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Old 08-21-2020, 09:49 PM   #1
outblasted
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Join Date: Jul 2015
Location: Sunnyvale
Motorcycles: 19' Yamaha R6; 06' Yamaha R6 (sold); 13' Ninja 300 (RIP)
Name:
Seeking suspension sag setup advice

Given:

Bike: stock 2020 R6
Rider: mostly stock, 216lbs me (with gear)

I watched Dave's sag setup video (https://youtu.be/yF86AvK2XVA), and thought I would do the same to my 2020 R6, but I am baffled by my results on the rear shock.

With help of folks holding the bike and handling tape measure, we measured 3 distances on front and back:

1) to (topped out): distance with the bike topped out
2) at (at rest) distance with the bike at rest
3) rd (rider): distance with the rider (me) on the bike

I got these results:

On the front, with full preload (preload nut turned in all the way),

Front, full preload (preload nut turned in all the way):
to: 138
at: 119
rd: 106 ---- sag: 32

Front, no preload (preload nut turned out all the way):
to: 136
at: 110
rd: 98 ---- sag: 38

Rear, factory setting (didn't get absolute reading, as I was counting turns from this point):
to: 661
at: 649
rd: 626 ---- sag: 35

Rear, -1 turn of preload (rel to fact. setting)
to: 662
at: 644
rd: 618 ---- sag: 44

Rear, -0.5 turn of preload (rel to fact. setting)
to: 658
at: 642
rd: 615 ---- sag: 43

Rear, +0.25 turn of preload
to: 661
at: 644
rd: 620 ---- sag: 41

Rear: +0.75 turn of preload
to: ---
at: 644
rd: 619 ---- sag: 42

I gave up there, because I started questioning my process and results, and thought I should watch Dave's video again.

My goal was to get the front into 35..40 range, and the rear to 30..35. Fork and shock have 140mm of travel per wikipedia specs (didn't find numbers in the manual).
The goals I set based on Dave's ballpark numbers.

Do these settings and their resulting measurements (and their progression) look reasonable to you?

I went on a short street ride after these experiments, but didn't feel any difference (not that I am trained to feel the difference...).

Thank you.
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Old 08-21-2020, 10:08 PM   #2
motomania2007
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Join Date: May 2008
Location: Merced, CA
Motorcycles: BMW R1200R, FZ09, FZR400, CR250R
Name: George
1) what is the full range of the suspension from fully extended to fully compressed. You should be able to find this online somewhere and it is going to be in the neighborhood of about 90-100mm

2) multiply #1 by .3 to get 30% of full range. Some prefer 35% (multiply #1 by .35) of full range. This is your target sag number.

3) have some buddies support the bike straight up and down with you sitting on it in full gear like you're ready to go riding.

4) have a first buddy position to measure the sag from a fixed point on the motorcycle to the axle.

5) have a second buddy lift the bike until the suspension is mostly fully extended and then slowly lower the bike until the bike is supported by the suspension. First buddy measures this first measurement we will call M1

6) have the second buddy push down on the bike until the suspension is substantially compressed and then slowly release pressure on the bike until the bike rises to the fully supported position by the suspension. First buddy measures this measurement we will call m2.

7) calculate the average of M1 and m2 by adding them up and dividing by 2.

8) subtract number 7 from number 1 and this gives you your current sag.

9) If your current sag is less than 30 to 35%, then you need to reduce preload and then repeat steps 4-8.

10) If your current sag is more than 30 to 35%, then you need to increase preload then repeat steps 4-8.

11) keep adjusting the preload until you get it in the right range.

12) repeat the process for the other end of the motorcycle.

That's how you set the sag
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Old 08-21-2020, 10:32 PM   #3
outblasted
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Join Date: Jul 2015
Location: Sunnyvale
Motorcycles: 19' Yamaha R6; 06' Yamaha R6 (sold); 13' Ninja 300 (RIP)
Name:
Ouchie, I wasn't doing it right then. Will do again tomorrow. Thanks.
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Old 08-24-2020, 10:07 PM   #4
NoLuV4uHaTeRs
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Join Date: Aug 2003
Location: Benicia,CA
Motorcycles: 2015 R1
Name: Chris
Sign up for track day with carters@track or funtrackdayz Dave Moss should be there to help with ANY suspensions questions.......
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Old 08-24-2020, 10:37 PM   #5
quicksparks
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Not just the sag matters, but spring rate, too. At 216 lbs you will probably need stiffer springs. Most bikes come from the factory sprung for a ~150 lb rider.

With stock springs if you get the race/rider sag within range by adjusting preload, your static sag will be zero or negative (have to press down to get suspension to compress at all, or beyond “topped out”). The fork should settle down some (10-15 mm I think) with just the weight of the bike. Similar for the shock but I think zero sag is acceptable for that, but just know that with the weight of the bike only (you’re not on it), the rear should be on the verge of going down (i.e. you shouldn’t have to push it down).
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