Tanaka pf4000 powered tadpole trike

73 mph? I didn't think that was even possible

Ok, I'm interested, since I run a 47R.

I'm presuming the gearbox had 18.75:1 ratio. What were your sprocket sizes?

Is that the Tanaka-specific 3-piece pipe, and did you have to modify it to fit?

How's your gas mileage?
 
5-7
The sun is in storage up in Pa now and I haven't run it in a while. It had 20 in wheels all the way around. I don't remember what gear I had on it when I did that speed run but it was way tall, had to pedal to get started and it took about 3/4 of a mile to get to top speed.

It was totally impractical but i just wanted to give it a try since I had some big sprockets laying around.
 
The pipe is the three piece and I didn't have to mod it just twisted at the existing joints to fit the sun. My ex is sending that pipe and the 47r to me and I'm gonna try to put it on the kmx but some modding maybe required
 
If you look at the picture of the sun you'll see that the top sprocket is bigger than the guard and it's the smaller one I ran day to day.

As I remember I was running the 47r around 9300 rpm for the speed run, maybe a little more and the chain ratio was around 2.5 ( overdrive) ,the tire was 20in and the gear box was 18.75.

Here is the math

9300/18.75*2.5*pi*20*60/12/5280 = 73.78 mph

So I think that's about right

It was about a 40 tooth sprocket on the gear box and a 16 on the axle
 
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Here is interesting data

* Roadster Touring Racing Recumbent HPV
Frontal Area(sq.m) 0.5 0.6 0.3 0.2 0.1
Drag Coefficient (Cd) 1.2 1.4 0.9 0.5 0.2
Rolling Resistance (Cr) 0.008 0.004 0.003 0.003 0.003
Bicycle Mass (kg) 15 25 10 10 22
Rider Mass(kg) 75 75 75 75 75
Total Mass(kg) 90 100 85 85 97
"Resistances of Cycling Machines Chart"

Reproduced with permission from Bike Cult: The Ultimate Guide to Human Powered Vehicles by David Perry.**Published by Four Walls Eight Windows.
 
Vehicle weight: 72.6 kg / 160 lbs
Crr: .003
Cd: .5
A: 0.2 m2 / 2.1527820833419 ft2
Fuel energy density (Wh/US gal.): 33557
Engine efficiency: .22
Drivetrain efficiency: .95
Parasitic overhead (Watts): 0
rho: 1.22 kg/m3
 
Giving these results


MPH KM/H Aero (a) Rolling (b) Total % Aero % Rolling Watts HP HP Aero HP Rolling MPG(US) L/100km
5 8 0.30 2.14 2.44 12.49% 87.51% 5.46 0.01 0.00 0.01 6,428.05 0.04
10 16 1.22 2.14 3.35 36.34% 63.66% 15.00 0.02 0.01 0.01 4,676.27 0.05
15 24 2.74 2.14 4.88 56.22% 43.78% 32.71 0.04 0.02 0.02 3,215.70 0.07
20 32 4.88 2.14 7.01 69.54% 30.46% 62.69 0.08 0.06 0.03 2,237.36 0.11
25 40 7.62 2.14 9.75 78.10% 21.90% 109.02 0.15 0.11 0.03 1,608.27 0.15
30 48 10.97 2.14 13.11 83.70% 16.30% 175.79 0.24 0.20 0.04 1,196.93 0.20
35 56 14.93 2.14 17.07 87.49% 12.51% 267.07 0.36 0.31 0.04 919.11 0.26
40 64 19.50 2.14 21.64 90.13% 9.87% 386.97 0.52 0.47 0.05 724.96 0.32
45 72 24.69 2.14 26.82 92.04% 7.96% 539.57 0.72 0.67 0.06 584.92 0.40
50 80 30.48 2.14 32.61 93.45% 6.55% 728.95 0.98 0.91 0.06 481.06 0.49
55 89 36.88 2.14 39.01 94.53% 5.47% 959.20 1.29 1.22 0.07 402.14 0.58
60 97 43.89 2.14 46.02 95.36% 4.64% 1,234.41 1.66 1.58 0.08 340.89 0.69
65 105 51.50 2.14 53.64 96.02% 3.98% 1,558.67 2.09 2.01 0.08 292.47 0.80
70 113 59.73 2.14 61.87 96.55% 3.45% 1,936.07 2.60 2.51 0.09 253.58 0.93
75 121 68.57 2.14 70.71 96.98% 3.02% 2,370.68 3.18 3.08 0.10 221.88 1.06
80 129 78.02 2.14 80.16 97.34% 2.66% 2,866.61 3.84 3.74 0.10 195.73 1.20
85 137 88.08 2.14 90.21 97.63% 2.37% 3,427.93 4.60 4.49 0.11 173.91 1.35
90 145 98.74 2.14 100.88 97.88% 2.12% 4,058.73 5.44 5.33 0.12 155.52 1.51
95 153 110.02 2.14 112.16 98.10% 1.90% 4,763.11 6.39 6.27 0.12 139.88 1.68
100 161 121.91 2.14 124.04 98.28% 1.72% 5,545.14 7.44 7.31 0.13 126.48 1.86
105 169 134.40 2.14 136.54 98.44% 1.56% 6,408.91 8.59 8.46 0.13 114.90 2.05
 
The pipe is the three piece and I didn't have to mod it just twisted at the existing joints to fit the sun. My ex is sending that pipe and the 47r to me and I'm gonna try to put it on the kmx but some modding maybe required

Man, that's FLYING! If the forum had a face off, you'd prolly win!

I was lucky enough that same pipe fit in my center-framed bike. Like you, I twisted the joints. The head pipe was 90* off, so I used the kart's headpipe. Everything bolted on, even the OEM muffler.
 
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