GPR Stabilizer

[Lucas]

Anyone out there got or used or know of anyone that has used a GPR stabilizer
I'm looking at one of these steering dampners for the 10R
got a great price on one just wanted to hear any imput on them

http://www.gprstabilizer.com/sport-bikes-kawasaki-c-33_37.html

[Lawnmower Man]

nope ... but that is the ugliest damper i have ever seen

[Tones]

Hmmm a rotary dampner - interesting. Sorry dont know anything about them. Didnt like the design in a shock, dampner may be different. Sorry Lucas, cant help much.

Cheers

[half_empty1]

a bloke in my club in the uk has one on his 10r,

says its the best damper he's ever used,

another one to consider if its available over there,

is the sprint steering damer, seen lots of 10rs using them here in the uk.

[MadKaw]

I've heard good reports on them, but they are bit ugly..

One thing I have heard is that as the rotary damper has a small pocket of air in it they don't perform as well as std hydraulic rod ones under "extreme" loads..
Probly why you don't see many on race bikes...

[Stereo]

One thing I have heard is that as the rotary damper has a small pocket of air in it they don't perform as well as hydraulic ones under "extreme" loads..
Probly why you don't see many on race bikes...

[MadKaw]

The key word is "many".. They are nowhere near as common as the hydraulic rod ones on race bikes, especially the bigger capacity bikes... Unless of course you are sponsored by GPR...
Honda even removed the electronic rotary damper and replaced it with a hydraulic rod one on there race bikes...

[MadKaw]

and to follow that up heres some speil from Max McAllister the owner of Traxxion Dynamics...

Hello everyone,

Let me add in a few things, to help Geremy out.

The Ohlins damper isn't gas charged with nitrogen. It is bleed to have no air in it, but in the top portion of the damper, there is a piece of foam that actually crushes to allow the oil to expand, and then the foam itself re-expands to normal size when cool. This foam is what will cause that damper to fail, but it takes a long long time for it to degenerate. Like a few years.

All of the dampers will "hydraulic lock" which is the simple problem of oil trying to move too fast through an orifice. Any orifice has a limit of how fast it can pass an oil of a given viscosity through it.

Rotary dampers meter oil through needles, seats, and as such orifices just like a tube style damper.

What Geremy called cavitation is actually "emulsion". This is how shocks worked in the period prior to "DeCarbon Style" shocks (nitrogen/oil separated). The oil and the gas charge just mix together to make a foamy sort of oil bath. This yields very inconsistent damping.

For consistency in any damping system, you need to remove as much air as is physically possible.

Cavitation is actually a "bubble" created by having the oil "pulled apart". It is actually a vacuum, not air. The same thing happens to all sorts of pumps (jet skis and boats etc) when they are able to pull more water through the pump than can be fed to it. It just tears the water apart.

Note that none of this is in engineering terms, just ones people will get hopefully.

I don't recommend rotary dampers at all, just because of the air in them. That is fine for dirt bikes, but no good for road riding.

Like I said, I am just trying to put things in terms that most people can easily grasp.

Oddly enough, what most people don't understand, is that a damper is basically SUPPOSED to hydraulic lock. It is is supposed to stop violent swings of the handlebars in your hands. It should make little or no damping at low speed (of the damper shaft, not the bike) and tons of damping at high speed (tank slapper, off-road excursion, bumped by another rider, etc). If it didn't try and lock up, it would only do 50% of what it is supposed to.

The other 50% is that it is supposed to stop oscillations before they start. That is why an air bubble renders rotary dampers useless for this purpose. They don't damp as the unit changes directions.

Note further that you bike should NOT wobble, with no damper on it. A damper is a safety device, not a repair for an ill handling bike.

The reason the air bubble is put into the rotary damper is that there needs to be some place for the oil to expand to as it heats. On an Ohlins, make no doubt about it, there is a piece of foam in it that collapses, not nitrogen. I have no knowledge that WPs are nitrogen charged, I thought they used a mechanical spring.

On Sprint Dampers, there is an oring on either end that the bearings expand against and sorta crushes them flatter. When the oil cools, the orings push back into shape.

This is just static observation, not a formal survey. Some might dispute my figures, but they aren't miles off.

Tobys look and feel cheesy to me. I don't like them, not when you can buy a nice piece like a Sprint for the same money.

Matris has just come to the US last year, and I have only seen one or maybe two at the track, and cannot comment on their function, but they do look very nice and trick.

Ohlins is very nice and typically fit very cleanly.

The Sprints, to me, are the best working dampers and are usually $1-200 less than an Ohlins. Their complete kits sell for $375 "racer net".
Their dampers are made by a guy who used to work for MacLaren F1. They are extremely well made, extremely well executed, and parts are readily available for service here in the US. They are trick, clean, and install in minutes.

I sell Sprints and Ohlins here.

Ohlins has ceased to sell damper parts to independent shops like mine, as they want to do damper service in house. (there was also scuttle about them updating shafts quietly without actually issuing any recall or formal public update). They want the dampers assembled with a vacuum machine that costs $6000, and no one in the US has bought one, so they have to do it themselves.

I would suggest you buy a spare damper before you send one in to Ohlins for service, as it may take a while...


========================
Max McAllister
President
Traxxion Dynamics, Inc.
Axxion Arm Systems, Inc.
========================

[Barrabob]

I was wondering if anybody watched that video.

Plenty of those rotary dampers in the states, I found something local and bought a fitting kit though.

[Lucas]

nope ... but that is the ugliest damper i have ever seen

Black one isnt so ugly in real life

talked to a guy (no names mentioned) who rides Oz superbikes and he said they are great
and they sell ohlins as well
so it's not just a sales ploy

[icebreaker]

I wanna see you get rid of those red factory tyre marks from the centre of your tyres first Lucas





hahahaha

[diesel]

hahahahahahahahahahahaha
OWNED!!!!!!!!!!!!!!!!
hahahahahahahahahahahaha

dorry mate, u know i love ya.......... but..........

hahahahahahahahahahahahahahahahahhaahahahahahhaahhha

[diesel]

i'm a ittle under the weather btw.
sorry

[Duane]

I wanna see you get rid of those red factory tyre marks from the centre of your tyres first Lucas





hahahaha

Well if he could keep the front tyre on the ground he'd be able to!

[hoffy]

the rotary dampers are widely used on all Paris-Dakar competition enduro bikes.
I couldn't imagin them using them if they are shit, as this I would dare say, would be the most challenging application dampers would have, copnsidering all the sand & ruts etc.