seeing whats out there.
I like retractable leash with two separate lines.

predominately urban mushing.
or on a bike

well the do have couplers for attaching to dogs on a leash, but I've heard that huskies can break the retractable leash. there are have duty couplers I've seen, here's the link:
http://mydogscool.com/store/double-dog-leash-coupler/

if you want a double line for urban mushing i would look in to getting the tug n' tow. its like a retractile leash on steroids   . I'm defiantly going to invest in one when Leo is old enough to start urban mushing.
http://www.tugntowbikeleash.com/store/bike-joring-1

For bikejoring skijoring or scootering I would recommended a "mushing" 2 dogs line you can check out selections at ctcdoggear-usa, Alpine Outfitters, blackicedogsledding, howlingdogalaska this type line has a bungee in it for the "give and take" of the "joring" for walking I recommend a simple coupler or splitter for a leash. I have a hip belt that helps a lot for the skijoring and the walking then a bungee lead 2 dog for the other styles exercise (scooter bike).

I don't like the retractable at all - can cut your hand on it, the thing can let loose from its attachment inside the case, the retractable part can dysfunction at a critcal moment...

As to joring/mushing etc, I bow to others with more experience than I.

I agree with the others, the retractable is just too unpredictable...I foresee it snapping. My little girl has snapped a regular lead (the metal part wore...probly due to her pulling...she was after a bunny at the time) as for any other recommendations, I am useless, I'm still doing one lead in each hand...the arm that walks Mishka is probly longer than my other arm, haha

Can't do one lead in each hand as i probably need a flashlight at night.

it's on rollerblades.
I have a husky and somebody just moved in with a staffie.

I bought this crappy ring system with 2 regular type latches.


my flexi leash has been industructable.

I'm talking countless distance with hard yanks, it is the tape kind not the cord.

https://www.youtube.com/watch?v=qt9Ka8uIJa0

i liked this but the braking system looks subpar.

it is cheap.

main concern is their too close to each other.


and goly most gear people posted wasn't cheap

Alpine outfitters make some awesome gear, I would definitely check them out.