Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Senior Member
    Join Date
    Dec 2005
    Location
    Atlanta
    My Bikes
    1982 Schwinn Super Sport S/P, 1984 Miyata 610, 1985 Panasonic LX 1000
    Posts
    576
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Sheldon Brown Suntour Cassette Sprocket Spacing Table

    At this link is a table of cassette sprocket spacing http://sheldonbrown.com/k7.html useful when mixing rear drivetrain indexing components from different manufacturers.

    For Suntour 7 speed, the spacing between sprockets is listed as

    3 x 2.8 mm(L)
    3 x 3.0 mm(H)

    Question: Does '3 x 2.8 mm(L)' refer to the three smallest diameter sprockets or the three largest diameter sprockets?

    My Suntour Accushift 7 speed shifters index well mated to a Shimano HG 7 speed cassette and Deore LX rear derailleur. Not perfectly, but very well. From the table at the above link, I noticed that if I use three eight speed spacers (width=3.0mm) in place of several seven speed spacers (width=3.15mm) I could hit the 4.8mm c-c sprocket width almost exactly--within 0.05mm.

    It wasn't easy, but I found some eight speed spacers locally. I had guessed that 3 x 2.8 mm(L) meant the three largest diameter sprockets. When that didn't improve things, I tried the 8 speed spacers between the smallest sprockets. Same, no progress from vg before the changes to pure perfection.

    Is it that the incremental improvement from vg to perfection given this set of components is just not possible?

  2. #2
    Senior Member masi61's Avatar
    Join Date
    Oct 2005
    Location
    SW Ohio
    My Bikes
    Puch Marco Polo, Saint Tropez, Masi Gran Criterium
    Posts
    989
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hi MRMW,

    Good to see you are still at it analyzing the SunTour indexing .
    I'm thinking that since there are 7 cogs, then it would make sense there would be 6 spaces between those cogs.
    If you've noticed, the cog spacing between your smaller cogs (H) is thicker. I really didn't have the dimension committed to memory but 3.0 sounds right.
    The larger cog spacers (L) are thinner 2.8mm.

    I think what you're trying to do is interesting. I have no direct experience with it but am eager to know how it turns out.
    If you have a woodworking disc sander you could lightly sand the 3.0 spacers. Be aware that one of the "spacers" is actually part of the outer locking cog so you might have to sand away some metal.
    Personally, I would probably stick to all SunTour and not try to mix and match like that.
    Too bad the parts are becoming so scarce.

  3. #3
    Gone, but not forgotten Sheldon Brown's Avatar
    Join Date
    Jul 2002
    Location
    Newtonville, Massachusetts
    My Bikes
    See: http://sheldonbrown.org/bicycles
    Posts
    2,301
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mrmw
    At this link is a table of cassette sprocket spacing http://sheldonbrown.com/k7.html useful when mixing rear drivetrain indexing components from different manufacturers.

    For Suntour 7 speed, the spacing between sprockets is listed as

    3 x 2.8 mm(L)
    3 x 3.0 mm(H)

    Question: Does '3 x 2.8 mm(L)' refer to the three smallest diameter sprockets or the three largest diameter sprockets?
    "L" stands for "Low," "H" stands for "High."

    The low gears are the larger sprockets

    Sheldon "Abbr." Brown
    [COLOR=blue][CENTER][b]Harris Cyclery, West Newton, Massachusetts[/b]
    Phone 617-244-9772, FAX 617-244-1041
    [URL= http://harriscyclery.com] http://harriscyclery.com[/URL]
    Hard-to-find parts shipped Worldwide
    [URL=http://captainbike.com]http://captainbike.com[/URL]
    Useful articles about bicycles and cycling
    [URL=http://sheldonbrown.com]http://sheldonbrown.com[/URL] [/CENTER] [/COLOR]

  4. #4
    Senior Member
    Join Date
    Feb 2005
    Posts
    541
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i'm glad someone else did this; now i can hijack it!

    sheldon reckoned my xc pro rear mech wouldn't work with a 7 speed shimano freewheel and a some old 105 shifters. now loooking at the chart it seemed as though the most important measurment was the centre to centre one, which for both the shimano and the suntour were the same. why is it you didn't think it would work? i only ask because my shifting has gotten a little crappy lately

  5. #5
    totally louche Bekologist's Avatar
    Join Date
    Oct 2004
    Location
    A land that time forgot
    My Bikes
    the ever shifting stable loaded with comfortable road bikes and city and winter bikes
    Posts
    18,012
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    you guys are soooo retro.....for an authentic and easy retro fix, go friction shifters (downtube or barcon) and you can shift 5,6,7,8,9 and 10 speed cassettes in back with no worries.....heck, you could make a three speed casssette for the back and have it shift smoothly if the jumps weren't too much.
    "Evidence, anecdote and methodology all support planning for roadway bike traffic."

  6. #6
    Senior Member Steev's Avatar
    Join Date
    Jul 2005
    Location
    Backwoods of Ontario
    Posts
    2,120
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I'm surprised you find that combination to work. I have tried the same setup (Suntour Accushifts, Shimano RD and cassette) and found it to not work to any degree.
    Did you do anything special in set-up to get it to work?
    There was a thread discussing this fairly recently.
    SunTour rd with DA bar-ends ?? Will it Work?

  7. #7
    Gone, but not forgotten Sheldon Brown's Avatar
    Join Date
    Jul 2002
    Location
    Newtonville, Massachusetts
    My Bikes
    See: http://sheldonbrown.org/bicycles
    Posts
    2,301
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dooley
    sheldon reckoned my xc pro rear mech wouldn't work with a 7 speed shimano freewheel and a some old 105 shifters. now loooking at the chart it seemed as though the most important measurment was the centre to centre one, which for both the shimano and the suntour were the same. why is it you didn't think it would work? i only ask because my shifting has gotten a little crappy lately
    Theoretically it should not work because Shimano systems use more cable travel per click than Sun Tour does (and less than Campagnolo)

    Generally, you need to use the same brand of shifter as the rear derailer to get the correct travel.

    One exception to this is using Sun Tour _6-speed_ shifters with a Shimano rear derailer and _7-speed_ cluster. In this instance the two mismatches cancel each other out.

    As to the difference in spacing between Sun Tour and Shimano 7-speed clusters, this is more of an issue when you're using a Sun Tour freewheel. If you're using a Shimano freewheel or cassette, the superior Hyperglide sprocket design generally makes up for the small mismatch of using a Sun Tour derailer and Sun Tour 7-speed shifter.

    The shifting quality of Sun Tour cassettes is very much inferior to Shimano Hyperglide, and slightly inferior to the older Shimano Uniglide.

    Sheldon "Interchangeabilitude" Brown
    Code:
    +-------------------------------------------+
    |         How to Write Like A ******:       |
    | http://guidenet.net/resources/******.html |
    +-------------------------------------------+
    [COLOR=blue][CENTER][b]Harris Cyclery, West Newton, Massachusetts[/b]
    Phone 617-244-9772, FAX 617-244-1041
    [URL= http://harriscyclery.com] http://harriscyclery.com[/URL]
    Hard-to-find parts shipped Worldwide
    [URL=http://captainbike.com]http://captainbike.com[/URL]
    Useful articles about bicycles and cycling
    [URL=http://sheldonbrown.com]http://sheldonbrown.com[/URL] [/CENTER] [/COLOR]

  8. #8
    Senior Member
    Join Date
    Dec 2005
    Location
    Atlanta
    My Bikes
    1982 Schwinn Super Sport S/P, 1984 Miyata 610, 1985 Panasonic LX 1000
    Posts
    576
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by masi61
    I'm thinking that since there are 7 cogs, then it would make sense there would be 6 spaces between those cogs.
    If you've noticed, the cog spacing between your smaller cogs (H) is thicker. I really didn't have the dimension committed to memory but 3.0 sounds right. The larger cog spacers (L) are thinner 2.8mm. I think what you're trying to do is interesting. I have no direct experience with it but am eager to know how it turns out.
    I was in a rush when putting up the OP. This morning clarity is upon me.

    1. The hypothesis in the original post, i.e. that 7 speed perfection might be possible with the correct spacers was flawed...because of the current mix of Suntour 7 speed shifter with Shimano RD. I had neglected the issue of shifter cable pull matching to RD movement in response to that cable pull.
    2. The corrected hypothesis: With Suntour 7 speed shifter, Suntour indexing RD and Shimano HG cassette, indexed perfection may well be attainable with a custom cassette with each sprocket spaced correctly center to center.

    --HG 7 speed sprockets are 1.85 mm wide.
    --HG 7 speed spacers are 3.15mm wide.
    --HG 8 speed spacers are 3.0mm wide.
    --HG 7 speed c-c width is 5.0 mm.
    --Suntour 7 speed c-c width is 3@4.8mm(low) and 3@5.0mm(high).

    Quote Originally Posted by Sheldon Brown
    Theoretically it should not work because Shimano systems use more cable travel per click than Sun Tour does (and less than Campagnolo)

    Generally, you need to use the same brand of shifter as the rear derailer to get the correct travel.
    That the Suntour 7 speed shifters, Deore RD and HG cassette index very well I take no credit for working out. I was able to google several past posts from reliable voices which reported that Suntour 7 speed shifters, Shimano 105 RD's and either Sachs or Shimano freewheels/cassettes indexed fine.

    Now that I am custom cassette enabled, and have managed to get my hands on several 3.0 mm 8 speed spacers (no easy task!), testing the hyothesis is on hold until I can locate a Suntour indexing RD capable of wrapping 35 teeth in order to handle the 48-38-28 front 13-28 HG rear. If anyone has one, please PM me.

    Now that I've thought it through, I'm pretty damn optimistic.
    Last edited by mrmw; 12-31-06 at 12:48 PM.

  9. #9
    Senior Member
    Join Date
    Dec 2005
    Location
    Atlanta
    My Bikes
    1982 Schwinn Super Sport S/P, 1984 Miyata 610, 1985 Panasonic LX 1000
    Posts
    576
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    nice link sheds a great deal more light on the subject

    http://mitglied.lycos.de/fanfan/radzeug/suntour_en.html

  10. #10
    Senior Member
    Join Date
    Feb 2005
    Posts
    541
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ok, if i get some suntour shifters - say superbe pro 7spd indexed - they would work perfectly with my xc pro rear mech and shimano 7 speed freewheel?

  11. #11
    Senior Member masi61's Avatar
    Join Date
    Oct 2005
    Location
    SW Ohio
    My Bikes
    Puch Marco Polo, Saint Tropez, Masi Gran Criterium
    Posts
    989
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dooley
    ok, if i get some suntour shifters - say superbe pro 7spd indexed - they would work perfectly with my xc pro rear mech and shimano 7 speed freewheel?
    Negative.
    As people have been saying, the Suntour Winner freewheel doesn't have the same high to low spacing like the Shimano does. For a shot at perfection with these shifters and rear mech, go with the Accushift compatible Suntour freewheel.

Posting Permissions

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