Page 1 of 2 12 LastLast
Results 1 to 50 of 98
  1. #1
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87

    Chain skipping and falling off

    I have a problem with chain skipping on my Dean Colonel 29er. It’s got about 250 miles on it. The drive train is Sram X0 in back and Shimano XT in front with X0 shifters. When I’m really torquing the cranks while I’m on the center chain ring and on about the third to fifth sprocket (from the inside) in back and I hit some rough trail that bounces the rear end, the chain skips. The skip seems to be at the front, not the back. Worse than that, at least three times when I’ve been pushing up a short hill in those gears, the chain has come off and fallen on the bottom bracket inside of the smallest chain ring. The front derailleur will still be positioned on the middle ring.

    Thinking that the front derailleur might be out of adjustment, I’ve increased cable tension so that the chain will barely drop from the large to middle, but that didn’t help. The chain length seems spot on. Large to large has the rear derailleur stretched so that the chain is almost going straight through the pulleys.

    Any suggestions?

    Thanks.

    ChuckD
    Last edited by Monument247; 07-24-2006 at 08:04 PM.

  2. #2
    Over the Hill
    Reputation: dstepper's Avatar
    Join Date
    Feb 2004
    Posts
    1,747
    This won't address all the problems you are having. My 5-Spot was dropping the chain off the granny onto the frame. In rock gardens had to stay in middle ring to keep tension on chain.

    Tried this and has worked well http://www.ajsbikeparts.com/web-AJBIKEPARTs/AJ's Frameguard.htm

    Now the skipping sounds like a weak spring in rear derailleur...borrow another derailleur...see if it helps.

  3. #3
    mtbr member
    Reputation: Martin6's Avatar
    Join Date
    Jul 2006
    Posts
    344
    I had this same problem and it was driving me crazy. I ended up replacing the middle chain ring and it solved the problem.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    3,061

    Just curious...

    Quote Originally Posted by Martin6
    II ended up replacing the middle chain ring and it solved the problem.
    What was wrong with the old middle ring that caused it to skip and fall off? Just worn out? Bent? Missing teeth? Something else?

  5. #5
    mtbr member
    Reputation: Martin6's Avatar
    Join Date
    Jul 2006
    Posts
    344
    Kevin,

    I couldn't visibly see anything wrong with the old chain ring besides just normal wear. The bike only had a dozen rides on it at the time. I had already replaced the chain and cassette with no luck. It wasn't until I put the front tire against a wall and applied pressure on the pedal that I could see the chain was slipping on the chain ring. This is on an 06 Epic Marathon.

  6. #6
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    3
    For the front derailleur you will need to adjust the low limit screw in order to get the derailleur cage to keep the chain on.

    Try swapping out the rear deraileur, your chain could also be too long but I doubt that would be the case on a new bike.

    hehe.. I'm so used to being in a shop when giving advice not trying to diagnose over the Internet

  7. #7
    mtbr member
    Reputation: Martin6's Avatar
    Join Date
    Jul 2006
    Posts
    344
    Quote Originally Posted by Popps
    For the front derailleur you will need to adjust the low limit screw in order to get the derailleur cage to keep the chain on.
    Good advise. I did make the adjustments to the front derailleur as Popps suggests, because I was having the same problem of the chain falling to the BB when it would slip. All is good now.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    I got some good news today, in a way. It seems that my problem is a known problem with the new Shimano XT middle ring shift ramps. They advise using an LX middle ring until they work out a fix.

    Thanks to everyone for the replies.

    ChuckD

  9. #9
    Soft AND Tender
    Reputation:
    Join Date
    Jun 2005
    Posts
    140
    Monument247,

    Can you elaborate on the "problem" with new XT middle rings? I just put a new one on and experienced the skipping thing this weekend when riding.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    46

    Porblems with LX chain rings also

    Just a head's up, I had a brand new LX crank and chain rings on my brand new bike, and had the same problem, every thing was brand new. I finally replaced the middle chain ring with a Tru Vativ and have had no other problems. The point is that the new LX middle chain rings may have problems as well. At least I had problems with mine.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    redclayrambler - Where did you get the Truvativ ring? What did it cost? I see one at Jenson for $24.48.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Feb 2006
    Posts
    413
    Any compatibility issues with the Truvativ middle ring in between Shimano chain rings?

    Also, for everyone here having this skipping issue, what chain are you running?

  13. #13
    mtbr member
    Reputation:
    Join Date
    Jul 2006
    Posts
    12
    Quote Originally Posted by redclayrambler
    Just a head's up, I had a brand new LX crank and chain rings on my brand new bike, and had the same problem, every thing was brand new. I finally replaced the middle chain ring with a Tru Vativ and have had no other problems. The point is that the new LX middle chain rings may have problems as well. At least I had problems with mine.
    Yup same here, same exact problem with a brand new LX crankset. Switching from and 8-speed to 9-speed chain seems to have helped the problem a LITTLE bit, but it's still happening. I'll be replacing the rear derailleur soon (it's ten years old, and a little worn out), and the middle chainring if that doesn't fix it.

    edit: Ok, I just got off the phone with Shimano. They confirmed that this is a known problem with the XT chainrings, but that my case is the first they've heard involving LX chainrings. The guy was a little suprised, since they've been sending out LX rings to the affected XT owners, which seem to be fixing the problem (BTW, the new chainrings are free under warrantee).
    Last edited by tick; 07-26-2006 at 03:52 PM.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    cbratt - The problem is pretty well explained in the initial post.

  15. #15
    MTB B'dos
    Reputation: LyNx's Avatar
    Join Date
    Oct 2004
    Posts
    20,038
    Actually I find the best and cheapest replacement is an old Deore middle ring, they're string as hell and cheap. I had to do the same thing with the middle ring on my RF RideXC cranks when I first got my bike with them. Also had to replace the Shimano XT HT2 middle ring when I got that in only amonth or so, but that I think was due to a worn chain, but it did tend to "fall off" before it started skipping.
    One day your life will flash before your eyes, will it be worth watching??
    MTB Barbados
    My Phantom pics

  16. #16
    mtbr member
    Reputation:
    Join Date
    Jul 2006
    Posts
    12
    Well I just got back from my LBS... I explained the problem with the middle ring to them, and got them to call Shimano to verify that this is a known issue. I should have my (free) replacement chainring from Shimano in a week or so . If this doesn't work, then I'll buy a middle ring from a different manufacturer. No sense in spending money on a new chainring for a brand new crankset, right?

  17. #17
    mtbr member
    Reputation: Martin6's Avatar
    Join Date
    Jul 2006
    Posts
    344
    Ok, I just got off the phone with Shimano. They confirmed that this is a known problem with the XT chainrings, but that my case is the first they've heard involving LX chainrings. The guy was a little suprised, since they've been sending out LX rings to the affected XT owners, which seem to be fixing the problem (BTW, the new chainrings are free under warrantee).
    Thanks for the heads up on the warrantee from Shimano. I'll make the call tomorrow for a new chainring.

  18. #18
    surly and rigid
    Reputation:
    Join Date
    Apr 2004
    Posts
    43
    Just a quick note. Most other rings aside from shimano will not work great on a shimano crankset. Watch the spacing. Good luck

  19. #19
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    46
    Any compatibility issues with the Truvativ middle ring in between Shimano chain rings?

    Also, for everyone here having this skipping issue, what chain are you running?
    redclayrambler - Where did you get the Truvativ ring? What did it cost? I see one at Jenson for $24.48.
    I got the chain ring from a local bike shop, and I think it cost about twenty something.
    I was not sure at all if the Tru Vativ would play nice with the other Shimano stuff, but the guy at my shop said it should not be a problem, and he was right it seems to work just fine.
    Unfortunatey I don't know what model Tru Vativ ring it is, but they were both 32 tooth with shifting ramps.
    Hope that helps.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    594

    same exact issue here

    Monument247, did the LX middle ring fix the problem? This is driving me crazy too.

    On my Turner FLux I have a brand new 32T XT middle ring (M760 crankset) and I am having the exact same issue described in your original post. The combination of being in the middle ring, 3rd to 5th cog , bumpy terrain, and applying serious torque to the pedals results in a horrible grinding/popping. If I can, I try to look down to see the trouble while it is occuring and I have seen the chain halfway off of the middle ring even though I never shifted. The grinding noise is the chain trying to climb back up onto the middle ring while under torque.

    I have checked the following:
    -New SRAM PC 990 cassette
    -New SRAM PG 991 chain
    -New Shimano XT 32t middle ring
    -Chainline when in the middle ring and middle cog is straight
    -One BB spacer on the drive side with Shimano M760 crank set + 73mm bb shell
    -In my big ring / big cog combo my rear derailleur is stretched tight, but I can shift into this big/big combo without blowing things up
    -checked for stiff chain link
    Eat Food. Chop Wood. Ride Bike.

  21. #21
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    11,814
    I just mounted a XT hollow tech II crankset. I had some issues setting up the FD.

    I was surprised but had to lower the FD about 3mm to match the shimano spec of 1-2 mm clearance. The old cranks were Race face.

    Problems went away.

  22. #22
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    Dave in Driggs wrote: "Monument247, did the LX middle ring fix the problem?"

    I don't know, yet. I don't think that I'll see the replacement ring until next week. I'm confident, though, that it'll fix the problem. Why don't you call the place you bought the bike and get them to call Shimano for a replacement ring? It sure sounds like you have the same problem. While waiting, my temporary solution is to run on the small ring with the rear on the outer sprockets which gives me similar ratios. No skipping problems that way.

    jeffscott - The XT derailleur comes with something called a Pro Set alignment block to set the gap, so I don't think that spacing is causing this particular problem.

    Thanks for your input.

    ChuckD

  23. #23
    mtbr member
    Reputation:
    Join Date
    Feb 2006
    Posts
    413
    Monument, what chain are you running? It seems that most people with this problem are running SRAM chains on XT cranksets. I'm trying to figure out if trying a Shimano chain would solve the problem without having to go to an LX middle ring.

  24. #24
    mtbr member
    Reputation:
    Join Date
    Nov 2005
    Posts
    51
    I seem to have the same problem with my Shimano 9 speed chain on my XT middle ring. Everythings pretty brand new. Otherwise the index shifting is nicely dialed in. I get the skip when heavily torquing with no shifting being attempted -- usually while motoring down an easy trail and suddenly coming upon some short, steep techy section. Expecting an LX ring to try next week. I've been making a point of staying in the smallest chainring more often to avoid occurances.

  25. #25
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    594
    Quote Originally Posted by jcbikeski
    I seem to have the same problem with my Shimano 9 speed chain on my XT middle ring. Everythings pretty brand new. Otherwise the index shifting is nicely dialed in. I get the skip when heavily torquing with no shifting being attempted -- usually while motoring down an easy trail and suddenly coming upon some short, steep techy section. Expecting an LX ring to try next week. I've been making a point of staying in the smallest chainring more often to avoid occurances.
    Which chain are you running?
    Eat Food. Chop Wood. Ride Bike.

  26. #26
    mtbr member
    Reputation:
    Join Date
    Nov 2005
    Posts
    51
    HG93 I think is the model number of the chain. It's the XT (and XTR?) one

  27. #27
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    Sram PC 951. Shimano says it's a problem with the shift ramps. I think that, if it is indeed happening with a lot of Sram chains, it's just because they're very popular. I'll know any day now when my chain ring gets here.

    ChuckD

  28. #28
    mtbr member
    Reputation:
    Join Date
    Feb 2006
    Posts
    413
    Quote Originally Posted by Monument247
    Sram PC 951. Shimano says it's a problem with the shift ramps. I think that, if it is indeed happening with a lot of Sram chains, it's just because they're very popular. I'll know any day now when my chain ring gets here.

    ChuckD
    I think you're right. The Shimano support rep I talked to didn't even ask me what chain I was running and simply promised to send me an LX middle ring. Shimano would blame SRAM if they could, so it seems to me that the problem lies in the middle ring regardless of the chain being run.

  29. #29
    mtbr member
    Reputation: 2gunnz's Avatar
    Join Date
    Jun 2006
    Posts
    116

    how far back

    Does anyone know how far back they are covering the chainrings? I have a 2004 giant vt2 that has the same problem everyone is describing.

  30. #30
    mtbr member
    Reputation:
    Join Date
    Feb 2006
    Posts
    413
    Did the VT2 even come with an XT crankset? The new shift ramps were a very recent change to the XT chainrings, so your bike is probably suffering the same symptom caused by a different problem, such as worn or bent chainrings. Have you changed your chainrings since you bought the bike 2 years ago? If not, this would be a good place to start.

  31. #31
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    3,061
    Quote Originally Posted by 2gunnz
    Does anyone know how far back they are covering the chainrings? I have a 2004 giant vt2 that has the same problem everyone is describing.
    FWIW, I put a new XT crankset on my bike about a year ago. I didn't have this particular chain skipping problem mentioned by the OP and others, but the middle ring did wear really fast - it only lasted one chain and I'm careful about checking for chain wear. (I replaced it with a Race Face ring which is still working well.)

    I agree with TLud on this matter... if you haven't changed the ring since you bought the bike, it's probably just worn out.

  32. #32
    mtbr member
    Reputation:
    Join Date
    Aug 2004
    Posts
    15

    XTR chainrings are no better

    This is happening on XTR stuff as well. Just put an entire new drive train on the '04 Blur (Sram 990 cassette, Sram 991 chain, Sram x-9 deraileur, new xtr middle chainring, new bottom bracket, new free wheel assembly - and of course all new pivot points) and this problem just started. The LBS is requesting another XTR chainring as they too think this is the problem.

    Nothing like expecting the bike to ride like new and then having this nasty problem start up.

  33. #33
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    594

    Update

    I posted this over on the Turner forum as well.

    Turner recommended I try moving the drive-side spacer over to the non-drive side (M760 crankset) despite what Shimano says. They also recommended that I ditch the SRAM chain for an XTR and make sure my b-tension screw was adjusted properly.

    I made all three changes at once but I did leave my like-new XT middle ring on and I haven't experienced the popping/grinding since. I have a section of trail that was causing the problem every single time I rode it and I have ridden it three times since making the change with no issues. Woohoo!
    Eat Food. Chop Wood. Ride Bike.

  34. #34
    mtbr member
    Reputation:
    Join Date
    Nov 2005
    Posts
    51
    I read a lot about how things like a crank spacer can affect the chainline and thus this problem, but at least in my case it's hard to see how a couple millimeters in or out of the chainring from the frame would matter. I've seen the problem with the rear in a middle-ish gear and the difference between two rear gears is more than a spacer on the crank. Also in my case the front deraileur seems well centered over the middle chainring so it's not gently trying to push the chain off. So a chainline being a little off would seem to affect more extreme gears more than the middle ones that are the problem.

    I have a shimano chain so it's not the potential SRAM chain issue. I have no stuck links. I've read that loose pivots can affect this, but all seems very solid. My RD hanger seems straight. I can't see how chain tension would be involved since the problem happens in the middle chainring and not the smallest one and anyway experiments showed removing one more link pair made the link too short.

    I do suspect it relates to the shock compressing while torquing hard on the peddles, but not sure what to do about that notion.

    I still need to try the LX chainring to see if that helps like some have suggested.

    Anyway, for now if I'm careful to avoid the middle ring when doing anything other than cruising then all is good.

  35. #35
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87

    New ring, not fixed.....

    The FedEx person delivered my new middle ring today. I installed it and took my usual desert ride. The short slow climbs worked perfectly where the chain skipped or fell off before. I was happy. At my turnaround point, there's a downhill section then uphill. Nothing steep. I went down and picked up speed and stood and torqued the pedals on the uphill. I deliberately rode over rocks to bounce the rear end and the chain skipped on each pedal stroke. I turned around and went back and tried it again. It happened again. At the end of the ride, I went down a road that has a quick downhill followed by a steep uphill. You try to maintain momentum and clear the hill by staying in a larger gear and standing going up to clear the top. It's bumpy and the chain skipped again. Problem not solved - just different.

    I looked closely at the two rings tonight and, if I didn't know better, I think they sent me another XT ring. The markings are identical except one says EC and the other ED. The old one's black and the new one is silver. They both say m9 S-32. Is it possible that they sent me another XT ring by mistake? There's a picture below if I did things right.

    Thanks.

    ChuckD
    Attached Images Attached Images

  36. #36
    mtbr member
    Reputation:
    Join Date
    Nov 2005
    Posts
    3
    I'm a LBS owner having the same issue. Having the problem with my XTR Crankset (middle) and XT Crankset (middle). Shimano said there is an issue with Middle XTR, XT, LX rings. I just replaced mine today with race face (on my XT crank) at first I thought it was problem solved but had another issue up rocky climb on my test ride. It doesn't seem to matter if it's on my hardtail or FS. I did mess with the B tension screw(all the way screwed in) this helped some.
    I've be working in the bike business for 15 years, and I'm stumped.
    This is my set up
    SRAM X9 Rear Derail
    SRAM PC99 Chain
    XT Crank with Race Face Rings
    Also both bikes are 29....how bout everyone else.

  37. #37
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    Twitches - So, the Race Face wasn't the solution? Have you tried a Shimano chain? I'm using a Sram, but I'm thinking about trying the Shimano chain from my Fisher Piranha. The problem bike is a Dean Colonel 29er. Since you have a Shimano contact, are they recommending any workarounds?

    ChuckD

  38. #38
    mtbr member
    Reputation:
    Join Date
    Nov 2005
    Posts
    3
    From what I hear the problem is more with 29ers. I'm going to try my shimano chain with the race face rings. I'll post the results later.

  39. #39
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    46
    From what I hear the problem is more with 29ers. I'm going to try my shimano chain with the race face rings. I'll post the results later.
    Like I posted earlier my chain skipping problem seems to have been fixed by changing out my LX ring (brand new ring and drive train) for a Tru Vativ ring. But it's interesting that my bike is a 29er also, could this be because of having to use more chain with the longer chain stays?
    I really don't think that should matter much, I don't hear much about this on the 29er forum.
    Any way hope you get it fixed

  40. #40
    WIRVNTANASHRSH?
    Reputation: climr's Avatar
    Join Date
    Oct 2005
    Posts
    228
    Quote Originally Posted by Monument247
    The FedEx person delivered my new middle ring today. I installed it and took my usual desert ride. The short slow climbs worked perfectly where the chain skipped or fell off before. I was happy. At my turnaround point, there's a downhill section then uphill. Nothing steep. I went down and picked up speed and stood and torqued the pedals on the uphill. I deliberately rode over rocks to bounce the rear end and the chain skipped on each pedal stroke. I turned around and went back and tried it again. It happened again. At the end of the ride, I went down a road that has a quick downhill followed by a steep uphill. You try to maintain momentum and clear the hill by staying in a larger gear and standing going up to clear the top. It's bumpy and the chain skipped again. Problem not solved - just different.

    I looked closely at the two rings tonight and, if I didn't know better, I think they sent me another XT ring. The markings are identical except one says EC and the other ED. The old one's black and the new one is silver. They both say m9 S-32. Is it possible that they sent me another XT ring by mistake? There's a picture below if I did things right.

    Thanks.

    ChuckD
    I'm not sure of the angle of that picture, but to me it looks like your chain is not sitting right on the ring. There should be no gaps between the chain and the ring, and it should sit evenly on the ring all the way around. If your chain is new then this is either wierd, or it could just be something about the picture.

    For what it's worth, I solved this problem by switing my XTR rings to blackspire super pro rings. I'm also using a shimano chain (with an SRAM powerlink), but I believe the new ring is what solved it. good luck,

    Brad

  41. #41
    less is more
    Reputation: venus1's Avatar
    Join Date
    Aug 2006
    Posts
    823
    The only time I had the skipping thing it was a bad link in the chain. New chain fixed it. I think it is recommended to buy a new chain whenever you change a chain ring? Is this true?
    Finesse is everything.

  42. #42
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    594
    That sucks that you are still having the problems. FWIW, the Shimano rep that I spoke to told me very plainly that there is no difference between the XT and LX middle rings except for the color. I too sent an XT ring back for replacement and I am curious to see what they send me.



    Quote Originally Posted by Monument247
    The FedEx person delivered my new middle ring today. I installed it and took my usual desert ride. The short slow climbs worked perfectly where the chain skipped or fell off before. I was happy. At my turnaround point, there's a downhill section then uphill. Nothing steep. I went down and picked up speed and stood and torqued the pedals on the uphill. I deliberately rode over rocks to bounce the rear end and the chain skipped on each pedal stroke. I turned around and went back and tried it again. It happened again. At the end of the ride, I went down a road that has a quick downhill followed by a steep uphill. You try to maintain momentum and clear the hill by staying in a larger gear and standing going up to clear the top. It's bumpy and the chain skipped again. Problem not solved - just different.

    I looked closely at the two rings tonight and, if I didn't know better, I think they sent me another XT ring. The markings are identical except one says EC and the other ED. The old one's black and the new one is silver. They both say m9 S-32. Is it possible that they sent me another XT ring by mistake? There's a picture below if I did things right.

    Thanks.

    ChuckD
    Eat Food. Chop Wood. Ride Bike.

  43. #43
    WIRVNTANASHRSH?
    Reputation: climr's Avatar
    Join Date
    Oct 2005
    Posts
    228
    Quote Originally Posted by venus1
    The only time I had the skipping thing it was a bad link in the chain. New chain fixed it. I think it is recommended to buy a new chain whenever you change a chain ring? Is this true?
    yes. changing the chain often at the first indication of stretch will prolong your drivetrain the most. If your chain/rings/cassette have worn together for a long time, it's recommended to replace them all together.

  44. #44
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    venus1 wrote: "The only time I had the skipping thing it was a bad link in the chain. New chain fixed it. I think it is recommended to buy a new chain whenever you change a chain ring? Is this true?"

    Not when the drivetrain and the whole bike have 500 miles total and it's a known problem with Shimano XT. I hate to think of paying all that money for a great bike and high end components and find out I have to spend money and time to debug Shimano's problems.

    climr - The gaps you see in the chain are really indentations in the chain ring around the teeth. If you look at the black ring, you can see all of these odd shapes. It looks like computer aided design gone wild.

    redclayrambler - I checked specs on the chainstay length on my 29er compared to a 26er Dean Colonel and the difference is 3/4". That would add 2 full links to the chain between the two. I would think that longer stays would make for better shifting anyway because of less acute angles for the chain.

    Before I got the new ring, the skipping occurred while on the cassette third through fifth sprockets from the inside. The new ring fixed that skipping, but now it skips on the sixth sprocket. I can make that happen quite easily.

    I'm to the point where I'm ready to spend money on a different ring and chain, but I hate doing that if I can't be sure that it'll fix the problem. What I probably will do is move the middle ring from my Alivio crank on my Fisher over and see what happens. That ring is steel with less pronounced pins and ramps. If that fixes it, I'll put up with less than smooth shifting until Shimano comes out with a fix that works.

    Thanks.

    ChuckD

  45. #45
    WIRVNTANASHRSH?
    Reputation: climr's Avatar
    Join Date
    Oct 2005
    Posts
    228
    Quote Originally Posted by Monument247
    Not when the drivetrain and the whole bike have 500 miles total and it's a known problem with Shimano XT. I hate to think of paying all that money for a great bike and high end components and find out I have to spend money and time to debug Shimano's problems.
    So your chain is 500 miles old? IMO, 500 miles is alot for a chain. My last cassette (XT) was toast after 800 miles and I generally replace my chains every 250-300. Of course this is very variable, if you don't mash often and your drivetrain doesn't get muddy then your stuff will last longer.

    Sorry if you've already said you're using a new chain, I didn't read every message.

    climr

  46. #46
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    climr - You didn't read every message???? But it's such an interesting thread.

    We must ride in entirely different conditions. My chain length is spot on after 520 miles. No sign of wear. I live in the Arizona desert just 4 miles from the Black Mountains, so I do no riding in wet, muddy conditions. Just sand, big and small rocks, crushed stone, silt and snakes. I ride my mountain bike about 250 to 300 miles a month year round. I get several thousand miles per chain/cassette on my road bike. I certainly don't expect that from a mountain bike in the desert and mountains, but if I had to replace a chain a month, I'd be looking to buy it in bulk. I'll keep a close watch on my chain length.

    Thanks.

    ChuckD

  47. #47
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    594
    Quote Originally Posted by Monument247
    I'm to the point where I'm ready to spend money on a different ring and chain, but I hate doing that if I can't be sure that it'll fix the problem. What I probably will do is move the middle ring from my Alivio crank on my Fisher over and see what happens. That ring is steel with less pronounced pins and ramps. If that fixes it, I'll put up with less than smooth shifting until Shimano comes out with a fix that works.
    Monument247, I recommend you try a new Shimano CN-7701 chain on that new LX ring you just installed before you move anything else around. Also, pay very close attention to the toe-in/toe-out of the front derailleur and make sure it is perfectly parallel to the chain rings. Lastly, make sure the height is set to "one penny's thickness" above the chain ring teeth at its closest point. I have not had a single skip/pop/grind since making the three changes (posted above) that included a Shimano CN-7701 chain and I am still using the XT middle ring.

    Good luck!
    Eat Food. Chop Wood. Ride Bike.

  48. #48
    Bike Pimp
    Reputation: D@WS's Avatar
    Join Date
    Sep 2005
    Posts
    242
    There should be no call to change your chain every 250 miles.... that would be every two weeks for some folks.

    My set up:
    Maverick ML7/5
    XT crankset circa December 2005
    SRAM 990 chain
    Shimano R770 front der
    SRAM XO long cage rear der.
    No skipping issues...

    This seems to be a recent phonomenon. And not terribly common as i have sold quite a few XT equipped bikes in the last few months and have heard this issue from only three customers.

    Shimano told me that it was an issue with the ramps as well. When they said they were sending LX c-rings, I imagined that they had older ones as XT and LX are virtually the same middle rings.

    Monument 247: How frustrating! That's a great bike, I want you to enjoy it. I will call Shimano again tomorrow and see what they have to say.
    Wrenchscience.com
    ...Your local bike shop....

  49. #49
    WIRVNTANASHRSH?
    Reputation: climr's Avatar
    Join Date
    Oct 2005
    Posts
    228
    Quote Originally Posted by D@WS
    There should be no call to change your chain every 250 miles.... that would be every two weeks for some folks.
    .
    unless your chain shows stretching of 1/32-1/16" after then.... Ok 250 may be a little of an exaggeration, but I know that my last cassette lasted 800-900 miles and I had been through 3 chains that had stretched and needed replacement. I guess it depends on where and how you ride. Around here you're either climbing or descending and it's often muddy. Dryer, flatter trails and I imagine you'd get a lot more life.

    Point is, measure your chain for stretch and replace it early.

  50. #50
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    87
    Dave in Driggs wrote: "Monument247, I recommend you try a new Shimano CN-7701 chain on that new LX ring you just installed before you move anything else around. Also, pay very close attention to the toe-in/toe-out of the front derailleur and make sure it is perfectly parallel to the chain rings. Lastly, make sure the height is set to "one penny's thickness" above the chain ring teeth at its closest point."

    Okay, I'm taking your advice. I ordered the chain and I may see it by the end of the week. In the meantime, I set up the derailluer as you recommended. It was about 3.5 mm above the big chainring. It's now where you say it should be. When I put the penny in the space, Abe gets a headache. See the attached picture.

    I took the bike for a ride after the adjustments and.....it made no difference. I'll see what the chain does. I have a new Sram chain around for my road bike and I may mount it while I wait for the Shimano to see if it makes any difference. Thanks

    ChuckD
    Attached Images Attached Images

Page 1 of 2 12 LastLast

Posting Permissions

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