Just finished building up a stumpy 07 1st ride out and when I brake very hard the back end shakes like it’s trying to get me off! makes for some nasty clonking noises as everything rattles about! I am wondering where to start shock? rotors? pistons? pivots? anyone out there have any tips! (am running juicy 5’s with a 160mm rotor on the rear)
Thanks

Spin the wheel and look at the rotar end on to see if it wobbles side to side.

If it does you need to replace.

Other than than warn bushing perhaps?

check the following:

calliper/mount bolts
rotor bolts
QR tightness
wheel bearings (can you feel the wheel knocking if you wobble the tyre with your hand?)
suspension bearings (check for side to side wobble then remove shock and cycle it through the full range checking for tight spots/roughness)

As above…

is the caliper securely fastened?
Rotor securely fastened?
Rear wheel done up tight?
Any play in the wheel – grab the top & try to rock it side to side.
Any play in the suspension bearing/bushings/pivots? Is there any lateral movement (slop) in the rear end of the bike if you push & pull sideways on the seatpost area?

Does the rotor spin freely in the caliper? If so, it’s unlikely to be massively bent as Juicy’s have such tight clearance between the pads & rotor.

Stumpys are renowned for going through lower eyelet bushes on the rear shock. What you describe seems a bit dramatic for this but if it’s the original bushing that came with the bike then this will almost certainly need changing.

Looks like I’ve got my work cut out for this evening… thanks to all suggestions above!

Sorry Gent but the 2007 Stumpy didn’t have a lower shock bushing since the 2005 and 2006 design had that reputation you talk of.

If there is no slop when you lift the saddle then the cartridge bearings in the linkage are ok. Check the main pivot axle behind the BB is tight too – an 8mm allen key for the tubular bolt and 19mm socket for the nut.

Find your FSR Manual here:

http://www.specialized.com/ca/en/bc/SBCGlobalPages.jsp?pageName=downloads

yours is a 120

It could possibly be the arms on your disk brake rotors hitting the pads? You might want to check how much the caliper sits over the rotor.

HTH