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Thread: 2020 Cutthroat

  1. #1
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    2020 Cutthroat

    60cm frame with a GRX 600 build:

    2020 Cutthroat-_dsc4852.jpg

    2020 Cutthroat-_dsc4853.jpg

    2020 Cutthroat-_dsc4859.jpg

    2020 Cutthroat-_dsc4860.jpg

    2020 Cutthroat-_dsc4866.jpg

    2020 Cutthroat-_dsc4875.jpg

    2020 Cutthroat-_dsc4876.jpg

    2020 Cutthroat-_dsc4877.jpg

    2020 Cutthroat-_dsc4880.jpg

    2020 Cutthroat-_dsc4885.jpg

    2020 Cutthroat-_dsc4881.jpg

    With the low/swale part of the saddle at 83.5 cm from the center of cranks:

    2020 Cutthroat-_dsc4890.jpg

    The floor is level and the ribbon is level. 40cm of spacers under the stem. The stem looks like it is probably a +-6 degree stem. The top of the bars is roughly 1.5cm below the ribbon, which is lower than I had hoped (and the ribbon is about 1 cm above the top of the thick cushy bar tape).

    The drivetrain consists of a 46-30 crank and a 11-34T cassette, but the low gear is not nearly low enough. On steep climbs, it's a slow grind for me while unloaded, which is okay, but with a full bike packing load, I would trade 3 of the top end gears for 3 lower end gears. I think a 2x should provide all the low gears you need--otherwise what's the point? Does anyone know what setup would provide the lowest gear?

  2. #2
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    Unfortunately the dropped chainstay means you probably couldn't fit a smaller inner ring, not that there is one for GRX yet. If you want a lower gear there are a few options:

    1. Fit an 11-40 MTB cassette. This should probably work with the stock rear derailleur, though you may well need a longer chain, and perhaps a longer B-tension screw. Set the chain length so it's enough to go around 46x40 without damage; if there's no tension in 30x11/13, don't worry about it, as you shouldn't be using those gears anyway. This should NOT require the use of a Roadlink or similar. (Last year I had 42x27 + 11-40, and this worked fine with an Ultegra RX RD.)

    2. If 30x40 still isn't low enough you will need a bigger cassette. Shimano make 11-42, which should be okay with a MTB RD + Wolftooth Tanpan, or Wolftooth make a 45T cog to go on an 11-40 cassette. Wolftooth say 45T will work with 2x, within limits. Both Shimano and Sunrace sell 11-46 cassettes, with quite different intermediate ratios. Some people have allegedly used these with 2x, but I've never seen a pic. Again, doing this will need a longer chain.

    3. Give up and switch to 1x. IIRC, Salsa say you can fit down to a 36T ring. With a 50T rear cog this gives a similar low gear to 30x42, so doesn't really help.

    4. HTFU! ;-)

    When the new Cutthroat was announced I ended up buying a slightly used 2019 frameset so I could have lower gears, and will be running 36x24 rings with an 11-40 cassette...

    Best of luck.

  3. #3
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    Hi satanas,

    Thanks for the response!

    When the new Cutthroat was announced I ended up buying a slightly used 2019 frameset so I could have lower gears, and will be running 36x24 rings with an 11-40 cassette...
    I was looking at a used 2017 cutthroat (light blue/silver), but it was only $350 cheaper than the 2020 Cutthroat, so I opted for the 2020 Cutthroat. I just looked at the Salsa specs, and the 2017 Cutthroat seems to have the same bottom bracket, PressFit 41mm x 92mm, so how come the earlier Cutthroats are able to accommodate lower gears?

    36x24 rings with an 11-40 cassette
    What components are you using? I need that 24x40 low gear!

    I don't even understand the GRX group. According to Salsa, the GRX cranks won't work on the 2020 Cutthroat's 92mm BB--they're too short. I've pored over the Shimano GRX docs, and I've looked at lots of websites that are selling the GRX cranks, but there doesn't seem to be any spec stated anywhere for the spindle length/max bottom bracket width. Did Shimano invent a new standard, i.e. BB86? According to what I've read 73mm BB's and 92mm BB's (with press fit bearings) put the ends of the bearings in exactly the same place.

    I can return my 2020 Cutthroat, and I'm thinking about doing just that. Oh yeah, after one month of use, I sheared off the 30T chainring while riding a steep, dirt trail while in the lowest 34T cog. I thought I snapped my chain! I had to fiddle around and affix the small chainring back onto the big ring with three of the damaged chainring bolts that I found lying on the trail, so that the little chainring wouldn't saw my frame's bottom bracket in half while limping home in the big chainring.
    Last edited by happyriding; 04-19-2020 at 08:57 PM.

  4. #4
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    Whoops - I forgot Salsa aren't using the GRX cranks, which as you say won't fit; no road-ish cranks will since the BB shell is too wide.

    The factor limiting gearing with the new frames isn't so much the BB shell but rather the dropped ("bent") RH chainstay (and also the FD mount, see below). If you use a chainwheel that's too small the chain will hit the underside of the stay, virtually impossible with normal straight stays, as on v1.

    FWIW, I have M9000 XTR cranks (Q=158mm), with the inner ring swapped from 26T to 24T. The arms should clear the chainstays by ~3mm (according to Salsa support quite a while back) but with the current lockdowns I haven't been able to switch the $#@! pressfit BB and check. FWIW, SRAM XX or XX1 Q156 GXP cranks should clear by a bit more, and Salsa were okay with using those; this is with the v1 frame - NOT v2 on which smaller double rings won't work. I also wanted to minimise Q, another reason for me to avoid v2. Another problem for me with the v2 frame is the FD mount, which forces the use of a road braze-on FD, with quoted minimum ring sizes of 46x30T, also limited by the dropped stay. If you want a low gear your only options are to use a huge cassette with 2x, or an even huger cassette with 1x...

    Since I'm an old spinner rather than a young racer, 30x34 was never going to be a low enough gear for me, plus I wanted to keep the Q down and my knees happy; YMMV.

    The new frame looks nice, and IMO the geometry is better, but you have to be able to live with the gearing that will fit on it, and I knew I could not.

  5. #5
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    You could run an MTB rear derailleur and Cassette with your GRX Shifters and Crankset.
    Here's to sweat in your eye.

  6. #6
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    Quote Originally Posted by mudncrud View Post
    You could run an MTB rear derailleur and Cassette with your GRX Shifters and Crankset.
    Can you provide a link where I can read up on that possibility?

    Leanard Zinn doesn't seem to think it's possible:

    Question:

    with fact that the GRX mechanical levers will shift on an XT cassette, doesnít that mean the cable pull is will work with an XT rear derailleur. And, if thatís correct, would it be possible to run a GRX shifter with and XT-SGS rear derailleur with an 11-40t cassette and a 48/31t crankset and still be within the 47t capacity of the rear derailleur.
    Answer:

    No, the fact that the GRX shifter and derailleur shift on an XT cassette means nothing about the cable pull of the derailleur other than that it is matched to the lever so that it will shift on cassettes with that same spacing between the cogs.

    For instance, if you were to use a Road Link derailleur-hanger extender, you could get some Shimano road derailleurs (with a road shifter) to work with an XT cassette, even though if you were to instead use an XT derailleur with that road shifter, it would not work on that cassette.
    As for Di2, the GRX right shifter will work with the XT Di2 rear derailleur only if there is either no front derailleur, or an MTB Di2 front derailleurónot a GRX or road Di2 front derailleur.
    https://www.velonews.com/gear/techni...arbon-braking/

  7. #7
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    As far as I can tell, the Salsa front derailleur hanger puts the Shimano GRX 810 front derailleur too far outboard. As a result, I have to put a bunch of slack in the cable before clamping it down in order to prevent the derailleur from over shifting and dropping the chain to the outside of the big chainring. In order to get the front derailleur positioned inboard as far as possible, I have to set both the high and low adjustment screws at the limit of their range, which means I cannot use them to fine tune the adjustment. Also, all the slack in the cable makes the low trim position inoperable: the first click of the left shifter takes up most of the slack in the cable (rather than trimming the front derailleur), and the second click takes up the remaining slack and upshifts to the big chainring.

    I emailed Salsa about the problem, and they are looking into it. I think the Salsa derailleur hanger needs to position the front derailleur 3-4mm further inboard.

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