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Seatpost with a lateral side to side adjustment?

bus_terbus_ter Posts: 337
edited July 2014 in Workshop
I'm looking for a seatpost with a lateral side to side adjustment for the saddle. I'm struggling to find anything online that I can actually buy.

Steve Hoggs makes reference to the FSA 'Datahead' seatpost but this is discontinued.

I found a Bontrager seatpost "The one-bolt seatpost head provides adjustment along three axes: fore and aft, side to side, and up and down" which sounded promising but it seems this head is only available on their aero posts. I need one for a standard oversized round tube.

Can anyone help with this?

Posts

  • Monty DogMonty Dog Posts: 20,614
    I have one the the FSA seatposts you mention and because of the way the top cradle clamp is fixed, it doesn't offer any side-to-side adjustment. Presume you're trying to adjust for some form of biomechanical requirement?
    Make mine an Italian, with Campagnolo on the side..
  • bus_terbus_ter Posts: 337
    Long standing pelvic asymmetry issue (I think). I'm shimmed on my right foot since a bike fit and I sit on the left side of the saddle so the right side pushes against my thigh and chaffs and wears away my shorts prematurely in this area. If I consciously sit central on the saddle my bum automatically works itself back to the left within a few minutes. I figure if I can move the saddle 5-10mm to the left of the centre line and my bum stays in the same position it wants to be in now I will actually be sitting dead centre on the saddle.
  • sungodsungod Posts: 12,199
    are you sure you wouldn't still do that if the saddle were shifted laterally?

    fwiw i've also got a slight asymmetry, but fortunately shim resolves it

    if your sit bones are 'tilted', maybe a saddle built up on one side might work? perhaps you could experiment with some firm foam and tape
    my bike - faster than god's and twice as shiny
  • bus_terbus_ter Posts: 337
    I don't know if I would still sit the same with the saddle moved slightly laterally, but I would certainly like to try.

    My shim was diagnosed by measuring the angle of my leg on both sides and adjusting until they were the same. I have 7mm on my right foot. It's been a couple years since this fit and I can't remember if it helped or not with the saddle issue. I think I also have a slight hip rotation issue. Looking at an imprint of my sit bones one side sits in front of the other. I'm not sure about tilt, that could be the issue?

    Really I need a fitter who is really clued up in the subject of pelvic symmetry. Mine I'm pretty sure wasn't.
  • rolf_frolf_f Posts: 15,959
    I wonder whether it might not be easier to get the asymmetry via the cranks, pedals - ie offset those and the bars (fairly easy of course) relative to the saddle. I think the result would be more or less the same.
    Faster than a tent.......
  • Ben6899Ben6899 Posts: 7,188
    Rolf F wrote:
    I wonder whether it might not be easier to get the asymmetry via the cranks, pedals - ie offset those and the bars (fairly easy of course) relative to the saddle. I think the result would be more or less the same.

    I reckon this would work.

    Engineering high-five, Rolf!
    Ben

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  • I'd imagine its nothing to do with your actual pelvis as such, but rather your leg length discrepancy which is skewing your pelvis as your shorter leg is reaching down further and thus rotating your pelvis.

    I've got similar issues- one leg considerbly shorter than the other- it used to give me bad ITB syndrome pain after around 50 miles of riding. I had it diagnosed and shimmed the shorter leg which (coupled with a lot of pilates stretches pre/mid and post rides), kind of sorted it out.
  • me-109me-109 Posts: 1,173
    Visit a local machine shop with a spare seatpost. See if they can machine a new top, or slot the existing top, so you get sideways movement possible on the clamp. Obviously some clamp types make this easier to do than others.
  • sungodsungod Posts: 12,199
    bus_ter wrote:
    I don't know if I would still sit the same with the saddle moved slightly laterally, but I would certainly like to try.

    My shim was diagnosed by measuring the angle of my leg on both sides and adjusting until they were the same. I have 7mm on my right foot. It's been a couple years since this fit and I can't remember if it helped or not with the saddle issue. I think I also have a slight hip rotation issue. Looking at an imprint of my sit bones one side sits in front of the other. I'm not sure about tilt, that could be the issue?

    Really I need a fitter who is really clued up in the subject of pelvic symmetry. Mine I'm pretty sure wasn't.

    which area are you in? maybe someone can give a local recommendation

    in london there's cyclefit, they have a proper physio who also understands bike fit...

    http://cyclefit.co.uk/cycling-physiotherapy
    my bike - faster than god's and twice as shiny
  • bus_terbus_ter Posts: 337
    Interesting idea to offset the pedals and handlebars (the other two contact points on the bike). I've not heard of that bring done before. I wonder if it would introduce any undesirable side effects.

    My location is the North East (near Newcastle). The cyclefit physio/bike fitter sounds like the ideal person to visit.
  • rolf_frolf_f Posts: 15,959
    Ben6899 wrote:
    Rolf F wrote:
    I wonder whether it might not be easier to get the asymmetry via the cranks, pedals - ie offset those and the bars (fairly easy of course) relative to the saddle. I think the result would be more or less the same.

    I reckon this would work.

    Engineering high-five, Rolf!


    Actually low five! On my way home from work yesterday, mulling this one over, it occurred to me that a much easier approach than fiddling with the pedals would be just to move the cleats! A fair bit of potential for a lateral offset and easy to engineer if there isn't enough. You'd want stiff soles and as wide a platform as possible but it would allow the idea to be tested. I'm guessing here that the offsets would be pretty small.
    Faster than a tent.......
  • pirniepirnie Posts: 242
    bus_ter wrote:
    Interesting idea to offset the pedals and handlebars (the other two contact points on the bike). I've not heard of that bring done before. I wonder if it would introduce any undesirable side effects.

    My location is the North East (near Newcastle). The cyclefit physio/bike fitter sounds like the ideal person to visit.

    If you're near Newcastle you could go and visit Physiohaus. They're not cheap but do seem to really know what they're on about
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