I know I talk about cart balance on here quite a bit. Two wheeled carts must be balanced properly to ensure BOTH the human and the pony have a good time when driving. (This does not apply to four wheeled vehicles.)
I have written a few posts about how to balance an easy entry cart. You can find them here:
I worked very hard over the last 3 years to get my Hyperbike to balance for Zorro. Some of the time it worked for us and other times it really didn't. The straw that broke the camels back was when I would get the bike out BEFORE I would catch Zorro, and he would turn and walk away from the gate. Then, walk away from me when I went to get him.
This has stopped since I started using my KBike.
I knew the balance wasn't perfect and I knew that I was working ALL THE TIME to keep things from bouncing and I also knew that I wasn't 100% successful all the time. This started to make Zorro uncomfortable. I believe the constant up and down motion of the shafts (unless I was actively standing in my stirrups and using my tummy muscles) was wearing to him. I know I would get home from a drive completely exhausted. Not just from the physical balancing, but from the mental exhaustion of stopping all the time to tweak the harness and try to help him.
Balance is so many different things. I'll try to cover the main ones here.
When moving on flat terrain:
This is the easiest time to balance any two wheeled vehicle. If you are simply walking and not moving over varied terrain it's so easy to see if the shafts are sitting lightly in the shaft loops or even floating (which is what I prefer!). The pony isn't doing anything to cause the shafts to pop up or bear down on their back. It can also be deceiving. Things can look pretty good when walking along on flat ground leading you to believe all is balanced.
Moving up into a trot is a great way to check the vehicle balance. On flat ground if it isn't balanced, the shaft ends will either bounce violently up and down or they will bear down on the pony's back. If they are bouncing, this typically means you need to add a little more "weight" at the pony end of the shafts by moving your seat forward. Too much weight in the shaft loops will cause your shaft loops to move around quite a bit. They will move slightly forward and back as your cart moves because the weight is causing them to shift as you shift in the seat. If there is too much weight at the pony end, then you need to move your seat back.
When climbing hills:
This can be tricky. When driving a two wheeled vehicle you are always going to need to adjust your body slightly for going up hill. And of course what goes up, must come down, so you'll again need to adjust your body for the down hill drive as well.
If your pony is pulling hard from the shaft loops as you go up the hill, you can see the shaft loops falling back from the saddle and there is weight in the shaft loops, then you'll need to both move your seat back and shorten your traces. You want the shaft loops to always hang straight, no matter if you are traveling on flat ground, climbing hills or going down.
If your shaft loops push forward as you go down hill and then your breeching engages, you need to shorten your traces and adjust your hold back straps (the straps that attach to the breeching body of the harness and then wrap around the shafts). There are times when the footmans loops are just not in the correct spot on the shaft making this a very difficult adjustment. This can feel so frustrating!
I did write a blog about trace length. You can find that here: How to Adjust Your Traces
Shafts that are too long or too short:
In an easy entry style cart if your shafts are a little too long it's not as detrimental to the overall balance of the vehicle provided you have traces that are long enough to allow the pony to be forward in the shafts. You want the tip of the shafts line up with the point of the pony's shoulder. If they are too short this is a real problem as you won't be able to get the shaft to the point of the shoulder. This will mean the end of the shafts will jab the pony in the shoulder or neck when it turns. Most ponies object to this. Some will object violently.
When your shafts are too long with a bike, this make everything harder. The pony is too far away, so if things get a bit red neck you run the risk of having a hoof in the face. If your pony has to be pushed forward with a bike it's VERY difficult to get the balance correct.
Too long shafts will also make the turning radius difficult, causing the bike to act more like an easy entry cart.
Too short of shafts are often also too narrow. This will cause pinching and rubs on the pony pulling the bike. Over time you will end up with a sore pony.
It's amazing what a small change of 2 or 3 inches can do when you are dealing with these smaller equines! People have told me that 2 or 3 inches won't make a difference and yet I have found it can make all the difference.
The Shape of the Shafts:
The shape of the shafts actually plays a big part in getting the vehicle to balance correctly. There is a lot of engineering that goes into the shape of the shafts. This is why purchasing a vehicle from someone that does not drive is so tricky. How can they know their vehicle is working correctly? If they don't drive their own vehicles then they can't possibly troubleshoot.
A big pet peeve of mine is very large gig ends. There is no need to have a long gig end on the end of a shaft... and the gig end must always turn AWAY from the pony. When the gig end points straight down at the ground, this is a safety issue, and a great way to have your pony get its bit, or the bit end of the driving lines, caught on the end of the shaft. I would prefer straight shafts to the curved end in that case, as the lines can slip off. On the gig end they are firmly caught and you must move very fast to disentangle them!
Another thing about gig end shafts - your shaft loops should hang in the curve of the gig, not behind the curve...
What does balanced look like?
Normal movement for the shafts in the shaft loops is forward and back, a sliding motion. To see this is completely normal.
When you see the shafts themselves moving up and down (bouncing) then you have a problem. Most of the time, you will also feel this in your legs as you will actually bounce.
When I drive the KBike, the shafts stay completely level at all times. I don't have to stand in my stirrups or sit forward in my seat at all. This is because of the shape of the shafts and the fact that we can customize the length to perfectly fit our pony. It's amazing how much the shape of the shafts, the fact that they can be lengthened or shortened, turned in or out to make them wider or narrower, makes all the difference in balancing the vehicle.
Though we do have to work a little bit when driving a two wheeled vehicle, to help our ponies, having a balanced vehicle should NOT feel impossible! If you are struggling to get your cart or bike to balance please reach out to me! I am always happy to help you trouble shoot through photos and videos.