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Dropper post might hit 2nd bottle mounts

Hi, first post and a new bike to boot. I’m wanting to buy the X- Brand dropper post for my 2021 Trek X-Caliber 8, I’ve just measured from the seat rails to the top water bottle mount (which also sits inside the tube) and its around 38cm, the total length of the dropper post is 41cm for the 125mm version. I am I looking at this wrong or won’t it fit to my desired height?


  • reaperactualreaperactual Posts: 1,091
    edited August 2020
    Drop you current seatpost down as far as it can go and measure your maximum insertion depth, remove the top bottle mount bolt and you may be able to drop the post in further if needed?

    Measure your current seatpost in normal position from the middle of the saddle rail clamp to the top of the seat post for stack height.

    Compare your measurements with the max insertion depth and stack height of the dropper post.

    Be aware the max insertion measurement may include the actuator at the bottom if internally routed which may be a factor with overall length so it could possibly still fit.

    You may find that you won't need to fully insert the dropper for the saddle to be at the correct height for you when in the fully raised position. If the 125mm won't fit you may have to settle for a 100mm dropper.

    Chain Reaction Cycles list all the measurements for the Brand X if you scroll through the images on the listing.
  • Just been and measured I use a 20cm Stack height and I have 19cm clearance in the tube from top to bottom,  guess this limits me to the 120mm Oneup dropper?
  • reaperactualreaperactual Posts: 1,091
    Yeah, the only other Brand X is 100mm but if the Oneup fits then the point is get as big a travel dropper you can fit within the space you have available.

    So removing the bolts didn't work or something inside still restricted the max insertion depth?

  • Yeah the bolt have an inner housing for their threads looks like they'd have to be drilled out
  • reaperactualreaperactual Posts: 1,091
    The Oneup is the perfect solution. Looks like a solid dropper too, gets great reviews and worth a few extra quid to get a good amount of travel with your limited space. 😎👍
  • Thanks for your help, looks like it doesn't come with a leaver or cable. The search will now continue for these
  • reaperactualreaperactual Posts: 1,091
    Any generic shift inner and outer cable will work. Matching Oneup remove lever is in stock for £42 at Leisure Lake Bikes:-

    Nice but a bit pricey although you could use any cable operated lever as long as the shift cable end threads through it and anchors with a grub screw, (bottom up routing)

  • Does that £42 one come with a mounting bracket or is it just the lever
  • reaperactualreaperactual Posts: 1,091
    edited August 2020
    The only one in stock at the moment when you choose an option is the 22.2 bar clamp version which is the one you will need if you have the original Shimano brakes still on your Trek?

    The unit itself is convertible to the I-spec and Sram standards so in the future you should be able to buy conversion kits if you decide to upgrade brakes.

    The Oneup lever sold in the U.S. comes supplied with the inner and outer cable too. Although it doesn't state if cable is supplied on Leisure Lakes maybe worth emailing or waiting to see if there is one in the box before you buy shift cables.
  • Excellent it's just come back in stock so will go for this one. Thanks again for your help
  • reaperactualreaperactual Posts: 1,091
    No worries Pal. 👍
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