Denny
Canned Monster
The red bar is the one you need the most and will do the most good. The triangles on the back of the roll bar are the ones you don’t need.
Full Suspension Big Block Mini-Buggy Build
- Thread starter SquidBonez
- Start date
SquidBonez
Active member
Yeah I'm going to keep them
SquidBonez
Active member
Got the new shocks and rear tires mounted. I had to cut and re-weld the front shock mounts because the new shocks are a bit longer than the old ones, but that didn't take long at all. One note about the new shocks is that they are about as tight in their softest setting as the old shocks were in their hardest setting, so that's definitely an improvement. It will still bottom out the front under heavy load, but this can at least be tuned to happen less often now (skidplates will help as well).
I also welded in new cage support bars. They are both great for cage rigidity and are also a conveinent mounting point for my switches, but they do make it a bit more difficult to get in and out of. That being said, I think adding side bars are out of the question. Instead, I have a new idea:
As before, blue is the bars/supports I'm going to add. Red is the bars I'm going to remove. I'm still going to have those triangulated supports, but I'm just going to extend them out farther. This will still add rigidity but won't make getting in and out of it that much more difficult. I'm also going to keep the welded bolts that the steering links pivot on, but instead of going straight over them with a supporting bar I will have a bar parallel to the angle of the cage bars, that way I still get some extra support but I can still have enough room to access and service the steering links if need be.
I also welded in new cage support bars. They are both great for cage rigidity and are also a conveinent mounting point for my switches, but they do make it a bit more difficult to get in and out of. That being said, I think adding side bars are out of the question. Instead, I have a new idea:
As before, blue is the bars/supports I'm going to add. Red is the bars I'm going to remove. I'm still going to have those triangulated supports, but I'm just going to extend them out farther. This will still add rigidity but won't make getting in and out of it that much more difficult. I'm also going to keep the welded bolts that the steering links pivot on, but instead of going straight over them with a supporting bar I will have a bar parallel to the angle of the cage bars, that way I still get some extra support but I can still have enough room to access and service the steering links if need be.
Last edited:
SquidBonez
Active member
Another update. I've been working on the cage and front suspension. The front of the frame still hits the ground when the front suspension is fully compressed. I am going to remake the spindles and drop the axles that the front tires ride on as low as possible to raise it up. Looks like I can get a roughly 1-1/4" raise in the front if I do this. I put the front tires on to planks of wood which are a combined thickness of 1-3/8" and it doesn't bottom out this way, so I'm confident this will fix or mitigate the problem.
Of course, I can just get larger tires but I want to keep the tires I have now since I like their size/tread pattern. Worse comes to worse I could cut/re-weld the rear shock mounts to drop the rear (which I don't want to do since I like the stance as it is) or just buy some bumper protectors and stick them on the bottom of the frame to protect the floorpan once it goes in. Ideally I want this thing to be as low as possible to keep COG down but also not so low it bottoms out.
Final note: I also want to tune the steering effort/angle. The way it sits now, the angle is great but the steering is very heavy with just 1 tire hooked up to the steering. This will obviously get easier the faster you go but I still want the option to tune it. So I'm going to drill another set of holes in the steering links to allow me to fine-tune this.
Of course, I can just get larger tires but I want to keep the tires I have now since I like their size/tread pattern. Worse comes to worse I could cut/re-weld the rear shock mounts to drop the rear (which I don't want to do since I like the stance as it is) or just buy some bumper protectors and stick them on the bottom of the frame to protect the floorpan once it goes in. Ideally I want this thing to be as low as possible to keep COG down but also not so low it bottoms out.
Final note: I also want to tune the steering effort/angle. The way it sits now, the angle is great but the steering is very heavy with just 1 tire hooked up to the steering. This will obviously get easier the faster you go but I still want the option to tune it. So I'm going to drill another set of holes in the steering links to allow me to fine-tune this.
SquidBonez
Active member
These shocks are actually longer and stronger than the originals. Problem is that they also have a bit more travel, so I still bottom out. Plus I need to remake these spindles anyway.
Last edited:
SquidBonez
Active member
Modified the steering links today in order to reduce steering effort. I went from roughly 1.1:1 ratio steering to about a 1.9:1. Steers much better now while still retaining a decent amount of angle.
Note that these plates are not entirely accurate either since they are designed for the weight of a car, not a mini buggy. This is still with the old spindles. I'm going to try and introduce some ackerman into my new spindles since these ones have none. I heard it makes it steer better.
Note that these plates are not entirely accurate either since they are designed for the weight of a car, not a mini buggy. This is still with the old spindles. I'm going to try and introduce some ackerman into my new spindles since these ones have none. I heard it makes it steer better.
Last edited:
SquidBonez
Active member
Here's a better view of the new cage supports I've added. I did this a few weeks ago, just forgot to add a picture.
If you look closely you'll notice something different about the rear tire. Here's a closer look:
That's right - moon hub caps baby! Just like the old school VW buggies. But I'm thinking about grinding off the chrome and painting over them.
I also made new higher-leverage steering links and spindle arms. Still waiting on some metal to come in to finish the new spindles, but I'm going to add ackerman to the new ones. I also have some holes drilled for adjustment.
Last thing on my mind was the rear swingarm, specifically the axle support. I've seen people on YouTube add more hangers closer to the tires to reduce the strain on the axle, but I'm thinking since it's not a rigid-rear kart the suspension is going to reduce strain on the axle anyway. Should I bother with more supports? I've been told it's fine the way it is but I can't shake the feeling.
If you look closely you'll notice something different about the rear tire. Here's a closer look:
That's right - moon hub caps baby! Just like the old school VW buggies. But I'm thinking about grinding off the chrome and painting over them.
I also made new higher-leverage steering links and spindle arms. Still waiting on some metal to come in to finish the new spindles, but I'm going to add ackerman to the new ones. I also have some holes drilled for adjustment.
Last thing on my mind was the rear swingarm, specifically the axle support. I've seen people on YouTube add more hangers closer to the tires to reduce the strain on the axle, but I'm thinking since it's not a rigid-rear kart the suspension is going to reduce strain on the axle anyway. Should I bother with more supports? I've been told it's fine the way it is but I can't shake the feeling.
Last edited:
Denny
Canned Monster
Leave them shiny! Chrome is cool. You young kids nowadays and your paint over the world attitude. Sheesh!
SquidBonez
Active member
Yeah I might leave them chrome at this point. Seems like painting chrome is very difficult and it requires constant repainting. Might make some changes to the paint job at the end though to better match the chrome.
madprofessor
"Loose Cannon Creations"
How many inches are those coilovers? Are they nitrogen-filled? If so, my rear coilovers are just like yours, but are 17" long. Don't know how your standard swingarm mounting position compares to my cantilevered diminishing-resistance setup, but the shocks themselves' action is undoubtedly very similar.
Point is, I installed my long-travel 17" ones with the adjustment the way they came out of the box, and they were so spongy that I started planning how to parallel a little pair of springs to stiffen things up. Believed there was no way some spinning down of the spring adjustment nut could make enough difference when I could bounce them to full compression, but it really surprised me. Ran the nuts down until they suddenly got more resistance (lots of threads were still left to go), and tried them out.
It was amazing, at least twice or more as strong as before. With the engine mounted on the rack, and me jumping up and down hard on it, there was no way I could fully compress them. If not done already, I'd try maxing out the adjustment on all 4 of yours to see what you get, just might surprise you.
Also, silly to remind you since you already know this, but don't forget to use anti-seize on those bamboo threads, they gall really easy.
Point is, I installed my long-travel 17" ones with the adjustment the way they came out of the box, and they were so spongy that I started planning how to parallel a little pair of springs to stiffen things up. Believed there was no way some spinning down of the spring adjustment nut could make enough difference when I could bounce them to full compression, but it really surprised me. Ran the nuts down until they suddenly got more resistance (lots of threads were still left to go), and tried them out.
It was amazing, at least twice or more as strong as before. With the engine mounted on the rack, and me jumping up and down hard on it, there was no way I could fully compress them. If not done already, I'd try maxing out the adjustment on all 4 of yours to see what you get, just might surprise you.
Also, silly to remind you since you already know this, but don't forget to use anti-seize on those bamboo threads, they gall really easy.
Attachments
-
100_0172.JPG
SquidBonez
Active member
I believe mine are like 13.5". I'll try cranking them all down once I get to that point, but I want it to ride smooth.
madprofessor
"Loose Cannon Creations"
Since your standard-mounting configurations are subject to the standard increasing resistance upon compression of the spring, then adjustment just barely as tight as you need it to be with rider(s) on board at a standstill will give you the smoothest ride you'll be able to get. With that standstill amount of support, little speedbumps will be smooth, big ones not so much, but you will be able to hit as big a bump as you wish if you don't mind your teeth clacking together a little.
My cantilevered setup is not real smooth in the rear compared to the Monroe airshocks in the front, but the hard jounce of the swingarm expected of a big speedbump isn't any worse than the jounce of a small bump. The worst of it is over in the first 2" of travel, just keeps getting softer from there, and there's a ridiculous amount of travel built into it.
NOTE: The swingarm's extreme travel would not be reasonably possible without the engine being rigidly mounted on a rack. The engine wouldn't be able to run steadily/safely if it was flying up and down on the swingarm on hillocks and ditches.
Attachments
-
IMG_20200114_141946.jpg -
IMG_20200114_142349.jpg
SquidBonez
Active member
True but you have much more travel in the rear than I do most likely. My rear travel is a little over 5" at the wheel.
madprofessor
"Loose Cannon Creations"
You still need enough spring resistance not to compress away half of that when you get in the seat, so adjusting barely to that minimum is all you can do to smooth it out. Ever thought about putting a pair of steering dampers on the swingarm too? They add no spring support at all, but they would slow both the compression upward and the return downward speed of the swingarm. I had considered it before. Do you think it would help or hurt things? It's aching my gray matter trying to visualize it.
SquidBonez
Active member
The rear shocks in their softest setting compress only a little when I sit in it (it basically makes the swingarm parallel to the ground rather than pitched back like it is now). It's soft but I'd rather run it softer than too tight. And that's actually a pretty cool idea to use steering dampeners, although you'd have to ensure that they weren't too loose/tight as well.
SquidBonez
Active member
Made some new spindles that raised the front off the ground by about an inch and now I have enough ground clearance to not bottom out any more. Now I can use the full amount of travel the front suspension is capable of. I have also been toying with the idea of have the spindle arms set up to incorporate some ackerman. I would need to chop my outer tie rods and re-weld them shorter since I'm bringing the spindle arms closer to the frame. These tie rods were originally set up for a zero ackerman setup and I can't adjust them to be any shorter.
However, is this even worth doing? I feel like most people would just go with parallel steering (zero ackerman). I know racing karts use ackerman but I'm not sure if it's needed off road. I looked at some spindles for a Honda Odyssey FL250 and it looks like they used to run parallel steering. However the FL350s seemed to use ackerman.
However, is this even worth doing? I feel like most people would just go with parallel steering (zero ackerman). I know racing karts use ackerman but I'm not sure if it's needed off road. I looked at some spindles for a Honda Odyssey FL250 and it looks like they used to run parallel steering. However the FL350s seemed to use ackerman.
Last edited:
your axles may need some support. The tires are too far away from the hanger bearings. Riding on rough ground you will experience flex in that 1 inch axle. and that leads to other disasters. The tires reasonably should be no further from the support bearings than 4 to 6 inches.
Da Redflash
Da Redflash
SquidBonez
Active member
OK, I thought it looked a little sketchy. When I ordered the axle bearings I ordered 4 just in case, so I'll just add some outer supports.
SquidBonez
Active member
Got the new spindles finished today and I have to say, I like the higher stance of the front end. Now it doesn't bottom out under full compression, however it only has about 3/4" of clearance under full bump. Still better than the alternative.
I also noticed something about my steering setup and plans to do ackerman geometry. I decided to stick with a parallel setup on the spindles themselves, but since I have a linkage steering system I think I can encorporate ackerman into it by simply tuning the tie rods going to them.
Rather than having these links in line with the frame I could have them pointed back towards the center of the axle and achieve the exact same thing, no spindle modifications necessary. This led me to realize that pretty much every single type of geometry is adjustable on this thing. Camber, caster, toe, bump-steer (by swapping washers on the links) and now ackerman. Completely unnecessary on a backyard-built buggy, but cool nonetheless.
I also noticed something about my steering setup and plans to do ackerman geometry. I decided to stick with a parallel setup on the spindles themselves, but since I have a linkage steering system I think I can encorporate ackerman into it by simply tuning the tie rods going to them.
Rather than having these links in line with the frame I could have them pointed back towards the center of the axle and achieve the exact same thing, no spindle modifications necessary. This led me to realize that pretty much every single type of geometry is adjustable on this thing. Camber, caster, toe, bump-steer (by swapping washers on the links) and now ackerman. Completely unnecessary on a backyard-built buggy, but cool nonetheless.