Drive Train sort of slipping under Load

Discussion in '"Shop" Talk' started by Ride On, Aug 11, 2017.

  1. Ride On

    Ride On Member

    Location:
    Colts Neck, NJ
    After converting a Frankenbike from a 3x10 to a 1x10 with a 30t narrow-wide chain ring and a SunRace Wide Ratio 11-42 Cassette it seems like there is some kind of slippage going when on the smallest cog. When its on the stand, everything seem fine... perfect indexing. But when under heavy load I feel the slippage. The weird thing is, say I start on the smallest cog...and visually confirm that the chain is sitting fine... then I pedal after a bit, say after 6 or 7 heavy cranks and I feel the slippage, then I stop the bike, look down and everything appears to still look fine. The chain stays on the smallest cog, so it isn't "jumping" gears. This issue does not seem to happen on any other cog other than the smallest.
    The chain, cassette, chain ring, and derailleur hanger are all relatively new. The chain has also been properly sized. I am using an old XT Derailuer (no clutch). I am guessing it could be the jockey wheels or a slightly bent cage. Perhaps a chain tensioner would help (which could explain why it is only happening on the smallest cog which would create the most slack)?
    Thanks in advance for any suggestions...
     
  2. 1sh0t1b33r

    1sh0t1b33r Well-Known Member Team MTBNJ Halter's

    Location:
    Orange County, NY
    Could be the B-screw or the chain is too long.
     
    bucknejo and qclabrat like this.
  3. C8N

    C8N Well-Known Member

    Location:
    Wayne
    qclabrat likes this.
  4. Ride On

    Ride On Member

    Location:
    Colts Neck, NJ
    Thanks I considered the Goat Link but it says its only compatible with Derailleurs with a clutch. I did install a longer B-Screw I'll play with that. Just curious... did you install a chain guide when you converted?
     
  5. ilnadi

    ilnadi Well-Known Member

    Location:
    CLinton, NJ
    loose cogs or riveted together? if the smallest cog is on the shoulder of the spline, it may be spinning around the hub.
     
  6. C8N

    C8N Well-Known Member

    Location:
    Wayne
    No chain guide and I haven't dropped the chain yet.. but I don't do anything scary.
    The older shimano rds are not designed to handle the big cog. You may need to get a newer rd to have this set up work.
     
  7. fidodie

    fidodie Well-Known Member Staff Member

    Location:
    Branchburg
    any chance the chain is climbing the chainring and dropping back in - even with the n-w, the angle may be too much.
    also check for a bent tooth, or bad/bent link in the chain

    put it in a trainer, and let someone watch what is happening.
     
  8. M3Tim

    M3Tim Well-Known Member

    Maybe the smallest cog isn't fully engaged with the freehub so is actually rotating fine, but not propelling the wheel forward. I had an issue when I used the Sunrace and had to switch to a very thin spacer to get enough engagement.
     
  9. qclabrat

    qclabrat Well-Known Member

    Location:
    Warren
    which model is the derailleur and how did you determine the proper chain length?
    always used the largest cog plus two links method.
     
  10. RSabarese

    RSabarese Active Member

    Location:
    Clark
    That's mostly true but if you have a later gen 10-speed rear derailleur a Goatlink will work. For instance on XT there was an M780 and M781 series, the newer M781 is direct mount compatible so the pivot point/bracket axle unit as Shimano calls it is wider and a Goatlink will work, the M780 (SLX M663, Deore M593) won't work as the bracket axle unit is thin / not direct mount compatible. Look at the number stamped on the back of the derailleur to tell.

    You may want to consider buying an SLX M7000 11-speed rear derailleur for $49 rather than $20 for a Goatlink and still have no clutch. Even though Shimano won't tell you ... they are compatible or so close in cable pull there is no difference. I've been on XT M8000 RDR and an Sunrace 11/42 10-speed for just over 18 months on 2 of my bikes with a Saint 10-speed shifter and also an SLX M7000 with all else identical on my fat bike.
     
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  11. M3Tim

    M3Tim Well-Known Member

    I have the XT M8000 and the Sunrace also, works sweet and no issues with 42t and B limit screws.

    I think you still need to figure out what is slipping before throwing money at it though. If the cog is slipping on the freehub, a new derailleur is not going to help.
     
  12. C8N

    C8N Well-Known Member

    Location:
    Wayne
    M8000 was designed for the wide range cassette. OP said his is an older XT which prolly can't handle the wide range cassette. Someone correct me if im am wrong but anything pre M8000 and M7000, can only handle upto 36t.

    What I found when I did the 1x conversion, was that the longer B screw made the chain wrap really bad on the smaller cog.
     
  13. RSabarese

    RSabarese Active Member

    Location:
    Clark
    If you run a Goatlink, my experience is M615 (Deore), M675 (SLX) and M786 (XT) all work reasonably well with the 11/42. My wife, son and both daughter's bikes are setup that way today. Many people have found 11/40 works w/o the Goatlink but have heard that's the limit and it stinks on the 42 but I have not tried that setup.
     
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  14. C8N

    C8N Well-Known Member

    Location:
    Wayne
    Yep!
     
  15. Ride On

    Ride On Member

    Location:
    Colts Neck, NJ
    I didn't think that the M7000 would be so inexpensive... definitely worth thinking about. BTW off the top of my head I am pretty sure I have an M780. It came off a 2011 bike. I think it makes the best sense to get rid of the old derailuer as who knows how straight the cage is. For 42 clams I would pretty much have a brand new drive train (with all of the other new stuff on it). I can use the M7000 11sp with 10sp Slx shifters?

    BTW... thanks to everyone who responded to my question!!!! Lots of good info!
     
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  16. C8N

    C8N Well-Known Member

    Location:
    Wayne
    I am pretty sure m8000 and m7000 will work with a 10spd shifter. I think that's what a lot of guys on mtbr do.
     
  17. Ride On

    Ride On Member

    Location:
    Colts Neck, NJ
    Yep... I by-passed the cage, compressed the suspension and added two links. It is an XT (M780).
     
  18. Ride On

    Ride On Member

    Location:
    Colts Neck, NJ
    That could be a possibility...(I believe M3Tim was thinking the same thing)... The smallest 4 or 5 cogs are loose. There is a spacer sits behind the cassette that I may not need. I can't remember if it came with the Sunrace Cassette or if it was always there. I could try removing that. I'll have to re-examine how the cassette is sitting on the hub. Thanks!
    I
     
  19. M3Tim

    M3Tim Well-Known Member

    If the cogs are loose then you need more spacer thickness not less!
     
  20. RSabarese

    RSabarese Active Member

    Location:
    Clark
    Yes, my son's bike has Deore M610 shifters and a similar setup. All 10-speed Shimano mountain shifters pull the same cable per shift, the mechanics of XT / XTR with ball bearings and instant release are the added bonus. As long as it's "Dynasys" your good.
     

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