CCDB CS Coil - Mega...
 

[Closed] CCDB CS Coil - Mega 275 using all the travel.

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USING ALL MY TRAVEL!!

CCDB CS Coil.
Weight 77kg
400lb spring Valt.
Nukeproof Mega 275 2016 bike
Lsc 2
Lsr. 2
HSC 4
HSR 2
Help please
Thanks
Followed setup procedure and still using all my travel on a reasonably tame run?
Do I need a heavier spring the CC calculator says 400?

Just picked up a 450 (not tried it yet) but can't believe that all the spring calculations are so far out! Is it to do with the new light weight steel alloys? being used on the Valts?

Ta


 
Posted : 23/04/2017 5:56 pm
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What's the sag like? Should tell you if you need a heavier spring.


 
Posted : 23/04/2017 6:25 pm
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Sag was 20mm with 400lb so pretty spot on!
It's about 18mm with 450lb - so we'll see.


 
Posted : 23/04/2017 6:33 pm
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Cane Creek base tune for the mega has different settings

LSC 12
LSR 12
HSC 2
HSR 2

They recommend a lot more low speed compression than you're running. How many turns of preload are you running? 400lb spring on a mega (it's a medium compression tune) is maybe a bit much for someone only 77kg. Cane Creek suggest 350lb spring rather than 400 as well


 
Posted : 23/04/2017 6:54 pm
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Sorry my settings are as you stated.
Lsc 12
Lsr 12

Sorry!

The spring calculator is wrong for me as is the TF and fox.


 
Posted : 23/04/2017 7:55 pm
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The problem is it's undersprung not over sprung, blows through its travel on a fairly tame track.
3 turns of preload.


 
Posted : 23/04/2017 7:57 pm
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So - from my noddy understanding of suspension, if your sag is ok once you're on the bike and your preload is ok then it's mostly a sign that the spring rate is good

If you took all compression and damping off then even if you put a heavier spring on, you'll still probably use all the travel

The damping is what keeps everything in shape once the spring is right. If you're using too much travel and it's a fairly tame ride then I'd push the LSC up - alternatively if you don't feel it's bobbing then maybe up the LSR as it may just be packing down. Then try it on a "bigger" ride


 
Posted : 23/04/2017 8:19 pm
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20mm shaft sag equates to about 34 percent actual sag when correcting with the Megas leverage ratio at that point in the travel (2.7).

So it's undersprung. A true 30 percent, or 17.7mm on the shock shaft will give you more support - but I also agree with turning the LSC up - go for a 425lb spring with more LSC or a 450lb spring with LSC run a little more open.


 
Posted : 23/04/2017 8:44 pm
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Thanks guys ๐Ÿ˜‰


 
Posted : 23/04/2017 8:58 pm
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Can't some of that "fine tuning" on the sag be managed by playing with the preload? Least if you have a 450lb spring you can have a play before touching the compression


 
Posted : 23/04/2017 9:06 pm
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Mojo seems to think it's better to go with a harder spring and as little preload as possible.

[img] [/img]

400lb spring with differing levels of preload vs 450lb spring - so adding more preload will effect bottom out resistance at the expense of increased resistance throughout the stroke and a higher initial breakaway force.


 
Posted : 23/04/2017 9:35 pm
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Cane creek advise softest spring and let the damping do the work?


 
Posted : 23/04/2017 9:39 pm
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Link?


 
Posted : 23/04/2017 9:42 pm
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Damping won't affect the sag - it's the spring weight and preload that does that

Edit. What's the scale at the bottom Tom?
Edit. And the scale at the side

Otherwise it's just some straight lines that may or may not show that a 400lb spring with 3 turns of preload has a similar endpoint to a 450lb spring with no preload


 
Posted : 23/04/2017 9:43 pm
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No one has suggested it does.

The scale at the bottom is shock stroke I presume.


 
Posted : 23/04/2017 9:46 pm
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TMB, souce of graph http://forums.mtbr.com/shocks-suspension/coil-rear-shocks-pre-load-vs-spring-rate-417239.html

left scale is force

Correlates with...

http://www.sportrider.com/technicalities-spring-rate-and-preload#page-5

the point is, it gives you a rough idea of the difference between preload and spring rate.


 
Posted : 23/04/2017 9:56 pm
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Interesting link - cheers!


 
Posted : 23/04/2017 10:12 pm