Results 1 to 17 of 17
  1. #1
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    55

    Are Shimano XT M770 Cranks Normally Noisy?

    I just bought and installed a brand new set of Shimano XT cranks on my bike and immediately noticed that while in the middle chainring, I hear a lot of noise, specifically chain noise. Just a little background on my bike, it's a 2006 Marin Northside Trail that was bought late last year from a bikeshop as new old stock. I've upgraded everything on it and haven't really had a chance to take it on the trail so all the components more or less just have a few miles of around the block riding.

    I just took off my Raceface Evolve DH tripple crank set which was bullet proof, but they were heavy and shifting was just ok. I had the bottom bracket shell faced and the threads chased and everything went together smoothly with the XT cranks but it sure seems that this crank produces much more noise than my Raceface crank set which was dead silent. The chain is an XTR chain (lubed with triflow) that is practically brand new along with the XT cassette and Shadow derailleur. I have readjusted the front derailleur so that's spot on. Shifting is magnificent, but I just want to hear from owners of XT cranks. If it's "normal", I can deal with it.

  2. #2
    *****************
    Reputation: Bikinfoolferlife's Avatar
    Join Date
    Feb 2004
    Posts
    12,378
    I have both an M770 XT as well as several older XT versions, can't say as there's any extra noise on the 770, but haven't really tried to compare, either. Maybe it's the different materials of the middle ring but that sounds like a stretch...
    "...the people get the government they deserve..."
    suum quique

  3. #3
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    1,050
    My M770 XT is dead silent. Since you adjsuted the FD, and shifts spot on, and it is a hard tail, I would do would be a visual chain line check.

    Look at the chain line from the rear when you are in the middle chain ring and 4th gear (4th largest cog), or granny ring with 2nd gear (or something that should be a perfect fit) - your chain line should be faily square if not perfectly straight. If not, then experiment with the spacer(s) came with your 770.

    For example, I had to put the spacer on the non-drive side when I changed my crankset from RF Deus to 770 XT:


    Good luck.

  4. #4
    mtbr member
    Reputation: Jlar's Avatar
    Join Date
    May 2006
    Posts
    508
    Quote Originally Posted by hatake

    For example, I had to put the spacer on the non-drive side when I changed my crankset from RF Deus to 770 XT:


    Good luck.
    Curious, why did you put spacers on the non-drive side?

  5. #5
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    55
    I am all confused now. I've seen some pictures with no spacers being used, some with just a spacer on the drive side, spacer just on the non-drive side and a spacer on both sides. Looking at the instructions that came with the crank, are you suppose to use a spacer on both sides if you aren't using a E-type deraileur? Looking at my chain, it looks dead straight. I really don't want to take it to the bike shop if necessary. Thanks for the help guys.

  6. #6
    mtbr member
    Reputation: V.I. Clyde's Avatar
    Join Date
    Mar 2008
    Posts
    30
    Installed a M770 crankset a couple of months ago. Shifts smoothly and very quiet under low through high torque pedaling in all rings/gears (running HG93 chain with XTR front & rear ders; XT cassette). I used the spacer set-up exactly per the instructions for my set-up (68mm BB).

    You may want to recheck your install to make sure everything is torqued correctly. I personally had a hard time getting past the "light torque concept" on the threaded black ring on the left side until I spun the cranks and they were reluctant to spin more than two times by hand. ("Oh, duh, I get it now!") I took it all back apart, reinstalled and everything works great.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    55
    Quote Originally Posted by V.I. Clyde
    I used the spacer set-up exactly per the instructions for my set-up (68mm BB).
    One on each side?

  8. #8
    mtbr member
    Reputation: V.I. Clyde's Avatar
    Join Date
    Mar 2008
    Posts
    30
    I don't remember. I'll have to get back to you when I go home tonight. But from the instructions I went with the setup for 68mm BB, no E-type der.

  9. #9
    mtbr member
    Reputation: V.I. Clyde's Avatar
    Join Date
    Mar 2008
    Posts
    30
    Lbsigman,

    I popped on to Shimano Tech Docs and the instructions show two spacers on the drive-side, one on the non-drive side (all were 2.5mm that came with the crankset).

    http://techdocs.shimano.com/media/te...9830616011.pdf

    Hope this helps.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    1,050
    Quote Originally Posted by Jlar
    Curious, why did you put spacers on the non-drive side?
    M770 (X-Type) no spacer on drive side?

    I posted this a while back asking if there were any reasons why I shouldn’t put the spacer on a non-drive side, because moving from 05 X-type Deus to X-type XT changed the chain line on my 2004 Rocky Mountain Slayer. Weird I thought, but it was visually off and misalignment was audible when pushing uphills. I haven’t compared the ring offsets on both cranks, but some people say XT 770 has wider q-factor (wider cranks?) that it maybe pushing out the ring outward – or something like that. Anyway, I couldn’t think of any reason to run the spacer on non-drive side, so I swapped it out. After this operation, no more clicking, no problem whatsoever (although I’m riding more SS these days than this bad boy slayer). So I quit worrying and went riding

  11. #11
    mtbr member
    Reputation:
    Join Date
    Jun 2007
    Posts
    447
    Mine was noisey as hell too. Would be OK for a couple of laps until trail dust got into the external bracket area. Nothing could quiet the cranks until I completely took them apart, cleaned them, and reinstalled. Would be nice and normal for a couple of laps, and then same garbage noise all over.

    Installed Square Taper Phil Wood with Middle burn cranks and have never had a noise since, and that was 6-7 races ago. Haven't looked at the cranks since.

    My XT's are now a showpiece on the wall of overrated crap I have fallen for over the years.
    ... And I Am You,
    And What I See Is Me!

  12. #12
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    378
    if you have a 68mm bb shell, you should be running three 2.5 mm spacers, 2 drive side, 1 non drive side. 73mm bb shells should have one 2.5mm spacer on the driveside.

    i've been running a 68mm bb shell backwards for a few years now (1drive, 2 nondrive) to improve chainline, as the recommended shimano spacing pushes my crank out too far, causing a **** chainline on alot of older frames (based, i think, on whether the frame was built around a 47.5 or a 50mm chainline). it made my ride noisy in the spec configuration.

    now the only problem i found that might, might happen, is breaking off a bb shell on the non driveside, as that cup is shorter (threaded section) to begin with, and adding another spacer leaves even less in the way of thread depth on the cup. never really noticed a q-factor problem, but then again, my riding isn't that nuanced...

  13. #13
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    55
    Quote Originally Posted by cjn1014
    if you have a 68mm bb shell, you should be running three 2.5 mm spacers, 2 drive side, 1 non drive side. 73mm bb shells should have one 2.5mm spacer on the driveside.
    Ok, that is what I have on my bike. Well, I put it on the middle ring up front and the 4th largest cog in the rear and I can see it ever so pushed out at the front; barely noticible to the point where I had to use a straight edge to confirm that my eyes aren't deceiving me. So, it looks like I might try and remove one 2.5mm spacer on the drive side. Should I move that spacer to the non-drive side or just keep it off?

  14. #14
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    378
    i try to match up the middle chainring with the #5 cog (the actual middle on a 9 speed cassette). i can get through my entire cassette while in the middle ring pretty cleanly (quietly with no horrible chain angles) that way.

    whatever you do, if you have a 68mm bottom bracket shell, you have to run three total 2.5mm spacers, in some configuration. otherwise, you'll probably crush the dust/water shield between the two cups, and you probably won't be able to preload your bearings properly after installing the non driveside crankarm.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    55
    Here are some pics and I know it still may be impossible for you guys to really get a true first hand look at it. When I took these pics, I had it in the middle chainring and the #5 cassette ring in the rear.




  16. #16
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    378
    that looks ok to me. a bad chainline will produce noise (and bad shifting) at the extremes of the cassette, not all the way through the entire range. bad at 1-2, or 8-9, ok in 4-5-6.

    different question. is your chain wet to the touch? i've noticed when i lube my chain (t9 boeshield) the chain sounds horrible, until the lube sets up and dries a bit. this has been the case with any crank i've tried, whether it be 770, 760, deus, evolve, whatever. maybe a lube that sets up a bit drier would help.

    as the rings wear in, to mesh with the chain, noise should diminish.

    have you narrowed this down to chain noise? if so, is it more in the crank or the cassette? or is the noise from the crank turning? can you pop the chain off and give the cranks a spin?

    if the rd is a bit off, you'll get noise in the cassette. too mush bearing preload will cause noise in the crank while spinning with the chain removed.

  17. #17
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    1,050
    Looks pretty clean.

    I would swap out the middle ring with your old Evolve (assuming they are 4-arm design) to see if you can isolate the issue to the ring. If Evolve ring quiets it down, then a) XT ring is indeed noisy and can't do anything about it, and/or b) use other rings (that really sucks for you tho ) How about the granny ring? Does it make any noise? In my personal experience, going from Deus to XT had no audible difference...

Posting Permissions

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