2nd 212 build... heavy duty

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by Tony01, Sep 10, 2017.

  1. Tony01

    Tony01 Member

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    Starting with a '69 CT1 as my frame. No more old schwinns. I've found their limit ~8hp.

    Built up some new wheels. Husky 26x50mm steel rims, 11g spokes, rear hub moped (drum brake) and front hub a SA HDS22 dynohub. 12V maint-free system coming soon...

    Going to use the same 212 block I've put 13000 miles on.. We shall see how long a 212 really lasts!

    Pictured is dirtbike after I stripped most of the crap off it, and before I stripped it further. And my first mockup photo. seems like about a 4-5" drop from original. Going hardtail. Hows the mockup look thus far? Gonna have a gas tank on it too so I need to figure that in at some point for the look.
     

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  2. curtisfox

    curtisfox Well-Known Member

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    Looks like a good start, if you could incorporate the tank into the top frame part. It has the forum or shape all ready there, should make a good build...........Curt
     
  3. Tony01

    Tony01 Member

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    man if I had the skills I would definitely make my own tank. For now I'll be using the 1gal tank that's on my bike currently.

    Swingajig:
    I made the assumption that the swingarm is square/straight to the head tube. Everything from there is right on the money. The swingajig does move up and down, but the final location is bounded by the endpoints of my chainstays, which are shown in the next post.

    KIMG0092.JPG

    KIMG0093.JPG
     
  4. Tony01

    Tony01 Member

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    Sleeving lower frame rails in prep for chainstays. Frame is starting to take shape. Trying to finish the rear end tomorrow so I can get started on motor mounts, and all the small ****.


    KIMG0090.JPG

    KIMG0095.JPG
     
  5. curtisfox

    curtisfox Well-Known Member

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    That frame has a Simplex look where the tank goes. Just a thought, my old Monark twin had a 2 piece tank. Gas tank half clamped to the frame, then studs stuck through where the tool box clamped to the other side. Weld one up and fill it with goo sealer. LOL..............Curt
     
  6. Tony01

    Tony01 Member

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    well I screwed up a little, so i had to flip the dropouts to have enough meat on the chainstays. cut em too short :(

    the jigarm worked great. Added a brace under the frame rails that ties them to the center part, on the underside.

    Slotted the tubes for the dropouts. Made a jig for the seat stays. Measured out where to cut for the frame tube, made a support from tubing... tacked it together... looks like a frame now. Can take out the piece of metal that was holding the lower rails together.

    KIMG0096.JPG

    KIMG0097.JPG

    KIMG0098.JPG

    Frame is tacked together now. Need to make gussets and supports.
     
  7. culvercityclassic

    culvercityclassic Well-Known Member

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    Looks good so far, really looks more like a motorcycle than a motorized bike. You use this bike for a daily ride? If so what is your commute as far as miles?
     
  8. Tony01

    Tony01 Member

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    Thank you! Yeah bike was daily until a couple months back when i got a car so I started mixing it up. avg commute was 25mi with 200 per week since last summer. I seen every problem!

    Yep.. not based on a bicycle frame any more. Deep down I knew this would happen...


    Well I did some more work yesterday. Did some finish welding and the rear spacing only shrunk an eighth of an inch when I pulled out the jigarm. Now to figure out how to mount a jackshaft and align it with the engine. I'm thinking of using some steel plate I have here from something else to line up the side cover to the JS somehow, like a torque converter backing plate type deal. And still need to decide on the style and size of jackshaft. Since the 5/8" jackshaft on my schwinn is bent, I'm thinking of moving up to a 3/4" JS and want to rethink the current setup.

    KIMG0105.JPG

    The box tubing the frame is resting on is the same stuff I used to make my 2-speed, dual JS transmission from.. And I still have 5ft of the stuff :D

    KIMG0104.JPG

    KIMG0100.JPG

    .100" wall 7/8" tubing.. no tubing benders or notchers!
     
  9. MEASURE TWICE

    MEASURE TWICE Active Member

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    Like seeing the progress of DIY stuff! The jig, how was it fastened temporarily to assist with keeping warpage and other undesirable from happening?

    It is a bit small for me to see.

    Also if closer up or clearer how that rear suspension is to be operating. I really think I need that on my off road bike, but mostly I am standing on pegs anyway. The un-classy extra foam added to my banana seat helps but only so much.
     
  10. Tony01

    Tony01 Member

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    Jeff, there is no rear suspension. The swingarm was the frame jig for the rear. It did warp a little but not much.

    Yesterday did the motor mounts. Still haven't decided on jackshaft mounts, whether to go with the typical minibike weldment kit like you have Jeff, or continue using the flanged bearings. I think I will just do the flanged bearings again. They have lasted me thousands of miles and I could replace them anytime I want to. They do also seem to be heavier duty than the typical 1-3/8 OD bearings used on the weldment kit, and they come in 3/4" ID also which I will upgrade to when I have cash for a new transmission.

    Today I built a new rear wheel using a motobecane rear hub, 11g spokes, and a husky 50mm steel rim. Pics tomorrow.

    Here's the mockup photo from yesterday with the 212 just sitting there before I put the motor mounts in. The front wheel is built already in the pic, it's a 50mm husky steel rim laced with 11g spokes to a Sturmey Archer HDS22 dynohub.

    mockup.jpg
     
  11. MEASURE TWICE

    MEASURE TWICE Active Member

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    Those sturdy looking pillow bearing blocks that include a oiling cap would be what I would spend more on if I had to do it again. Also the looseness of the bearings in the holder (if you can call it that) I had to deal with to make it where I was satisfied with it not spinning inside the holder itself you do not want to experience. There should be a set screw that holds the bearing for replacement and so it is fastened well to the block. The sprockets in the kit could be more accurate too. I know you are looking for perfection in the working hardware. And maybe unlike what I have done so far with my bike, for the other side of the coin, aesthetic looks, you have some good lines in the frame you have going on!
     
  12. Tony01

    Tony01 Member

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    Thanks! Alright then flanged bearings it is. Yes I am looking for perfection. About 500mi ago my jackshaft got bent at the output sprocket. Probably cause the chain jumped and got caught up. I bet that is what snapped my seattube as well. I've been riding with a nasty bent js for a while now. It's very scary and I was probably losing 5-10mph on the top end.

    IMG_3806.JPG IMG_3809.JPG IMG_3811.JPG

    Yep that's right I'm cutting out dropouts for the dirt bike fork. It is spaced at 5" and I need it at 100mm which is a 1/16 under 4". Half inch per side. Dropouts are gonna be a quarter inch thick steel at the axle. I don't want to replace the fork seals, so I'm just going to cut the springs down to drop it.
     
  13. Tony01

    Tony01 Member

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    Welding on the fork is done. I finished my dropouts. Clamped the steel pieces together, tacked, an hour or two later of grinding and welding then grinding again and welding to the fork over a period of 5 hours to keep it cool, and here we are. I still messed it up though. There are apparently boogers on the inside from too much heat, as the fork bottoms out as seen in the photo. No problem though, it still has the 3" of travel I wanted just not the range I wanted but w/e. I'll just drop it in the crowns then.

    Time for another mockup! Love these mockup makes me feel like the build is almost done. If it looks weird, it's cause the forks are too tall; the front end will be a few inches lower.

    IMG_3812.JPG

    IMG_3820.JPG

    IMG_3818.JPG

    Think I'm gonna have to make a new intake cause it hits.... F*CK
     
  14. Tony01

    Tony01 Member

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    Well I haven't had much time to work on it, but I've made some progress. The hard stuff is done.

    Shortened my forks. When I welded the dropouts I guess I used too much heat and it probably caused boogers on the inside.. on both sides, which prevent the fork from compressing fully and get it stuck even with springs in place.

    So what I did is I simply shortened the damn fork. I still had about 3" of movement, which is exactly the amount I want anyway. But now at full extension the tire is only about 5" from the bottom crown. Also fabbed up a top brace for the lowers, which is actually a stop for the fork in case it tries to compress more than it should and get stuck (and stop the tire). Hard to see but its behind the lowers in the 2nd pic.

    IMG_3823.JPG

    IMG_3827.JPG

    The last couple days I've been making the jackshaft mount. I used the same 4x4 box tubing and will be using the same flange mount 5/8" bearings. I finished cutting out the mount and installed the bearings and a fresh jackshaft, and lined it up to the motor crank. Flat and parallel. Clamped an I-beam level to the crankshaft with the shoulder up against the 4-bolt mount pattern for squareness and went off that. Welded it all together.

    IMG_3832.JPG

    Removed some of the gusset material at the head tube, along with the old gas tank mounts that were on the sides. Had to do this to allow my 1gal gas tank to seat all the way down on the tube. Welded in some 5mm bolts to mount my 1gal gas tank on. It is not like the typical kit 1.9l or 2.5L tanks with the studs coming out of the tank, the 1gal tank has much better construction overall, same type gas cap, but the mounts are just flanges with holes similar to the strap that is used for the underside of the top tube. Much, much better design.

    IMG_3834.JPG

    Cut out the old front mounts and welded in mine, for the boss on the 212 cylinder that used to hold the pullstart cover, throttle linkage plate assembly, and gas tank I think..

    Tomorow I will install a hinge and shock mount for my seat, and will have to modify the frame under the seat to suit. I have a junk shock off a cheap bicycle but the spring says 750lb/in, which is not going to work unless it is leveraged. I'm gonna put it about a 1/2 the distance from the hinge, between hinge and seat pan spring perches.. but this will still not be enough to even get it to move a tiny bit. I just need a different spring, or a better complete shock.
     
    #14 Tony01, Oct 4, 2017
    Last edited: Oct 4, 2017
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  15. Tony01

    Tony01 Member

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    Geez I really need to finish this build thread. I lost my phone (under the bed) for over a month and went through two cheapies, taking build photos, so I don't have all the pics in one place. But I got the bike running and just slapped a cvt on her.

    Motor revs out much higher than it used to with a clutch which tells me I made a mistake with gear ratios. Actually it's in the cvt. I thought it would shift to a 1.4 for an overall of 6.8 but I guess it maxes out at a 1.6 or something. This is the 20 series symmetrical one with the 7" driven pulley. It has 4 holes for spring tension and comes stock on #3. I will set it at #1 (high gear sooner) one of these days before going to a taller final drive ratio. The motor revs high but my top speed is actually lower according to the butt dyno. Well here it is. I'll update this thread later on with more progress pics that I was taking as I went.

    I've put about 200mi on it thus far. The rear wheel needs retensioning of the spokes (rear feels muddy sometimes), the rear brake still needs to be hooked up, and the engine block needs the deck resurfaced. Still the same high mileage predator, still haven't opened the case since I bought it and removed the governor in summer '16. This bike is just begging for some chrome fenders!
     

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  16. MEASURE TWICE

    MEASURE TWICE Active Member

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    Before changing springs I want to see you doing that dirt hill climbing thing! HAHA. Looks nice sleek design.
     

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