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  1. #1

    Default Custom primary chain?

    Hey guys, I知 running a chain primary with the stock 37 tooth clutch basket and a non compensator type 25 tooth motor sprocket on a 73 fx in the stock swing arm frame. I ran it open last year and this year I知 enclosing it in a tin primary. for the most part I知 able to keep tension on the chain no problem with my adjustable trans plate until it stretches to the point that the transmission is slid all the way back and bottoms out on the swing arm ear on the frame. So my question is this, the primary chains are 428-2-82 but does anyone make one that痴 one or two links shorter? Anyone know of a company that would be willing to make a custom one? I tried calling a few places with no luck. Also if I did have one made is there any reason I couldn稚 have one made with a master link in it? I know on my 45 flathead the primary chain has a master link and I致e never had in issue because of that. Thanks!

  2. #2

    Join Date
    Dec 2018
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    Yes, an 80 pitch primary chain is available but it won't help you. Way too short for your sprocket tooth count.

    If you keep it lubed properly in the tin primary it should last. Running it open leads to short life as you have found out.

    Jim

  3. #3
    Senior Member

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    The 428-2 master links are available here:

    Connecting Link for Double Row #428 Chain
    Connecting Link for Double Row #428 Chain
    Harley-Davidson Replacement: 40055-39
    Fits 1937 and later Harley Big Twins.
    https://www.bmikarts.com/Connecting-...in_p_7213.html

    and

    Diamond Chain Company 428-2 Riv
    Roller Chain - 428 / 1/2 in Pitch, Riveted, 2 Strand, Carbon Steel Material
    inside width: 5/16 in
    pin diameter: 0.174 in
    roller diameter: 0.335 in
    tensile strength: 8400 lbs
    Price is by the foot
    https://www.motioncanada.ca/productD...p?sku=01467912


    Compare that to the factory 428-2 primary chains, available in 82 or 76 link depending on model...also see dimension chart on page 8:

    https://www.diamondchain.com/wp-cont...motorcycle.pdf

  4. #4

    Default

    Awesome thanks guys! I just ordered two of those master links, I figure I can just buy a normal 82 link primary chain and shorten it to a 81 link using the master and I’ll keep the spare master link in my tool roll. You guys have any preference on primary chain brands? I know the diamonds can be had on eBay for as little as ten dollars and the ultimas are $50 and I see them all the way up to $100. What’s your experience? I’m not making any real power just a 74” bike with electronic ignition solid lifters and a super e. No burnouts or wheelies but I do go threw the gears pretty good and do some decent engine braking.

  5. #5
    Senior Member

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    I don't know, but typically, the $ cheaper $ it is, the cheaper it is. like I tell the guys at work, you can buy 3 cheap ones, then buy a good one, or just buy a good one.
    Sometimes you actually get what you pay for.

    compare thickness of sideplates, pin diameter, and tensile stength.

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