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Spring too soft? Shock bottoms out...

kuksul08

Monkey
Jun 4, 2007
240
0
Alright so I thought my shock was too stiff and I couldnt get the right sag, so I used a spring rate calculator which said I should have a 400lb spring on my VP Free (I had a 450lb before).

So I put on the new spring, and it feels very plush, the sag is just right, but no matter what I do to my shock it still bottoms too easily. I jumped about 7-8 stairs to flat today and it's the first time I felt a real solid CLUNK when it bottomed.

The shock is a manitou 6-way swinger which has high and low speed compression, bottom out resistance, SPV pressure, preload, and rebound. I have 100psi in the chamber, 3 out of 6 turns in on the bottom-out, 1 turn in on the high speed and no low speed damping. Sag is at 30% (1 inch on the shock).

I've experimented screwing in the bottom-out adjuster but it doesn't do anything..haha. What should I do? Put more preload or put the 450 back on and deal with it...
 

1453

Monkey
try more air in the chamber and crank up the bottom resistance and put on the 45 spring. the shock set-up guide don't usually assume you will be doing hucks-to-flat-on-concrete stuff, and plushness + bottom-out resistant doesn't come cheap
 

kuksul08

Monkey
Jun 4, 2007
240
0
try more air in the chamber and crank up the bottom resistance and put on the 45 spring. the shock set-up guide don't usually assume you will be doing hucks-to-flat-on-concrete stuff, and plushness + bottom-out resistant doesn't come cheap
So you're saying I can't get the best of both plushness and big hit capability in one? Would this be due to my shock or just the suspension design of my bike?

When I have the 450 spring on there, it never bottoms...it's just not as plush
 

1453

Monkey
So you're saying I can't get the best of both plushness and big hit capability in one? Would this be due to my shock or just the suspension design of my bike?

When I have the 450 spring on there, it never bottoms...it's just not as plush
you could, but it will cost you, you may have to go custom to get that, be it revalving the shock(if that's posible for the Swinger) or a different shock. The average off-the-shelf shock are designed to be a compromise between plushness, bottom resistance as well as accomadate a wide range of ride body weight. THe average shock set-up guide also don't anticipate that you do huck-to-flat on concrete.

I believe that's one of the draws of high-end shocks like Avalanche for people who wanted both features, so they can custom-tune the shock for their liking and find the right combination between compliance and being forgiving of loading-dock type drops

actually come to think of it there was a long and messy thread on how to use high and low speed compression damping to tune your ride, try searching for it and try various methods and see what works for you.

edit: I think this was it.
http://www.ridemonkey.com/forums/showthread.php?t=182140&highlight=shock+tuning+hsc+lsc
 

buildyourown

Turbo Monkey
Feb 9, 2004
4,837
0
South Seattle
That shock is a pile. They blow easily, an Manitou will take 3 months to get it back to you.
Pick up a cheap DHX and you will be soooo much happier.
 

mandown

Poopdeck Repost
Jun 1, 2004
14,097
1,523
Transylvania 90210
bottom-out will be a function of spring rate and valving/damping.

sag is a spring-rate issue.

by process of elimination (you already have the right sag) you must adjust the valving/damping.

you need to ramp up the compression damping. if you can do high and low speed compression adjustments, then for big hits, you will want to twak the high-speed adjustment.

as stated above, the purpose of a shock is not to allow you to do an "8 foot to flat on concrete" and have it feel like a pillow. if you want that, you will need to pay for a shock with speed-sensitive valving (not the Marzo SSV of old) and/or have your shock custom tuned (like Avy will do).
 

kuksul08

Monkey
Jun 4, 2007
240
0
Wow awesome thanks for the link 1453.

I will keep trying to adjust it, maybe minimize the drops, and wait until the shock breaks to give me an excuse to buy a vivid or ccdb.


From reading that..it looks like I need low speed compression for the trails and high speed for drops...
 

Avy Rider

Monkey
Feb 26, 2003
287
0
Muskoka,Canada
To land the type of drops you described you actually need to greatly increase the LOW speed damping. I went through this last year in setting my newly rebuilt Avalanche with the separate hi/low adjuster.

I was under the very wrong notion that running more high speed compression and backing off the amount of low speed compression would make the bike plush and suck up big flat landings. WRONG!!! Craig at Avalanche spent a good 30 minutes or so of his lunch break with me on the phone patiently explaining how the valving actually responds to flat landings vs true high speed hits. You will be mostly using your shocks low speed compression valving on a drop to flat unless for some odd reason you don't bend your arms or legs when landing. The bodies natural response takes the edge off the impact enough that the high speed valving isn't being activated like you would think.

High speed compression comes into play when you are hitting square edged abrupt bumps at a high velocity. Rocks and roots are perfect example of obstacles that will activate your high speed compression circuits.
What will help your landings is definitely adding more LSC and if you find that the bike is feeling harsh over roots/rocks at high speed try backing off your HSC until it smooths things out but not bottoms.

I'm only passing along what was taught to me be someone who certainly knows more about suspension than most. Take it for what it's worth and good luck to you.
 

mandown

Poopdeck Repost
Jun 1, 2004
14,097
1,523
Transylvania 90210
interesting. perhaps the LSC is the way to go. however, if he has poor form and doesn't absorb the landing foces, he may be in need of HSC.

pick a drop, open all the compression valves and hit it. do you bottom? twak the HSC and see how it changes the landing. then open it back up and twak the LSC and see how it changes the landing. hit the same drop over and over until it feels the way you think it should feel (within the ability of the shock).
 

Avy Rider

Monkey
Feb 26, 2003
287
0
Muskoka,Canada
Bear in mind that few shocks can truly separate the high and low speed circuits so reducing the low speed compression will likely have an effect on the amount of high speed compression available.
 

kuksul08

Monkey
Jun 4, 2007
240
0
Thanks everyone. I just went out and put both compression adjustments to full out and it felt basically like a spring...obviously. I then put low speed compression all the way up to see what it feels like. It definitely wallowed less and felt more stable. Then I put low speed back out and high speed up. I only felt a difference going off stairs and running into curbs...

In the end I put them both at 1 turn in, both are out of a total 2.5 turns.. we'll see how it works on a trail
 

dh415

Chimp
Dec 6, 2006
56
0
novato
something i learned that might help u is how ever much u way put that much psi in the shock chamber but then again it might not work for u and manitous r always gona clunk i owned one and hated it
 

dhkid

Turbo Monkey
Mar 10, 2005
3,359
0
Malaysia
screw in the bottom out resistance on your shock. it would make a huge difference.

yes more low speed compression would help. but screwing in your bottom out resistance would help much much more because the swinger is a position sensitive shock.

i used to have a vp free, and thats the reason i got rid of it, it blew though the travel mid stroke. loads of ending stroke compression helped with that.
 

Spokompton

Monkey
May 15, 2005
321
0
Spokane WA
Also make sure you are not preloading the spring too much.

If it is preloaded too far, you will actually be bottoming out the spring on itself before the shock has compressed completely.

This recently happened to me. I was messing around with preload and started clunking my rear shock on small hits. It turned out I had turned the preload too much and causing the coil to bind up. Loosened the preload and hasn't ever bottomed out since.

Just a thought.