HI, I own a trek 4500 with disks, I do a lot of trails... Im looking to get a frame not too expensive but with full suspension, and transfer the parts from the 4500 to the new frame.

im looking into the

KHS FR2000 frame with 4,5 OR 6" adjustable rear travel. The FR2000 is made of 7005 aluminum and has a Romic coil shox in the rear.

the other option is the

KHS FR1500 with 4,5 OR 6" adjustable rear travel and Fox Vanilla R Pro

or the

KHS XC204 frame offers 3.5" of travel on a 4-bar design, mated to a Stratos rear coil shock. .

What i dont get it why one is 3.5 of travel and the others are 4, 5 or 6. What does that mean, which one is better for trails,...

Which one should i get.