[BKQuill]

I'm building a pair of gap jumps back to back, these are being built on a trail that I have that I'll primarily be riding my DH bike on it. They're going to be boxed in using railroad ties, I was thinking about 42-44" tall for the take off and 36-40" tall for the landing. A couple question's that I have, do these dimensions seem pretty decent? But even more important, what distance should I make the gaps? I was thinking 15-18', but I'm looking for others thoughts to be sure. I know it's a matter of speed x angle x height x blah, blah, blah. I just want a decent set of jumps, I'm 40 years old and not looking to break any records or bones, no backflips or big air contests, but still want it to be fun and decent for when the "good" riders come over and ride.

 

[Mr Ridiculous]

The last jumps I built were some kickers at my buddy's house, and one of them is about the size of what you're planning, in terms of ramp size. Our take-off ramp wasn't very vertical, and when i hit it wide open I was gapping a little over 30 ft. Normally it was closer to 20-25 feet. so I'd say with a bit more vert on the take-off those sound about right. That's just one dude's opinion who hasn't seen them though, so take it with a grain of salt naturally.

 

[Tdiddy]

find a few gap jumps that you really like. Ones that seem to flow really nicely at trail speed. Then, ride the section that you want to put the gaps on and determine what your trail speed for that section is. Gaps that you don't have to pedal like mad for, or brake check too much are a lot more fun for everyone. So if you determine your trail speed for that section first, and then compare it to other sections with gaps that you like, you can then work out the height and distance that way.

If you've hit enough gaps in your day, then you should be able to reasonably judge the size you can get away with according to the terrain you're building. If you're out by a little bit, you can always raise or lower the lip of the take off a little to suit.

 

[BKQuill]

Good advice, thanks to both of ya.

 

[Pegboy]

I built some jumps with similar size ramps a few years ago. I first built the take off ramp which was not too steep. With a non-kicker ramp of that size you can jump to flat fairly comfortably. I hit it a few times at 1/2 and then-3/4 speed and landed flat which on a big bike is no big deal. I was then able to make a good judgment as to where I would land at speed which is where I built the landing. Then, because I'm not a "experienced" jumper, I built the landing ramp back about 8 feet so it was almost a table top, that way coming up short was not disastrous.

After time the dirt for the 8' table area was used for another jump once I knew I would no longer stand a chance of casing it. all said and done, the gap is about 25' lip to lip. It's not video worthy but it's fun. You can always modify the take off and landing to make it steeper, and your trajectory higher, once you get comfortable.

 

[gemini2k]

Just make sure you build the jumps so that they scare you a little bit now, i.e. on the edge of your skill level. You don't want to get bored of hitting something too easy after only a few rides.

 

[rocketmatt17]

I agree with gemini2k if you look at it once and then hit it then its too small. Its has to be challenging enough that you have to work up to it. just my 02 cents

 

[BKQuill]

I agree with gemini2k if you look at it once and then hit it then its too small. Its has to be challenging enough that you have to work up to it. just my 02 cents

Very true!

If Jeremy or Matt will ever get their arse's over here...

 

[stumpjump]

Just make sure you aren't measuring in pinkbike feet.

 

[William42]

There are alot of dudes who know what they're doing on the DJ forum. I'd post this question up there and make it clear you're looking for DH style jumps. Guys like zachdank and kidwoo know what they're doing.

 

[buildyourown]

This is such a subjective question, nobody could possibly give you a accurate answer based on dimensions. You just have to "see" the jump and shape it.

 

[kylechs5]

20 feet is a super long gap try like 15 at most if your just trying to have fun i think a lot of people over estimate gap length like they say i hit a 20 footer when it was closer to 15 just think about it if you make a 20 footer you could put two basketball hoops in between the lip and landing.

 

[stringbean]

with the lip, dont give it heaps of kick, but dont leave it to mellow. at a trail near me we have a set of 3 40ft+ doubles in a row, and all have the same 'style' ramp. try to keep the curve of the upramp consistent, and not have a megga kick or have the lip mellow out so much and you should be pretty right. as for landing, most of the time you can judge it pretty easily by looking at it, sometimes not aka; fairclough in the F1RST extras.

 

[BKQuill]

Just make sure you aren't measuring in pinkbike feet.

In that case, it's a 50' gap!

20 feet is a super long gap try like 15 at most if your just trying to have fun i think a lot of people over estimate gap length like they say i hit a 20 footer when it was closer to 15 just think about it if you make a 20 footer you could put two basketball hoops in between the lip and landing.

So true, which is why I was thinking 15-18' and have a 3 foot"ish" extension on the land too help prevent casing's.

fairclough in the F1RST extras

You get bonus points for that reference.

 

[chic06]

i really think if you're ta planning on using a downhill bike to hit these with lips that size you should have a gap closer to 20 feet because odds are the lips will be more melow which tend to send you further out than up. also if they are downhill jumps you will probly be hitting them with a decent amount of speed which will probly result in you moving the landing back after you overclear it a few times.

 

[CRoss]

For a DH bike the shape of the lip will be important. If you give the jump a consistent curve or arc it will feel very poppy. If you take the very last part of the lip and make it a flat/consistent angle the jump will mellow out. The longer the flat section at the end of the lip the more mellow and consistent the jump will be. A poppy lip will have the largest range of possible landing distances. The mellower the lip is the better the chances of landing in the same place everytime. It is a game of trial and error to find a good combination between poppy and mellow/dead feeling. For the DH bike a dead feeling lip is not always a bad thing.