Yes you jump on 29 wheel hardtail bike, but the difference comes in comfortability and feeling, hardtail bikes do not have suspension, so jumping on a hardtail bike will give less comfort also when you and then land on the ground surface, hardtail bike will give different feeling than full suspension bikes which you can easily learn by jumping on a daily basis, and the proper way of learning and improving skills on hardtail bikes is that you can take start as a beginner by performing small jumps, and then from small to bigger, bigger to biggest jumps, in the beginning, it is hard to learn jumps on hardtail because on the lip of the jump you have to lift the handlebar of your hardtail bike, which is a little bit difficult for beginners. But in reality, hardtail bikes are not made for jumping and drops, if you want to make changes in your bike ad upgrade parts of your bike then it might be possible for you can whip and jump on your hardtail bike without any issue.
The main problem is that if you are a skilled learner and you know very well about jumps and drops, then you might fail with your hardtail bike, because these bikes are not consistent for jumps and these will jump randomly, a single big jump you might perform with them but in the next one you won’t be able to reach the same height, but full suspension bikes work ina opposite way, those are made perfectly for jumpings.
The wheelsets of hardtail bikes are not able to tolerate enough stress and force after jumping when you land on the ground surface, carbon rims are strictly not allowed to install in hardtail bikes if you use your bike for jumpings and drops, even if the wheels are of aluminum metal, after hitting your wheels on the ground, if you are repeatedly performing jumps, metal wheelsets would bent and deform, all the force and stress of your bike is transferring into the ground by passing directly through the front and rear wheels.
Weight Of The rider:
If you are a heavy rider and you are riding 29 wheel hardtail bike, you are ruining your bike with your hands, weight of the rider also plays a major role in performing jumps on a hardtail bike. if your weight is less and you believe that you will do bigger jumps on a hardtail bike without any issue, then never perform bigger jumps it might affect your bike, smaller jumps would be better for you with 29 wheel hardtail bike.
Spoke Tension:
if you want to jump with a hardtail bike, then make sure to check the tension of your spokes before jumping and increase the tensioning, larger wheels would perform much better on jumps with greater spoke tensioning.
Tight the spokes of the rear wheel on both sides( drive and non-drive side). it is a little bit difficult because you have to re-dish or re-lace the wheel from the beginning, it is also time-consuming and expensive, but if you are a mechanic and you have the skills of wheel lacing and dishing you can do it on your own.
Hardtail Frame:
no dought frames of these are hard and stiffer but, due to the lack of suspension on the bike, the frame is badly affected by stress and force when you hit the ground on a bike. chain stay tube and the top tube of the frame would result in breaking and cracking if you are continuously jumping on 29 sized hardtail bike.
Headset Of The Handlebar:
the headset is tightly held with the nuts and bolts but if you are performing jumps, the headset is badly affected and it might become loose and your handlebar starts to wobble, it also happens with hardtail bikes if these bikes are used for jumping.
Fork:
Hardtail forks have no suspensions and also you have to buy a new tapered fork because non-tapered forks are not widely used for jumping and whipping. you have to look for a new fork that might absorb bumps and jumps because hardtail forks are rarely used for jumping and whipping. weight of the hardtail forks is much greater than the normal jumping forks, so you have to replace the hardtail fork with a new frame-compatible fork.
Normal Saddle Or Dropper Post For Jumping On a 29-wheel Hardtail?
The seat or saddle of a hardtail bike is the most common and important thing which needs to be changed with the dropper post, dropper posts are more comfortable than normal saddles and also give you a smooth ride without quick-release saddles.
Weight Difference Between 27.5 wheels And 29 Wheels:
29 wheels are higher in weight and 27.5 wheels have lesser weight when you install 29 wheels on a hardtail bike, it probably causes a big effect in jumping and whipping but smaller 27.5 wheels would be a better solution with a hardtail bike. if you install smaller-sized wheels on hardtail bikes then you will feel a little bit of difference, you will feel more comfortable and stability is also improved but larger 29-sized wheels are usually not a better solution on hardtails.
Suspension Feedback On Hardtail:
When you jump and you’re pushing with your pedals towards the downward position, you will not get any response, and your feet would definitely hit the pedal after landing the hardtail bike on the trail surface, this is the biggest cause of hardtail bikes and, the jumping distance from the ground is also limited as compared to full suspension bikes.
When you jump and lift from the ground surface, never stand up on the pedals, but bend and flex your heels through which you can easily reach higher level jumps on a hardtail bike. never speed up your bike, because the increased speed would not perform jumps on these bikes, if you want to perform higher jumps, just give your body more athlete position, bending and flexing position, and flexing your hips, which will allow you to jump higher on the trails.
Apply to push force on the pedals so that when you lift up at the lip surface your body would be in a vertical position and when you are landing on the ground, your hips would be in a bending shape.