Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6
  1. #1
    Senior Member
    Join Date
    Aug 2006
    Location
    NW AR & Central LA
    Posts
    2,543
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Cogs from Two Cassettes?

    I posted this over in the mechanics area and got one reply which was helpful. I would like opinions/advice from my brothers and sisters here at 50+

    My road bike has an 8-speed Sora triple drive train. I had the original equipment 12-24 cassette changed to a SRAM 11-28 for a century with a good bit of climbing, allegedly 6,300'+. The original cassette is in good shape. The original equipment cogs are: 12, 13, 14, 15, 16, 18, 21, 24. The new cogs are: 11, 12, 14, 16, 18, 21, 24, 28.

    I've been training with the new cassette, and it appears that, for me, the 11-tooth cog is a bit too much. One the other end, the 28-tooth cog is great for hills > or = 10%

    Is there any mechanical reason that I could not have the 11-tooth cog removed from the new cassette and replace it, in the proper size order of course, with either the 13-tooth or the 15-tooth cog from the old cassette?

    Thanks for any assistance.

  2. #2
    Senior Member guybierhaus's Avatar
    Join Date
    Sep 2005
    Location
    Oley, PA
    My Bikes
    Flat bar road bike, trail bike and MTB
    Posts
    878
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Sounds like it would work as long as the 12 and 13 cog is a free by itself cog. It's a simple enough thing to do if you have the cassette lock ring tool. +1 on the 28 cog. I changed to a 11 x 32 cassette for hill climbing; although also had to change dérailleur.
    BierHaus Bertolette Road Bike, built 2007
    BierHaus SRT Trail Bike, built 2010
    Fuji Mt. Pro - 2007

  3. #3
    tsl
    tsl is offline
    Plays in traffic tsl's Avatar
    Join Date
    May 2006
    Location
    Rochester, NY
    My Bikes
    '96 Litespeed Classic, '06 Trek Portland, '13 Ribble Winter/Audax
    Posts
    6,257
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    On all four of my 8-speed cassettes, only the two smallest gears are separate. The other six are in a cluster. If it's the same with yours, which is likely, you can swap the 11 & 12 for the 12 & 13. To get rid of the 11, you'll have to switch both of the two smallest gears for reasons that will become apparent as soon as you remove the cassette.

    It sounds like you're going to hire this done. For about $11 at Nashbar, you can buy the tools required--a cassette lockring tool and a chainwhip. It's actually easier (and faster) than fixing a flat. Give it a try yourself.

    Once you do, you may end up like I did, owning multiple cassettes, each appropriate to specific riding conditions. On my Sora road bike, I run a 13-23 around town and a 12-28 in the hills. On my Alivio hybrid, I run a 12-23 on the canal paths, and an 11-32 when fireroading.
    My two favorite things in life are libraries and bicycles. They both move people forward without wasting anything.
    The perfect day: Riding a bike to the library.—Peter Golkin


    Lucky for me, I work at a library and bike to work.

  4. #4
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,044
    Mentioned
    1 Post(s)
    Tagged
    1 Thread(s)
    You may on certain brands of cassettes also need to change the lockring as it can be "tooth specific".

    If you are of a mind to, you can take the "carrier" apart and mix and match the lower gears as well. On many carriers, the lower cluster is held together by long screws or bolts or even rivits that can be carefully drilled out. Keep everything in some sembalance of order while you sort through it. The spacers between the gears are "speed" specific, ie 8 speed spacers are one thickness, 9 speed another etc.

    There will be families of gears that you will get better results with (example...Shimano HG50) because the shifting details (ramps and climbing areas) will line up with adjacent gears but experimentation may produce some interesting results.

    The gears do not need to be bolted back together in the cluster as they will retain their positions via the splines.

    There are some good articles on this in the Sheldon Brown series along with his nifty gearing calculator.

  5. #5
    Senior Member freeranger's Avatar
    Join Date
    Jun 2005
    Location
    Kentucky
    My Bikes
    06 Lemond Reno, 98 GT Timberline mtn.bike
    Posts
    1,013
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If you do swap and go with the 12T, you'll probably want to use the lockring that came with the 12. If memory serves me (remember this is a 50+ forum!), there is something different about an 11 or 12 tooth cog that requires a different lockring for each (something about an 11 is dif). At least when I changed over my mtn. bike cassette, I read something about the 11T cog requiring a dif. lockring.

  6. #6
    Roadkill byte_speed's Avatar
    Join Date
    Sep 2004
    Location
    East Tennessee
    My Bikes
    2002 Lightspeed Classic; 2010 Pedalforce RS
    Posts
    842
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by maddmaxx View Post
    ..The spacers between the gears are "speed" specific, ie 8 speed spacers are one thickness, 9 speed another etc...
    Thanks Madd, I think you just fixed a shifting problem I've been having.
    I cleaned & regreased the bearings, etc. on my rear wheel and in the
    process replaced a cracked plastic spacer. I bet I accidentally put an
    8 speed spacer in my 9 speed cassette. I was wondering why the
    rear derailler suddenly wouldn't adjust.

Posting Permissions

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