1978 Castrol 6 Hour on Youtube. Historic XS11 Win.

[xs650man]

At the start of the tire change on the XS, why are the crew jumping up and down on the back of the bike ?

[CaptonZap]

I think it was to compress the swing arm so that the rear axle could be removed. If a guy on each side was ready with the cable, and the third guy jumped on the bike, the first two guys could hook the cable. You can see the guy jump on the back to unhook it at the end of the pit stop.
JAWAG

CZ

[xs650man]

Ok cool, is that the cable thats supposed to be in the tool kit lol. That pit stop is my favorite bit of the video, and the bit at the start where he nearly lost it.

[CaptonZap]

Ok cool, is that the cable thats supposed to be in the tool kit lol. That pit stop is my favorite bit of the video, and the bit at the start where he nearly lost it.

Yep, thats the cable, You can get by without it by removing the top shock bolts, but that would have added another 20 seconds to the pit stop time.
CZ