer ring.

    Or you could just use a triple tensioner like a
    e13_heim.jpgE*13 Heim 3RS

    or the

    Bionicon c.guide v.02
    Mountain: Orange Patriot FR, SubZero & Evo2LE.
    Road: Tifosi Race Custom.
    Do it all bike: Surly Disc Trucker 700c/29er
  • JimboMJimboM Posts: 380
    You could but... why? If you're going to do that you aren't benefitting from lost weight, increased clearance or the strength of a proper bash. Plus adjusting the limit screws to render the outer ring useless is the biggest waste of time i've ever heard. You may as well use it as an outer ring when you need it if you're going to leave it there. Adjusting the stops will not benefit you at all.

    All makes sense but I wasn't looking at saving weight etc just want to get rid of the annoying rattle of the chain slap, didn't realise you could get 3 ring tensioners so will look a bit more into one of those.

    Thanks to all for the feedback

    Jim
    Cannondale Synapse 105
    Giant FCR3
    GT Avalanche 3.0
    Canyon Nerve AM 6.0
  • Chunkers1980Chunkers1980 Posts: 8,035
    One of the new clutch rear mechs
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