Advertise on Bikeforums.net



User Tag List

Results 1 to 15 of 15
  1. #1
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)

    Making a custom cassette - few questions

    Ok, I'm making a custom cassette.. are there any guidelines or theories I should follow?

    I'm mostly making a custom cassette to build a 7 speed "straight block" out of various donor MTB cassettes to get closer gearing for the road

    A few questions:

    * Is there a maximum tooth size difference I should avoid? Like going from say, 18t to 28t is probably too much, but is there a guideline to follow?

    * If I have something like 13-26 with a 53/39 up front, I should be able to run a short cage road RD, right? (specifically, Tricolor RD-7401)

    * Does it matter if the spacers are different sizes (assuming friction shifting)?



    as a general aside, I don't understand why more bikes don't come with straight blocks.. it seems like the gearing leaves a lot of overlap
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  2. #2
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    405
    Mentioned
    30 Post(s)
    Tagged
    0 Thread(s)
    with older types of cassettes they come apart..
    used 3 wee bolts to make assembly line simpler..

    nowadays note the 'megarange'.. 24 and 34t are next to each other..


    an IGH eliminates overlapping ratios.

  3. #3
    7-speed doomsday prepper ThermionicScott's Avatar
    Join Date
    Aug 2011
    Location
    CID
    My Bikes
    1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX
    Posts
    8,257
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by frantik View Post
    Ok, I'm making a custom cassette.. are there any guidelines or theories I should follow?

    I'm mostly making a custom cassette to build a 7 speed "straight block" out of various donor MTB cassettes to get closer gearing for the road

    A few questions:

    * Is there a maximum tooth size difference I should avoid? Like going from say, 18t to 28t is probably too much, but is there a guideline to follow?

    * If I have something like 13-26 with a 53/39 up front, I should be able to run a short cage road RD, right? (specifically, Tricolor RD-7401)

    * Does it matter if the spacers are different sizes (assuming friction shifting)?



    as a general aside, I don't understand why more bikes don't come with straight blocks.. it seems like the gearing leaves a lot of overlap
    Shimano still makes 13-14-15-17-19-21-24 and 13-15-17-19-21-23-26 cassettes. But you can't have a 13-26 straight block.

    But yeah, you should be able to use the short cage, as you're only asking for 14+13=27 tooth capacity. And you're on the right track -- the spacers don't all have to be the same thickness for friction shifting, but you still need to make the cassette thickness correct in the end.
    Quote Originally Posted by chandltp View Post
    There's no such thing as too far.. just lack of time
    RUSA #7498

  4. #4
    Senior Member
    Join Date
    Jan 2012
    Location
    Spokane, WA
    My Bikes
    Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520
    Posts
    2,227
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    I would use same thickness spacers just for ease of assembly and consistency. What I do when I make a custom cassette is that I try to get the thickness of the gear and the spacer the same for all of the gears. For example, I will try to go for 4.8mm for gear/cog for 8 speed cassettes and so on. Even though you are friction shifting, it would be slightly annoying when shifting to have to move the lever a different amount for different gears. I just like consistency and knowing that if I move the lever a certain amount, it will shift.

    PLus then you can use that same cassette with an indexed shifting bike.

  5. #5
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by ThermionicScott View Post
    you can't have a 13-26 straight block.
    straight...er block

    i could buy one but that's not as much fun as making my own out of cassettes i have here. i will also be able to ensure i have it geared for my optimal range
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  6. #6
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    ok, i made a custom cassette, but looking at it, it doesn't seem like the hyperglide ramps are lined up correctly. the width of the teeth are also way different which makes me wonder just how well this cassette would shift

    i swapped a hyperglide hub onto this wheel to improve shifting so I don't want to make it worse with a crazy cassette lol

    13-14-15-16-17-18-26

    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  7. #7
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    I had 3 cassettes I was using, and was trying to mix/match cogs from an 8speed and a 7speed cassette. I noticed the two 8speed cassettes were almost identical, so I guess the HG pattern changed at some point.

    I just put the 7 speed back together and will just use it as-is, or buy a new cassette if i'm not happy
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  8. #8
    7-speed doomsday prepper ThermionicScott's Avatar
    Join Date
    Aug 2011
    Location
    CID
    My Bikes
    1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX
    Posts
    8,257
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    That's interesting, a straight block plus bailout. Don't worry about the HG gates not lining up, it won't shift any worse than a pre-HG cassette.

    As Sheldon noted, Shimano actually made several versions of most of the cogs concurrently, because the gates had to be in different spots depending on the cogs surrounding a particular one.
    Quote Originally Posted by chandltp View Post
    There's no such thing as too far.. just lack of time
    RUSA #7498

  9. #9
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by ThermionicScott View Post
    That's interesting, a straight block plus bailout. Don't worry about the HG gates not lining up, it won't shift any worse than a pre-HG cassette.
    This hub used to have a uniglide freehub body but I swapped it to hyperglide to get the advantage of improved shifting, so I would be moving backwards lol

    the setup for 52/39 x 13-14-15-16-17-18-26 would be pretty good and given me 11 unique gears, vs the 9 i end up with on the stock cassette. I don't really get the point of having a front deraileur and extra chainrings to add only a tiny bit more range

    maybe one day when I'm bored I'll try out the straight block with the mismatched gears and see how it shifts
    Last edited by frantik; 10-31-12 at 12:41 AM.
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  10. #10
    Bicycle Repair Man !!! Sixty Fiver's Avatar
    Join Date
    Sep 2007
    Location
    YEG
    My Bikes
    See my sig...
    Posts
    26,067
    Mentioned
    17 Post(s)
    Tagged
    2 Thread(s)
    Being able to make your own custom cassettes can be very enjoyable... theoretically speaking Shimano has single cassettes but no-one seems to be able to get them.

    Back in the good old days, getting a custom freewheel or cassette was something every good shop was able to do and companies offered cog boards and cassette and freewheel bodies that could be built up for custom gearing or allow for cog replacements.

    I have boards for just about every freewheel ever made and a Shimano board with UG cogs so have built up a good number of them from salvaged bodies and freehubs.

  11. #11
    Senior Member
    Join Date
    Feb 2009
    Posts
    4,008
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by frantik View Post
    This hub used to have a uniglide freehub body but I swapped it to hyperglide to get the advantage of improved shifting, so I would be moving backwards lol

    the setup for 52/39 x 13-14-15-16-17-18-26 would be pretty good and given me 11 unique gears, vs the 9 i end up with on the stock cassette. I don't really get the point of having a front deraileur and extra chainrings to add only a tiny bit more range

    maybe one day when I'm bored I'll try out the straight block with the mismatched gears and see how it shifts
    AS long as you are using friction shifting the ramps won't matter. In the days before indexing the cogs were cut square.

  12. #12
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,828
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    I've tried integrating MTB cogs into a 7spd road cassette to make a 13-20, and IME the shifting where the HG doesn't match is worse than Uniglide; the cogs need to be designed to work together IMO.

    As far as I'm concerned, HG and a straight block isn't going to happen until I can buy it, unfortunately

  13. #13
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    I've tried integrating MTB cogs into a 7spd road cassette to make a 13-20, and IME the shifting where the HG doesn't match is worse than Uniglide; the cogs need to be designed to work together IMO.
    yeah i think the fact the teeth are aligned all funky would also make shifting worse.

    Truthfully I'm not 100% satisfied with the shifting with the stock HG cassette.. I still get some slippage especially when going from 17 to 21t. This HG cassette and chain are from 1989, the first year HG came out so maybe the technology continued to improve. My diamondback with 1x7 drivetrain shifts buttery smooth and its got a super cheap thumb shifter and Shimano Altus RD! It does have a narrower chain though; I'm wondering if a newer 8speed chain would improve shifting.

    Another option I'm thinking of is using one of the 8 speed cassettes and dropping the biggest cog. 39 x 11-12-14-16-18-21-(24 or 26) gives me a great range of useable gears. i wouldn't even need the 52t chainring. looks like i may end up with another 1x7 drivetrain
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  14. #14
    Chainstay Brake Mafia
    Join Date
    Mar 2011
    Location
    California
    Posts
    5,853
    Mentioned
    14 Post(s)
    Tagged
    0 Thread(s)
    well i guess i won't be doing the 11-26 cassette on this freehub body since the 11t requires a hyperglide-C (compact) body and the 7 speed freehub body i'm using is the old style. it's even got threading on the outside for compatibility with uniglide

    do you have to start with the gear that has the "teeth" for the lockring? or can you use a larger gear? if it's best to use the small cog with the teeth for the lockring, the lowest cog i can start with is 13 i guess. i could also start with 14 if i used a uniglide lockring cog i have
    Last edited by frantik; 11-01-12 at 06:27 PM.
    1986 Diamondback Apex ~ 1988 Diamondback Ascent EX ~ 1989 Jamis Dakar ~ 1989 Specialized Stumpjumper Comp
    1993 Trek 8300 Composite ~ 1993 Diamondback Axis Team Titanium ~ 1995 Diamondback Apex

    Join the Chainstay Brake Mafia!

  15. #15
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,828
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    There are at least a couple of quite good reasons why you don't want a small cog smaller than 13t anyway.

Posting Permissions

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