Author Topic: Setting the suspension on the C14  (Read 43470 times)

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Offline Staylo

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Re: Setting the suspension on the C14
« Reply #25 on: March 22, 2017, 08:52:53 pm »
I should also add that often people who think they need a softer spring actually need a stiffer spring.  If your spring is too soft you have to put a lot of preload into it to get the sag numbers that you need, but that in turn increases the amount of force required to move the shock, causing it to feel stiffer than it actually is.

Example(stolen from online): Using a 100 pound linear-rate spring, preloaded one-quarter inch, you have preloaded 25 pounds of force into the spring, so it would take more than twenty-five pounds of force before it would further compress. In other words, the spring will not compress until 26 pounds of force were applied.

So, in our example, if you are traveling down the road and apply less than 25 pounds of additional force though bumps then the spring(and shock or fork) will not move, and feel very stiff.  BUT, by moving to a stiffer spring you would require less preload, and therefore the spring would react to inputs of less force making the suspension(and spring) feel softer.

Your best bet is to find a suspension tuner that you can trust and have them check your current springs against your weight.
Lancaster County, PA
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Offline connie_rider

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Re: Setting the suspension on the C14
« Reply #26 on: March 22, 2017, 09:03:05 pm »
I'm beginning to understand better, but still too poor to buy the aftermarket shocks.
Would buying a stiffer spring help the stock suspension, and (if so) what spring would I need?
I'm 210 lbs. with gear.
Occasionally have the wife with me.
Seldom carry a lot of gear, but do carry tools etc. (mebbe 20 lbs)

I assume I should set the sag to my weight, and (mebbe) adjust for 2 up.

Ted
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Offline Staylo

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Re: Setting the suspension on the C14
« Reply #27 on: March 23, 2017, 12:46:12 am »
I'm beginning to understand better, but still too poor to buy the aftermarket shocks.
Would buying a stiffer spring help the stock suspension, and (if so) what spring would I need?
I'm 210 lbs. with gear.
Occasionally have the wife with me.
Seldom carry a lot of gear, but do carry tools etc. (mebbe 20 lbs)

I assume I should set the sag to my weight, and (mebbe) adjust for 2 up.

Ted
In my opinion, I wouldn't bother spending any money respringing that stock Kawasaki shock and forks. They're just not very good units to begin with. Plus, if you haven't had them serviced in a long time, or ever, then their performance is already degraded because the oil has probably lost its viscosity and is no longer providing the proper damping anyway.  I do understand money being tight, but you would be much better served to keep the money you would spend on re-springing the stock parts, plus labor to have them done if you don't have the tooling or knowledge to do it, and save that money towards a new Penske shock, which would come ready to install straight out of the box, and the Traxxion kit. Putting new springs on your stock equipment will make an improvement, but is just not going to get you all the way to where you want to be.  As Matt mentioned earlier, the valving in the forks and the shock are not set up very well and will not give the proper damping to go along with the new spring, so you're spending money to "upgrade" your suspension with new springs, and afterwards still having an improperly set up suspension.

Regarding determining the proper spring rate, your best bet would be to speak with a suspension company like Traxxion or Penske and let them advise you on the spring rate that would be correct for your application. As far as how to set the bike up regarding weight, etc.,  you're going to have to make a compromise. Going from one-up riding to two-up riding is a humongous difference in weight, and no single spring is ever going to be able to properly handle those two loads, so if you ride 90% of the time alone then set the bike up for that situation, understanding that when you are two-up the bike is not going to handle as well because of the additional weight. If the majority the time you ride two-up, then set the bike up for that scenario, understanding when you are riding solo it's not going to handle as well. If you ride 50-50, then I don't know what to tell you.  ;)
« Last Edit: March 23, 2017, 12:51:57 am by Staylo »
Lancaster County, PA
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Offline curt1480

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Re: Setting the suspension on the C14
« Reply #28 on: April 14, 2017, 10:26:50 pm »
It would be nice to watch the video for all of us non talented people

Offline Doc

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Re: Setting the suspension on the C14
« Reply #29 on: November 08, 2017, 01:45:30 am »
Here's a chart to give you some base line settings. The "just right" worked well.

https://www.dropbox.com/s/gf9rw08qwk83x35/C-14%20Suspension.pdf


It’s been a while but the link to pdf is disabled - could you repost?

Offline Daytona_Mike

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Re: Setting the suspension on the C14
« Reply #30 on: November 08, 2017, 04:00:23 am »
I should also add that often people who think they need a softer spring actually need a stiffer spring.  If your spring is too soft you have to put a lot of preload into it to get the sag numbers that you need, but that in turn increases the amount of force required to move the shock, causing it to feel stiffer than it actually is.

Example(stolen from online): Using a 100 pound linear-rate spring, preloaded one-quarter inch, you have preloaded 25 pounds of force into the spring, so it would take more than twenty-five pounds of force before it would further compress. In other words, the spring will not compress until 26 pounds of force were applied.

So, in our example, if you are traveling down the road and apply less than 25 pounds of additional force though bumps then the spring(and shock or fork) will not move, and feel very stiff.  BUT, by moving to a stiffer spring you would require less preload, and therefore the spring would react to inputs of less force making the suspension(and spring) feel softer.


Sorry to tell you that this is totally not correct. Preload can never  change spring rate.  Preload cannot  make a spring softer or harder or feel softer or harder.
Preload only raises and lowers the chassis ride height or SAG.  Again,  increasing preload does not compress a spring and make it stiffer - ever- it just raises the bike. Chassis geometry or Ride height or Sag settings (all the same)
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