Results 1 to 9 of 9
  1. #1
    mtbr member
    Reputation: OttaCee's Avatar
    Join Date
    Jul 2013
    Posts
    128

    m8000 11-42T Cassette - Lasted only 1200 miles??

    Purchased XT M8000 cassette 11-42T back in May 2017 and after 1200 miles all but 3 cogs had teeth so worn that chain skips even after chain replacement.

    Has anyone seen premature failure in this cassette?

    Asked Jenson to open a RMA since it was still under 2 year warranty and it was rejected for "normal wear and tear"

  2. #2
    ninjichor.com
    Reputation: ninjichor's Avatar
    Join Date
    Jul 2018
    Posts
    623
    I have an 11-46 M8000 cassette that skips on the 11 and 13t cogs under strong torque, but it pedals fine on the other cogs, if a bit noisy in the 46t. I ran it from around Dec to July, and just swapped on an old X01 11spd 10-42 cassette, which has 2500+ miles and no skipping issue.

    Which cogs are skipping for you? Mine has over 1500 miles on it (3/5 being pavement miles), but had the issue far earlier than that. I actually wanted those gears for the road, as I like to push low RPMs--currently spinning 85 RPM in my 3rd cog, which only nets me about 16-17 mph and maybe 120 bpm, when I know I can push closer to 20 mph. Was considering getting a bigger chainring instead, so I could use the middle of the cassette more.

    Can't tell the problem from just looking at the cassette. Not really sure how my HG-checker tool operates. I'm putting torque on it, but not 100% sure how to determine which cogs are worn or not. I can get the tool to skip easily under torque on a number of different example, from old NW chainrings, to near geared chainrings. Just watched this vid and will try again:



    What's odd is that I'm currently using a 3 chain rotation with my drivetrain (XT 11 spd chains). I swapped them out after ~400-500 miles, which was enough to wear down the factory lube, and just lubed the 3rd chain rotation for the 2nd time (will rotate back to 1st chain after this 3rd chain hits ~800 mi); I get over 100 miles per chain lube application, sometimes over 200 if I haven't degreased and just reapplied lube. I do this to keep the drivetrain supposedly fresh, but I use the 11 and 13t cogs a lot on pavement since I am trying to actually get a workout on the road, so I wouldn't be surprised if they're worn. Chains are definitely not failing the 0.50 chain checker gauge, and the all skipped on the same cogs, but not on the older SRAM cassette (pulled off a '13 bike).

    My plan is to switch back to 10 spd, rather than get another Shimano 11 spd cassette. Save on replacement costs that way.

  3. #3
    mtbr member
    Reputation: NZPeterG's Avatar
    Join Date
    Mar 2008
    Posts
    591
    Quote Originally Posted by OttaCee View Post
    Purchased XT M8000 cassette 11-42T back in May 2017 and after 1200 miles all but 3 cogs had teeth so worn that chain skips even after chain replacement.

    Has anyone seen premature failure in this cassette?

    Asked Jenson to open a RMA since it was still under 2 year warranty and it was rejected for "normal wear and tear"
    Haha
    Sorry that's fair wear and tear.
    How many chains have you used in the 1200 miles?
    Almost any 11speed drive train need a chain replacement every 1000 to 1500 KMs.
    But I have seen worn out chains at 800kms in the dirt/mud.
    It's just part of life with 11 and 12 speed bikes.
    If you're interested in longer life go back to 2×10
    After all it's only money.

    A service manager from a far off land down under.

    Sent from my SM-G930F using Tapatalk

  4. #4
    mtbr member
    Reputation: OttaCee's Avatar
    Join Date
    Jul 2013
    Posts
    128
    Quote Originally Posted by ninjichor View Post
    Which cogs are skipping for you? Mine has over 1500 miles on it (3/5 being pavement miles), but had the issue far earlier than that. I actually wanted those gears for the road, as I like to push low RPMs--currently spinning 85 RPM in my 3rd cog, which only nets me about 16-17 mph and maybe 120 bpm, when I know I can push closer to 20 mph. Was considering getting a bigger chainring instead, so I could use the middle of the cassette more.
    11 and 13t were first skipping then 37 and 46T right after (same ride). Stayed out of 11 and 13 on the next ride then all but 21-24-28 were usable on power.

  5. #5
    mtbr member
    Reputation: OttaCee's Avatar
    Join Date
    Jul 2013
    Posts
    128
    Quote Originally Posted by NZPeterG View Post
    How many chains have you used in the 1200 miles?
    2 chains - One lasted 800 miles other 400 miles
    Guess its time to stock up in chains and keep replacing them

  6. #6
    mtbr member
    Reputation: NZPeterG's Avatar
    Join Date
    Mar 2008
    Posts
    591
    Quote Originally Posted by OttaCee View Post
    2 chains - One lasted 800 miles other 400 miles
    Guess its time to stock up in chains and keep replacing them
    Yes stock with chains being so cheap.


    Sent from my SM-G930F using Tapatalk

  7. #7
    Wanna ride bikes?
    Reputation: *OneSpeed*'s Avatar
    Join Date
    Oct 2013
    Posts
    5,330
    Replacing your chain more frequently will extend the life of your cassette. I got 410 miles on my first chain with an XT cassette. Cassette looks fine, no skipping.
    Rigid SS 29er
    SS 29+
    Fat Lefty
    SS cyclocross
    Full Sus 29er (Yuck)

    Stop asking how much it weighs and just go ride it.

  8. #8
    ninjichor.com
    Reputation: ninjichor's Avatar
    Join Date
    Jul 2018
    Posts
    623
    Well, I count this as 2 cases of wear and tear that happened way earlier than expected. I can get 4k out of cassettes with my normal method. This m8000 cassette was an outlier.

    What chain were you using? I generally prefer XT chains, but rode the stock setup with the KMC 11spd chain that I've since tossed.

  9. #9
    Birthday Collector
    Reputation: ATBScott's Avatar
    Join Date
    Jun 2006
    Posts
    2,603
    I have an M8000 cassette on a new bike I have had only about 6 weeks. Riding it twice a week, have approximately 12 rides on it - most are in the 10 -12 mile range but a few were only 6 or 7 miles. I have spent maybe 10 minutes or so in the 42t cog in the 14-15 hours of ride time on the bike so far - my 42t cog is showing distinct wear, with an XT chain & drivetrain that gets wiped off each ride. I just checked - chain still look 'new' to my chain checker. I am wondering if the 42t alloy cog material wasn't hardened prior to anodizing dark grey? Anyone else have a new cassette basically disintegrate? I'm a long time pro mechanic/shop owner who is now semi-retired and actually getting to ride my bike again! This sorta sucks. Hoping a call to Shimano will get this taken care of - the other steel cogs still look new. I usually change a chain every 60 hours or so of riding (which for me is about 50 miles or so). This gets me 4 or 5 chains per cassette and usually swap out the chainrings at the same time I change a cassette. I don't shift under load or have any other real bad habits. I just noticed this on a ride today when I shifted to my low gear and heard some creaking/popping noises in my low gear. Couldn't believe the condition of the 42T teeth when I took a close look.
    R.I.P. Corky 10/97-4/09
    Disclaimer: I sell and repair bikes for a living


Similar Threads

  1. Is the XT M8000 11-42t cassette compatible with a 2x11 drivetrain?
    By NoDamage in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 9
    Last Post: 12-15-2016, 02:48 AM
  2. Will Xtr m9000 RD work with Xt m8000 11-42t cassette?
    By yeti575inCA in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 3
    Last Post: 09-22-2015, 02:34 PM
  3. C&B SEEN CABS-1200 1200 Lumen Bike Light & Headlamp Kit review
    By Skyraider59 in forum Lights and Night Riding
    Replies: 5
    Last Post: 12-21-2014, 07:56 AM
  4. stock fork. lasted 71 miles
    By Limey Johnson in forum Shocks and Suspension
    Replies: 5
    Last Post: 09-28-2011, 03:15 PM
  5. Replies: 1
    Last Post: 08-12-2005, 10:38 AM

Members who have read this thread: 75

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.