Question 1

Does this include power link?

Accepted Answer

If you mean the connector link, every one of these chains I've used contains it.

Question 2

Does this chain rust ?

Accepted Answer

They all do if not cleaned and and lubed on a regular basis.

Question 3

Will this fit a Specialized Crossroad Sport?

Accepted Answer

I don't have a Specialized Crossroad Sport, so I googled its specifications.  The Specialized Crossroad Sport has 27 speeds (3 front chain rings x 7 rear cogs = 21 speeds).  In term of the width of the chain, the SRAM PC-830 will fit all of these 3x6=18, 3x7=21, and 3x8=24 speeds.    So in term of chain width, the SRAM PC-830 will fit the Specialized Crossroad Sport.  
In term of length, please count the number of chainlinks you currently have on your bike.  If there are more than 114 links then the SRAM PC-830 is too short (because the SRAM PC-830 has only 114 links).  If your bike has 114 links then it is a perfect match and you are lucky.  If your bike has less than 114 links then you'll have to remove some links from the PC-830 to make it only 114 link.
Here is my estimation:  My mountain bike has 32 teeth on the largest front chainring and 40 teeth on the largest rear cog, and the PC-830 with 114 links fit perfectly.  I googled the Specialized Crossroad Sport has 48 teeth on the largest front chainring and 34 teeth on the largest rear cog.  If you do the math (48+34 )- (32+40) = 10.  That means your bike will need 10 more links than my bike, which is 114 + 10 =124 links.  So you will need a chain with 124 links.  The PC-830 is too short for your bike.
That is just my calculation.  Please count the number of links on your bike to make sure.

Question 4

Will this work on a 3X8? 3 gears in the front and 8 in the back.

Accepted Answer

“6/7/8” refers to the rear shifter, so your 8-speed cog set will be covered.  Since it’s for a mountain bike, it should be long enough for a 3-speed front shifter.

ASIN	B00H2B6BGC
Best Sellers Rank	#16,095 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #16 in Bike Chains
Brand	SRAM
Brand Name	SRAM
Customer Reviews	4.6 out of 5 stars 918 Reviews
Item Length	57 inches
Item Pitch	0.5 inches
Item Weight	14.88 ounces
Load Capacity	3E+2 N
Manufacturer	United States
Material	Alloy Steel
Material Type	Alloy Steel
Model	46.2758.114.005
Number of Links	114
Part Number	46.2758.114.005
Pitch	0.5 inches
Plate Thickness	7.1 millimeters
Recommended Uses For Product	City, MTB, Race, Trekking, Hybrid
Roller Diameter	8.5 millimeters
Strand Type	Single
Tensile Strength	1250 pounds_per_inch
UPC	802774851655
Unit Count	1 Count

SRAM PC-830 6/7/8-Speed Road/MTB Bike Chain 1/2" x 3/32" 114L fits Shimano Campy

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