Single Wheel Dual Sport Trailer - CRF250L

Discussion in 'Some Assembly Required' started by Lapchik, Jul 17, 2019.

  1. Lapchik

    Lapchik Tinkeritis posterboy

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    Pivot bushing assembly. The split collars will be welded on one side to prevent the pin from turning. That way the wear is only on the brass bushings. The pin is 5/8" rod with a section of heavy wall pipe slipped over one end. I TIG welded that together and then ground a nice bevel on it with a flap disc on my angle grinder. I will later put a grease zerk in the top of it for lubricating the bushings. That requires more precise equipment than I have at home, so the grease mods will have to wait.

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    In addition to the Evelyn Wood sped reddin' course, I took another course of hers in tenaciously quick TIG'n. I figured since I will be grinding and beveling that cap to make it look all pretty, I might as well try to weld it as quickly as possible. I cranked the amps, set the pulser on the welder, laid fill wire across and burned it down. It actually turned out ok, which is modus operandi for me. Anytime I try really hard, I fall flat on my face.

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    #21
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  2. Lapchik

    Lapchik Tinkeritis posterboy

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    This hitch setup will allow for greater than 90° angles between the bike and trailer. The trailer won't tip over because the vertical pivot is on the bike and the horizontal pivot is farther back. There are some hitch designs out there for this type of trailer that have the pivots too close together and allow the trailer to pivot [lean] when at extreme angles like this. Hitches with the horizontal pivot on the bike side can actually allow the hitch to roll under when the trailer and bike are at an angle. The last thing you want when you are backing up is for that trailer to tip over. My trailer should lean a little when jackknifed like this, but it won't tip over. I think. It works when I do 3D drafting in my head. We'll see I guess.

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    #22
  3. Danger4u2

    Danger4u2 KX500 is Danger4u2

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    I'm watching too. Like your welds.
    #23
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  4. Lapchik

    Lapchik Tinkeritis posterboy

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    Today I did some touch up welds, hand filed a few parts, disassembled everything, and threw some primer down.

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    #24
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  5. OU812

    OU812 Legend in my own Mind! Supporter

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    CADVR bound?
    ;)
    #25
  6. Lapchik

    Lapchik Tinkeritis posterboy

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    Nope, not this year. Schedule didn't work out.
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  7. Lapchik

    Lapchik Tinkeritis posterboy

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    Made some new parts today. I made the thick washers out of some round stock on the lathe. They are for mounting the fender. Some acorn nuts will hold it all together. All that is mostly for show. I could have just trimmed down the countersunk bolts and mounted them top-down towards the tire, but why half-ass something I am making for myself? Also shown in this picture are the axle plates, which I ground the corners and edges on.

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    I ground down the slug-and-plug welds in the center of the height adjustment arms. Could have left them, but it looks better this way. 4-1/2 years ago I made a video on how to do slug-and-plug.



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    I drilled into the horizontal pivot pin (with a lathe) so I could throw a grease zerk in it. I cleaned up the chamfer on the head while I was at it. Turns out a lathe and carbide tooling is more accurate than my left hand "vise" and my right hand mounted angle grinder with a flap wheel. It's got an 8MM zerk, and that was too big to drill all the way down with. It's only a 7MM hole just deep enough for tapping the threads for the zerk. Below that, I went to a much smaller size. I got lucky and hit the channel I made while drilling cross-ways using a drill press and no vise. The bushings are not graphite or PTFE impregnated, so I have to be able to lube them.

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    #27
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  8. OU812

    OU812 Legend in my own Mind! Supporter

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    :(
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  9. Lapchik

    Lapchik Tinkeritis posterboy

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    Not a big update, but a few items with progress. The bushings for the rack mounting bolts are welded in. The main tube, fender brackets, swingarm, axle blocks, and shock tower components are all in primer. Next up is the hitch. Once everything is welded and working I'll finish the paint.
    #29
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  10. Lapchik

    Lapchik Tinkeritis posterboy

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    Paint! I had Jarvis throw a little hot rod red on it. That should help keep a low profile.

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    #30
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  11. Lapchik

    Lapchik Tinkeritis posterboy

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    Final assembly for the trailer side has started. Still working on the hitch. I hate bulky gloves and only use these for vise pads and fire pit stuff.

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    Horizontal bushings installed.

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    Swingarm parts installed. Still need to cut down the threads that are sticking out, but that's what you get when you use off the shelf stuff. Shouldered bolts that size are either custom order or custom build, and I would rather just cut cheap bolts to size. Next I'm working on the cooler carrier hardware.

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    #31
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  12. Lapchik

    Lapchik Tinkeritis posterboy

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    Welded up the hitch arms, and then threw them on the bike. Hopefully I will be able to tack a few parts together later tonight.

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    Reattached the stainless mesh, but used button head cap screws instead of pop rivets.

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    Replaced one mesh bolt with an eyelet to hold down the cooler.

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    #32
  13. TWChristy

    TWChristy BeenTHEREcrashedTHAT

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    0E916B59-5E56-4B3C-B94F-F058DF6156DE.jpeg Wow you got way more technical than I did. I just cut up a ttr125 !
    #33
  14. Lapchik

    Lapchik Tinkeritis posterboy

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    The only thing I have laying around is a GS550 Suzuki, which is way too bulky to pull behind my Honda.
    #34
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  15. Lapchik

    Lapchik Tinkeritis posterboy

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    Well, I done f***ed up. I didn't put a temporary brace in by the bushing end when I welded on gussets, and it pulled bad. I had to add 3/4" of width back into it. I decided to bend the solid rectangle stock instead of cutting and rewelding or starting over. Strategic use of fire can fix a lot of problems.
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    As a bonus, I can haul these with no modifications or adjustments to the cooler hauler. I hate carrying gas inside my SUV. (Also.....12 gallons x 60 mpg = 720 mile range.....:evil)

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    #35
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  16. Lapchik

    Lapchik Tinkeritis posterboy

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    #36
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  17. Lapchik

    Lapchik Tinkeritis posterboy

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    Hitch is done, including a guard to keep road debris off the cargo.

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    The metal hits the ground before the fender does.

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    The trailer will be nearly touching the license plate when the fender touches the tire.

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    #37
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  18. flinders_72

    flinders_72 Long timer

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    #38
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  19. Lapchik

    Lapchik Tinkeritis posterboy

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    At extreme angles, it tips over a little. A hitch mounted up high might fix this, but the bike isn't strong enough for that. KIMG2658.JPG
    #39
  20. Lapchik

    Lapchik Tinkeritis posterboy

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    Went around the block a few times to try it out. Can't really tell that it's there other than during braking and very show maneuvers. Took it back apart and painted the hitch. Should be ready for the road tomorrow!

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    #40
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