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Offline fishface

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Re: Re: How suspension and geometry works
« Reply #20 on: January 11, 2011, 01:13:55 PM »
good post clear and concise, that's exactly what I did when I got mine, set the rider sag and then experimented with different damping settings using small changes and one change at a time.
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Offline williamr

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Re: How suspension and geometry works
« Reply #21 on: January 12, 2011, 12:15:28 PM »
btw - there is an addendum to the owner's manual for the 'R' with recommended suspension settings. I can't post a link - can't remember where I found it, but here's the relevant page

Suspension Setting Chart
The method to adjust the front and rear
suspension is the same as described for the
Daytona 675 in the accompanying
handbook, with the exception of the
following:
Front and rear suspension rebound
damping - count the number of
clicks out from the fully screwed in
position;
Front and rear suspension
compression damping - count the
number of clicks out from the fully
screwed in position.
Note:
The motorcycle is delivered from
the factory with the suspension set
at the standard settings, as shown
in the table below.

Brakes
Brake Fluid Level Inspection and
Adjustment
The inspection and adjustment of the brake
fluid level in the reservoirs is the same as the
Daytona 675. Refer to the Maintenance
section in the accompanying handbook.


LOADING                               FRONT                        
              Spring Pre-Load  Rebound Damping  Compression Damping
Solo
Riding
Standard         7                            4                         4
Softer             7                            6                         6
Sport              7                             2                        2

Rider and         7                            4                         4
 Passenger


                                    REAR                        
               Rebound Damping  Compression Damping
Solo
Riding
Standard         8                            8                          
Softer             10                           10                          
Sport              6                             6                        

Rider and        8                             4
Passenger                                                



Number of turns out from the fully screwed in position.
Number of clicks out from the fully screwed in position.
Warning
The rear suspension unit spring pre-load is
not rider adjustable.
Any attempt to adjust the spring pre-load
could result in a dangerous riding
condition leading to loss of control and an
accident.


Sorry about the crappy formatting. I'm assiming that you use the compression damping to set the rear sag? (don't get my 'R' until March)

Rob
« Last Edit: January 12, 2011, 12:17:46 PM by williamr »

Offline fishface

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Re: Re: How suspension and geometry works
« Reply #22 on: January 12, 2011, 03:33:27 PM »
no, the r has a standard notched double ring on the rear shock...
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Offline jcp

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Re: How suspension and geometry works
« Reply #23 on: January 12, 2011, 06:18:19 PM »
Manufacturers are wary of owners adjusting pre-load they don't want owners to undo the preload adjuster-the notched ring which holds down the spring on the outside of the rear shock-and then complain when a powerful spring flies off and breaks their hands or adjusting it so the spring is either so tightly down or so loosely up that the handling is wrecked.
If it ain't broke....fiddle with it until it is!
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Offline fishface

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Re: How suspension and geometry works
« Reply #24 on: January 12, 2011, 09:10:12 PM »
Fair enough, if you don't feel confident then get someone who is, served my apprenticeship a a mechanical fitter so was no big deal for me, also during my career had to deal with some heavy plant springs that would launched you into space if it went wrong  :002:
« Last Edit: January 12, 2011, 09:14:15 PM by fishface »
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Offline williamr

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Re: How suspension and geometry works
« Reply #25 on: January 15, 2011, 03:21:44 PM »
Odd  this. The warning about the preload is repeated in the new owner's manual, but it's clearly adjustable. Most bikes have no problem with the owners adjusting preload. I don't see any problems in adjusting it.

Maybe this falls into the same area as the warning about not exceeding 80 mph if you carry a load not exceeding 5 Kg on the pillion seat. Not many 5Kg pillion passengers around my part of the world. I use a top box in everyday riding - it's kept empty as a place to park my gear. With that I think I'm probably confined to 30 mph and first gear lol.

Rob

Offline rob13

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Re: How suspension and geometry works
« Reply #26 on: March 13, 2011, 09:56:26 PM »
I want to experiment with suspension settings on mine. Having hit a few back roads these last few days, I've noticed the roads which I'm playing on are very bumpy and I'm getting a lot of feedback from the bike responding to those. I've usually ran bikes which were known for their softer suspension and whilst I like having less fork dive when on the brakes, I probably am better suited to a slightly softer setting. I'll sort sag out first but what advice could be given? The bike is currently on standard settings. I'm finding that the bike is skipping across bumpy surfaces and kicking me up the backside in the seat. Is this to do with rebound?

Offline bazzer

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Re: How suspension and geometry works
« Reply #27 on: March 01, 2013, 10:31:17 PM »
Preload changes the initial forced needed to move the suspension at all. Until preload force is reached the suspension does not move at all. One it starts moving its movement is dependant on the spring rate.

If you have a 100lb per inch spring and it has no preload and you put 300lb on it, it will move 3"
if you put 100lb of preload on it and 300lb load , it will move 2"
if its got 100lb of preload and you put 500lb on it, it will move 3"

So you don't change the rate by preloading only the initial point it starts moving.

Hope this makes sense.


Offline kiwist

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Re: How suspension and geometry works
« Reply #28 on: April 19, 2013, 01:41:57 PM »
My first post, bought a 2010 st 2 weeks ago, loving it but found the rear suspension hard but then I'm used to cruisers... so am interested in this thread ...addressing bazzers post, it would be completely wrong to preload so the bike did not sag at all?  Eg make the preload exceed the rider/bike weight?

In which case the pre load should simply set he position in the available travel and 1/3 down with rider on board seems to be accepted amount when "static" which makes sense to me given g forces in bends etc which at the extremes would almost double the riders weight, and you need a bit of travel left even when cornering at the extremes

I'm 100kg plus so need the pre load upped a bit compared to most i guess  :001:

My bike has std st front end but str rear shock so i can adjust the damping once the pre load is right. It does seem to be about right with 10 threads showing it sags about 30mm when i sit on it

Offline Jonathan

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Re: How suspension and geometry works
« Reply #29 on: June 05, 2013, 05:20:01 PM »
*Originally Posted by williamr [+]
Without getting involved in the complexities of setting up suspension, pre-load has one very simple job.

It's there to ensure that the shock is within its correct operating range, so that it neither tops out nor bottoms. With rider and bike supported by the suspension it should have an amount of sag equal to about 1" or 1/3rd of its operating range. The fact that it does alter the ride height is no relevant. It should not be used to alter the ride height, although many riders do use it that way. Neither does it alter the spring rate.

If you're riding on roads smooth enough that the full operating range of the shock isn't used you can use pre-load to tweak ride height a little, but that isn't its intended use.

By altering ride height at the rear you're effectively altering the steering geometry - the head angle and trail. That's best done by adjusting the front fork height, keeping geometry changes and suspension changes seperate.

So with preload (sag) and steering geometry set, you can then play with the real suspension settings of damping and spring rate (but altering spring rate - usually be replacing the spring unless your forks are air assisited) will require re-setting the sag.

Rob

I'm a little confused here. So what you are saying is that if my rear suspension is compressed by 2.25 inches when I sit on the bike I should not adjust the rear preload? I always thought I was supposed to adjust it so that I would have only 1 inch of sag.


 


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