Advertise on Bikeforums.net



User Tag List

Results 1 to 23 of 23
  1. #1
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    derailleur problem

    I have a Giant Quasar

  2. #2
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    I have a Giant Quasar
    Thanks for sharing

    Now what's wrong with it?
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  3. #3
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    wow that didnt work. I typed a whole message and thats all that showed up?

    ok starting over.

    I have a giant quasar with suntour accushift 1500 derailluers with indexed shifting. When shifting into and out of the largest rear sprocket, the chain doesnt seem to line up with the upper derailluer pulley. It still shifts, but it makes a rubbing/grinding noise. the rest of the gears shift perfectly. any ideas?
    thanks in advance

    also does anyone know what this bike would have sold for originally?

  4. #4
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hehe, I was wondering if you were expecting us to diagnose it telepathically

    It sounds like the limit screw on the rear derailer may be adjusted incorrectly. The rear derailer has two screws on the back, one which limits how far IN the derailer can move (low gear limit), and the other limits how far OUT the derailer can move (high gear limit). You should try loosening the low gear limit screw so that the derailer can move a little further inward.

    See http://sheldonbrown.com/derailer-adjustment.html#rear for details on RD adjustment.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  5. #5
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    That was my first idea. the limit screws are set correctly. The largest sprocket to the 2nd largest is a much bigger jump in size than the rest of the sprockets. Could the shifter just not be pulling it up as much as it needs to?

  6. #6
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    That was my first idea. the limit screws are set correctly. The largest sprocket to the 2nd largest is a much bigger jump in size than the rest of the sprockets. Could the shifter just not be pulling it up as much as it needs to?
    Are the freewheel, derailer, and shifter all original stock parts? None of the Accushift freewheels that I've seen had a markedly larger jump between top cog and 2nd cog compared to the others... this page has a list of sprocket spacings for SunTour freewheels that you can compare yours to: http://sheldonbrown.com/k7.html#spacing

    Can you make it shift fully onto the big cog by putting the shifter into indexed mode? What if you simply tighten the adjusting barrel on the derailer so that the derailer pulls 1 mm inward on ALL the cogs, will that work?

    By the way, most SunTour freewheels shift pretty poorly compared to a modern ramped freewheel. I've successfully replaced SunTour Accushift freewheels with cheap 6-speed and 7-speed freewheels from Nashbar, and they work a lot better since they have nice shift ramps.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  7. #7
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I do not know if they are all original parts. I am not the original owner. I tried tightening the adjustment barrel, but it still had the same problem. It will always shift into gear, it just has a delay and grinding. I didnt know you could take the shifters out of indexed mode. how do you do that? I have a couple shimano 600 freewheels, I may just try to swap it out and see if it gets better.

  8. #8
    = cyclist's tan rat_factory's Avatar
    Join Date
    Jun 2005
    Location
    the big D in the big T
    My Bikes
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper
    Posts
    297
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    My Cannondale SM500 has(had) Suntour Accushift 7sp stuff. For years i've had alignment problems with it and shifting. The cables and pulleys had to be pristine and the hangar had to be in super-precise alignment to work. I'm not sure if it was an Ultra-7 freewheel or what (the year of my bike pre-dates microdrive), but finally the pawls failed and I got a new nickel-plated ramped Sunrace freewheel -- miles of improvement. Then a week or so later one of the X-Press shifter pods broke a lever, so I am upgrading everything to an old Shimano Alivio groupset i had lying around. I tried the shimano shifters with the Suntour X-1 rear derailleur and things did not line up like the OP was describing. Perhaps your bike had some upgrades and there were slight spacing differences that never were resolved. The Alivio groupset is roughly the same performance level as X-1 and so far things look promising. Try the Shimano Freewheel and i'm sure you will notice some improvement.
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper

    ich bin

  9. #9
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    I do not know if they are all original parts. I am not the original owner. I tried tightening the adjustment barrel, but it still had the same problem. It will always shift into gear, it just has a delay and grinding. I didnt know you could take the shifters out of indexed mode. how do you do that? I have a couple shimano 600 freewheels, I may just try to swap it out and see if it gets better.
    Yes, every Accushift downtube or bar-end shifter can be switched to friction mode. There is normally a knob or a metal tab on the side of the rear shifter that allows it to switch modes. You may have to remove the shifter from the frame temporarily in order to turn the knob, if it is very stiff.

    I wouldn't try swapping to a Shimano 600 freewheel right now, since it will only complicate things until you figure out what the problem is. A Shimano 7-speed freewheel, while very close in spacing to a SunTour 7-speed freewheel, is not *exactly* the same (see that link I sent earlier!!). I've had good luck getting a Shimano freewheel to work with a SunTour shifter and derailer, but at this point adding another variable to the problem won't help you...
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  10. #10
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rat_factory
    My Cannondale SM500 has(had) Suntour Accushift 7sp stuff. For years i've had alignment problems with it and shifting. The cables and pulleys had to be pristine and the hangar had to be in super-precise alignment to work. I'm not sure if it was an Ultra-7 freewheel or what (the year of my bike pre-dates microdrive), but finally the pawls failed and I got a new nickel-plated ramped Sunrace freewheel -- miles of improvement. Then a week or so later one of the X-Press shifter pods broke a lever, so I am upgrading everything to an old Shimano Alivio groupset i had lying around. I tried the shimano shifters with the Suntour X-1 rear derailleur and things did not line up like the OP was describing. Perhaps your bike had some upgrades and there were slight spacing differences that never were resolved. The Alivio groupset is roughly the same performance level as X-1 and so far things look promising. Try the Shimano Freewheel and i'm sure you will notice some improvement.
    Hmmm... I would think that Suntour X-1 is significantly better than Alivio (which is low-end OEM Shimano stuff).

    It's unfortunately the case that a Shimano shifter won't work with a SunTour derailer. Some people have improvised little tricks to make them work right!
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  11. #11
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Ok it is definately an alignment issue. I realized it shifts perfect when in the large chainring. any idea where to go from here?

  12. #12
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    Ok it is definately an alignment issue. I realized it shifts perfect when in the large chainring. any idea where to go from here?
    Weird... I can't actually think of a problem that would cause the LARGE cog to work with the LARGE chainring, but NOT the small chainring. Did you try friction mode?
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  13. #13
    Senior Member
    Join Date
    Aug 2005
    Posts
    370
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hmm, havent tried that yet. i'll have to try it

  14. #14
    = cyclist's tan rat_factory's Avatar
    Join Date
    Jun 2005
    Location
    the big D in the big T
    My Bikes
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper
    Posts
    297
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by moxfyre
    Hmmm... I would think that Suntour X-1 is significantly better than Alivio (which is low-end OEM Shimano stuff).

    It's unfortunately the case that a Shimano shifter won't work with a SunTour derailer. Some people have improvised little tricks to make them work right!
    Besides the cast alloy outer parallelogram face on the X-1, the Alivio rear mech weighs 5 grams less than than it. Alivio is available aftermarket and is right behind Deore. I'm not really sure, but I think X-1 was behind the crappy XCE, not XCExpert, mind you which is very nice. But then again it was a while back and I can't remember what happened 5 minutes ago. The front mech I'm using is acutally a Shimano FD-MC21, which is newer Alivio stuff and also weighs 60 grams less than the X-1 front derailleur.

    All I know is that new(>1987?) slant-derailleur Shimano shifts better than any of my Suntour stuff ever has. This bike is plagued by breaking and bending parts and spends more time in the repair stand than it does being ridden.

    Oh and what tricks do people use to correct different cable pull and pivot points?
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper

    ich bin

  15. #15
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    24,010
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    That was my first idea. the limit screws are set correctly. The largest sprocket to the 2nd largest is a much bigger jump in size than the rest of the sprockets. Could the shifter just not be pulling it up as much as it needs to?
    Hmmm. That sounds to me like you have a Shimano mega-range freewheel and Suntour shifters and derailleurs. That's not a combination that was made in heaven. Suntour freewheels had different spacing between the largest cogs.

  16. #16
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rat_factory
    Oh and what tricks do people use to correct different cable pull and pivot points?
    Some derailers have more than one point at which you can connect the cable... in some cases you can connect the cable at a slightly different distance from the pivot, and thereby alter the mechanical advantage of the derailer. Search the forums or r.b.t, and you'll probably find a hack or two!

    UPDATE: here's Sheldon Brown's trick for using a pre-1997 Dura-Ace shifter with a different Shimano derailer (Shimano's pre-1997 DA had a different actuation ratio than every other indexed derailer Shimano has ever made, bizarrely enough). http://sheldonbrown.com/dura-ace.html#alternate
    Last edited by moxfyre; 08-09-06 at 03:16 PM.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  17. #17
    = cyclist's tan rat_factory's Avatar
    Join Date
    Jun 2005
    Location
    the big D in the big T
    My Bikes
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper
    Posts
    297
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by moxfyre
    Some derailers have more than one point at which you can connect the cable... in some cases you can connect the cable at a slightly different distance from the pivot, and thereby alter the mechanical advantage of the derailer. Search the forums or r.b.t, and you'll probably find a hack or two!

    UPDATE: here's Sheldon Brown's trick for using a pre-1997 Dura-Ace shifter with a different Shimano derailer (Shimano's pre-1997 DA had a different actuation ratio than every other indexed derailer Shimano has ever made, bizarrely enough).
    Hmm, i knew i had seen that 'alternate cable routing' somewhere. I should have know it was Sheldon's site . I will definitely give it a try. Then again, if I go with my Alivio stuff I know it is compatable with itself.
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper

    ich bin

  18. #18
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rat_factory
    Hmm, i knew i had seen that 'alternate cable routing' somewhere. I should have know it was Sheldon's site . I will definitely give it a try. Then again, if I go with my Alivio stuff I know it is compatable with itself.
    That Sheldon, he's a crafty one

    The basic idea is, if your shifters pull the derailer TOO FAR, then shorten the lever arm on the derailer so it moves less. If you shifters pull the derailer NOT FAR ENOUGH, then lengthen the lever arm so it moves more.

    There won't always be a reasonable way to do this while securely clamping the cable, but it's always worth a shot.
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  19. #19
    = cyclist's tan rat_factory's Avatar
    Join Date
    Jun 2005
    Location
    the big D in the big T
    My Bikes
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper
    Posts
    297
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hey look what I found. I know its not for Suntour but Shimano and Campy can live together:
    http://www.sheldonbrown.com/harris/shiftmate.html
    '82 Miyata 310, '87 Scott Boulder, '87 Schwinn Le Tour, '91 Cannondale SM500, '96 Schwinn Clear Creek, '99 Schwinn MesaGS, '05 Rockhopper

    ich bin

  20. #20
    Neat - w/ ice on the side dalmore's Avatar
    Join Date
    Oct 2005
    Location
    Big Ring. Little Cog.
    My Bikes
    2005 Dahon Speed TR, 2006 Dahon Mu SL, 2000 GT XiZang, 1999ish Rock Lobster, 2007 Dean Animas CTI
    Posts
    1,200
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    I have a giant quasar with suntour accushift 1500 derailluers with indexed shifting. When shifting into and out of the largest rear sprocket, the chain doesnt seem to line up with the upper derailluer pulley. It still shifts, but it makes a rubbing/grinding noise. the rest of the gears shift perfectly. any ideas?
    Please bear with me - I'm trying to learn here. What makes everyone think this is a derailluer problem? Why not a stretched chain? Would a stretched chain show additional problems? Is that the reason for dismissing that possible cause?

    Sorry for not getting the picture.
    Current favorite bumper sticker: Wag more. Bark less.

    Change you can believe in - Bigfoot Nessie 08

  21. #21
    cyclist/gearhead/cycli... moxfyre's Avatar
    Join Date
    Oct 2004
    Location
    DC / Maryland suburbs
    My Bikes
    Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
    Posts
    4,172
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dalmore
    Please bear with me - I'm trying to learn here. What makes everyone think this is a derailluer problem? Why not a stretched chain? Would a stretched chain show additional problems? Is that the reason for dismissing that possible cause?

    Sorry for not getting the picture.
    It's a good question! But this is slightly different from the (typical) symptoms of a stretched chain.

    The OP says chain makes grinding noises after shifting, but he doesn't say anything about the chain "skipping" or "jumping". The hallmark symptom of a stretched/worn chain is that when you apply too much force to the pedals, the chain loses its grip on the cog and suddenly slides over the top of it. This doesn't cause problems in shifting the chain, it only causes problems when pedaling. Furthermore, chain wear *almost always* is more of a problem on the SMALLER cogs. This is for at least two reasons:
    (1) The smaller cogs have fewer teeth than the large cogs, so they get worn out faster because their are fewer teeth to spread out the wear
    (2) The smaller cogs have fewer teeth than the large cogs, so there are fewer teeth for the chain to grip

    Sheldon Brown has a fabulous article on chains, with a section explaining what exactly causes "chain and sprocket wear" (the two basically contribute to each other in a vicious cycle): http://www.sheldonbrown.com/chains.html#wear
    My bikes | Linux and Python stuff | Photo gallery

    Sheldon Brown, I miss you. Thanks for the advice, ideas, humor, and infectious enthusiasm for everything bikes...

  22. #22
    Neat - w/ ice on the side dalmore's Avatar
    Join Date
    Oct 2005
    Location
    Big Ring. Little Cog.
    My Bikes
    2005 Dahon Speed TR, 2006 Dahon Mu SL, 2000 GT XiZang, 1999ish Rock Lobster, 2007 Dean Animas CTI
    Posts
    1,200
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks that's helpful. I appreciate it.
    Current favorite bumper sticker: Wag more. Bark less.

    Change you can believe in - Bigfoot Nessie 08

  23. #23
    Extra Medium Member redtires's Avatar
    Join Date
    Jul 2006
    Location
    Louisville, Co
    My Bikes
    Fuji Roubaix 1.0 (Sampson Kalispell Ti GONE); VooDoo Wanga (Specialized Stumpy: GONE)
    Posts
    1,613
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by fadetoblack6902
    I have a Giant Quasar
    Personally, I think you should have just stayed with this and watched the direction the thread took.

Posting Permissions

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