Mish Mash cassette?

mr_eddy
mr_eddy Posts: 830
edited August 2019 in Workshop
Further to my last post about the new rear mech I am now getting closer to a nice 1x setup.

I have the RX400 clutch rear mech on & working well with my Tiagra 4700 shifters, I have the 40t front superstar Narrow/Wide ring up front so chain tension is sorted! Currently I have a choice of 2 cassettes namely a 12-32 and a 11-28. The 12-32 has a single 12t cog and then the rest is one-piece. The 11-28 is all single rings with spacers.

I prefer the closer ratio of the 11-28 but 40/28 lowest gear is a bit too high on gravel, Obviously the 11-32 is better but then I have these bigger jumps in the middle of the cassette. Any reason why I could not remove the 11 and 12t sprockets from the 11-28 and then use the 12t single sprocket from the 12-32 and add in a 36t sprocket from a old MTB setup - The 36t sprocket was running on XT 10 speed so by my reasoning that should work ?

The RX400 GRX rear mech supports up to 36t (says on the box).

Ultimately if this works I would have a weird looking cassette that is 12-36t but crucially the first 9 gears would be very closely spaced with a big 36t sprocket as a bail out gear. I would loose the 40/11 combo and have my lowest gear as 40/12 which at 90/100 rpm is still fast enough for flat tarmac.

Thoughts ? Will the jump from 28t to 36t be an issue ?

Comments

  • My Voodoo came with 8-speed 11-34, with a jump from 26T to 34T. It works, but the transition isn't graceful, the 26T to 30T jump on my road wheels is much smoother.
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    2020 Voodoo Marasa
    2017 Cube Attain GTC Pro Disc 2016
    2016 Voodoo Wazoo
  • The Rookie
    The Rookie Posts: 27,812
    mr_eddy wrote:
    Any reason why I could not remove the 11 and 12t sprockets from the 11-28 and then use the 12t single sprocket from the 12-32 and add in a 36t sprocket from a old MTB setup?
    Yup, the reason why you can't 'just' do it is that the smallest sprocket usually fits into a groove inside the second largest, you'll be trying to put it up against the third largest. You can make it fit by filing off the section on the smallest that fits it it though.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mugensi
    mugensi Posts: 559
    I bought a Cube Attain for use on the turbo trainer over winter but have also take it out on the road a few times. It has Claris 8spd set up. The cassette is an Acera 11/36 with a jump from 26T to 36T on the last two cogs. It has a compact 50/34 up front. The jump to 26 to 36 is huge but manageable because I'd only ever be using it on climbs and low cadence where the jump isn't as noticeable. The 36T is really a bail out gear and the 34/26T is more than enough for most of the climbs/hills I'd be on. Your 40/36 would give a higher ratio and should be more than enough for all but the steepest of climbs.
  • svetty
    svetty Posts: 1,904
    The only way to find out is to try it - if the shifting from the 28 to the 36 works OK you're sorted
    FFS! Harden up and grow a pair :D