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  1. #1
    Senior Curmudgeon FarHorizon's Avatar
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    Single-bolt seat-post with greatest adjustment range?

    I have a Brooks B135 saddle with the double rails. The stock "friction discs" are worse than useless for heavy riders - sit on the saddle wrong & it tilts fore and aft. I've stripped the stock 13mm nuts, installed a larger bolt & nut, nothing works - the problem is the limited contact area of the friction washers.

    To get away from the stock clamp, I've bought a "seat sandwich" from Harris Cyclery that allows the saddle to be mounted on any single-bolt seat-post. So far, I've tried the saddle on a Kalloy and a similar post, but there is a problem. Although the saddle no longer slips, it is impossible to get the saddle level. Even at its tilt-limit, the nose of the saddle is slightly higher than the rear. When I say "slightly," I mean "just enough to be uncomfortable."

    So my questions are two:

    1. Is there a way to modify the seat post to allow for a more nose-down position? And if not -

    2. Is there a brand of single-bolt seat-post that will allow more fore-and-aft tilt than "normal?"

    Thanks - FH
    Nishiki road bike, Raleigh road bike, Electra Cruiser Lux 7d, Electra Townie 3i, Electra Townie 1, Whatever I find today!

  2. #2
    Senior Member dsbrantjr's Avatar
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    You could make a wedge from aluminum, hard plastic or even hardwood to go between the "sandwich" and the post to tilt it farther down.

    If it is a non-setback type of post, could you turn it around 180 degrees and possibly get more adjustment that way?

    Or perhaps you could file the adjustment slot farther to allow more tilt.

  3. #3
    Senior Curmudgeon FarHorizon's Avatar
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    Hi @dsbrantjr -

    Thanks for some excellent "out of the box" thinking!

    Idea 1 (beveled wedge) won't work because the position of the plate is between the upper & lower rails of the saddle, which are parallel to each other. A wedge might bend the rails, but probably wouldn't change the tilt. Such a wedge, to be effective, would need to replace the bottom rail-retainer between the seat post hemisphere and the lower saddle clamp. I could 3-D print such a thing, but I wouldn't trust it not to fail under heavy use.

    Idea 2 might just work. I could reverse the post (which DOES have a slight set-back) and may try this soon.

    Idea 3 occurred to me also, and although I may yet go there if idea 2 fails, the post itself is already pretty abbreviated and I'd worry about structural integrity. OTOH, I'm sure that some safety factor exists in the design, and a small change (all I need) might be doable.

    Thanks again for most excellent suggestions! FH
    Nishiki road bike, Raleigh road bike, Electra Cruiser Lux 7d, Electra Townie 3i, Electra Townie 1, Whatever I find today!

  4. #4
    coprolite fietsbob's Avatar
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    Re Q2; A: Vertical bolt .. Campagnolo... I have 2 , circa 1980. friction mechanisim between 2 parts within an arc

    Horizontal bolt, for basic seatposts Brompton Pentaclip. available Now (dual rail seats only, perhaps your not 4 wire)
    those have a 360 degree rotation possibility..

    Multi plate friction holds the angle. and the friction plates and the steel bolt are the only parts not Aluminum.


    Fore and aft adjustment range is the saddle rail length issue ..

    another Brompton piece is the SAP a pin that attaches to top of seat post.*

    Installed, its horizontal tube takes the saddle clip , saddle positioned above it..

    *Making just 1 length of(folding) bike frame the SAP moves the rider closer to the bars, for shorter reach needs.
    Last edited by fietsbob; 03-19-15 at 08:25 AM.

  5. #5
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    I ride Brooks and use this seat post from Nitto. Nitto Dynamic S83 (100080746) at CambriaBike.com

    It uses 2 bolts to set the angle. Normally a Brooks should be set up with the heal of the saddle about 1/4" higher than the center letting the nose go where it wants.

  6. #6
    Senior Curmudgeon FarHorizon's Avatar
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    Hi @davidad -

    Do you use a plate between the rails of the saddle? Do the dual mount bolts fit forward and aft of the seat sandwich?
    Nishiki road bike, Raleigh road bike, Electra Cruiser Lux 7d, Electra Townie 3i, Electra Townie 1, Whatever I find today!

  7. #7
    A little North of Hell
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    infinite adjust

    Quote Originally Posted by FarHorizon View Post
    2. Is there a brand of single-bolt seat-post that will allow more fore-and-aft tilt than "normal?"
    Specialized and Moots style heads do.

    Don't know how good they hold up to Heavy riders.
    [SIGPIC][/SIGPIC]
    XXXI

  8. #8
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    Quote Originally Posted by FarHorizon View Post
    Hi @davidad -

    Do you use a plate between the rails of the saddle? Do the dual mount bolts fit forward and aft of the seat sandwich?
    I'm not sure what you mean by a clamp other than the one built into the seat post. The 2 bolts allow for a precise seat angle.
    You can also find versions with more set-back if you need it.

  9. #9
    coprolite fietsbob's Avatar
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    Consider your 4 rail saddle choice has created unanticipated issues you would have avoided with a 2 rail

    and a Selle Anatomica has a much longer adjustment range than Brooks , by design.

    and that you may have to drill new holes in your 'seat sandwich'..

  10. #10
    Senior Member
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    The problem with using the spacer in LaPrade style posts is that the bolt is in a fixed position relative to the post so it can limit the adjustment range of the clamp. Try a Campy style post where the bolt position is relative to the clamp, you should get the same range of adjustability as without the spacer.
    FF185DD3-0A41-41D7-9707-69C6EB1C2DD7.jpeg

  11. #11
    Senior Curmudgeon FarHorizon's Avatar
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    Alas, I need a much longer post than Campy makes. My best option may be to add more holes in the sandwich and then use my choice of two-bolt posts.
    Nishiki road bike, Raleigh road bike, Electra Cruiser Lux 7d, Electra Townie 3i, Electra Townie 1, Whatever I find today!

  12. #12
    coprolite fietsbob's Avatar
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    A double step, Chromoly tube , in the frame, with its own seat post binder and a smaller seat post in the top would work too.

    My 1 bolt Campg seat post From my AlAn Road bike is a 25,0mm ..

  13. #13
    Senior Member spiker's Avatar
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    I went to a local machine shop and had them grind out a couple cm's on the slot.
    I needed a bit more nose up and this worked great.

  14. #14
    Senior Curmudgeon FarHorizon's Avatar
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    I tried an older, single-bolt Kalloy post this evening - same issue... The Campy post-miscengation idea might work, but my first choice is to spend no extra $$. If a rat-tail file can slightly lengthen the existing post-slot, then that's my preferred option.

    Thanks again - FH
    Nishiki road bike, Raleigh road bike, Electra Cruiser Lux 7d, Electra Townie 3i, Electra Townie 1, Whatever I find today!

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