Dynamic sag for Wilbers info. please

[Wedders_Gasman]

I have acquired a pair of Wilber shocks for my 1200gs but have I question I can't seem to find an answer to. I have searched all available threads and scoured the interweb with no luck.
Setting up the preload for the shocks. It says in the instructions 1/3rd of the travel which is OK, I can measure the travel of the front with tie wraps, but I don't know how to do the rear.
Any body know
1. the actual measurements or,
2. how to measure the travel on the rear or,
3. the full comprehensive setting instructions with low speed, high speed, compression, preload etc. etc. etc.
Thanks

 

[Slowdown]

Timely post, as I'm just putting new shocks on mine

I was using this guide...

Seems straightforward enough - assuming there's 2 of you to do the second measurement

as to part 3 - WP have a guide

as do many many other sites via Google

 

[Wedders_Gasman]

Thanks for the reply, but the diagrams show how to do static sag which is not a problem, it is knowing what the "dynamic (sat on the bike) sag should be".

 

[Slowdown]

Well, ok, the diagram is missing someone sitting on the bike.

Now the WP link says:-

A few technical terms explained
Before you actually start your test rides, it is worthwhile knowing a little shock-absorber jargon. To start with, spring pre-load. This setting influences the height at which your motorcycle will ride. The higher the spring pre-load, the higher the riding height of the motorcycle. The spring pre-load can be adjusted by turning the spring collar/spring retainers, which may also be fitted with a locking ring. When you place the motorcycle on its wheels, the front fork will settle, by several centimetres, under the weight (sprung mass) of the bike. This is known as the "negative spring distance", "sag" or "neutral riding position". This negative spring distance (without rider) should be somewhere between 15% and 35% of the total spring distance (fork or shock stroke). Example: the total spring distance is 120 mm. The negative spring distance therefore should be between 20 and 40 mm. This can be easily measured by winding a cable tie around the shock-absorber spindle(s). With rider, the spring distance should be between 35% and 50%. Example: the total spring distance is 70 mm, so the negative spring distance should vary between 25 and 35 mm.

Yes?

 

[Micky]

Get the total suspension movement from the handbook.

Measure from a fixed point on the bike, front mudguard to the ground and then maybe the rear seat lower edge to the ground. ... a known point front and rear.

Sit on the bike with normal gear and luggage and take those same measurements again... they will be less... that's the sag.

OK get someone else to take those same measurements!

The sag should be 25% to 30% of the overall suspension movement.

Overall suspension movement = 4"

Sag = 1" then thats 25% = OK

Sag = 1/2" then that's 1/8" or 12 1/2 % = too hard

Sag = 2" then that's 50% = too soft

Having got the preload set right then and only then do you adjust the rebound damping... and you want as minimum of this as you can get away with. Too much rebound damping and the bike will ride tail down and you'll feel every bump. Set too little and you'll just boing boing boing down the road like Zebidee ...



www.adventure.gs

 

[Wedders_Gasman]

Thanks for the replies, but nobody seems to understand what I need to know.

I know HOW to set it up.

What I don't know is how to measure/acquire the full travel of the rear shock so that I can set it to approx 30%. Wilbers don't give this information and it may not be the same as the standard shock.

The front is easy with tie wraps but you can't use that method on the back.

 

[st247]

What I don't know is how to measure/acquire the full travel of the rear shock so that I can set it to approx 30%. Wilbers don't give this information and it may not be the same as the standard shock.

Have a look here post 3 in particular. There's also some shock setup data on this how to feature.

 

[Micky]

Thanks for the replies, but nobody seems to understand what I need to know.


What I don't know is how to measure/acquire the full travel of the rear shock so that I can set it to approx 30%.

The front is easy with tie wraps but you can't use that method on the back.

Like I said, it's in the handbook The Wilbers will be made for the same length of travel as original, just that the spring rate and damping will be better



www.adventure.gs