main and reserve size

[iranianjumper 2]

is there any relation between size of main and reserve canopy?

[likestojump 3]

iranianjumper

is there any relation between size of main and reserve canopy?

It's really situation dependent. For example, if I one flies a 107 main and a 126 reserve, they have about a .85 relation.

If one has a biplane, then one canopy will be more dominant.

If one is towing a two-out streamer, then their relation is irrelevant.

[BobParker 0]

There doesn't have to be. But for safety in two-out scenarios, it's best to have them roughly equal in size. Your choice.

[DrewEckhardt 0]

iranianjumper

is there any relation between size of main and reserve canopy?

No.

Your main should be sized to land you anywhere when things are going well - you're not unconscious, not suffering from a concussion, did not dislocate your shoulder, did not break your leg, and eyes are not covered in blood from a scalp wound (I've seen all of those happen on exit or in freefall).

Your reserve should be sized to land you safely under any condition.

Early in your skydiving career the two should be the same size, although later the limit past which it's imprudent to down-size comes first with your reserve.

For instance, I have a 105 main and 143 reserve. If I was current and jumping a cross-braced canopy a 95-97 would be fine, although an even bigger reserve would be most prudent.

Single canopy reserve rides are much more common and less preventable than two-out situations and therefore the situation you want to optimize for.

[mrkeske 0]

As far as I know, there is one true safety reason for mantaining both at roughly the same size, two-outs.

For all the rest, I think the bigger the better, espeacially in a case were yor're in any way hindered from flying well(an injury during freefal for exemple).