I can't jump any longer than 40 feet!!!

[Dvraptor]

I really enjoy jumping my dirtbike (250cc), and I have no problems going over small doubles or tabletops, but something stopping me from hitting those 70 feet tabletops, I always land flat after 40 feet.
I think the problem is that my mind telling Me that if I only have enough speed to jump 60 feet it will result in a rough landing.
What do I have to do to gain confidence and speed to clear longer jumps - and land on the backside?

Any advice, besides just leaving my brain in the truck...:think

 

[KawieKX125]

Tell yourself you can and leave the fear(not the brain) in the truck. also, keep on going a bit more than a bit more. it will hurt, but it is the best way.

 

[YoTRacer158]

get behind someone who does the bigger jumps and match their speed

 

[Hucker]

Casing a tabletop is nothing compared to casing a double. There is a 60 table at the local track, I did it about 50 times in one day, just over and over and over. Hit it with a little more speed each time and finally got it.

Just stick with it, you'll get it. You don't have to clear it the first day....

 

[Dvraptor]

And what about the riders weight?

Thanks for all the advice!

Another tricky jump question:

To riders, one skinny (130lbs) and one a little less skinny (195lbs) is jumping with, lets say a 250cc at the same speed.
What will the difference be regarding the length and height of the jump?

I guess the fatter rider will need a little more speed - but how much?

There's seems to be a reason why Mad Mike, Pastrani, Clovers and all the other stunt jumpers are relatively small...

The big Swede - Dvraptor
6.2", 196lbs - hopefully going down to 172 over the next months...

 

[BullDog KX125]

there is a 70 foot table at my track. i was doing the same thing...landing in a very slight dip at about the 50 foot mark. one time i went a little fast and hit 60 feet (dead flat) i had no problem. it doesnt hurt, just land level, and under power. then i tried it and almost over shot it :P. i was beating myself up for not doing it earlier :)

im one of those skinny riders, so i cant help ya there..

 

[buffmaster]

You have to do what Hucker said, keep doing it till ya get it right. I was out w/my buddies and keeping up with them(not a common occurance), but I still landed every jump quite a few feet shorter than they do. Then I remembered that I out-weight them by 60-70 lbs.! Just twist it a weee bit more.;)

 

[Anssi]

Originally posted by Dvraptor

I guess the fatter rider will need a little more speed - but how much?

Basic physics dictate that this is not true. If you take off at the same angle and same speed, you will fly the same distance whether you weigh 50kg or 200kg. However, added weight will wreak havoc with suspension functionality and it will naturally be harder to get a bike up to speed when the rider is very heavy. Fortunately our friends in Austria have come up with a solution.

The big Swede - Dvraptor
6.2", 196lbs - hopefully going down to 172 over the next months...

The bigger Finn - Anssi
191cm, 90kg - going down to 85 but no chance of getting under that.

The big Austrian - 520 SX
107 kg, lots of grunt

 

[MikeT]

Re: And what about the riders weight?

Originally posted by Dvraptor
Thanks for all the advice!

Another tricky jump question:

To riders, one skinny (130lbs) and one a little less skinny (195lbs) is jumping with, lets say a 250cc at the same speed.
What will the difference be regarding the length and height of the jump?

I guess the fatter rider will need a little more speed - but how much?

I am 6'3" weigh 195lbs and I can jump 60 foot table tops on a 125 all day long. I think the speed difference between the two different weight riders is negligable. I don't want to break out my Physics book today but I think in our application nearly the same speed should do the trick.

 

[Hucker]

Referring to my last post, my buddy and I were both jumping that same table over and over. He wieghs about 160, I weight about 230. When I finally started to clearn it, I told him to shadow me and figure out the speed. When he did, he told me I was going WAY faster then he needed to be. There is a big difference between our take off speeds. When he finally figured it out, I shadowed him, and I couldn't believe he was clearing the jump going so slow (compared to who fast I had to go to clear it)

Food for thought...

 

[JMD]

Sorry, but gravity works the same on 1 pound as it does on a ton, disregarding wind resistance, which is negligible in your case. Remember that Italian guy who dropped weights from the crooked tower about 400 years ago? :p It may take more horsepower to get the fat rider going the same speed, but once he attains the same speed as the skinny one, their flight paths should be identical. As stated earlier, landing is a different story, because that involves momentum, which is half the mass times the velocity squared. But even there, you can see that velocity, being squared, plays more a role than weight (mass, for our purposes here). :cool:

 

[Hucker]

So your saying that a 300lb guy, and a 100lb guy will go off the jump at the exact same speed and go the exact same distance? That makes no sense to me at all.

:edit:
Ok after thinking about it, I understand it now. Thank god I work with computers and nothing else.

Thanks for the explanation :)

 

[yardpro]

all objects fall at the same rate 9.8m/s2 (the two is "suuared but can't make that sign on this post). As you leave the jump face the two ridersare traveling in two vectors horizontal and vertical. The vertical vector is affected by gravity only, since the mass is reacted on by the above formula, and thete is no variable for mass (weight), the both will ascend to the same same height , stop and return,both staying at equal altitudes. this deals with the height aspect.. now, since you were both at the same horizontal speed, during the same time you will travel the same distance. and since it takes the same time for you both to rise and fall, you will land in the same place. This is a basic physics problem we had to work in physics101. Where the difference is is that the big guy takes more energy to achieve and maintain the same speed, and therefore has more stored energy which is released when you get air.

As for the application of this theory, I am 6'4" 250 lbs, and jump 100' jumps (110 being my longest). I hit them at the same speed as my 150lb friends. The springboard of the suspension will give you a little less lift if your suspension is not set up for the extra wieght.

Remember, the stored mass is released upon impact, so the landing force of a big guy is more than that of a small guy, so don't come up short, it's generally better to go long. in either case crank the throttle open, this will stiffen the supension and also help translate the vertical vetor into the horizontal vector.
Hope you could follow and found it useful ( after all you asked for it)
:cool: :cool:

 

[MikeT]

Originally posted by yardpro

As for the application of this theory, I am 6'4" 250 lbs, and jump 100' jumps (110 being my longest).

I don't know if I really want to ride with you..... 110 feet? I'm scared. On the other hand, maybe I just won't tell the wife and I'll work up to it! ;)

 

[Hucker]

:head spinning:

Um, yeah great, um thanks...for the um.. I have a headache. :)

I get what your saying, I just read every other line and it comes out in simple english :)

Actually I do go higher than my lighter friend, but that probably because I pre-load the suspension right before take off...

 

[yardpro]

yo hucker-

 

[yardpro]

yo hucker-
Anybody who reads ginsberg aught to be able to follow my ramblings:D

mike t-
100'(especially on a tabletop (no 100' doubles for me only~70')) isn't as far as you think, Seth warms up on 150', and a local track here in the mx starved east coats of nc has a 100' table top that about 50% of the "D" riders jump. It puts you even with the power lines, what a rush!!!:p

 

[Dvraptor]

+100 feet...
And I can't even manage to do over 40...
Well, I guess I have to go out, twist my right hand a little (maybe a lot) moore and prepare for a wild ride if I ever gonna makit :scream:

 

[hjgird]

I also had a mental block on distance. The biggest problem is fear of over jumping and too much time to think.
I've never over jumped a fairly big jump but does not look like fun at all.
When I approached a jump I looked at the take off ramp. Boy it seems to steep and high. Suddenly it feels like I'm going way to fast to hit an obstacle like that, and I back off and come up short. I kind of overcome this by shadowing someone else, and being tired of feeling like a p****, but I still have a tendency to go too slow. Time after time I to a double 100% the first time I try it, but come up a bit short the second time. Luckily just enough for the back wheel to hit the wrong side of the landing but for the front to go over. Same thing with table tops.
I think I'm the best at bounce landings at the track. (When you come up just short, and you bounce back up and skip the landing ramp completely with your feet above the pegs) :)

Landing short on a 65-70 foot tabletop is not as bad as it seems. Either try to shadow someone who consistently jump it, or go a bit faster each time until you clear it. What I find helps when coming short landing with the rear wheel first, is giving a lot of gass just before landing, and moving my ass to the back. Moving to the back help you keep your feet on the pegs, and prevent banging your balls on the tank. It also lessens the risk of being bounced of the front end.

At my age (nearing 30), it hard to decide if my guts overshadow my ability or if my ability is more than I have the guts to try.

 

[High Lord Gomer]

Originally posted by yardpro
and a local track here in the mx starved east coats of nc has a 100' table top that about 50% of the "D" riders jump. It puts you even with the power lines, what a rush!!!:p

Where is that?!? I walked off the long tabletop at Devil's Ridge and figured about 90', but I might have been off.

 

[Cool Blue]

The faster you hit a jump the smoother the ride. You have probably been getting pretty beat up off the jumps. All it will take is more throttle and put the fear behind you. :D

 

[yardpro]

gomer-

kenly claims there tabletop is 110, but i measured with a measuring wheel and it's ~90. Meeks track near hubert has a true 100 footer. the track was designed for a pro in the late80's-early90's who went to school in wilmington. Awesome, but it embroiled in a legal battle and is currently offline.

 

[Whoops]

I think this time change has messed me up because I am not following the gravity vs distance arguement. Sure, if the 160lbs rider and the 250lbs rider dropped off a tower in Italy they would hit the ground at the same time. But, since we are talking about trajectory the riders have to go up before they go down. If that is the case, does it take the same energy to lift a 160lbs rider to the same height as a 250lbs rider? I don't think so.

Whoops

 

[Anssi]

Do we really want to get into the physics of this? Yes, it takes more energy to lift 250 lbs to the same height as 150 lbs. However, due to the wonderful laws of physics, the 250 lbs. going horizontally at the same speed as 150 lbs, already has proportionally just that much more kinetic energy.

There is no way around this. No matter the weight of the object, launched at the same angle and velocity, it will have the same trajectory (not including air resistance which is relatively insignificant at MX speeds and variability by rider size).

What the weight of the rider does affect is acceleration or deceleration on the jump face and how the suspension works. When a serious fatso hits a jump, a weak bike will decelerate or at least accelerate less than if the rider was lighter. Therefore, even though the riders travel just as fast on the level ground just before the jump, their speeds will change on the jump face and thus the takeoff velocity will not be the same.

 

[bud]

:)