Steering damper

[aff-man]

Well when i got the bike it came with a steering damper that wasn't attached. The person i bought it off said it stops the bike from being able to fully lock steering wise(hence no steering lock so she took it off). But how much of a difference do they make. Is it worth putting back on the 400??? :spudwhat: :spudwhat:

[Two Smoker]

Depends, get it up to 180-200kmh plus on a bumpy road and see if it tank slaps...... that or in mid corner when it gets bumpy

[Motoracer]

Well when i got the bike it came with a steering damper that wasn't attached. The person i bought it off said it stops the bike from being able to fully lock steering wise(hence no steering lock so she took it off). But how much of a difference do they make. Is it worth putting back on the 400??? :spudwhat: :spudwhat:

Saved me from an off at Pukie once on me old ZXR400SP. It's up to you but I'd put it on if I was you.

Edit: Then again, I never used to commute on it so it's a different story altogether. Best to try it for your self with out it and only if you think you need it, put it on. You'll get plenty of warnings usually if that's in the bike's nature.

[merv]

If the bike feels good with no steering shakes no matter what speed you go, I'd leave it off.

[DEATH_INC.]

If the bike feels good with no steering shakes no matter what speed you go, I'd leave it off.

I'll second that.I don't run a damper unless I need to.

[Mongoose]

I reckon its either an inherent design fault or a safety catch all the number of bikes that have them. Guzzi is bad for putting them on EVERYTHING whether it needs it or not. Like the Cali, never felt like a slapper ever.

[FROSTY:Me]

Ive gotta dissagree with MR on this one _i own hs old zxr and I took the damper off.
I've never so far needed the damper.
The zxr is one of the sweetest handling bikes Ive ridden.
Id take the bloody thing off completely. set the tyre pressures etc and see if you get slappers.

[wkid_one]

Yeah - Honda for years refused to put a damper on their bikes stating it was a case of poor design that other manufacturers put them on their bikes. However, by sheer virtue of the fact the bigger bikes are shedding weight and increasing hp - tank slappers are a neccessity.

I saying that - I never felt like I needed one on the R1 - a bike 100% of people warned me off due to the flightyness of the front end. Yes I had a couple of slappers - but nothing that made me want a damper.

Try this impulse test to see how bad your bike really is.....

Caution: perform this test at your own risk. I claim no responsibility for your actions. Disconnect your steering damper if you have one, or adjust it to a minimal setting. Bring your bike up to a constant speed on a straight, flat surface. With the bike moving straight ahead, and with your hands off the bars, whack one handlebar very quickly in the same plane that you would normally apply force to the handlebars to steer the bike. That is, give it a not too large, yet firm and quick input *whack* in a plane perpendicular to the steering axis. It may take some experimentation to whack it just right. You are basically exciting the wobble mode with an impulse input. If the steering borders instability, a very small steering input will produce a large wobble. If the steering is moderately stable, you may see a few oscillations before they die out entirely. If the steering is very stable, there will be no wobble at all. Note: prepare to catch the bars in case your steering is unstable! The degree at which the front-end oscillates for this test tells you your wobble stability for the test conditions. Now repeat the test. Try varying the speed in 10 KPH increments and observe how the response changes. If you normally carry a lot of load, put it all on the bike and perform the test again.

Why does the impulse test work? An ideal impulse input has an infinite amplitude, yet an infinitesimally small time duration. The quick “whack” to your bars approximates the impulse input. Theory dictates that an impulse input has a flat frequency response- it excites all frequencies at the same level. Associated with the wobble mode is a specific natural frequency, which is excited by the impulse. The response of the front end to this input is to oscillate at the wobble natural frequency. If this vibration mode is very stable, the oscillations will die out on their own. If the vibration mode is marginally stable the oscillations will take a long time to dissipate. If the vibration mode is unstable the oscillations will grow until your front end oscillation hits both steering stops!

You may also want to perform this test while decelerating. This places additional weight on the front wheel and therefore the vibration of the front-end figures more prominently in the control of the bike.
Now dial in some damping from the steering damper. Repeat the impulse test. If your bike showed signs of instability before the damping was added, crank up the damping until your impulse test generates an output wobble that quickly dies out. I’d say that 1 or 2 oscillations of the front end are tolerable. More than that and I’d feel a little uneasy. By adding damping in this way, you can tune the instability out of your steering systems while maintaining a quick response to steering inputs.

So when does this steering damper tuning matter the most? How about when you’re leaned over in a canyon around a 35 KPH turn with a passenger and camping gear and you have to grab a handful of brakes to avoid a family of yaks that are crossing the road. You will say a prayer of thanks to the steering damper gods then.
If you had a data acquisition setup and a few accelerometers, you could measure the steering gain and stability numerically from the impulse test responses. This is how the major manufacturers develop their bikes to handle well. The wobble mode impulse test is standard practice for evaluating steering response.

[aff-man]

The bike doesn't have it on at the moment so i might put it on to compare. But on reflection the 250 didn't have one and i don't think the 400 could be worse. The front end wobbled horribly on the 250 when pushed really hard. but when relaxed riding was practiced( ) it handeled great so maybe the 400 will be the same, i'll just have to wait and see.

[Motu]

The steering damper is just part of the ride on the XS1 - wind down the big black knob on the straights,coming up to a corner your left hand is unwinding the damper between downshifts,you have to decide how much damping you need for a series of corners,fully on for a fast straight.Getting it wrong adds excitement,forget to back it off in a corner and you run wiiide,forget on the straights? well,you don't forget it next time!

[scumdog]

My low-tech scoot doen't have one and will never need one with the amount of fork rake it has.
Quicker steering = more chance of needing a damper

[aff-man]

got it up on speed today (not to much though) but when braking the front end gave a bit of a wobble. Will steering daper get rid of this????

[scumdog]

Yeah, probably but you might have to work in your 'gargre' in this weather while putting your 'daper' on!!

Braking causes the front to go down and the rear to rise - reduces your fork-rake i.e. makes your forks more straight up and down.

The more straight up and down the forks the 'quicker' the steering but it makes it more 'twitchy' hence the need for steering damper.

Thats why most cruisers don't have one but most sports bikes do.

[aff-man]

weather up here is a cold but sunny. Hmmmm interesting will try with it on and see what happens.Thanks