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  1. #1
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    Prophet drivetrain help needed please

    Ok, I helped my mate choose a nice '05 Prophet - his first "good" bike. He loves it! But...
    Had it checked at the shop when bought. The shop does great work and I've never had a problem there. Our first ride was a friggin road ride and near the end of a 3 hour ride the chain breaks. Got a new chain. It breaks on the very next ride. Take it to the nearest shop, rear cogset is a bit dodgy so he buys a new chain and also gets a new rear cogset.
    He's not doing his own maintenance, the bike mechanics install everything and it always looks fine and survives the parking lot test.
    The new rear action still sucks (it was bad before), his largest 3 gears in the back are ghosting and are a pita. Have taken it to the shop at least 2 more times and it gets adjusted and new cables and...
    I feel bad because this bike still isn't right after 9 months now and my mate keeps spending money on it over and over. The frame has been checked and it's not warped or misaligned.
    Any help/advice would be appreciated!
    '05 Prophet
    Rear Cogs - Sram X9, NEW
    Rear Derailleur - Sram X9, NEW
    Chain - Sram something, NEW
    Rear Shifters - Sram X9

    I can always take pics, if you want a specific view let me know which view.

    Thanks!

  2. #2
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    i use xram deralliers but only use shimano chains, cassettes and chain rings.....i've had a 2006 prophet for 4 years now so i know a little bit about the bike

    long, possible tip:

    what i found when i bought a newer xram rd was that sram had made a design change (comparing 2005 rd and 2008 rd), the little hole where the cable sits in the rd had been changed just a few degrees different....the result of this little change was that the cable didn't really want to go into rd after coming out from the end of the inside of the swingarm., when i forced it in there (felt like kinking the cable almost), it was obvious that there was now too much tension that i imagined would effect all shifting and movement of the rd....so i didn't even bother trying to ride it that way....i went ahead and pulled the cable out and went with a full length derailleur cable for the rd, and now run the cable OUTSIDE the swingarm, just zip tied it in a couple key places..this way the cable has a gentle bend that goes into the rd cable hole with ease and natural curve

    the bike shifts fine this way, no ghost or jumping...been running it this way for 2 years, ride the bike everyday..and the cable does not get dirty like it used to before from the opening it used to have on the downtube....

    let us know if you get it figured out....
    "He can make even a global summit meeting seem like a kegger." M. Dowd, NY Times, 19 July 2006

  3. #3
    ballbuster
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    Second that

    Quote Originally Posted by adamantane View Post
    i use xram deralliers but only use shimano chains, cassettes and chain rings.....i've had a 2006 prophet for 4 years now so i know a little bit about the bike

    long, possible tip:

    what i found when i bought a newer xram rd was that sram had made a design change (comparing 2005 rd and 2008 rd), the little hole where the cable sits in the rd had been changed just a few degrees different....the result of this little change was that the cable didn't really want to go into rd after coming out from the end of the inside of the swingarm., when i forced it in there (felt like kinking the cable almost), it was obvious that there was now too much tension that i imagined would effect all shifting and movement of the rd....so i didn't even bother trying to ride it that way....i went ahead and pulled the cable out and went with a full length derailleur cable for the rd, and now run the cable OUTSIDE the swingarm, just zip tied it in a couple key places..this way the cable has a gentle bend that goes into the rd cable hole with ease and natural curve

    the bike shifts fine this way, no ghost or jumping...been running it this way for 2 years, ride the bike everyday..and the cable does not get dirty like it used to before from the opening it used to have on the downtube....

    let us know if you get it figured out....
    Ghost shifting on FS bikes... once they are adjusted correctly that is (the basics) usually boil down to rear derailleur cable routing and length. Use good shifter housing and make sure there is plenty of slack. If the housing is straight at rest and bent sharply when compressed, it will ghost shift. The trick is to get a good partial bend to bridge the pivot point.

    Heh.... I have a bud with a Blur and Avid BB7s. A few years back I was following him up a middle ring seated climb. I watched his rear brake actuator arm bob up and down while his suspension bobbed up and down. If that was his derailleur cable, it would be ghost shifting that much.

  4. #4
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    Has the freehub been replaced? A dirty freehub could cause some ghost shifting when coasting.
    2012 Cannondale Flash Carbon 29er 3
    2009 GT Peace 9R SS
    2008 Cannondale Prophet 4, Lefty Max TPC

  5. #5
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    The freehub has not been replaced. It doesn't ghost while coasting, only immediately after shifting. Guess I'll need to trade rides with him next time and do some more analysis
    Thanks for the help! The first thing I'll look at is his rear cables, angles and such, compressed and not.
    Ta!

  6. #6
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    is the rd a short cage?
    If so, it could be an issue depending on the gears being used.
    what about chain length?
    I know you said the LBS did all the work...but sometimes we know MORE than the LBS!
    good luck...it sounds like your 99% of the way there.

  7. #7
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    i have an 05 prophet thati've owned since new, it originally came with shimano dual-control brakes and an xt rd. i hated the dual control and replaced it with X9 shifters and X9 long cage rd. When i switched to SRAM i replaced the swing arm cable housing with a slightly longer piece from the down tube cable stop to the rd but left it routed through the swing arm. I use SRAM PG990 cassettes and PC991chains.
    I ride alot and i ride tight twisty trails with lots of rocks and trees/branches that hate rd's, and usually destroy a rd every year or so and have never had a problem using different model year X9 rds.
    Check your derailleur hanger too ?

  8. #8
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    forgot to mention you bb bearings.
    if one is loose, the torque when hammering can create a sucky chainline and cause skipping.

  9. #9
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    If you have access to a bike stand you could hang the bike in the stand and remove the shock (disclaimer: Use some sort of strap to keep the swing arm from dropping and banging up the frame). Now you can easily cycle the suspension while the cranks are turning (also shifting, have a buddy help with this) and observe the chain line. I had problems with my 05 prophet and found that the cable was to blame as well as an out of alignment dr hanger. I also went a step further, removed the smallest cog in back (11T) added a spacer to the back side of the cassette and adjusted the dr for the new chain line (it's now a 8 spd 9 spd). The shifted cassette gives a more usable chain line and allows me to stay in the bigger front rings on harder climbs. My next setup will be a 9 spd 10 spd...

  10. #10
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    Went around last night and took some photos of the bike and drivetrain. Also had a bit of a play around.
    Placing the bike upside down and running through the gears shows that the three largest cog gears are useless. This is without any pressure from the cranks. I know it's never this bad when it's fresh from the shop but I was appalled at how bad it was.
    The rear derailleur cable didn't have any real kink in it, there also seemed to be some slackness to the cable inside the swingarm. I think the cable length is certainly sufficient.
    Wasn't able to check it out with the suspension compressed but since it was so bad uncompressed I didn't think it was relevant for now.
    Grrrr, it seems like what should be a simple problem to fix
    I'll try to post the photos tonight.

  11. #11
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    As it gets worse when the dr is extended the dr hanger is most likely bent. Go to a different shop and have them check the dr hanger alignment and after that the B tension should be checked.

  12. #12
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    Ok, grabbed some pics so let me know if anyone sees any obvious problems. If you need any specific views let me know!
    All the help is appreciated. He did have some worries about the drailleur hanger but i couldn't see it.
    Attached Thumbnails Attached Thumbnails Prophet drivetrain help needed please-001.jpg  

    Prophet drivetrain help needed please-002.jpg  

    Prophet drivetrain help needed please-003.jpg  

    Prophet drivetrain help needed please-004.jpg  

    Prophet drivetrain help needed please-005.jpg  


  13. #13
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    The hanger needs to be checked against the rear rim with a special tool. Looking at it, "eye balling it", will not get you any closer to fixing this issue. Any reputable shop would do the dr alignment first given the problmem that is happening. I'd pull the cable and check it for kinks. With the cable and the chain off move the dr to its full extension and note how much force it takes. Install the cable but leave the ends out so you can slide the cable to make sure there is no binding going on especially in the area where the cable slides the most. If all of that checks out I'd try a new shifter up front (if you can talk the shop into trying one (even a lower level shifter should work).

  14. #14
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    Definitely looks like the hanger is bent, maybe even the whole drop out....Buy a new hanger.....it is designed to snap off to prevent damage to the frame hence the reason why it's called replaceable hanger....
    If you try to adjust it, it will either snap off then or weaken the material to such an extend that it'll snap off on the trail when you shift hard or miss a shift.....
    "Common sense isn't always that common!"
    Custom Prophet and Custom "Leftified" Delta V

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