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Suspension set up.
Posted: Wed Dec 21, 2011 12:48 pm
by Garnet
I found this Ohlins owners manual online. It gives a nice walk through of basic suspension set up.
http://www.ohlins.com/Products/OwnersMa ... 241-02.pdf
Re: Suspension set up.
Posted: Wed Dec 21, 2011 11:16 pm
by vanzen
Garnet wrote:I found this Ohlins owners manual online. It gives a nice walk through of basic suspension set up.
The popular "suspension tuning" agenda here often seems to begin and end
with the replacement of some sacked, antiquated, pre-load adjustable only shocks
with
NEW-retro, still antiquated, one size fits all, pre-load adjustable only shocks ...
And so I was delighted to find that someone will be thinking about a formula
that might result in a chassis that actually works well,
and then, not so terribly surprised that there were no replies !
Good link, Garnet.
Re: Suspension set up.
Posted: Wed Dec 21, 2011 11:38 pm
by Garnet
Well I did just replace "some sacked, antiquated, pre-load adjustable only shocks
with NEW-retro, still antiquated, one size fits all, pre-load adjustable only shocks ..."
on my winter bike.
But I still want to understand where the resulting improvement in handling has come from. And I have the forks to deal with next.
Re: Suspension set up.
Posted: Thu Dec 22, 2011 10:37 am
by Manfred
Thanks for posting that link - most helpful even if one doesn't have Ohlins.
Re: Suspension set up.
Posted: Thu Dec 22, 2011 12:41 pm
by vanzen
Garnet wrote:Well I did just replace "some sacked, antiquated, pre-load adjustable only shocks
with NEW-retro, still antiquated, one size fits all, pre-load adjustable only shocks ..."
on my winter bike.
But I still want to understand where the resulting improvement in handling has come from. And I have the forks to deal with next.
Conversely, if one "fits" the median stature and weight model
as used by the factory engineers to determine ergos and suspension criteria,
"off the shelf" per the factory specs and after market retrofits
actually work quite well – if in good operating condition.
Re: Suspension set up.
Posted: Thu Dec 22, 2011 1:48 pm
by twist
I just purchased a set of werks shocks built for my style and weight. It was my understanding the adjusting the sag front and back should be roughly the same, 30-35. I have to shim the front springs but am waiting until the holidays are over to round up some friends to help with holding the bike so measurements can be taken. From this article fro ohlins, I seem to need a bit more research to pinpoint what sag is best for me. happy halidays all!

Re: Suspension set up.
Posted: Thu Dec 22, 2011 4:05 pm
by Garnet
Front sag should be greater than rear as the forks have a longer travel than the shocks. My guess BTW.
I did find in a /5 factory manual that the front ride height (F3 in Ohlins manual) should be around 90mm with a 75KG (165#) weight, though they didn't specify where on the bike the 75KG should be placed.

Re: Suspension set up.
Posted: Thu Dec 22, 2011 4:27 pm
by Garnet
vanzen@rockerboxer.com wrote:
Conversely, if one "fits" the median stature and weight model
as used by the factory engineers to determine ergos and suspension criteria,
"off the shelf" per the factory specs and after market retrofits
actually work quite well – if in good operating condition.
I almost "fit" the median stature and weight model

but the roads that I ride don't fit the model that most aftermarket shock makers think of as classic BMW habitat. As a result I did do some homework before ordering the next heavier spring weight and next heavier dampened shocks. The result is a bike that many would not like on the street as many of the small bumps are felt, but once dragging a foot peg around a corner or blasting down a rough road, the bike feels very planted with none of the severe bounce back that comes from inadequate rebound damping and over pre-loaded spring settings.
Re: Suspension set up.
Posted: Fri Dec 23, 2011 1:03 am
by Roy Gavin
I have an Ohlins on my GS, and the rebound damper at the foot of the shock also adjusts compression, something the writer of the instructions seems totally unaware of.
So you can make up your own mind how accurate the rest is.
IMHO the rider sag figures are a bit low for anything but smooth pavement.
They dont give a figure for base preload, but every new shock I have ordered has been supplied with 18mm, with the instructions to adjust it +- 2/3 mm maximum.
The "Custom" shock Ohlins suppied for my 90 kg weight / GS/ touring/ some dirt, gave rider sag of 42/43 mm, with i8 mm preload. They supplied a 450 lb spring, which is the default spring for the GS anyway.
Matched with 5/6 mm more rider sag at the front it works just perfectly.
Each click of the damper changes the previous setting by around 10% so 7/8 clicks out is around 1/2 way no matter how many slicks you have to play with.
If you have the set up spot on for solo use it will be OK with a passenger - chances are you will be going a bit slower anyway, and I have never found that winding only the back preload up made much of an improvement.
So not really impressed with the instructios at all.
Re: Suspension set up.
Posted: Fri Dec 23, 2011 1:22 am
by Garnet
Many Ohlins that mortals can afford have only one damping adjuster that does compression and rebound at the same time. The 36P twin shocks that fit 70 to 84 airheads has no damping adjuster at all, only a pre-load adjustment.
It seems the instructions are written for a track bike.
As for sag figures, I would have thought that a percentage of travel rather than an imperial number would be more practical. I did a search of their site but could find no specs for sag or ride height for individual bikes.
Still think there is some useful info there.