Here we go again

Discussion in 'Motorized Trikes' started by SimpleSimon, Jul 18, 2010.

  1. SimpleSimon

    SimpleSimon Active Member

    As most of you probably know, my trike got backed over and smashed by a hit and run driver Tuesday while I was in the Comcast office paying my bill. I've been pretty bummed out - the frame was twisted, the engine crunched, and the rear axle frame bent - it is pretty much a write-off.

    So, with the encouragement of several folks here I decided to see what I can do to get back on the road again. I have a whole bunch of 1.5 x 1.5 x 1/8 inch angle iron "(steel bed frames, actually), and I have a sawzall with hacksaw blades. I can get a 4 foot long 1.5 x 1.5 inch square tubing joint for $5 from the local scrap yard, which is sufficient to make a drop center front axle assembly, and the front boom the sliding boom for the BB will fit into.

    So, I spent today doing a sketchup model to clarify my ideas. Attached is a view of that as a basic frame and wheels only. I'd appreciate any and all comments, suggestions, etcetera. As drawn it is intended to be a rear suspension twin rail ladder frame, although I need to check some references on shocks to ne sure I size that mount correctly; as a consequence the shock tower is not yet drawn in.

    Attached Files:

  2. Turtle Tedd

    Turtle Tedd Member

    SS..if anyone can design a good tadpole ,I would bet on you..Steel would be better than aluminum..have a lifetime of experience with both materials..welded aluminum joints are an entirely different design than steel when any stress whatsoever is involved..I myself would use steel also..Thanks for your pms regarding the design of my tadole but I am putting that build on hold for a while till I am fully recovered from my MB crash last Dec..will stay tuned in for progress reports on your tadpole..I like the looks of that frame and the larger rear that 26 rear and 20s in front? Are you going for rear or full suspension?
    Last edited: Jul 18, 2010
  3. AussieSteve

    AussieSteve Active Member

    That's looking pretty good, Patrick. Looks like you'll be able to get a fair bit of rear suspension travel. Great drawing, too. What software are you using?
  4. srdavo

    srdavo Active Member

    I like what you have so far. Looks good.

    Let's skip ahead to the engine power..... what are you thinking? Rack mount or do you want to fix your current HT engine. (I have some 50cc HT engine parts.... square jug, with good fins)

    I've also got an extra pair of matched, bicycle headtubes & steertubes; if you want them to build your kingpins.
    Last edited: Jul 18, 2010
  5. SimpleSimon

    SimpleSimon Active Member

    Addressing the questions in order, yes, Tedd, I intend to go with a 26" rear wheel (since I have a good stout one already laced with 12 gauge spokes) and 20" front wheels. I prefer steel myself, since that is a material I am both more familiar with and am already in possession of.

    Aussie, the software is Google SketchUp, which is a truly excellent 3D modeling tool with a great range of flexibility and excellent support. Best of all, it is free from Google. I use it a lot.

    Srdavo, I think I am going to go with an R/S engine GEBE kit, which vegaspaddy has been kind enough to make me a truly excellent deal on. I should have that in about a week. I know the GEBE kits are usually a vertical rack mount, and this design will accomodate that very well - however, if the engine dimensions will allow, I'll cantilever it forward off the rear triangle frame. I am uncertain if that is feasible, but if it is it will lower the visibility of the engine assist quite a lot.

    It is that remaining uncertainty that leaves me unready to complete my design at this point, along with needing to check shock reference guides for dimensions. I know the majority of tadpoles use a variant of a sling seat, but as it happens I have a stout, very comfortable, adjustable backed steel office chair I am contemplating sacrificing to the cause. It has a lockable swivel feature, and an internal gas shock central support stem with about an inch and a half of vertical travel. I figure that chair, with a rear suspension, will make for a very smooth ride.

    Have you got a pic of the headtubes? If they'll work in my design (which is readily adaptable to changes) that would be very useful indeed. As the sketch shows, I intend to go with a center column steering system to a bell crank and tie rods to the steering arms.

    Thanks for the comments/questions, guys. It is this sort of interaction that makes this community my favorite place on the 'net.
  6. augidog

    augidog Banned

    simon, this is all really good order to help you in your planning, i'd like to pass on that the eho35 requires a near level mounting position, it can't be "rotated" like the tanakas. however, after you see the components, you may agree that it (maybe) could be made to fit nicely in front of the rear wheel if you're willing to provide the mimimal stretch necessary...pedal-chain routing might be a can o worms tho.

    i'll be looking forward to updates :cool:
    Last edited: Jul 19, 2010
  7. SimpleSimon

    SimpleSimon Active Member

    I was aware the contemplated engine would need a level mounting position - what I am contemplating is cantilevering a "shelf" forward from the near vertical rear triangle stays (which will be 1/2" square tubing) to mount the engine to, with the belt run (pulley center to pulley center) nearly horizontally. Engine dimensions will determine if that is feasible, as I'll need to allow clearance in the vertical plane for the action of the rear suspension. I am contemplating a single rear shock forward from the "ears" on the top crossmember tie of the rear assembly. I may fabricate a pivoting swing arm to translate the plane of motion through a sharp angle, or perhaps go with a pair of lighter shocks at the upper corners of the rear triangle.

    I'd like to keep the profile of the final design as low as I can, partly as a matter of aesthetics and partly as a matter of reducing drag. For similar reasons I may drag the frame components to a shop with a good drill press and lighten the angle iron by turning it into "drillium" style material. By my calculations I can drill out 3/4 inch diameter holes on 2 inch centers, staggered by a 50% offset for the two flats of the angle iron, and reduce frame weight by about 25-30% while actually making it stronger (the internal shifting of stress lines in the steel that drilling it creates stiffens flat plate if not excessive).

    The rear pivot is intended to be a hardened 1/2" steel head bolt, on which I intend to mount a pair of sprockets on a common bearing sleeve on the right side. That will put my chain run internal to the ladder frame rails, and will give me a short final drive loop that pivots freely on the rear triangle pivot axis - which means that chain idlers and guides are minimal, That, of course, is part of the consideration in whether or not I can forward cantilever the engine mount as well - there has to be unimpeded clearance for the top chain run.

    Those sorts of considerations are a large part of why I like SketchUp so much - checking swing arm clearances is simplicity itself with a simple flat diagram in that program.
  8. moondog

    moondog Member

    Hi SimpleSimon,

    Why not use an electric hub motor for the rear ?

    Trikes like yours could have plenty of ways to mount batteries low.

    That would also allow using SLA batteries and they are somewhat cheap.

    I have all you would need except batteries, cheap.

    Thanks, Steve
  9. srdavo

    srdavo Active Member

    Last edited: Jul 19, 2010
  10. SimpleSimon

    SimpleSimon Active Member

    I do recall seeing the pics of that stretched cruiser - beasutiful job he did there. Augi's engine is mounted at a forward rake of about 20 degrees on Sabrina, as well.

    The kingpins are modeled on the design you've posted links to previously, I take it? If so, then yes indeed, they will serve me very well, as that is exactly the model I intended to follow in fabricating some. The nice part is, they'll fit very well into the drop center axle I intend to build. The steering arms will function well to hook the tie rods from the bell crank to as well.

    Question: where did you get those truly excellent looking front wheels? They are exactly the type I have in mind, especially if I can affix a disc brake rotor mount to them.

    I want to mount the caliper casing to the tops of the kingpins, so they swing with the wheels - if I can figure out how I'll also mount a 50 watt rectangular fog light fixture to each so that the headlights pivot with the steering. Tail lights will be a combination orange blinker, and a red brake light, with turn signal lamps on outboard stalks. I intend to put a rack for pannier type bags on the rear triangle , but keeping it just clearing the rear wheel, as the rack will of course move with the rear suspension.

    A compressed air canister type boat horn (which I already have), and front fenders I intend to fabricate by lost foam molding of fiberglass, with integral top mounted turn signal/running light nacelles, and it will be truly what I want it to be.

    Many thanks for the kind offer - I'll gladly accept.

    PM incoming.
  11. Alaskavan

    Alaskavan Guest

    The other day, as I was driving home, I came upon a guy riding a tadpole. I stopped to check it out. It was an HP Velotechnik Scorpion. Full suspension. I truly believe that front suspension on a trike is the "Holy Grail". Especially after the last "leg suck" incident I had (I'm still using crutches). A couple of inches higher COG would be worth it in my opinion. Rear suspension is not IMO near as important (though desirable). The trike reacts a lot more mellowly to a bump on the rear tire than it does to one on the front.
  12. SimpleSimon

    SimpleSimon Active Member

    And I absolutely agree. Unfortunately, there is no hope of my purchasing such, nor is the construction of such within my skills. I can and have designed just such a trike, but I recognize that building it is way beyond my skill level.
  13. GearNut

    GearNut Active Member

    10 ball joints and 2 shocks and you have yourself independent front suspension.
    The ball joints are a bit pricy though.
  14. SimpleSimon

    SimpleSimon Active Member

    Actually, I've got a design with twin double A-arm and angled shocks that I've developed,
    The geometry is straight forward enough, but fabricating it is beyond my skills and equipment. Each side requires two A-frame members that, while quite similar, are different enough to present separate fabrication issues. Of course, the other side is a mirror image of that.

    The nice thing about the design is that it lends itself readily to either a recumbent tadpole overall design, or to a crank forward semi-upright bike. In addition, it will accommodate wheel sizes between 18" and 26".
  15. GearNut

    GearNut Active Member

    That sounds very cool!
    I have had a design stuck in my head for years. I do not have nor know how to do CAD programs, or else it would all ready be drawn up.
    The A arms are simple to make with a particle board jig and a mig welder.

    I wish you all the luck, good fortune, and godspeed with your new build!
  16. vegaspaddy

    vegaspaddy Member

    hi SS,

    Box should be on your doorstop tomorrow, anyhow here is some info straight from the manual.

    The Subaru Micro series engines are designed to run in a wide range of positions. The patented oil lubrication system is elegant in its engineering simplicity. The natural pressure changes in the crankcase caused by the piston movement in the cylinder are harnessed to pump the oil throughout the engine. Oil is pumped from a reservoir in the base of the engine through a network of one-way valves for reliable lubrication and long engine life without the need to keep the engine level.

    and also.....

    NOTE :
    If the engine is operated at upside
    down, white smoke may be
    exhausted from the muffler.

    upside down now THATS crazy me thinks i would be a little more worried than just WHITE SMOKE along with trying to change the oil !!!!!!

    so as far as been able to get it to fit snugly i dont think you have too many worries....

    send me a pm when you get everything checked out..

    Last edited: Jul 21, 2010
  17. vegaspaddy

    vegaspaddy Member

    IN section 3 , page 6 of the service manual (link 2 in the above message)it goes into more detail about the engine running at various points off center.

    kudos to r/s for having there service/ repair manuals online so everybody can access them and not get ripped off having to buy seperate ones later.
  18. SimpleSimon

    SimpleSimon Active Member

    Been a bit busy and distracted, but I've received the package from vegaspaddy, and today, from srdavo. Thanks a whole bunch guys!

    After receiving the GEBE kit I realized I'd need to modify the design a bit to lengthen, allowing clearance for the engine to swing. So I've drawn a new frame - same basic design but longer, and I modified the rear triangle a bit - I realized I'd engaged in overkil as far as strength of materials required severely in the first design.

    Attached Files:

  19. SimpleSimon

    SimpleSimon Active Member

    What with the trip to Oregon and all, I've made small progress to date. I do have the angle iron prepped for my detail cuts, but it is going slowly because my Dr gives me enormous grief about staying off my right foot until the wound on my heel finishes healing up, so I can't be at the workbench for long at all.

    I expect to get the components of the ladder frame cut and finished this week, then next week the rear triangle pieces and the rack. I need to get an 8' joint of 1.5" x 1.5" square tubing for the drop axle, then fab that up. Since the drop axle has a 15 degree back tilt for Ackerman compensation, the ladder frame side rails need to be cut to fit that angle.

    Attached is a finalized sketch with the major frame components dimensioned on it.

    Attached Files:

  20. Turtle Tedd

    Turtle Tedd Member

    SS...that one looks like an excellent frame design to me..cant beat that square steel tubing..should be a strong trike and will be able to take to being motorized