Need to know the difference

[TrueBlue]

I have a 02 Viper. In 03 I had the upgraded shocks installed ( all 4 ) that yamaha offered to it's customers for 300.00 dollars. My question, is the 02 center and rear shock springs the same as the upgraded ones. If I remember right I think the shocks were the only change

Does anyone know how to determine if your springs are no longer any good. The shocks & springs have 3,500 miles on them. No jumping. Trail riding only.
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[Mtnviper]

The OEM center shock spring is a multi-rate spring, while the updated spring is a straight rate (coil's evenly spaced) spring. Not sure about the rear one, but I believe the rate may be slightly different as well.

Testing springs, require's a spring rate pressure guage. You can kind'a tell if they're starting to go south, when you have to keep tightening the preload adjustment, to prevent the sled from bottoming. This can be an indication that the shocks are getting soft as well.

 

[BETHEVIPER]

the rear is different as well. as for the bottoming test, springs have little to do with bottoming. springs are for returning your suspension shocks so they can take another hit and to hold the weight of the sled and rider at a spacific point.

to judge if your spring is bad by having to keep tightening it is not a good guage. your shock could need to be stiffer valved or rebuilt if it is bottoming too much.

bushings in your suspension being wore out will make your sled sag and require more spring preasure to get the same ride height, wore out bushings make a skid act like it has a soft shock as it can move around without even moving the shock.

in my opinion, 3500mls on an aluminum shock you should have the oil changed at the minumum, on a fox it would need every thing, a kyb will probly just need the oil changed. on that rear shock while it is in being worked on , have them make it a tad stiffer valving, they came a little soft. i could always run mine in the fast side of the fra adjuster and it still rode smooth.

when you install your front shock back in either shim your bushings in the front( this wont last) or install bushings from the upper end of a rx1 shock in both ends of the shock. you will need to use a blade and shave about 1mm off the outside of them to get them to fit but they will be tight and make your front shock actualy work.

also look for my posts on rear skid fixes, there are a few to make this skid ride better, handle better and last longer.

 

[terret725]

yea the oem oil in the yamie shocks are junk a tech shoed me the oil after like 1000 miles in a shock compaired to the oil he was puting back in and it was like water it was all broken down

 

[Mtnviper]

Ok, perhaps I need to need to re-phrase this. If you have to keep tightening up the spring pre-load to maintain the correct ride height, (as long as rider weight is the same) then it can be an indication that a spring is getting soft.

Soft springs can cause bottoming due to reduced ride height/spring rate.

A clasic example of a to soft spring, would be the 97 XTC. While it's true that XTC shock's are valved soft, the center shock spring only has a rate of only1.2 kg/mm. When riding in rough terrain it would bottom so badly it could pound the center shock to death. That is one reason why Maxx perf and other's came out with an updated spring, for this sled.

Soft/worn shocks can also cause bottoming, due to poor rebound/compression dampening. This because as dampening wears/soften's, suspension stroke speed increases, (because of less resistance). What can happen then, as compression stroke speed increases to a point where it overcomes the stored energy in the spring, causing the suspension to bottom out. As you can see either a poor shock (uncontroled suspension travel speed) or a weak spring (not enough stored energy) could cause a bottom out condition.

It is the spring's job to support the weight of the sled/rider, and maintain proper ride height, not just static, but also while moving/riding.

The shock's number 1 job is to control suspension stroke speed. Except for air shock's they do not control ride height. Yes gas shock's do have pressure in them, but it's not for ride height. The primary purpose of gas pressure is to prevent oil foaming caused by rapid shock travel speed's (fast rough terrain riding)

A stiffer spring with it's added stored energy will have a faster extension speed , and a slower compression speed. This usually requires a shock with more rebound control and less compression valving.

A softer spring would require less shock rebound valving to let it extend faster, thus allowing the suspension to drop quicker to it's center point and be ready for the next bump. A softer spring would also require more compression valving to reduce suspension compression speed, since there is not as much stored energy in the spring to slow the compression rate down before the suspension bottom's out.

Both the spring and shock need to work together to provide good suspension performance. When you change one it effect's the other. To say "if your bottoming out, you need to change the shock's" is not always true. Yeah you could put stiffer shock's on it, but it could ride like chit when your not hammering on it. Like the 02 OEM Viper shock's!
The correct fix, (providing your suspension is not worn out), would be spring/shock matching set.

So to answer TrueBlue's original question, the spring's are probably ok at 3500 miles. But the shock's and "W" arm bushing's can wear at a faster rate, and should be checked out.