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  1. #1
    www.lugoftheirish.com
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    Custom 650b frame

    So I have a set of the Sun Charger 650b wheels and a set of Kirk's Neo Motos so I suppose it is time to start doing something with them. The Ventana 650b 4" travel rear assembly should be here in a couple of weeks so in the meantime I started cutting up some tubes and seeing what's what. Still a lot to do but not bad headway for an afternoon.

    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  2. #2
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    Going to spec a White Brothers 650b specific fork for it?

  3. #3
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    In an ideal world, yes. But, without knowing the A-C length for the WB 650b specific, I used a Fox 130mm fork as specs. I have one in the shop and it works with the 650b wheels.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  4. #4
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    Very cool, will be neat to see this built up. I was just checking out your site. I build old cars and eco-friendly 4WDs for a hobby with a lot of metal work... Since I recently got obsessed with MTB about a year ago and have been exploring frame building and have always loved geometry, the only math class I always got A's in I have a feeling someday maybe later in my life when I am retired or something like that (I'm only 29) I'll get into frame building, if I am patient enough to resist getting into it now. This gentleman recently moved to and is planning to set up shop in the neighboring town where my vehicle building shop is. http://www.edwincycles.com/ We have a pretty good collection of welders and metal guys who are all great interesting guys and do killer work, hopefully we can get hgim plugged in an I can hopefully resist the tempation for some custom frames...

  5. #5
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    Get her finished before St. Patrick's day!

    Can't wait to see the finished product.

  6. #6
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    St. Patrick's Day might be a tall order. Largely depends upon when the rear assembly darkens my door.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  7. #7
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    Quote Originally Posted by Loretta
    In an ideal world, yes. But, without knowing the A-C length for the WB 650b specific, I used a Fox 130mm fork as specs. I have one in the shop and it works with the 650b wheels.
    What will your HT angle be with the 130mm Fox? And will you run it as 5" in front and 4" in back with the Ventana rear end?

  8. #8
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    The A-C length I used was 490mm and 20% sag of 130mm of travel. That gives me a 70 degree head angle. 4" travel in the rear.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  9. #9
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    Should be nice! what tubing are you utilizing for the front triangle?

  10. #10
    www.lugoftheirish.com
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    Pacenti HM 31.8 ST, Zona 31.8 TT , Deda 38mm 9/6/9 DT. External sleeving on the ST along with ample gusseting at the DT/HT junction.

    Not sure what the total frame weight will be but it will be somewhere between 4 and 12 pounds.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  11. #11
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    4.5 pounds for the whole frame or just the front triangle portion? If that's for the whole fame - Amazingly awesome!!

  12. #12
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    Actually that was a joke. Frame weight will probably fall in the 6.5 to 7 pound range. Just a hunch.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  13. #13
    Sail On!
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    Sure would be great if we could see some more work in progress pix.

  14. #14
    www.lugoftheirish.com
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    Probably won't do a whole lot more to it until the rear assembly arrives but I will take plenty of photos of the build along the way. I can also take some more pics of what I have so far and post them up.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  15. #15
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    "4-12 lbs, should hopefully be somewhere in this range"

  16. #16
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    Got a call from Theresa over at Ventana to let me know my 650b rear assembly will be here tomorrow. Hoping to make some headway on the frame over the weekend and will report back after that. I'll take plenty of pics along the way.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  17. #17
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    Quote Originally Posted by Loretta
    In an ideal world, yes. But, without knowing the A-C length for the WB 650b specific, I used a Fox 130mm fork as specs. I have one in the shop and it works with the 650b wheels.
    The 650B 130mm WB fork is within 10mm A-to-C lenght of a 130 Fox.

  18. #18
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    The downside to the WB 130 fork is that it is only available in thru-axle and my Charger wheels are QR hubs.
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  19. #19
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    If you call and order direct they should be able to do QR for you. Takes a few weeks though...

  20. #20
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    Update. I ended up going for the 5" travel option and changing the frame angles. Head tube is 70.5 degrees and seat tube is 73 degrees.

    Lower pivot



    Rocker arm pivot and gusset


    Full frame mock-up

    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  21. #21
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    Lookin good!

  22. #22
    Geritol Power
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    Nice garage Tim. Gonna be good to see the finished product Thanks for sharing the construction picts.

  23. #23
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    Brazed up the seat tube pivot mount to the gusset. Now all that is left is to braze this onto the seat tube, add the lower shock mount, braze in the top tube, file and clean up the fillets, paint, and build it and ride it.



    Shamrock Cycles- Hand built frames from the mountains of Indiana.

  24. #24
    TNC
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    I'm just curious on your choice of the 70.5 HA for a 5" bike. I have no doubt your preference was well thought out here, but when more manufacturers are generally going slacker on 5" and longer travel bikes, 70.5 seemed a little steep. What wheelbase do you think you'll end up with, and what's the chainstay length with the provided swingarm? The setup looks very well done, and I'm impressed with anyone who can roll their own.

  25. #25
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    Agreed that the head angle is a little steeper than other 26" bikes but this is something of a "beta" bike and I wanted to try a head angle somewhere between my 29er and 26". I want something that will perform in Pisgah but much of the riding around here in Indy doesn't really call for a slacked out 5" travel bike. So I wanted something that could serve a little bit of double duty. This should give a trail of ~79mm but if I don't like the way it rides then I'll tear it apart and build another one.

    Also, wheelbase is 44". Chainstay is 17.45"
    Shamrock Cycles- Hand built frames from the mountains of Indiana.

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