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A couple of suspension questions

Posted: Tue Oct 14, 2008 9:28 am
by the_finch
I'm getting ready to finally tune my suspension and had a couple of questions. Keep in mind that I weigh about 210lbs. (Approx 96kg). I have the stock "pasta noodle" FZR600 suspension on my 97 600.

I have a set of Racetech .90 lb./in springs and gold valve emulators, seals, etc. for the front end. Will the .90's be sufficient for street duty (and maybe the occasional track day eventually) for my weight, or will I need .95's?

I was going to use 20w fork oil, does it sound like that's proper for what I'm doing, or do I need a lighter weight oil?

Any clue as to what setting I should set the valve emulators to when I install them?

Also, the final question. I was looking at getting a replacement spring for the FZ1 shock I'm gonna install, but I don't have any clue as to what springrate I need. From what I understand, it fits in place of the FZR shock no problem (except for possibly a ride height adjustment with new dogbones) and the springrate is too wimpy to use, and the stock FZR shock's spring (approx 700 lb./in. I think) probably isn't designed for that much weight. I may occasionally carry a passenger, so keep that in mind.

I know we have a couple of suspension gurus on here (most notably YamahaGeorge) who know this alot better than I do, and this is my first attempt as suspension tuning on any vehicle (if you don't count playing around with the coilovers on my buddy's 2005 Pontiac GTO 6.0L SCCA car), so any help is welcome.

Thanks in advance!

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 1:40 pm
by haunter
.9's should be great street and the occasional trackday

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 4:20 pm
by the_finch
haunter wrote:.9's should be great street and the occasional trackday
Awesome. Thanks for the help on that. Anyone have any clues on preload or the catridge emulator settings?

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 4:58 pm
by YAM93
I have .90kg/mm's on mine and i'm only 160-165 pounds with gear on. I say you should get the 1.0kg/mm, but that's just me. The .90's will probably be ok, but you are considerably bigger. I'd say around 775 pound spring rate for rear shock at your weight.

:headbang:

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 5:16 pm
by haunter
YAM93 wrote:I have .90kg/mm's on mine and i'm only 160-165 pounds with gear on. I say you should get the 1.0kg/mm, but that's just me. The .90's will probably be ok, but you are considerably bigger. I'd say around 775 pound spring rate for rear shock at your weight.

:headbang:

racetech told me .9 :D

I just use their calcualtor cuz I dont know any better :)

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 5:43 pm
by Xian_13
the_finch wrote:I'm getting ready to finally tune my suspension and had a couple of questions. Keep in mind that I weigh about 210lbs. (Approx 96kg). I have the stock "pasta noodle" FZR600 suspension on my 97 600.

I have a set of Racetech .90 lb./in springs and gold valve emulators, seals, etc. for the front end. Will the .90's be sufficient for street duty (and maybe the occasional track day eventually) for my weight, or will I need .95's?
I was going to use 20w fork oil, does it sound like that's proper for what I'm doing, or do I need a lighter weight oil?

[/quote]

The proper spring for you to use, on a track is .94... the closest available spring would be a .95.
On the street, the .90 will be fine.
However on the track, your bike is subject to forces much stronger then the street.
Save yourself the headache, get the .95.

Also, where did you get 20w Fork oil?
I will admit. I do not know what oil stock forks use.
Pending the valves in the fork on the race bikes, I use 5w 7.5w or 10w.
The ONLY time I have 10w in a fork, is when I learning the limits of a different fork on a bike.
Like an 05 GSXR front end on a FZR.
I do this, so I know I wont run out of valving... (i.e. Better to have more)
What ever the case, is is always replaced with 5w or 7.5 come Go time.

XIII

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 6:28 pm
by yamaha_george
haunter wrote:
YAM93 wrote:I have .90kg/mm's on mine and i'm only 160-165 pounds with gear on. I say you should get the 1.0kg/mm, but that's just me. The .90's will probably be ok, but you are considerably bigger. I'd say around 775 pound spring rate for rear shock at your weight.

:headbang:

racetech told me .9 :D

I just use their calcualtor cuz I dont know any better :)
Hi,
0.9 is fine as to the tuning of the golds I believe I gave that on my site http://www.saltmine.org.uk/fzr/project-1.html

as to springing try the new link I put on the site WIKI yesterday that if memory serves gives values of stock springs. Im currenly using a BUSA spring but will drop that down to the GSXR 600 for my lighter weight and then test with a 100lb passenger and see what that gives.

Re: A couple of suspension questions

Posted: Tue Oct 14, 2008 9:43 pm
by mszilves
I would agree with George, .90 for street should work well. You don't want the suspension too stiff for street use, unless you like sore arms. 20W oil should be good also. I have .85s in mine right now (I'm 175 dry) and find them a tad on the stiff side. No matter how hard I brake, I still have 1-1.5" of unused travel on my forks. I started with 15W oil, found that it still didn't have enough rebound damping, so switched to 20W and it's pretty well setup. I'm running the recommended 2 turns out on the emulators.

If you need more info, just let me know.