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  1. #1
    bikerpilot
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    '03 SJ FSR/Selle San Marco Aspide/Thomson post combo??

    I'm riding an '03 Stumpjumper FSR, with a Thomson seatpost and a Selle San Marco Aspide saddle. Because of the seat tube angle, and I guess the way the seat rails are angled, I'm having a hard time getting my seat flat. The post has to be tilted almost all the way forward, almost all the way to the last degree mark. With the seat clamped in at that angle to get it flat so it sits right, it keeps slipping on me. I like the seat to sit almost all the way forward to put me more on top of the cranks, but during my rides, it starts to slide back. I've tightened the seat post clamps onto the rails as tight as I dare, but it seems it's not holding tight enough because of the angle. I'm also scared that because of the angle, the back bolt may not be getting enough thread bite into the nut thing on top of the clamp. Has anyone else encountered a similar situation with a Thomson post? I know they're some of the strongest and reasonably lightest out there, but I'm worried about pushing the clamp to too much of an angle or overtightening it and something going bad wrong. My digital camera batteries just died, so when I get some more in it, I'll post a picture to show what I'm talking about. Hopefully someone can help.

  2. #2
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    Quote Originally Posted by Andrew-FSR
    I'm riding an '03 Stumpjumper FSR, with a Thomson seatpost and a Selle San Marco Aspide saddle. Because of the seat tube angle, and I guess the way the seat rails are angled, I'm having a hard time getting my seat flat. The post has to be tilted almost all the way forward, almost all the way to the last degree mark. With the seat clamped in at that angle to get it flat so it sits right, it keeps slipping on me. I like the seat to sit almost all the way forward to put me more on top of the cranks, but during my rides, it starts to slide back. I've tightened the seat post clamps onto the rails as tight as I dare, but it seems it's not holding tight enough because of the angle. I'm also scared that because of the angle, the back bolt may not be getting enough thread bite into the nut thing on top of the clamp. Has anyone else encountered a similar situation with a Thomson post? I know they're some of the strongest and reasonably lightest out there, but I'm worried about pushing the clamp to too much of an angle or overtightening it and something going bad wrong. My digital camera batteries just died, so when I get some more in it, I'll post a picture to show what I'm talking about. Hopefully someone can help.
    Some non-setback seatposts I've seen are definitely tilted more in one direction.
    If yours is like that, could you have it mounted backwards?

  3. #3
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    Little OT here:

    What is the big deal with Thomson seat posts and stems? Everyone has them but what is the big deal? My specialized post works fine and I think the elevation adjustment is pretty nice. The specialized stem is CNC machined like the Thomson.

  4. #4
    bikerpilot
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    Maybe....

    Quote Originally Posted by fsrxc
    Some non-setback seatposts I've seen are definitely tilted more in one direction.
    If yours is like that, could you have it mounted backwards?

    I honestly thought about that, and looked at it real hard for awhile. I couldn't make any sense of which way should be forward or back, or even if there is a specific forward or back. Both bolts are the same length, and the clamp seems to be perfectly symmetrical. I've already turned it around backwards from the way I had it, and same thing. Maybe I didn't give it enough of a chance mounted the other way. I'll change it back and see if I can get it to lock down good.

    Quote Originally Posted by Lumbee
    Little OT here:

    What is the big deal with Thomson seat posts and stems? Everyone has them but what is the big deal? My specialized post works fine and I think the elevation adjustment is pretty nice. The specialized stem is CNC machined like the Thomson.
    The seatposts I know are very strong and reasonably light. I have to have a very long post, so I like to make sure it's plenty strong and not flexy. I've got Thomsons on both my bikes. The clamp design is very nice, infinite adjustability with the two bolt design, as opposed to the set notches on other designs. Plus, I like the fact that the clamp is directly atop the post, as opposed to set back like on some posts. I like to run my seat forward to get more on top of the cranks, and the zero setback head helps that a lot. <<<(Just one man's opinion.) I can't speak for the stems, I've never had one. I've heard they're strong and as stiff as a whatever you can think of that's really stiff, but also that they're kind of heavy...

  5. #5
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    I use a Thomson post, since they are one of the few companies that make a zero set back (straight post) that is 30.9mm.

    Your problem with the seat slipping is the clamp. You probabley have a zero degree clamp, and you need a 12 degree. See this link: (2nd page)

    http://www.lhthomson.com/docs/seatpost.pdf

    I just put a straight post with a 12 degree clamp on my 04 FSR XC. Works great.

    You can see in the picture it is at a 14-15 degrees angle, but that is an addition to the 12 degree clamp angle.

    Hope this helps.
    Attached Images Attached Images

  6. #6
    bikerpilot
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    That's it.

    That's the info I was looking for. It all makes sense now, thanks so much. I'll have to see about getting ahold of one of those clamps. Do you know if they are available seperately, or do you have to buy a whole new post? Thanks again.

  7. #7
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    You could talk to your LBS about ordering a clamp. I am not sure if that is possible. They would know.

    You could also talk to Thomson direct. I have no experience with Thomson, but some mfg are very kind(to the their customers).

    Another option is a new seatpost. Either mail order or LBS.

    You old one, if in good shape, should sell for ~$40-45 on ebay.

    Some options.

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