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Discussion Starter #1
So I have measured my preload and set it as best I can with 2 people. I know the rear is accurate, front may be off as much as 10mm, in either direction. However, when downshifting under braking (in first especially) I hear a little bit of a tire chirp. I am almost 100% certain it is not from the front, as the front does not appear to slide or lose traction under braking, and while I have had the rear squirm around when I am braking hard, it was only after setting up my preload that I noticed a brief chirp.

Anyone have any ideas what would be causing this?
 

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So I have measured my preload and set it as best I can with 2 people. I know the rear is accurate, front may be off as much as 10mm, in either direction. However, when downshifting under braking (in first especially) I hear a little bit of a tire chirp. I am almost 100% certain it is not from the front, as the front does not appear to slide or lose traction under braking, and while I have had the rear squirm around when I am braking hard, it was only after setting up my preload that I noticed a brief chirp.

Anyone have any ideas what would be causing this?

You are blipping the throttle on downshifts?
 

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The cause of your problem is riding too hard with a passenger on board.

Or too much rear preload causing the tyre to skim the ground under heavy braking. You choose.
 

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You want around 30-35 with you on it, and 5-10 without. Amorti hit the nail on the head.
 

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Yes. I have 0mm of static preload and 16mm with me on the bike (rear).

Why did you set it to zero?
I like firm suspension but you have to have some extension available :)
 

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OK remind us how you set this up again as ive forgotten and need to do mine again... Measure from where to where on the rear?

Centre of axle to some fixed point on the tail.
 

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Discussion Starter #9 (Edited)
Why did you set it to zero?
I like firm suspension but you have to have some extension available :)
0 is the static (without me on it) and sky, I'm almost 100% that its 20-35mm for front and 15-20mm rear.

Is this wrong?

As a note this is what I read on motionpro.
 

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Thanks BR

If I remember correctly, you should measure with the rear wheel off the ground first to find the start point. Then with the bike on the ground without you on it, this is the static, then get on this is the loaded. If you have no movement of the suspesion when on its own weight from the raised measurement your shock has too much preload on the spring.
 

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I'm almost 100% that its 20-35mm for front and 15-20mm rear.
Other way around :thumb:

There should be a small amount of sag between no weight on the wheels, and the weight of the bike (this is static sag).
 

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If I remember correctly, you should measure with the rear wheel off the ground first to find the start point. Then with the bike on the ground without you on it, this is the static, then get on this is the loaded. If you have no movement of the suspesion when on its own weight from the raised measurement your shock has too much preload on the spring.
:plus1:


I'm almost 100% that its 20-35mm for front and 15-20mm rear.
Other way around :thumb:

There should be a small amount of sag between no weight on the wheels, and the weight of the bike (this is static sag).

http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm
 

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Thanks BR

If I remember correctly, you should measure with the rear wheel off the ground first to find the start point. Then with the bike on the ground without you on it, this is the static, then get on this is the loaded. If you have no movement of the suspension when on its own weight from the raised measurement your shock has too much preload on the spring.

Yep, that's correct. You have to have some sag in the suspension or there's nothing left for extension as you unload it.
 

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0 is the static (without me on it) and sky, I'm almost 100% that its 20-35mm for front and 15-20mm rear.

Is this wrong?

As a note this is what I read on motionpro.

It does all come down to personal preference but you should have some static sag in it.
Work on 25-30% of travel front and rear and adjust from there to suit your personal preference.
Also check that the forks are not hitting mechanical bottom under braking as that will cause front tyre lockup and chirping.
 

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Discussion Starter #15
Front tyre doesnt appear to be locking, I know (with near certainty) they are not bottoming out. I have 2 lines showing on a my F4i on front preload. The rest of the settings are stock. I weigh 140lbs.

Set up the rear preload to have 26-28mm of travel. Went for a ride and still heard the chrip once.
 

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Front tyre doesnt appear to be locking, I know (with near certainty) they are not bottoming out. I have 2 lines showing on a my F4i on front preload. The rest of the settings are stock. I weigh 140lbs.

Set up the rear preload to have 26-28mm of travel. Went for a ride and still heard the chrip once.

Is this during downshifting or are you using the rear brake?
 

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Discussion Starter #17
Downshifting. I can only replicate it in 1st due to local speed contraints haha. I never touch the rear.
 

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Downshifting. I can only replicate it in 1st due to local speed contraints haha. I never touch the rear.

Then maybe it's just poor matching of RPM to road speed?
 

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Sorry to hijack but just checked my settings:

Suspension

Current:
Front
Top compression 3 turns out
Bottom quarter turn only

Rear
Top 10 clicks
Bottom 35 clicks

Sag
Rear
10mm static sag
Rider sag 65mm (FAT GIT)

Front
Static sag 30 mm
Rider sag 48mm



The rear is after adjusting the preload on the shock! it was 35mm static sag. I need a resprung rear spring that much is clear, the front rider sag was lower than the static as the rear took all the weight and the front raised up when I sat on it! Its better now ive adjusted the rear shock :)

Question, the lower adjuster on the front forks is this rebound? Mine is only 1/4 turn from fully in does this seem right?? CBR1000 RR5 forks
 
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