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  1. #1
    1:18
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    Idea! Stumpjumper FSR owners...

    I would need some info about the frame, preferably in XL size. How much can the seatpost be lowered without hitting the rear shock or linkage?

    I made some brief calculations and got 7 inches (18 cm) for M size frame. Assuming that all models have the same swingarm and chainstay length and comparing the Stumpjumper geometry chart, where the seat tube is 3,5 inches longer (M vs. XL), the XL frame should have the clearance about 10,5 inches (27 cm). Correct me if I'm wrong.


    Here is M frame, distance approx. 7 inches.

  2. #2
    mtbr member
    Reputation: Back2Kill's Avatar
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    I have an XL and it measures 10". On downhill rides my seat doesn't go quite low enough for me. I plan to cut 1.5" off the bottom of the seatpost.

  3. #3
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    On my 05 Stumpy (XL) there is a stop inside the....

    seat tube that will not allow insertion of the seat post past a certain point. It is just a small round metal disc, maybe 3mm across, that is tack welded in place. It's not very thick, but sufficient to prevent insertion of the tube past that point. With that stop in place I can only get about 7 1/2" of seat tube insertion. It is there to prevent exactly what you are worried about Vette, over insertion of the seat tube causing damage to the shock. I believe that the 04's (first year for the semi-interupted seat tube on the stumpies) were the same way, as are the 06 models. Depending on how much lower you want your seat tube to go, you can create another problem as well. There is also a small hole on the back of the seat tube. This is the minimum insertion hole. The idea is if you can see the seat tube through the hole and it comletely covers the hole, you are good to go. If you can't see the seat tube through the hole, your seat tube is not inserted far enough and the leverage could cause damage to or crack the seat tube/top tube junction. According to my measurements, minimum seat tube insertion is 4" for the XL frame. This only gives you a total of 3 1/2" (+ or - 1/4") of seat adjustment. So if you really need to slam your seat down for decsents, and your frame has the stop installed, you may run into problems getting the seat tube short enough to allow your prefered seat height for decsents, but still having enough seat post to meet minimum insertion requirements for everything else. A simple test to see if your frame has the stop is to pop the quick release and push the seat post down. If it stops before poping out the bottom of the seat tube, you've got the stop. So slaming the seat post isn't really an option. If that is what you need to do, a different model might be the way to go, the Stumpy is designed as an XC and Light Duty Trail bike, not a decsender. But if you are worried about adjustment range for fitting reasons, you can always cut the seat post, as Back2Kill mentioned, or get a shorter one. The stock seat post for an XL frame is 400mm in length. So base your calculation on that. Sorry for the length of the post. But, I'm not sure what you are wanting to do, so figured I'd better cover all the bases.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  4. #4
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    Good info. I didn't know about that little hole. You are correct on the lower stop. The seatpost would never make contact with the shock. There is defintely plenty enough post for me to cut some off.

    Sometimes, what a bike is "designed" for and what you do with it are not always the same thing.

  5. #5
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    Don't I know it!!...

    But I was not suggesting that the Stumpy wouldn't decsend well. Mine decsends better than any FS bike that I have owned to date. But rather that it wasn't designed to be a stellar decsender. I've riden enduros and a big hit or two that felt like that was what they were made for! Slower on the climbs, but scarry fast on the decsents. But the Stumpy certainly is a competent bike when decsending, no doubt. I guess I wasn't too clear on that one. The idea was, that if decsending was the goal, and the seat post slam was desired, then a differnt model would suit the purpose better. I know the old enduros (don't know about the new design) and the big hits have no restriction to prevent slaming the seat post right to the head if desired. The only limitation being contact with the shock.

    Anyway, my reason for mentioning the design parameters was to give the reason for the limitation. I know some riders like to drop their seat post for steep decsents on any bike they ride. Unfortunately there are limits when it comes to the Stumpies, and probably the new FSR XCs as well.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  6. #6
    1:18
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    Squash, thanks a lot.

  7. #7
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    Quote Originally Posted by Back2Kill
    Good info. I didn't know about that little hole. You are correct on the lower stop. The seatpost would never make contact with the shock. There is defintely plenty enough post for me to cut some off.

    Sometimes, what a bike is "designed" for and what you do with it are not always the same thing.
    I think that the hole on the 'XL' and 'L' is under the sticker warning, so, you'd have to make a hole in the sticker to see this hole.

  8. #8
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    Uh, no it is 2" below the warning sticker. Clear as a bell. Very useful now that I know what it is

  9. #9
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    Quote Originally Posted by Back2Kill
    Uh, no it is 2" below the warning sticker. Clear as a bell. Very useful now that I know what it is
    I think it is under the sticker, can't post a pic since I lent it to a friend. Maybe they changed the sticker location for 05? (my bike's an XL '04)

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