Go-Kart Steering Very "Heavy" (Hard to Turn)

[SquidBonez]

I'm currently building a full suspension mini-buggy/go-kart (full build thread is on my profile). My steering system is comprised of a standard go-kart steering shaft, two steering links, and then obviously the spindles (see picture below). All the pivot points in the steering are either heim joints or have bronze bushings, so it shouldn't be an issue of friction. The one problem I've been having is that the steering is pretty heavy.

I've managed to tune some of the effort out by reducing the caster angle (it was around 8° before, now it's down to 2°) and by changing the steering ratio (mounting the tie rods further from the pivot point on the spindles). I've also pumped the front tires to right under their max rates PSI and that alone made a difference. Before all this I was barely able to turn the wheel while sitting in it, now it's significantly easier but ultimately pretty heavy.

Keep in mind I have yet to see how it handles while moving because this project isn't a runner yet. I know it will get easier once you are rolling (and from what I've seen by pushing it around that's true) but I feel like it should still be easier than it is considering my tires are only 6.5" wide and 16" tall (which is concerning if i ever want to go bigger). Is there anything else I can do?

 

[redflash]

That is a trick looking setup.......but, but, butt...shoulda gone rack and pinion from the start !

only my less than humble opinion
Da Redflash

 

[SquidBonez]

That is a trick looking setup.......but, but, butt...shoulda gone rack and pinion from the start !

only my less than humble opinion
Da Redflash

Rack and pinion is great and all but for my application I wanted something that could be built to any size, and something that I could fabricate myself.

 

[redflash]

not raggin on you my buddy. just acknowledging that not all my cool and creative ideas work all the time either. I'm sure it will be somewhat smoother at speed.

Da Redflash

 

[karl]

If nothing is binding you simply need more leverage. That will reduce steering angle.

That's where the rack and pinion allows both

Rack and pinion is great and all but for my application I wanted something that could be built to any size, and something that I could fabricate myself.

I've shortened rack and pinions before, and extending to any size needed shouldn't be much more difficult. Cut, weld , zip tie boot , done.

Then fabricate yourself a custom mount and your done!

 

[Snaker]

Assuming you have the amount of steering wheel movement to wheel movement?
Any leeway on that? Like using more steering wheel for added leverage?

One thing I have done is to excercise all the ranges looking for binding.
I would jack it up and turn lock to lock.
Any difference from weight on ground?
I would unhook the springs and try throughout suspension range
The linkages, make sure each heim joint flex is somewhat centered and not maxed on opposing ends
Make sure the heim joints aren't extended beyond the angle specs where the sockets make contact.

 

[karl]

Assuming you have the amount of steering wheel movement to wheel movement?
Any leeway on that? Like using more steering wheel for added leverage?

Yeah, increase leverage at the sacrifice of steering angle.

You can only do so much without a rack.

It's probably gonna be fine once it's rolling, just as I said check it over for binding.
Make sure to lubricate the joints , and a grease zerk on the bushings won't hurt ( sorry im a mechanic had to say it)

 

[SquidBonez]

Assuming you have the amount of steering wheel movement to wheel movement?
Any leeway on that? Like using more steering wheel for added leverage?

One thing I have done is to excercise all the ranges looking for binding.
I would jack it up and turn lock to lock.
Any difference from weight on ground?
I would unhook the springs and try throughout suspension range
The linkages, make sure each heim joint flex is somewhat centered and not maxed on opposing ends
Make sure the heim joints aren't extended beyond the angle specs where the sockets make contact.

I have actually tested it through its travel before (and off the ground) and it is a lot easier when lifted. More steering wheel? As in a larger wheel? Maybe I could fabricate a custom steering "yoke" kind of like what's seen in the old Odysseys.

My current steering wheel is about 10"-11" in diameter, so it's pretty small. If I made a wider one, I could have more leverage.

 

[SquidBonez]

Yeah, increase leverage at the sacrifice of steering angle.

You can only do so much without a rack.

It's probably gonna be fine once it's rolling, just as I said check it over for binding.
Make sure to lubricate the joints , and a grease zerk on the bushings won't hurt ( sorry im a mechanic had to say it)

Yeah I've already kind of limited my steering angle as far as I'm willing go go. I started at a 1:1 ratio. Had more angle than I could ever want but it also was near impossible to turn. Now I have less angle but it's much more manageable to turn than before. I guess I'm limited using a standard go-kart style steering system. Only option I see without changing this system is to add a larger steering wheel.

 

[karl]

Only option I see without changing this system is to add a larger steering wheel.

I don't think that's what snaker was trying to convey , but you got it right!

Now I have less angle but it's much more manageable to turn than before. I guess I'm limited using a standard go-kart style steering system.

Thats what he was trying to go for, But you already covered it, so yup, that would be your limitation!

 

[SquidBonez]

I don't think that's what snaker was trying to convey , but you got it right!


Thats what he was trying to go for, But you already covered it, so yup, that would be your limitation!

I think I'm gonna try it out with the current wheel for now. I might make a custom one after I get it running if it really needs it.

 

[madprofessor]

Your multiple ratios with the transverse levers between the pitman arm and the spindles, the pitman itself, and the spindle arms makes for a complicated bunch of geometric combinations you could play with for a long time trying to come up with something, but it sounds like you've already done that. At that, it's already cost you more degrees of caster than is good enough for forward stability, you need more.
For $29 I wouldn't even hesitate to get one of these and see if it cures all ills in one smooth sweep................
14" Steering Wheel with Cap | K410223 | BMI Karts And Parts

 

[SquidBonez]

Your multiple ratios with the transverse levers between the pitman arm and the spindles, the pitman itself, and the spindle arms makes for a complicated bunch of geometric combinations you could play with for a long time trying to come up with something, but it sounds like you've already done that. At that, it's already cost you more degrees of caster than is good enough for forward stability, you need more.
For $29 I wouldn't even hesitate to get one of these and see if it cures all ills in one smooth sweep................
14" Steering Wheel with Cap | K410223 | BMI Karts And Parts

Unfortunately that wheel doesn't match the bolt pattern on my steering hub. Plus I'd need a wide & flat design wheel due to driver clearance.

How much caster should I be running anyway? I Googled caster angles for manual (non-powered) steering cars as reference and apparently most manual steering cars only run 1° to 3° of caster. Any more than that and you get into the range of needing power steering. I know racing karts run more than 3° of caster, but they use tires that are only 10" tall and are significantly lighter than a buggy like this.

 

[madprofessor]

How much caster should I be running anyway?

Everyone has their own ideas about that, as I do myself. I'm willing to trade off having to horse it hard to get around a corner for the benefit of freely straightening back up off the apex (or whatever racers call that) in its place.
The typical tight steering of a gokart where only a slight motion at speed achieves a big turning result is sketchy to me. So, 6-degrees of caster to make a kart go straight at speed all by itself is a good thing for me, but to each their own. There's a reason pro gokart racers have all kinds of adjustable angles in their steering to adapt with just some wrenches for what the conditions dictate from track to track, and weather as it comes.

 

[SquidBonez]

Everyone has their own ideas about that, as I do myself. I'm willing to trade off having to horse it hard to get around a corner for the benefit of freely straightening back up off the apex (or whatever racers call that) in its place.
The typical tight steering of a gokart where only a slight motion at speed achieves a big turning result is sketchy to me. So, 6-degrees of caster to make a kart go straight at speed all by itself is a good thing for me, but to each their own. There's a reason pro gokart racers have all kinds of adjustable angles in their steering to adapt with just some wrenches for what the conditions dictate from track to track, and weather as it comes.

I think I'll make my own steering wheel then too. Probably a yoke style as said before. Perhaps 15" wide? Should be a decent bit more leverage than my current 10.5" wheel. I already have an idea lined up for what it would look like.

 

[Functional Artist]

When I first saw this "set up" I was like, hmmm....kool
...but, kinda over-complicated lookin'
...& could be difficult to "dial in"

Why couldn't you just move, the bottom of, your steering column forward ~6"
...& turn the Pitman Arm downwards? (traditional go kart style)

* Before making a bigger/wider steering wheel, I'd "clamp a ~15" wide piece of board to your current steering wheel
...& use it as a test'er, to see how it "feels")

 

[madprofessor]

I'd "clamp a ~15" wide piece of board to your current steering wheel
...& use it as a test'er, to see how it "feels

Outstanding idea, FA, a very easy and good idea to get the gist of things. I would, however, use a piece of water pipe or similar to be able to wrap fists around it for a more approximate feel.

 

[SquidBonez]

When I first saw this "set up" I was like, hmmm....kool
...but, kinda over-complicated lookin'
...& could be difficult to "dial in"

Why couldn't you just move, the bottom of, your steering column forward ~6"
...& turn the Pitman Arm downwards? (traditional go kart style)

* Before making a bigger/wider steering wheel, I'd "clamp a ~15" wide piece of board to your current steering wheel
...& use it as a test'er, to see how it "feels")

To answer the first question, this steering was installed for 4 main reasons:
1.) cheaper and lighter than a rack and pinion
2.) waaaaay more adjustability than a rack and pinion
3.) to fit the steering linkages under my legs rather than in front of my feet in order to reduce the wheelbase of the buggy (wanted to keep it 60" or less - currently it's only 58").
4.) easy to design in order to mitigate bumpsteer (pivots of tie rods need to be in-line or at least close to the pivots of the a-arm).

As for the second part of your comment, that's a really good idea. I think I'll give that a shot when I'm deciding the exact width of the yoke.

 

[Functional Artist]

Um...I didn't see any pedals
...but, I would assume that your feet go, about where the upper A-frame support, connects.

IMO, it looks like "if" you connect the steering linkage, as mentioned previously
...it would still be under your legs

You may even be able to install a "guard" over the "moving tie rods"
...that you could rest your legs on (maybe even pad)
or maybe
Install a raised the floorboard, over them "moving tie rods"

Not tryin' ta tell you how ta do your kart
...just some "food for thought"

 

[SquidBonez]

Um...I didn't see any pedals
...but, I would assume that your feet go, about where the upper A-frame support, connects.

IMO, it looks like "if" you connect the steering linkage, as mentioned previously
...it would still be under your legs

You may even be able to install a "guard" over the "moving tie rods"
...that you could rest your legs on (maybe even pad)
or maybe
Install a raised the floorboard, over them "moving tie rods"

Not tryin' ta tell you how ta do your kart
...just some "food for thought"

Yeah the pedals aren't in yet. I have them Madd I just have to install them lol