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  1. #1
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    Endorphin - length of your steerer tubes?

    hey everyone,
    just bought a M knolly frame and am looking at some forks. it's on the way to me but i'm seeing some pretty decent priced forks coming off new bikes that are for sale online...so the tubes have already been cut

    going to take a week for the frame to get to me, so would u guys give me an idea of how long a steerer tube is safe to buy so i don't get one too short? or the length of the head tube?

    thanks

  2. #2
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    Hi sinfony78!

    Head Tube Length (and other geometry information) information can be found here: Knolly Bikes | Endorphin. For a medium frame, the head tube length is 118mm (4.6"). Assuming you're using a 1.5 Tapered fork - which will require in external lower headset cup, but probably use a zero stack upper cup - you'll need to add around 16-20mm (0.6 - 0.8") for the headset stack height. Then, it's just the additional steerer tube length required for headset spacers and the stem. If possible, I would allow for at least 30mm of headset spacers, which should be more than enough for most riders given "typical" stems and bars being used on these frames (i.e. 70mm stem and bar in the 700 - 750mm width range).

    Cheers!
    Noel Buckley
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    www.knollybikes.com

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  3. #3
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    thanks...the fork i'm looking at has a 197mm cut tube, about 10mm shorter than what you recommend, so that would only allow for 20mm of spacers (thomson stem is 40mm height)

    for other endorphin owners out there, how much room do you have in spacers? wondering if i can get away with 20...the fork is a 2013 fox coming off a trek remedy, very reasonably priced

  4. #4
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    this is on of the changes I made to my medium Endo. My Chilly has a 5 mm spacer and i started the Endo the same but have since gone to a 20 mm spacer. I am using a 150 mm RS REV fork with zero stack upper and lower cups with a thomson stem and it works perfect for ME. so if I could get a great deal on a 197 mm fork, i'd be comfortable. Hope that helps

  5. #5
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    Quote Originally Posted by knollybikes.com View Post
    Hi sinfony78!

    Head Tube Length (and other geometry information) information can be found here: Knolly Bikes | Endorphin. For a medium frame, the head tube length is 118mm (4.6"). Assuming you're using a 1.5 Tapered fork - which will require in external lower headset cup, but probably use a zero stack upper cup - you'll need to add around 16-20mm (0.6 - 0.8") for the headset stack height. Then, it's just the additional steerer tube length required for headset spacers and the stem. If possible, I would allow for at least 30mm of headset spacers, which should be more than enough for most riders given "typical" stems and bars being used on these frames (i.e. 70mm stem and bar in the 700 - 750mm width range).

    Cheers!
    Wait - so if I get a fork with a tapered steer tube for my 2013 Endo, it will raise the front end 1/2" or so? I am currently running a Marz 55 microswitch air with 1 1/8" straight steerer and ZS headset top and bottom. I love the head angle, seat angle and BB height with this configuration. I was thinking of getting an X-Fusion Slant (160mm) with the same axle to crown length, so back to my original question - if I order it with a tapered steerer, will I end up lifting the front end about 1/2" due to the required external lower headset cups? If so, won't that change the HA to 66*, slacken the eff. seat angle and raise the BB?

  6. #6
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    Quote Originally Posted by sinfony78 View Post
    thanks...the fork i'm looking at has a 197mm cut tube, about 10mm shorter than what you recommend, so that would only allow for 20mm of spacers (thomson stem is 40mm height)

    for other endorphin owners out there, how much room do you have in spacers? wondering if i can get away with 20...the fork is a 2013 fox coming off a trek remedy, very reasonably priced
    The easiest way to adjust handlebar height is adjusting the spacers below/above the stem. If you are close, but require a bit more height you can always get a handlebar with a higher rise (1.5 inches). The norm is about 1inch rise for most bars. This is about 10mm that is missing on the fork. It just depends on the fork deal relative to purchasing new bars.

  7. #7
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    Quote Originally Posted by Herzalot View Post
    Wait - so if I get a fork with a tapered steer tube for my 2013 Endo, it will raise the front end 1/2" or so? I am currently running a Marz 55 microswitch air with 1 1/8" straight steerer and ZS headset top and bottom. I love the head angle, seat angle and BB height with this configuration. I was thinking of getting an X-Fusion Slant (160mm) with the same axle to crown length, so back to my original question - if I order it with a tapered steerer, will I end up lifting the front end about 1/2" due to the required external lower headset cups? If so, won't that change the HA to 66*, slacken the eff. seat angle and raise the BB?
    The listed frame geometry on our website includes a 150mm 32 - 34mm stanchioned fork (RS Revelation, Fox 34, etc...) with a 1.5Tapered steerer tube, and an external lower headset: this is how we spec our build kits as well for this bike. If you deviate from this, you'll raise / slacken OR lower / steepen the front end of the bike.

    The steerer tube won't make any difference in geometry - it's the type of lower headset cup that you use that will make the difference. However, to run a 1.5Tapered steerer fork, you will NEED an external lower headset cup: to run a 1.125" steerer tubed fork, you can use either an external headset or a zero stack internal headset. Obviously, the zerostack option will lead to a slightly lower front end (by about 8mm, or 0.3") and will make the front of the bike a little more steep (by about 0.4 degrees).

    Cheers,
    Noel Buckley
    ------------------
    www.knollybikes.com

    Instead of PMs, please contact me here.

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