I have a dekerf implant hardtail with a 5" Z1 fork on it.... it rocks! I can do all kinds of things on it that I wouldn't normally try on a HT. and it's a lot stronger than a FS bike of the same weight. However, this bike was designed for a 4"+ fork and abusive riding. You giant is designed around a 3" fork and more all-round XC riding... a 5" fork, especially the very tall Z1, would likely chopper the angles WAY out, making the bike a handful on anything but downhill terrain. I tried a 6" fork on my implant and I could hardly ride a straight line with it... you actually had to press down on the bars to steer without losing control.You giant would likely feel the same way with a 5" fork. In general, you can go maybe 1" more than the frame was designed for, more than that and handling goes bad.
Also theres the added stress of a longer fork on your head tube- you might end up with a permanently creaky headset or broken frame.
try a good 4" fork though, like a marzocchi MX. I've ridden several XC hardtails with that fork on it, they all rode great.
bigandcanadian said:
I have a 2004 giant yukon, that I have been upgrading ever so slowly, and now the last thing on my list is the suspention... i was wondering if there was a way of determining how much is too much in the way of travel... right now there is sun xc 75 that bottom out every time I ride and I was looking at some z1's but was wondering if the 5" was too much and would change the sloap of my bike too much and eventually crack the fram.... help