Full Suspension Big Block Mini-Buggy Build

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got the back cage on today. I already have the gas tank mounted but I'm also using this bar to mount a storage box for tools.
20221105_160252.jpg
20221105_160259.jpg
I really like the look of it!
 
Last edited:

Denny

Canned Monster
Messages
8,227
Reaction score
4,451
Location
Mayberry, Indiana
You want your harness mounts lower than your shoulders to keep you in the seat. Might want to rethink the mounts for that.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
You want your harness mounts lower than your shoulders to keep you in the seat. Might want to rethink the mounts for that.
I was told the exact opposite by my dad who used to run stock cars. He told me horror stories of guys who ran shoulder mounts lower than their shoulders and how in an impact the straps would compress their spines down rather than just hold them back. He was the one who told me to run them in line or at the very least higher than my shoulders. Granted, it may be a little overkill but I'm going to drop them down anyway. They'll probably get mounted somewhere else.
 
Last edited:

Denny

Canned Monster
Messages
8,227
Reaction score
4,451
Location
Mayberry, Indiana
On drag cars they should be mounted no higher than shoulder tops and preferably a little lower. Especially in a rollover situation. No matter what your spine will compress in a rollover. This is all coming from a guy who broke his neck sleeping. You have all the information now. Do with it as you see fit.
 

madprofessor

"Loose Cannon Creations"
Messages
2,899
Reaction score
888
Location
Jacksonville, Florida
Just ran the orthopedic scenario in my head. Isn't it the lap belts' job to keep your back cheeks planted in the seat (nothing pulling down on your clavicles), and the shoulder belts' job to keep you from spilling out sideways, much less snapping forward? The upper cervicals (neck) should catch lateral side movement, not your dumbo flaps (ears). Level or lowered, the shoulder belts would do that if spaced close enough together.
Disclaimer: Not an orthopedist, just a meatsack around a perpetually damaged spine. Glowing a little from all the cobalt rays over the years.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Just ran the orthopedic scenario in my head. Isn't it the lap belts' job to keep your back cheeks planted in the seat (nothing pulling down on your clavicles), and the shoulder belts' job to keep you from spilling out sideways, much less snapping forward? The upper cervicals (neck) should catch lateral side movement, not your dumbo flaps (ears). Level or lowered, the shoulder belts would do that if spaced close enough together.
Disclaimer: Not an orthopedist, just a meatsack around a perpetually damaged spine. Glowing a little from all the cobalt rays over the years.
You know what I think you might be right. I'll probably just do it at a happy medium then. I'll have it set in line with the back of the seat which is actually a little shorter than my shoulders (about 2" or so). This isn't a stock car after all. If I hit something at 50+ mph I'm going to have much bigger problems to worry about...
 

madprofessor

"Loose Cannon Creations"
Messages
2,899
Reaction score
888
Location
Jacksonville, Florida
lap belts' job to keep your back cheeks planted in the seat
The high center console helped a little (those lower ribs are permanently caved in), but when I totaled the 280ZX it was the lap belt part of the factory shoulder harness setup that kept me from shooting out of the exploded passenger side window. Just in front of where I folded the car in half.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got some time to work on this again, and I designed a harness mount. However, my harnesses are too long and I don't want to cut them to shorten them. Instead, I'm planning on doing something like this:
Harness bar.jpg
Rather than bolt the shoulder harnesses too the bar, I'm going to run the harnesses over a bar (I used flat stock before which turned out to be too weak) and mount them to the bottom of the frame. This way, I still keep the correct angle for the harnesses over my shoulders without needing to shorten them.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
20221128_170310.jpg
Here is my idea partially mocked up. I'm going to weld another tube in between these bars (with the magnets on them) and run the belts over them. The ends of the belts will mount on the brackets sitting on the lower bar.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got it all welded up.
20221203_175552.jpg
Tried a test fit and while it does work, I can still wiggle back and forth even when it's tight. If I drop my shoulder enough I can even slip the shoulder belt off entirely (although I really have to work for it). I think it's down to the fact that the straps can slide side to side on the bar. To fix this, I'm going to buy a sternum strap to keep the belts together across my chest, but I'm also going to add this bent bar that will both lower the angle of the belts as well as keeping them from sliding side to side on the harness bar.
20221204_144050.jpg
I also noticed that the lap belt tries to ride up higher on your stomach if you tighten the shoulder straps too much, but that's more of a consequence of being a 4 point design rather than a 5 point with a belt to keep the lap belt in place.
 
Last edited:

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Now that I'm happy with the harness (finished it last week), I'm moving on to doing some supports for the axle. I'll be adding two more axle hangers closer to the tires.
20221212_160308.jpg
I was originally going to just do pieces of flat bar to connect the flanges to the rest of the swingarm, but I think I'm just going to use some square tubing instead. I'm going to have it set up something like this:
20221212_160308.jpg
From there it's just a matter of mounting the brake caliper and then the swingarm will be done.
 
Last edited:

TNThomas

Well-known member
Messages
374
Reaction score
348
Location
Washington
Now that I'm happy with the harness (finished it last week), I'm moving on to doing some supports for the axle. I'll be adding two more axle hangers closer to the tires.
View attachment 135423
I was originally going to just do pieces of flat bar to connect the flanges to the rest of the swingarm, but I think I'm just going to use some square tubing instead. I'm going to have it set up something like this:
View attachment 135425
From there it's just a matter of mounting the brake caliper and then the swingarm will be done.
Looking good! I like your shock setup, pretty easy to change your angles if needed in the future. Im at the same stage right now. Keep it coming, looking good!
 
Last edited:

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Finished the axle supports. Probably going to do one extra piece of flat bar to help the new flanges with lateral loads, but besides that they're complete.
20221218_171120.jpg
We're getting very close to completion here. The list of what needs to be done is as follows:
- pedals
- gas/brake linkages
-mounting master cylinder/caliper
- floor pan
- mount storage box
- wiring/mounting headlights and horn
- bolt on engine and sprocket
- small non-essential body panels (only about 3)
- random brackets for switches/cables
- final tuning
Once that's all done, it will be time for paint and clear coat. I'd say we're about 80% of the way done.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got back to work on the buggy today. Nothing too interesting to report on. I decided to go with the original gas tank I bought early on (I believe it's from a Kandi Spyder or similar Chinese buggy). It's a lot lighter than my custom tank and can hold a bit more fuel. I also began making my pedals; will post them when they are done.
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got some pictures for you today. I built the pedals and a new steering "yoke" (similar to the steering yoke of the old Honda FL250/FL350. All that's left is to create the center hub for connecting it to the steering shaft and wrap the handles with handlebar tape. This new yoke is obviously heavier than the old wheel as its larger and entirely made of metal. The old wheel was 2.5 pounds and this yoke is 5 pounds. However I'm willing to be just 2.5 pounds heavier for improved steering leverage.
20230115_165813.jpg
I think I nailed the FL250/FL350 inspiration though. What do you think?
s-l1600.jpg
As for the pedals, they have holes drilled into them so I can use the extra pieces above to extend them out so my girlfriend can reach the pedals (can adjust the distance with bolts).
 
Last edited:

TNThomas

Well-known member
Messages
374
Reaction score
348
Location
Washington
Got some pictures for you today. I built the pedals and a new steering "yoke" (similar to the steering yoke of the old Honda FL250/FL350. All that's left is to create the center hub for connecting it to the steering shaft and wrap the handles with handlebar tape. This new yoke is obviously heavier than the old wheel as its larger and entirely made of metal. The old wheel was 2.5 pounds and this yoke is 5 pounds. However I'm willing to be just 2.5 pounds heavier for improved steering leverage.
View attachment 135854
I think I nailed the FL250/FL350 inspiration though. What do you think?
View attachment 135855
As for the pedals, they have holes drilled into them so I can use the extra pieces above to extend them out so my girlfriend can reach the pedals (can adjust the distance with bolts).
Pretty dang cool!
 

SquidBonez

Active member
Messages
500
Reaction score
111
Location
New Jersey, USA
Got the new steering yoke mounted. Steers a lot easier now. I also increased the front tire size from 16" to 18" (same width, so the extra size shouldn't have affected steering effort much anyway). I did this to gain more ground clearance under full suspension compression, as it would still occasionally bottom out.
20230126_174913.jpg
20230126_174905.jpg
Even with the front tires being the same size as the rear, I still have a 2" difference in ground clearance from the back of the main frame to the front (it's sitting "nose down"). This means that I could go even larger with the front tires if I wanted to even if I kept the back tires the same and keep the frame in a nose down position. Many quads and crosskarts actually have very slightly taller front tires than rear as well, so this would actually be OK. For now, I'm keeping the tires the way they are.
 
Top