KOPS vs tried and tested

Discussion in 'Cycling Equipment' started by Randomchris, Jan 22, 2003.

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  1. Randomchris

    Randomchris Guest

    As some readers are probably more than well aware (!!) I am having some difficulty setting
    up a bike.

    I've never once looked to see if my knee falls in line with the pedal spindle with the cranks at 3
    o'clock. However, I looked today and found out I was around 4cm too far forward. That's a fair
    distance and obviously affects the size frame I go for. I'm wondering whether I should adopt the
    KOPS approach or just go with the set-up I have used (and found comfortable) for many years.

    I don't have the luxury of trying out a different position for a few rides as I already have a frame
    that may be the wrong size and I need to make a decision quickly otherwise I won't be able to swap
    it (if it is wrong).

    Cheers Chris
     
    Tags:


  2. I have the same problem with one of my bikes. I assume that you already have put the saddle back as
    far as possible. After that you can buy seat posts that have a bend to put the seat back further.
    Don't know what they cost, but I have seen them on the net. They look somewhat pricey, however,
    compared to a new frame, I expect they would be cheap. Another choice is a drainpipe seatpost, which
    has a similar offset. You can get one of there at big-wheel.com for a very modest cost.

    Good luck, Ernie

    RandomChris wrote:

    > As some readers are probably more than well aware (!!) I am having some difficulty setting
    > up a bike.
    >
    > I've never once looked to see if my knee falls in line with the pedal spindle with the cranks at 3
    > o'clock. However, I looked today and found out I was around 4cm too far forward. That's a fair
    > distance and obviously affects the size frame I go for. I'm wondering whether I should adopt the
    > KOPS approach or just go with the set-up I have used (and found comfortable) for many years.
    >
    > I don't have the luxury of trying out a different position for a few rides as I already have a
    > frame that may be the wrong size and I need to make a decision quickly otherwise I won't be able
    > to swap it (if it is wrong).
    >
    > Cheers Chris
     
  3. Random-<< I was around 4cm too far forward. That's a fair distance and obviously affects the size
    frame I go for. I'm wondering whether I should adopt the KOPS approach or just go with the set-up I
    have used (and found comfortable) for many years.

    KOPS is not a panacea or a hard constant but a place to start the fit.

    You have ridden 4cm in front and find it comfy? perhaps the top tube is too short or the stem. I
    would certainly try something closer to KOPS, you may have more power.

    Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
  4. Randomchris

    Randomchris Guest

    > I generally make a small change and ride it for a couple weeks. Is your saddle all the way aft
    > already? If not, make a 1-2cm move and give yourself at least a few hundred miles to think
    > about it. If you don't think it helps you then there is no point in dogmatic aherence to a
    > measuring system.

    Sounds very reasonable - unfortunately I've got to decide by the end of THIS week so I can swap my
    frame if necessary. I'm also unable to get out on the bike until the weekend!!

    > I don't know which seatpost you're on today, but if it's a type with very little (or no) set-back
    > like a Thomson, Syncros, or U.S.E. then you're going to need a different post to achieve best fit
    > on that frame. Such as Easton, Race Face, Ritchey, or other long post with plenty of setback for
    > the clamp. That will win you a couple centimeters of room.

    It's a non-descript alloy affair with very little set-back. It wouldn't be a problem shifting it
    back enough. I guess the real reason I started riding so far forwards was that the seatpost has so
    little set-back that just clamping the saddle in the middle of the rails gives quite a steep seat
    angle. So, before I knw anything else, it looked right therefore it must be ok!

    I normally have a tendency to move forwards on the saddle when riding hard, even at this angle, but
    perhaps that could be to do with the reach.

    In any case, the last thing I want to do is swap to the next frame size up and find that I have to
    run a 80mm stem because the saddle is better in the "correct" (KOPS) position. OTOH, if I keep my
    existing saddle position on the new bike, a stem of 110/120mm gives me the perfect reach. If I keep
    the existing (smaller) frame then I can easily achieve the KOPS position and have appropriate reach
    with a 120mm stem. But then what if I don't like it and end up with my saddle back in my current
    position.....? Use a 160mm stem?! And then there's the bar height - I'd need around 6cm of spacers
    on the smaller frame but that's another story!
     
  5. In article <[email protected]>, RandomChris
    <[email protected]> wrote:
    >> I generally make a small change and ride it for a couple weeks. Is your saddle all the way aft
    >> already? If not, make a 1-2cm move and give yourself at least a few hundred miles to think about
    >> it. If you don't think it helps you then there is no point in dogmatic aherence to a measuring
    >> system.
    >
    >Sounds very reasonable - unfortunately I've got to decide by the end of THIS week so I can swap my
    >frame if necessary. I'm also unable to get out on the bike until the weekend!!

    An indoor stationary resistance trainer can help, maybe you can borrow from a friend, would at least
    give you some saddle time with the different position.

    >It's a non-descript alloy affair with very little set-back. It wouldn't be a problem shifting it
    >back enough. I guess the real reason I started riding so far forwards was that the seatpost has so
    >little set-back that just clamping the saddle in the middle of the rails gives quite a steep seat
    >angle. So, before I knw anything else, it looked right therefore it must be ok!

    And once you're used to it, it feels right/normal even if it might be better some other way. That's
    why you need time to get confidence in the change.

    >I normally have a tendency to move forwards on the saddle when riding hard, even at this angle, but
    >perhaps that could be to do with the reach.

    It could, but there's a good chance this is due to bars being too low. Bars too low or reach too
    long often causes slipping, lower back pain, excess pressure in the crotch, and neck/shoulder
    tension. As you place your hands lower, your pelvis rotates forward. At some point most people start
    to find this uncomfortable, and they may obtain "relief" by curving the lower back, with predictable
    consequences. You can think about these things when fitting yourself, but it's a lot easier when
    someone can stand there looking at you. Before/after pictures can help too.

    When your fit decisions are time-constrained and you can't test the results, you end up making a
    guess. Sometimes guesses work out and sometimes not. One way to improve your guesswork is by having
    an experienced fitter help you work on the fit (in person, looking at you on the bike).

    --Paul
     
  6. Worth a read, if you haven't already seen it:

    http://www.bsn.com/Cycling/articles/kops.html

    Also, you might peek in at Lennard Zinn's site and plug in your measurements to get another
    builder's basic view on your fit/sizing. Using his "aggressive" rider positioning matched the
    numbers I've been using, (arrived at through trial and error over 22 years of riding and racing.)

    http://www.zinncycles.com/fit/index.html

    4cm sounds like a lot, but if you're truly too far forward in your current position, you'll have too
    much weight on your hands, and letting go of the bars will make you feel like you're going to fall
    forward if you don't grab something to support yourself. You're looking for balance here.

    Good luck,

    SB

    "RandomChris" <[email protected]> wrote in message
    news:[email protected]...
    > > I generally make a small change and ride it for a couple weeks. Is your saddle all the way aft
    > > already? If not, make a 1-2cm move and give yourself at least a few hundred miles to think about
    > > it. If you don't think it helps you then there is no point in dogmatic aherence to a measuring
    > > system.
    >
    > Sounds very reasonable - unfortunately I've got to decide by the end of
    THIS
    > week so I can swap my frame if necessary. I'm also unable to get out on
    the
    > bike until the weekend!!
    >
    >
    > > I don't know which seatpost you're on today, but if it's a type with very little (or no)
    > > set-back like a Thomson, Syncros, or U.S.E. then you're going to need a different post to
    > > achieve best fit on that frame. Such as Easton, Race Face, Ritchey, or other long post with
    > > plenty of setback for the clamp. That will win you a couple centimeters of room.
    >
    > It's a non-descript alloy affair with very little set-back. It wouldn't be
    a
    > problem shifting it back enough. I guess the real reason I started riding
    so
    > far forwards was that the seatpost has so little set-back that just
    clamping
    > the saddle in the middle of the rails gives quite a steep seat angle. So, before I knw anything
    > else, it looked right therefore it must be ok!
    >
    > I normally have a tendency to move forwards on the saddle when riding
    hard,
    > even at this angle, but perhaps that could be to do with the reach.
    >
    > In any case, the last thing I want to do is swap to the next frame size up and find that I have to
    > run a 80mm stem because the saddle is better in
    the
    > "correct" (KOPS) position. OTOH, if I keep my existing saddle position on the new bike, a stem of
    > 110/120mm gives me the perfect reach. If I keep
    the
    > existing (smaller) frame then I can easily achieve the KOPS position and have appropriate reach
    > with a 120mm stem. But then what if I don't like it and end up with my saddle back in my current
    > position.....? Use a 160mm stem?! And then there's the bar height - I'd need around 6cm of spacers
    > on the smaller frame but that's another story!
     
  7. x

    x Guest

    RE/
    >It's a non-descript alloy affair with very little set-back.

    Once you get the height and setback dialed in, do yourself a favor and get a two-bolt
    micro-adjustable post. They cost an arm and a leg, but those teeny little changes in attitude can
    make a huge difference in riding comfort.
    -----------------------
    Pete Cresswell
     
  8. Amit

    Amit Guest

    "RandomChris" <[email protected]> wrote in message
    news:<[email protected]>...
    > > I generally make a small change and ride it for a couple weeks. Is your saddle all the way aft
    > > already? If not, make a 1-2cm move and give yourself at least a few hundred miles to think about
    > > it. If you don't think it helps you then there is no point in dogmatic aherence to a measuring
    > > system.
    >
    > Sounds very reasonable - unfortunately I've got to decide by the end of THIS week so I can swap my
    > frame if necessary. I'm also unable to get out on the bike until the weekend!!
    >

    If you're having a problem with your position (and it sounds like you are) you might as well make
    the full correction (not just 1-2 cm at a time) and adapt to it, especially if this is the
    off-season for you. What's the point of being uncomfortable, if the proper position will make you
    comfortable ?

    > I guess the real reason I started riding so far forwards was that the seatpost has so little
    > set-back that just clamping the saddle in the middle of the rails gives quite a steep seat angle.
    > So, before I knw anything else, it looked right therefore it must be ok!
    >
    > I normally have a tendency to move forwards on the saddle when riding hard, even at this angle,
    > but perhaps that could be to do with the reach.
    >

    Being too far forward makes it more likely that you will tend to move forward when riding hard.

    > In any case, the last thing I want to do is swap to the next frame size up and find that I have to
    > run a 80mm stem because the saddle is better in the "correct" (KOPS) position. OTOH, if I keep my
    > existing saddle position on the new bike, a stem of 110/120mm gives me the perfect reach. If I
    > keep the existing (smaller) frame then I can easily achieve the KOPS position and have appropriate
    > reach with a 120mm stem. But then what if I don't like it and end up with my saddle back in my
    > current position.....? Use a 160mm stem?! And then there's the bar height - I'd need around 6cm of
    > spacers on the smaller frame but that's another story!

    If you're fitting yourself to a road bike, if your knee is 4 cm ahead of the spindle (the way KOPS
    is defined) I don't think you'll be comfortable. Although I'll admit I'm conservative when it comes
    to position.

    When in doubt go back to the rules of thumb established in the Lemond/Hinault books. Set your saddle
    height as prescribed and move your saddle back until it feels "right", rather than moving your
    saddle up or forward. On a typically sized bike the nose of the saddle will end up 5-8 cm behind the
    BB (personally I think seat tube angles tend to be too steep). Your upper leg should be close to
    horizontal when your foot is at the top of the stroke.

    Riders typically move their saddle forward to compensate for having it too high, I think you might
    have this problem. If your seat is lower, your bars will be lower too, so you might not have this
    spacer problem.

    Reading your post, it seems to me you should keep the smaller frame, your best position will be
    closer to KOPS (which you can achieve on the smaller frame with the 120 mm stem) than what you
    had before.

    -Amit
     
  9. Randomchris

    Randomchris Guest

    I think it's a result of too LONG a top tube. When I started cycling I had not a clue about
    fitting, so when I bought a bike and the bars were too far away, I shifted the saddle forward a bit
    - it's stayed that way ever since as the only other bike I've had since was sized up according to
    the first bike!

    I have a friend who's just shelled out on a brand new C40, went to the shop with his old bike, he
    sat on it, they said "yeah that's fine" and have built the C40 up to match. Turns out he's in a
    similarly forward position too, with the nose of the saddle about 2-3 cm behind the bb centre. I
    nearly went to that shop for a fit (in the end got a framebuilder to size me on a jig and got a
    bio-racer fit done for free - promotional offer - as a second 'opinion').

    Glad I didn't now....

    Qui si parla Campagnolo <[email protected]> wrote in message
    news:[email protected]...
    > Random-<< I was around 4cm too far forward. That's a fair distance and obviously affects the size
    > frame I go for. I'm wondering whether I should adopt the KOPS approach or just go with the set-up
    > I have used (and found
    comfortable)
    > for many years.
    >
    > KOPS is not a panacea or a hard constant but a place to start the fit.
    >
    > You have ridden 4cm in front and find it comfy? perhaps the top tube is too short or the stem. I
    > would certainly try
    something
    > closer to KOPS, you may have more power.
    >
    >
    >
    > Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    > (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
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