Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6
  1. #1
    Senior Member
    Join Date
    Sep 2008
    Location
    Baltimore, MD
    Posts
    155
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    8, 9, 10 speed mix-and-match

    So my current set up is a melting pot of different road components at different levels:

    Sora 8 speed Shifters (Triple)
    Tiagra Front Derailleur
    Ultegra Rear Derailleur
    7 speed cassette 12 - 28t with 4.0mm ghost spacer
    8 speed chain
    Truvativ Rouleur 10 speed Crankset 53/39t 172.5mm

    and EVERYTHING works PERFECTLY Fine!

    Except there is a little chain rub when the front is on 39t and rear on 11t (no one should get that combination anyway).

    Anyway I have spotted a great deal on some 10 speed Ultegra STI. I would like to ask you guys before getting in to any unnecessarily expensive experiment:

    Is it possible to make the 10 speed shifters to work on a 7 speed cassette with 3 ghost spaces if I:
    1. Pull out all spacers from a 10 speed cassette (3.95mm).
    2. substitute my 7 speed spacers (5.0mm) with 3.95mm spacers.
    3. Take up the extra spaces with aftermarket single speed spacers (they are cheap!)
    4. Adjust the rear derailleur low limit screw.

    I know this sound pretty extreme, but I already get a 7 speed cassette to work with a 8 speed shifter with 1 ghost space, why not 3 'ghost' gears? Theoretically the chainline will be straighter than before!

    The limiting factors are:
    1. Can the derailleur be set to a low limit that is THAT far (toward the HIGH) away from the wheel.
    2. Are the thickness of 10 speed cogs the same as 8 speed cogs?

    I just wanna know what you guys thing coz I dont wanna throw away my 7 speed cassette since it is still relatively new (less than 2500 miles)

  2. #2
    headtube. zzyzx_xyzzy's Avatar
    Join Date
    Sep 2008
    Posts
    804
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    http://www.sheldonbrown.com/k7.html#spacing

    Problem is the cogs on a 10sp cassette are thinner as well as the spacers, so subbing spacers from a 10sp cassette into a 7sp cassette will not get you 10sp spacing.

    Cog spacing on 7sp and 8sp are nearly the same, so that's why that works for you.

  3. #3
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    6,498
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    My 8 speed actually uses 7 speed cogs with thinned spacers.
    I had two 7 speed cassettes and picked up an 8/9 speed FH body for too cheap not to, so I thought why not?

    Basically, you just have to have the center to center spacing of the cogs correct for the speed of the shifters and a chain narrow enough to fit between them without rubbing.

  4. #4
    WNG
    WNG is online now
    Spin Forest! Spin! WNG's Avatar
    Join Date
    Sep 2007
    Location
    Arrid Zone-a
    My Bikes
    I used to have many.
    Posts
    5,420
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Everything all went wrong when companies decided to go to 9/10/11 speeds. Thinned cogs, chains, and sometimes chainrings, makes interchangeability with 8 and older problematic. No more simple compatible swaps with other bikes and equipment in your inventory.
    IMHO, for the average recreation cyclist, going to 9+ is simply flushing money down the drain.
    But we live in a consumerism society where having the latest and greatest boosts one's self-esteem.
    “You meet the nicest people on two wheels!"
    I'd rather add more life to my years, than years to my life.

  5. #5
    Senior Member parcoju's Avatar
    Join Date
    Apr 2008
    Posts
    80
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    As long as you properly choose where you want those "ghost gears," thus adjusting for good chainline, my instinct says that it should work. However, my instinct has proven me wrong before....

  6. #6
    STFD mcgreivey's Avatar
    Join Date
    Jul 2008
    Location
    North Bergen, NJ
    My Bikes
    '80 Windsor Carrera Sport, '02 Specialized Sirrus A1, '10 Giant Escape 2
    Posts
    778
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah, give it a try. Fiddle with it.

    Don't throw away the old cassette. Put it back on if the experiment doesn't work out.

Posting Permissions

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