Not sure what you mean by "jumps". Maybe you need new struts or shocks.
One can create bike jumps in many different ways. An individual can buy plastic already made bike jumps if they would like. They can also make them out of dirt and gravel. A popular way of making bike jumps would be out of ply wood bought at the local hardware store.
Possibly bad synchronizer.
*Why are jumps called jumps?In order to clear an "obstacle" of any sort, a horse must jump over it. Therefore these "obstacles" became known as jumps.
Typically there would be a few learning days leading up to the try-out where the coaches will teach jumps and so at your try-out you will know what to do, The better your jumps, the higher they score you and the more likely you are to make the team. Of course, there are other factors that go into making the team: tumbling, stunting, and motions. Good luck!
If it's doing that on dry pavement, It's supposed to do that.
The sport of horse racing over jumps is called steeplechasing, while racing with no jumps is called flat racing.
Wood and plastic are the usual materials to manufacture horse jumps. Plastic jumps are more durable than wood jumps and can stand more impacts than wood jumps.
If its more like a judder, clutch, could be oil or damaged plate.
16 Fences in the Grand National. Although some are jumped twice, making a race of 30 jumps in total.
Generally increase with depth, occasionally making abrupt jumps termed seismic-velocity discontinuities.
Jumps is a verb. It describes an action.