Results 1 to 7 of 7
  1. #1
    rockhound
    Reputation:
    Join Date
    Jul 2007
    Posts
    46

    Mojo HD and MRP g2 chainguide rub

    Is there any way to adjust the MRP chainguide to eliminate rub in the tallest gear (11t cog)??

    I could probably live with it; but if there is a way to fine-tune, I would appreciate the advice.

    The setup instructions were less than enlightening for the custom setup for the HD.

    Thanks!!

  2. #2
    rockhound
    Reputation:
    Join Date
    Jul 2007
    Posts
    46
    Maybe more info is needed to diagnose the cause of the misalignment:

    I went over the install, and noticed that there was some play in the cranks. I tightened them. However, the problem remains, but at least it only rubs in outside cog (11t) now. Previously it rubbed the two outer cogs.

    The chainring is not centered in the upper guide; it is skewed about 1 to 1.5 mm towards outside (away from the frame).

    There were two spacers (2.5 mm wide) between the bottom bracket cup and the shell. It appeared that the boomerang was about 2.5 mm wide as well. One spacer was omitted when the bottom bracket cup was put in.

    frame > spacer > boomerang > bottom bracket cup

    The trick is figuring out how to center the chainring to eliminate the rub, which might eventually score and weaken the plastic on the upper guide.

    Thanks,
    Mike

  3. #3
    mtbr member
    Reputation: c-wal's Avatar
    Join Date
    Jan 2004
    Posts
    447
    Mine rubs on my non HD Mojo too. That upper piece is replaceable, which is nice since mine came out of the plastic bag broken - nice QA on the manufacturing on the MRP side put it together tightened the screw too tight...

  4. #4
    meh
    Reputation: clewttu's Avatar
    Join Date
    May 2007
    Posts
    1,187
    screws in my upper guide stripped immediately, was like they were plastic...mine rubs some too

  5. #5
    mtbr member
    Reputation: phoenixsun's Avatar
    Join Date
    May 2010
    Posts
    232
    Quote Originally Posted by clewttu
    screws in my upper guide stripped immediately, was like they were plastic...mine rubs some too
    They are aluminum, and soft at that.

    Mine both rubbed, the first one cracked (they were cool about getting me a replacement), so when the second one also rubbed I put a spacer in between the two upper halves, 3 washers I believe and 2 for the tail as it was wider in the first place. The overlap on the molded pieces means its still clean and sound/ grind free.
    note to self, do not read rider down forum.

  6. #6
    meh
    Reputation: clewttu's Avatar
    Join Date
    May 2007
    Posts
    1,187
    yeah, soft is an understatement, after the first one stripped while installing (nothing close to excessive force) i babied the hell outta the second one and it still stripped

    will have to throw a spacer in when i get around to getting new bolts in there too

  7. #7
    GUIDANCE COUNSELOR
    Reputation: NoahColorado's Avatar
    Join Date
    Aug 2004
    Posts
    3,644
    Sometimes setting-up the upper guide on the G2 is a bit like tuning a ft. derailleur and may require a bit of physical "tweaking" to eliminate any noise. That assumes the guide was setup correctly in the first place and that your chainring is darn-near dead centered relative to the upper guide.

    In some cases rubbing can't be avoided in either the highest or lowest gear due to tolerances. It usually diminishes over time and is a bit of a tradeoff for reliable chain retention. We absolutely don't recommend spacing out the upper guide via spacers, not only does that allow enough space for your chain to jam or drop, but also compromises the integrity of that piece as well.

    Regarding the bolts, we acknowledge that the earlier alloy bolts (we now use steel) were a bit soft and prone to stripping if adherence to toque specs weren't followed. We offer free replacement of that hardware, just give us a call.

    We are more than happy to assist with setup or get replacement parts out to y'all, we can be reached 9-5, M-F at 970.241.3518. We want your guide working perfectly as much as you do!

    Cheers and happy trails!
    NOAH SEARS
    MRP - VP of Business Development
    Pivot Cycles - Team Rider

Members who have read this thread: 0

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.