Bicycle Mechanics - Problem with suspension seatpost

The saddle on my 08 Specialized Sirrus has started to turn around at the point where the bellows is.

There is a type of washer with pins in it like the pic below which slot into the post and stop it from turning, but the pins are broken so the saddle is not held in place and is able to turn around.

What is this part called? Is it easily replaceable or is there any other way I can fix it?

Thanks

Paul

195038195039195040

If you don't care about the shock replace it with a rigid post for about $20.00 or another shock post for $50.00 Specialized doesn't have parts for suspension seat posts

Yes, get rid of it. You will save yourself weight, aggrivation & pain. When I got back into riding, I started on a Trek hybrid w/ a suspension seat post. Once I got rid of it, the bike fit me much better & I was less fatigued after my rides. Shortly after I got rid of the hybrid seat, tires, and eventually the whole bike followed. However, that bike got me into cycling, so I'm thankful for that.

Want the suspension? These are top notch, and offer saddle setback,
which telescopic-plunger posts by their nature cannot offer..
Cane Creek ThudBuster... http://www.canecreek.com/component-seatposts.

NB, there are a number of elastomers available,
chosen, for the rider's weight range.

The internals of each post are unique to each maker, so your only hope of getting replacement parts is to contact the maker. Ask for both parts of the keyway system that keeps the top and bottom aligned.

If it came on a bike, and the bike isn't too old, you might also contact the bike company and ask about repair or replacement. Odds are you will not get the parts, but you might get a new post free if you ask nicely. Otherwise buy a replacement post with or without suspension as you prefer.

+1 on the Thudbuster, but you wouldn't normally need one on a single. They work great for tandem stokers.

+10 Great chance to replace with a traditional seat post. Replacements are available in the $10 to $20 range.

Buy a $19 Kalloy seatpost and learn to stand up over large bumps. It's more comfortable that way anyway.

I would also get rid of the suspension post. Aluminum frames are stiff and transmit road irregularities; the bike companies dampen this with suspension posts. You may consider a carbon fiber seat post. They soak up road bumps pretty well compared to aluminum.