Author Topic: 70's YardMan Mock-Up  (Read 3127 times)

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Offline birdman_express

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Re: 70's YardMan Mock-Up
« Reply #15 on: November 13, 2018, 12:25:51 PM »
I understand perfectly. Thanks so much!

My guess - use the 6x6.5 wheels and the 13x6.5-6 tires on front?

NP,  and that is a good combo.0
Marc Baker

ARC Dealer

Marc from ARC.... "Billet Billet"

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Re: 70's YardMan Mock-Up
« Reply #16 on: November 24, 2018, 06:37:13 AM »
Made some good progress on this. Got 8" wheels and mounted 16x7.5-8 tires (see my pre stretch idea to get bead to seat easier). Scratched my head a bit considering how to get this low, tires to clear fenders and keeping seat pan above tops of tires. I cut lower outer fender section off, flattened the step-down, then got it all to fit back together nicely... friggin' miracle. I'm happy with my solution. If I were more experienced with this I might have chosen a different donor frame.
 Made front axle plates on friends ironworker. Verified my pre-set 10 degree caster and camber and tacked in place.  Have 2 right hand spindles as that's what was in used parts bin and they are heavier duty than left side - 3/4" inner spindle shaft dia, and 5/8" outer so I'll have to mod. one dep if I go w/ front or rear steer set-up. Adj. camber w/ heim joints and caster - my plate is set at + 10 degree and the slot punched in to top of plate allows +9 to +15 degree range. Wedge adj. by arranging the washers above / below.
 Need to start considering an engine. I don't have a sub 17hp single, or a + 8hp flathead per build rules... To keep going forward, deviating from build rules I do have a 17.5 ohv single, and an 18.5 ohv single. + I have a 12.5 f.h. opposed twin and a 16 f.h. opposed twin. I can also get a 20hp ohv v- twin.
 If any of you weren't sure if you would definitely race this, which engine might you go with? Is there a brand new < 17hp ohv, vert. single I might find on a Black Friday or Cyber Monday sale? New would be nice, but I don't want to spend much...

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Re: 70's YardMan Mock-Up
« Reply #17 on: November 26, 2018, 05:13:48 AM »
 Got my discretely hidden frame reinforcement all welded, trans plate lined up and tacked in, trans mounted, chain and tensioner installed. Now considering where battery and fuel tank to go. Maybe if I inch cowl back a bit they'll fit in there. Next to reinforce cowl and set up steering column. Column runs straight in to engine head so may need to use a u-joint or 2.

Pics in reverse chron. order.


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Re: 70's YardMan Mock-Up
« Reply #18 on: November 26, 2018, 06:27:41 AM »

Can, should or shouldn't I use a u-joint or 2 to get steering column to clear head? I suppose I could run engine head forward but it sticks out front quite a bit. I think it'll clear grill but what about the weight out over front axle?

I see a lot of front steer set-ups. Can someone tell me why or the reason, advantage over rear steer?

Can ' should I plan on using 5/8" belt / pulleys? Do most of you use 1/2" or 58"?

I have not calculated final drive ratio yet. What might be front / rear pulley combo? I see what looks like around 8" engine and 5" trans input...?

Can I mount battery on running board just in front of left rear tire?