Thompson Seatpost sizing

Huck Finn
Huck Finn Posts: 157
edited October 2012 in MTB buying advice
I'm about to order a new seatpost for my 2010 Stumpjumper Expert and would like the size clarified if anyone knows for certain. As i'm away at uni, i dont have a vernier with me and a ruler is coming in at 31mm ish. Now i've noticed they sell the seatposts in 30.8 and 30.9 sizes and dont particularly want to order the wrong one.

If anyone knows for certain i'd be much obliged.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    looked on Speshs webby they list seatpost sizes.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The Rookie
    The Rookie Posts: 27,812
    30.9 is the common Spesh size, but the best way is to take it out and find out - they have it stamped on them!
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • njee20
    njee20 Posts: 9,613
    30.9, all alu and carbon Spesh frames (and most steel) always have been.
  • felix.london
    felix.london Posts: 4,067
    I'd be very surprised if it was 30.8!
    "Why have that extra tooth if you're not using it?" - Brian Lopes

    Votec V.SX Enduro 'Alpine Thug' 2012/2013 build

    Trek Session 8
  • Huck Finn
    Huck Finn Posts: 157
    Cheers chaps. I'll just check the spesh website first then. I cut the post down ages ago Beginner. Should have taken a note of the writing at bottom but didn't. Thanks all!
  • nicklouse
    nicklouse Posts: 50,675
    2010 Stumpy Expert http://www.specialized.com/gb/gb/bikes/ ... rbon#specs
    2010 Stumpy expert http://www.specialized.com/gb/gb/bikes/ ... rbon#specs
    2010 Stumpy expert http://www.specialized.com/gb/gb/bikes/ ... pert#specs

    all use 30.9mm
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Huck Finn
    Huck Finn Posts: 157
    Thanks Nic and all. Ordered!
  • njee20
    njee20 Posts: 9,613
    You could go back 20 years, and they'd still be 30.9!

    It was a seatpost size created by Spesh - when they first did the metal-matrix frames in the early 90s they made the seat tubes as thin as possible, then measured the ID. It's why it's one of very very few sizes that's not a multiple of 0.2. So Spesh say anyway!
  • ddraver
    ddraver Posts: 26,662
    Take the old one out and have a look what size is written on it?

    (not all of them do though)
    We're in danger of confusing passion with incompetence
    - @ddraver
  • njee20
    njee20 Posts: 9,613
    Why, when a thread is all of 5 posts do people read the first one and reply? :?
  • The Rookie
    The Rookie Posts: 27,812
    As they are dumbass donuts I guess.......
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • supersonic
    supersonic Posts: 82,708
    njee20 wrote:
    You could go back 20 years, and they'd still be 30.9!

    It was a seatpost size created by Spesh - when they first did the metal-matrix frames in the early 90s they made the seat tubes as thin as possible, then measured the ID. It's why it's one of very very few sizes that's not a multiple of 0.2. So Spesh say anyway!

    Not all of them have been though. Most recent ones yes, but the 1993 M2 Stumpy was 27.2, and there were some odd ball 30.4 sizes too.
    GT ZASKAR CARBON TEAM

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