should i get one? will i notice any difference?                                                                                                                                                                             

  I've no idea Julie, I'm not mechanically minded, but maybe this will help?   http://www.bikehps.com/ProductFiles/WhyYouNeedADamper.html   (if not I'm sure there are loads of members who can answer your question.)                                                                                                                                                                             

want some 1st hand knowledge really,watching one on ebay but give my style of riding do i actually need one?                                                                                                                                                                             

If you ride fast, then get one.  They are there to stop tankslappers which mainly occur riding quick.  If your bikes prone to shaking its head, then yes, you will notice a difference.                                                                                                                                                                              

  Ah righto, I see what you mean. I wish I could help, sorry I'm useless lol.                                                                                                                                                                              

noooo Sandi, you always find loads of interesting stuff no one else can! only head shaking occurs at low speeds ie on the cobbles... very scary and prob havent had it fast enough to notice any probs? what sort of speeds are we talking about ?                                                                                                                                                                             

  By the sound of it I think my bike coulda done with one of those damper thingys, my 125 only had a top speed of about 57 and that was down hill with the wind behind me, it was like being in charge of a pneumatic drill... drrrrrrr                                                                                                                                                                              

You should'nt really need it on a modern bike until you get up into the 90 - 100 + mph as the bike should be able to cope with it.  Above those speeds on bumpier jumpier B/C roads they're pretty much an essential piece of kit IMO. 
You'll know if you need one, if the bars slap from side to side on occasion, then buy one.  They take a bit of getting used to at the start if you've never used one before, just don't turn it uip too stiff, keep it on as low a setting as you need it, as it tightens the movement of the bars.  Usually position 5-7 suits me.

so can you give me an explaination of how it works and what draw backs there could be, also are there good and bad brands? see them a lot on sports bikes but dont know anything about them.                                                                                                                                                                             

Just edited my other post which may help.                                                                                                                                                                              

If you have it tightened too stiff it can cause tankslappers, just as if its too low a setting also.  You'll figure it out if you get one, there is only one adjustment on them that clicks up (tighten) or down (loosen), just find the setting that suits you and the bike if you need one.
Ohlins are a good brand but expensive, go for a Sprint cheaper and good, but pretty much any brand will do the job.  Just make sure there are no leaks in it if your buying second hand.

I dont usually hang around when on a run and only once have I had the steering go wobbly on me, coming out of a bend still leaned over a bit and hit a small bump, I was doing 100+ at that time though and now knowing when it might happen I can take necessary action. My mate on the other hand swears by them on his TL 1000 but that is a different beast to my 9. Sorry cant help with the techy side of them. 

Aye, as I say most bikes can handle it, I'm just used to riding with them now and had a few scary experiences on friends bikes without them, so it automatically goes onto any bike I own now.  But then again I do tend to ride abit quick most of the time with the people I'm out with.

thanks, the bike is very stable up to 120 in a straight line on a good road surface but not tested it beyond that.                                                                                                                                                                             

Julie

They work in basically the same way as a fork leg but without the spring.

There is a rod with a piston and shim stack (on the good ones) on the end and this slides in and out of a tube filled with oil.

So any force that is put through the steering is dampened as the oil passes from one side of the piston to the other.  And this has the effect of avoiding the forces building up through the steering that can cause head shake.

Cheaper dampers can make the steering quite heavy at slow speed whereas the higher end models can have slow and high speed damping.

What you have to remember is that they don't stop the steering from "wobbling" slightly at slow speed whilst on rough surfaces as they are designed to reduce shake at higher speeds.  As Drift says most modern bikes don't need them unless you spend a lot of time in excess of 90mph.

From what I've read in the past however, the 98-99 model R1 was quite "lively" over bumps at high speed and so Yamaha eased the rake out slightly to ease this on the 2000 model.

As such, I'm not sure you'd gain any real benefit from one to be honest.  If however you still fancy one, my advice would be to avoid anything that costs less than say £200 when new.  Hyperpro do a good one as do Ohlins.  Maxton also do a rotary damper that sits on top of your headstock and doesn't take up anywhere near the room of a conventional damper, but I don't know how much they cost.                                                                                                                                                                             

One last thing, I've never bothered with one, even when I had the VTR.  After all the occasional head shake when accelerating is part of the fun!                                                                                                                                                                             

mmm `eased the rake`wots that all about then?   mines an 01 so maybe i dont need one, just keep seeing them when out and about.                                                                                                                                                                             

somehow I dont think I`d find it fun Geoff!                                                                                                                                                                             

My advice Julie is that if it aint broke dont fix it....FWIW                                                                                                                                                                              

you are prob right DC !