Changing RockShox Dart 2 for MArzocchi All Mountain 4"

clanton

My sister's mate has a Giant Yukon which comes with 80mm Rockshox Dart 2 forks. She has been given a used set of Marzocchi forks with which to upgrade them - I'm not sure exactly which ones but I'm told they're 4" travel forks.
Will this have a significant effect on the geometry and handling of the bike?

nicklouse

For every inch (25mm) difference in axle to crown height change the head angle will change by one degree. axle to crown lengths can be found on the makers webbys. but you will need to know which Mars fork it is.

clanton

Thanks for that Nick. Turns out the MArzocchi fork is 1" longer than the current one so will make a 1 degree difference. the Yukon is listed as having a head angle of 70.5 degrees, I'm guessing that 69.5 degrees will feel a bit slack?

dav1

80mm on a yukon? what year is it?

my 07 had 100mm (4 inch) SR suntor forks.

clanton

Hi Dav1
It is an O7 and you're right does have the Suntour forks. I initially thought it had the Rockshox Dart forks on - ie before I saw the bike! However the difference is that the Marzocchi axle to crown length is 1" longer than the current Suntour forks. Tring to work out how much that will affect the handling and feel of the bike.

dav1

if you go over the reccomended length you will void the warranty on the frame.

I have tora U-turns on mine (same 07 yukon) and it does slow the seering up a touch when they are fully wound out to 130mm, personally i use the U-turn to move between 85-100mm rather then the longer travel.

I think there may be a risk of damaging the headtube/headset if you use it with a fork longer then the reccomemded though. Im not 100% on that so hopefully somone will confim/dismiss that statment.