Direct Drive Tahiti-NX3 direct drive.. just say no

Discussion in 'Motorized Bicycle General Discussion' started by KCvale, Apr 20, 2012.

  1. KCvale

    KCvale Well-Known Member

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    Unless you want to invest ~$80 in an alternative direct drive rear wheel sprocket and hub mount do NOT go with a 3-speed internal shifter hub for a regular build. The motor drive sprocket won't fit over the hub, by a lot.

    In short if you want to go direct drive and have better pedal go external gears as this was a nightmare.

    [​IMG]

    [​IMG]

    I didn't say I couldn't pull it off, it just cost me an extra $30 and an entire day (10 hours) of 'no fun' work to make it go.

    Just a tip on bike choice, avoid internal hubs if you don't budget an alt rear sprocket, but why? For ~$100 more than the sprocket mount you can Jackskshaft the thing.

    The warnings I wanted to get across to you guys aside, I was happy to put my KC's Kruisers stickers on this new difficult build too because, well, I pulled it off pretty well I think ;-}
     
    #1 KCvale, Apr 20, 2012
    Last edited: Jun 18, 2013
  2. flmotorbikes

    flmotorbikes New Member

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    Thanks for the heads up
     
  3. Ibedayank

    Ibedayank New Member

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    [​IMG]

    is your friend or one of these if you have one or know somebody that does

    [​IMG]
     
  4. KCvale

    KCvale Well-Known Member

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    Just snickers at the dremel tool for this ;-}

    The sprocket is 1/4" thick chromium steel with a 1 3/8" hole, you need a 1 7/8" centered hole to fit over a Nexus 3-speed hub.

    I have far beefier grinding tools than a whimpy Dremel like a real drill press with carbide metal cutting rasps and didn't bother to even try knowing how futile and inaccurate that would be.

    There is also another issue, once you get to mounting the sprocket you'll find that hub also has a lip for the spokes and getting the mounting bolts to fit that close to where the spokes mount just adds to the frustration.

    [​IMG]

    Then as if to just add insult to injury, that is not just a dust cover on the left, it is an integral part of the mechanics, the brake arm is permanently attached to it, and it needs to spin on the hub right where the sprocket is or the hub won't spin.

    [​IMG]

    So just to reiterate my warning about mounting a DD sprocket on a Nexus 3-speed hub... DON'T unless you budget in a bolt on hub sprocket mount, it just isn't worth all the hassle just for pedal side gears.

    The really sad part about this story is I also have a new high performance Macargi Pantera 7-speed shifter build in progress here.

    The only real difference between the Tahiti and Pantera is the hub and the HP shifter would of had no problem and frankly I think would have been better with the 3-speed and the DD customer happier with a 7-speed to pedal along.

    Alas, the Tahiti's rims are frigg'n RED and that would have blown the whole look of the shifter bike so a no go.

    Oh well, live and learn, and hard jobs as well as failures are teachers in themselves, this was just an exercise in learning from mine ahead of time ;-}
     
    #4 KCvale, Apr 21, 2012
    Last edited: Jun 18, 2013
  5. Ibedayank

    Ibedayank New Member

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    Dremel makes air tools.... Ya gotta post some links to one as all I have that looks like what i posted a pic of is a air powered diegrinder
     
  6. The_Aleman

    The_Aleman New Member

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    What's the old Texas joke?

    "I wanna Coke"

    "What kind?"

    "7up"
     
  7. KCvale

    KCvale Well-Known Member

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    Smiles at Aleman ;-}

    Here in Arizona it's:

    Bartender I'll take a beer.
    What kind?
    Jack Danial's with an ice water back, and make it a double ;-}

    Tools are tools, some are better at a given job than others, let's leave it at that shall we?
     
  8. KCvale

    KCvale Well-Known Member

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    Well bummer, this is just a flat no-go build with a DD sprocket on a Nexus 3-speed without a MM hub mount sprocket or a different hub like a coaster brake single speed.

    We went to do test rides on it this morning and it was failing before we we could even fire the motor up.

    I'll take in the shorts on this build but I'll move on to the next one one a wiser man, I just hope my sharing this with you rookies will save you some grief in bike selection in advance.
    That's what these sites are for too, pre-build advice not just how to fix something you did wrong to start with.
     
  9. Ibedayank

    Ibedayank New Member

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    ok what failed and do you know why...detailed pics and might be able to solve it

    no such thing as failure when trying something new just found a way that did not work
     
  10. KCvale

    KCvale Well-Known Member

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    The detailed pics are above.
    The rag joint sprocket mount interferes with the 3-speed hubs ability to spin at it's brake arm to hub pivot point.

    Unlike a coaster that just has a nut on the axle against a bearing behind the brake arm, the brake arm and the entire 1 7/8" 'dust cover' end piece are on piece, and compressing a sprocket on it won't let the actual hub spin free.

    The customer insists on a 3-speed so I went to Maniac Maniac's site to get a hub mount sprocket on it's way only to find they only go up to 1.77" hub size, I need 1.875" to fit that hub.

    I e-mailed Jim a couple of times but no reply yet so I may just end up having to make this a free jackshaft job unless I can talk him into swapping his Tahiti bike for a 7-speed Pantera, same bike, just different drives and a rag sprocket will work fine on that.
     
  11. Ibedayank

    Ibedayank New Member

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    KC strumey does make a 3speed hub with a diskbrake mount
    all hubs with a K in the part number are disk compatible
     
  12. BarelyAWake

    BarelyAWake New Member

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  13. KCvale

    KCvale Well-Known Member

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    Ya, nice 3-speed hub, but look how fat it is, you won't get a stock rear sprocket to mount on it, the hole is too small and the mounting bolts just won't fit around that outside lip.

    I solved this problem.
    I bought a Pantera 7-speed and swapping the wheels with the Tahiti.
    The customer direct drive will be a 7-speed pedal shifter. The DD sprocket mounts like a dream on that hub.

    The Pantera will become a 3-speed 4-stroke JS shifter for sale.
    I have all the parts and looking forward to building that one ;-}
     
  14. rustycase

    rustycase Gutter Rider

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    Thank you for the informative post, KCVale!
    Very helpful information.

    It's a very nice looking build.
    Probably goes to show almost anything is possible to motorize.
    The question you answer is, Why? If something else is easier...

    GREAT post!
    rc
     
  15. KCvale

    KCvale Well-Known Member

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    Thanks rusty, you got the point of the topic, why pick a bike that will be hard if not impossible with so many other options?

    This 'disaster' was adverted (to my advantage by the way) but I have the resources to do it with another cool build, most everyone else is just building themselves a single bike that needs to go without these types of problems.

    I started out reading these forums and gained a vast amount of advice before I ever built my 1st bike from those that came before me.
    I still consider that a debt to repay with my help for those that are coming behind me, and maybe even some new tips for those with much more experience than I have so far ;-}
     
  16. Ibedayank

    Ibedayank New Member

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    the right answer is.... Because we can


    some like a challange others like a itemized list of parts and a youtube video how to that goes togather like a snap togather model car
     
  17. killercanuck

    killercanuck New Member

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    Yea that sounds like a weird hub you got stuck with. But hey, if everything was so easy... eh? Sometimes our brains need a good kick in the butt to keep us humble. :p

    It takes all kinds of creativity to get where you want to be from where you are.
     
  18. KCvale

    KCvale Well-Known Member

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    Well this Tahiti went out the door with direct drive on the 7-speed wheels and front fork from a Pantera.
    The Pantera got a Springer front fork with front C brake.

    [​IMG]

    With a 'fat boy' back C brake and the V-brake on the Pantera's front fork and a SBP teeter-todder dual pull brake lever she stops on a dime, pedals up to start easy, and overall just your 'nothing to get excited about' basic ride I build every week.

    It's the Tahiti's original 3-speed Red wheels going on a different Pantera, a red one, my red one and destined to become a 4-stroke 3-speed shifter in short order is what I'm excited about ;-}
     
  19. JustAnotherBozoOnABike

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    ...too bad your pictures are no longer here, it makes the thread much less helpful.

    peace, bozo
     
  20. KCvale

    KCvale Well-Known Member

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    They are now, at least the topic pics.
    I have been having server issues since last Friday so using other places for my pics.
     

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