[ahoeff]

I recently cracked my 2003 Gary Fisher Marlin frame and under the warranty Trek is sending me a new 09 8500 frame. I plan on moving most of my parts over to the new frame but would like to update the fork. I will include a list of parts below to give an idea of what I am working with.
I have not decided on air or coil springs but I think something with 100 mm of travel is best. A lockout and rebound are pretty much a must. I am leaning towards a Rock Shox Reba or Sid but am open to other options as well. I would prefer to spend less the $600. I plan on making this more of beefy cross bike that will be quick and fairly light but able to take a beating as I am 6'4'', 225 lbs and ride aggressively.

Specs
2009 Trek 8500 frame, 21.5"
Truvativ Firex crankset with external bottom bracket
Avid BB7 Brakes
SLX Derailleurs and shifters
WTB FX28 Rims
Shimano XT Hubs
Chris King Headset
http://www.trekbikes.com/us/en/bikes/2009/archive/8500

 

[mtnbiker72]

Probably stick with a 100mm fork on that...maybe adjustable so you can go a little longer on some descents. The Rock Shox Reba line is stiff, light, and you can get the Air U-Turn version for 90mm-120mm adjustable travel.

 

[GTR-33]

I have a Fox F32 120 RL on mine and it's great.

 

[rkj__]

I like my Reba Team.

 

[tussery]

I would go with a Reba. Tons more adjustable than a Fox and they feel stiffer to me also (QR vs QR)

 

[Hardtailforever]

Reba is a great fork, I don't think you can go wrong there.

That said, I'd go with a SID if you can find a good deal. Basically all the stiffness and adjustability of the Reba (aside from U-turn) at lighter weight. I love my SID.