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  1. #1
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    Weld in seat collars

    Walt, if this shouldn't be here, let me know.

    I am going to have a run of weld in seat collars made. They will be made to use a 30.9mm seat post into 1.375x.035 (34.9x.9) tubing. They will be 2.5" OAL, .5" of that slips into the tubing.

    They will be machined from 17-4 bar stock.

    The minimum order to get these at a reasonable price is 50 pieces, that price is good for up to 199 pieces. I am not looking to make any money on these, just to help cover the costs of the minimum. I can comfortably cover 20 of them. Pricing below covers actual cost of parts + shipping to US, + $3 for cc fees/packing materials.

    12 will fit in a flat rate box. If we can get it up to 200 pieces, the price will drop about $5 per piece (if it gets close to that I will post here). If you are interested email me (rcpfab@gmail.com), once I have confirmation for at least 30 I will have them made.

    Thanks

    1 - $27
    2 - $45
    3 - $63
    4 - $81
    5 - $99
    6 - $117
    7 - $135
    8 - $153
    9 - $171
    10 - $189
    11 - $207
    12 - $225
    Last edited by RCP FAB; 01-25-2013 at 01:22 PM. Reason: Changing seat post size to 30.9mm

  2. #2
    pvd
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    30.9 is a more common size. Any chance of getting some of those done?

  3. #3
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    Just FYI

    1 3/8 x .065" is pretty much a perfect slip fit for 31.6 posts. 5 minutes on the lathe and you're good to go. That's a commonly available size in both stainless (304, anyway) and 4130.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  4. #4
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    Peter, I can do them 30.9 instead, if that's what people want, or I am sure he will do a mixed batch.

    Walt, I have had mixed luck using .065 wall tubing, one stick I ordered worked nice, the other was a little loose.

    Plus, 17-4 welds in nice, and you can leave the top half inch unpainted so the seat clamp doesn't mess up the paint.

  5. #5
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    Weird.

    Did you check the fit before you welded everything up? 4130 can sometimes be out of spec, just like any other tubing. Measure, check, doublecheck!

    I think I've done 40 bikes with the 31.6 posts using .065 4130 and I can't recall ever having a loose one - in fact I've always had to ream them post-weld.

    -Walt

    Quote Originally Posted by RCP FAB View Post
    Peter, I can do them 30.9 instead, if that's what people want, or I am sure he will do a mixed batch.

    Walt, I have had mixed luck using .065 wall tubing, one stick I ordered worked nice, the other was a little loose.

    Plus, 17-4 welds in nice, and you can leave the top half inch unpainted so the seat clamp doesn't mess up the paint.
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  6. #6
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    Yes, I did check, it was within the mills tolerances also, so my buddy ended up with a 4 foot cheater pipe, its been about a year now and it still hasn't bent.

  7. #7
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    Huh?

    What is their tolerance? 1 3/8 x .065 is about a 31.62mm ID which has always worked great for me. Even if it was 31.7 or so - once you distort it a little and such you'll need to ream a tad anyway.

    If I were you I'd do 30.9. That's a more difficult size to do yourself without lots of lathe time and you'll have better luck selling them to other builders.

    -Walt

    Quote Originally Posted by RCP FAB View Post
    Yes, I did check, it was within the mills tolerances also, so my buddy ended up with a 4 foot cheater pipe, its been about a year now and it still hasn't bent.
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  8. #8
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    Walt,

    I don't recall what the specs were, but the ID was 31.8, it *probably* would have worked, but I didn't want to risk it.

    30.9 seems like a good idea, it seems like all of the dropper posts are available in 30.9.

    Thanks

  9. #9
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    That is .058"

    You had the wrong size. That's the ID of .058".

    Everything dropper-wise comes in 30.9, *almost* everything comes in 31.6. So I would do 30.9 if I were you.

    -Walt

    Quote Originally Posted by RCP FAB View Post
    Walt,

    I don't recall what the specs were, but the ID was 31.8, it *probably* would have worked, but I didn't want to risk it.

    30.9 seems like a good idea, it seems like all of the dropper posts are available in 30.9.

    Thanks
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  10. #10
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    Quote Originally Posted by Walt View Post
    You had the wrong size. That's the ID of .058".

    Everything dropper-wise comes in 30.9, *almost* everything comes in 31.6. So I would do 30.9 if I were you.

    -Walt
    Coulda been

    I updated the first post, 30.9mm it is.

  11. #11
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    5 down, 25 to go!

  12. #12
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    Another 2 accounted for. If anyone wants these in 31.6 he said no additional charge to open them up after the batch of 50 are made.

  13. #13
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    Pmw

    Looks like Paragon ended up making 30.9 collars finally! Right on.
    MS2019

  14. #14
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    On that collar, I'm assuming the post only contacts the collar once its welded to a tube? Does that make for a flexy seat post interface, or do they come out feeling solid?
    Looks like a cool idea

  15. #15
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    Good thing I just bought all that straight gauge to make a bunch of these. Oh well. Good thing I just started sharing space in a CNC shop.

  16. #16
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    thedudeman- these type of fused-in collars have been standard operating procedure for years on many TIG welded frames with 27.2 posts, especially Ti builders. This was just a new size that covers all the dropper-post sizes, and as said by others, is more difficult/takes more time to fabricate at home (if you have a lathe).
    Adam- now with your new digs...how about a simple and relatively cheap steel yoke for 3" tires? :-)

  17. #17
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    Quote Originally Posted by Meriwether View Post
    thedudeman- these type of fused-in collars have been standard operating procedure for years on many TIG welded frames with 27.2 posts, especially Ti builders. This was just a new size that covers all the dropper-post sizes, and as said by others, is more difficult/takes more time to fabricate at home (if you have a lathe).
    Adam- now with your new digs...how about a simple and relatively cheap steel yoke for 3" tires? :-)
    Meriwether- so it must work pretty well then... Are these typically brazed or welded in?
    Thanks!
    Scott

  18. #18
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    Scott,
    They're usually (always?) fused/welded into a tube of the same diameter but smaller wall thickness. Then you weld (or braze I guess) the top tube and seatstays to the collar alone or split the difference to bolster the fused joint.
    See photos for example. 1st on is the fused tubes, the 2nd one is the top tube welded 50/50 on the collar and lower set tube. The seastays will be welded to the opposite side of the top tube.
    Weld in seat collars-collar-fused.jpg
    Weld in seat collars-seattube-weld.jpg

  19. #19
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    Why not just use one of the now available larger diameter butted seat tubes like the TrueTemper VERUSSTMAG?

  20. #20
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    Meriwether- thanks for the examples! The weld looks nice flush with the tube like that. I used the verusstmag on the build I'm doing- and it's the heaviest tube on the frame- I'm assuming you could save a bit of weight with this technique?
    Scott

  21. #21
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    Why do you want a tube for a 33.1mm seatpost? Or am I misreading the VERUSSTMAG specs somehow?

    The topper allows a lot of flexibility in what you use for the lower portion. If someone was making a seat tube for 31.6 or 30.9 specifically, I still might use the topper just because the extra wall thickness makes for a really nice beefy seatpost interface and also requires minimal reaming. You can use all sorts of different stuff for the lower portion to keep the weight reasonable.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  22. #22
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    VERUSSTMAG typo?

    Quote Originally Posted by Walt View Post
    Why do you want a tube for a 33.1mm seatpost? Or am I misreading the VERUSSTMAG specs somehow?
    I think it may be a typo... 34.9 OD minus the wall thickness (1.6 x 2)=31.7 ID

    (maybe it was accidentally calculated for the thin side of the tube 33.3?)

    The old .pdf version shows it for 31.6 post, which is what I received, and my 31.6 post fits well (so far).

    Weld in seat collars-hj.jpg

    http://henryjames.com/pdf/HJBpricelist2014.pdf

  23. #23
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    Quote Originally Posted by Walt View Post
    Why do you want a tube for a 33.1mm seatpost? Or am I misreading the VERUSSTMAG specs somehow?

    The topper allows a lot of flexibility in what you use for the lower portion. If someone was making a seat tube for 31.6 or 30.9 specifically, I still might use the topper just because the extra wall thickness makes for a really nice beefy seatpost interface and also requires minimal reaming. You can use all sorts of different stuff for the lower portion to keep the weight reasonable.

    -Walt
    That is a typo, it fits a 31.6 seat post, these are tubes that Chromag had TT draw for use with dropper posts.

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