In the threads about risers releasing I read "...we all know mini-risers and we don't use them any more..."
Well, I know mini-risers (Type 17), I think almost everyone has them on his skydiving-rig, but I don't know why you don't use them in Base.
Breaking strength? Cable suck on slider-down openings due to the higher forces put on the cable (smaller rings etc.)?
Yes, mini-risers have failed on at least one BASE jump. That's some scary stuff that needs to be avoided.
I think an important question is, given even a very small difference in breaking strength and cable suck, why would you *want* to use mini risers on a BASE rig?
I think (anybody with other ideas can correct me here) that their use in skydiving stems from three things. First, they make pulling the slider down (which in turn saves line wear) an option without making the slider grommets dangerously big. Second, in my experience, they make handling the risers (for carves, say) a lot easier. Lastly (and, if we're going to be honest here, probably the biggest contributing factor for most everybody, myself included) mini risers and their associated rings just look cooler.
Take away the collapsible sliders and give yourself just the one HUGE canopy (making carves less agressive and making the integrity of the risers that much more important), and "they look cooler" starts seeming like a pretty weak argument.
. . . Plus, of course, the difference doesn't really show on video.
I know, I know, that was just a technical question, I allways like to know 'why'
Jason may be sayn the same thing but here is my take anyway. In my opinion it makes no difference if you use the big rings or little rings, the geometery behind the 3-ring system will hold more than the riser material anyway.
Put a regular riser and a mini riser side by side. notice that the gromment size I believe are almost if not exactly the same size. Now look at the amount of web material left from the grommet hole and the edge of the riser. Its a lot less on the mini and thus is weaker and potentially more likely to break when put under the high shock loading of BASE jumping.
Yes they work well for skydiving and look cool. Then again the opens are not as aggressive and you have a reserve. But how cool will you look hanging from 3 riser connections. I am sure you can see the picture.
To make it clear: I have Type 8 risers on my rig and I never planned on changing them.
I does make a difference if you use big rings or small rings, whatever riser you use. With big rings you have a transmission ratio of 10:1 on every ring and get a 100:1 ratio out of the rings. With small rings you get only 25:1. That is multiplied by the ratio of the loop and that again is depending on the length of it (see the Vector tandem service bulletin). So cable suck would maybe become an issue with small rings. But then again I don't really think so since you can order Base-specific risers with small rings and they seem to work.
Breaking strength of Type 17 is 1330 kg, Type 8 is at 1650 kg, so the difference is not too big. You don't have to put a grommet in the riser, so that isn't making it weaker neither.
I just thought I missed something and wanted to know.
Now I go jumping with my Type 8 risers...
Cya, Obi
>So cable suck
>would maybe become an issue with small rings.
>But then again I don't really think so since you
>can order Base-specific risers with small rings
>and they seem to work.
Basic Research does not make BASE-specific risers with small rings. This is in part due to the data they have obtained on the G-forces during slider down openings. The forces near (but do not exceed) the maximum desirable forces on the cable and loop.
In other words the forces experienced on slider down openings aren't a problem for mini-rings, but there isn't much of a buffer zone either.
Posting Permissions
Reply With Quote
Bookmarks