General DH Discussion

PB Forum :: Downhill
General DH Discussion
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flag badbadleroybrown
Posted: Jun 2, 2012 at 10:47 Quote
J-Carmichael wrote:
Are you supposed to set say with compression fully off or with it in the middle? Thanks for the help!
Did you mean sag?
flag J-Carmichael
Posted: Jun 2, 2012 at 10:49 Quote
badbadleroybrown wrote:
J-Carmichael wrote:
Are you supposed to set say with compression fully off or with it in the middle? Thanks for the help!
Did you mean sag?

Sorry yes, that's what I meant
flag Nobble
Posted: Jun 2, 2012 at 11:01 Quote
J-Carmichael wrote:
badbadleroybrown wrote:
J-Carmichael wrote:
Are you supposed to set say with compression fully off or with it in the middle? Thanks for the help!
Did you mean sag?

Sorry yes, that's what I meant
you mean the compression adjustments? I'd start with them like 2 clicks from off and turn them up as you need them.

they shouldnt make a difference to your sag measurement
flag badbadleroybrown
Posted: Jun 2, 2012 at 11:15 Quote
J-Carmichael wrote:
badbadleroybrown wrote:
J-Carmichael wrote:
Are you supposed to set say with compression fully off or with it in the middle? Thanks for the help!
Did you mean sag?

Sorry yes, that's what I meant
Compression settings won't affect sag... Compression damping just controls the rate at which the damper can move, not the extent to which it can move.

That said, I usually turn the compression all the way up before I set my sag if I'm trying to do it alone just because it makes the suspension less prone to 'bouncing' as you're sitting there so you would, in theory at least, see less impact from suddle movements like getting back off the bike. If you have someone helping you who'll do the measuring while you're on the bike, it won't make any difference at all though.

Also, on a side note... I typically set my sag slightly high on the rear and slightly short of my target on the front for DH since, once you're actually going downhill there's a weight shift. So, if I'm after say a 30% sag front and rear, I'll set it up as 35% rear and 25% front on flat ground. Then, when I'm on a decline and the weight distribution changes, it balances out to 30/30.
flag ktmmxrider
Posted: Jun 2, 2012 at 11:15 Quote
Set your sag with the compression and rebound already adjusted. Or like don't un-adjust it to set the sag.
flag badbadleroybrown
Posted: Jun 2, 2012 at 11:16 Quote
ktmmxrider wrote:
Set your sag with the compression and rebound already adjusted. Or like don't un-adjust it to set the sag.
Should always set the adjustments after sag... because of the way leverage rates change through the suspension travel, the correct damping with 10% sag won't be correct at 30% sag.

Set sag first, then start dialing in your adjustments.
flag Nobble
Posted: Jun 2, 2012 at 11:19 Quote
badbadleroybrown wrote:
ktmmxrider wrote:
Set your sag with the compression and rebound already adjusted. Or like don't un-adjust it to set the sag.
Should always set the adjustments after sag... because of the way leverage rates change through the suspension travel, the correct damping with 10% sag won't be correct at 30% sag.

Set sag first, then start dialing in your adjustments.
the high and low speed compression adjustments shouldnt affect his sag reading... (think about it, the shock dosen't extend without a coil on it)
flag ktmmxrider
Posted: Jun 2, 2012 at 11:21 Quote
Compression settings have no effect on setting the sag. Trust me on this one. Been doing it in moto for 12 years now.
flag badbadleroybrown
Posted: Jun 2, 2012 at 11:24 Quote
Nobble wrote:
badbadleroybrown wrote:
ktmmxrider wrote:
Set your sag with the compression and rebound already adjusted. Or like don't un-adjust it to set the sag.
Should always set the adjustments after sag... because of the way leverage rates change through the suspension travel, the correct damping with 10% sag won't be correct at 30% sag.

Set sag first, then start dialing in your adjustments.
the high and low speed compression adjustments shouldnt affect his sag reading... (think about it, the shock dosen't extend without a coil on it)
Re-read what I said... or the post I made prior to that, between yours and KTM's.

I'm not saying they'll affect his sag. I'm saying his sag will have an effect upon the adjustment because of the variable leverage ratio in suspension designs. Compression damping and rebound damping won't impact sag... but, where your bike is in the travel will affect the leverage ratio working on the shock, which will affect the compression and rebound setting. So, if your sag is wrong and you dial everything in to feel just right it won't be 'just right' anymore once the sag is correct.
flag Nobble
Posted: Jun 2, 2012 at 11:29 Quote
badbadleroybrown wrote:
Nobble wrote:
badbadleroybrown wrote:

Should always set the adjustments after sag... because of the way leverage rates change through the suspension travel, the correct damping with 10% sag won't be correct at 30% sag.

Set sag first, then start dialing in your adjustments.
the high and low speed compression adjustments shouldnt affect his sag reading... (think about it, the shock dosen't extend without a coil on it)
Re-read what I said... or the post I made prior to that, between yours and KTM's.

I'm not saying they'll affect his sag. I'm saying his sag will have an effect upon the adjustment because of the variable leverage ratio in suspension designs. Compression damping and rebound damping won't impact sag... but, where your bike is in the travel will affect the leverage ratio working on the shock, which will affect the compression and rebound setting. So, if your sag is wrong and you dial everything in to feel just right it won't be 'just right' anymore once the sag is correct.
true, but that wasnt what he was asking, your post just made it more confusing in many ways. if he sets them with 10% sag and then goes to 30% I would hope that he would correct them if they feel wrong. but this is pinkbike, so I cant be sure.
flag badbadleroybrown
Posted: Jun 2, 2012 at 11:32 Quote
Nobble wrote:
true, but that wasnt what he was asking, your post just made it more confusing in many ways. if he sets them with 10% sag and then goes to 30% I would hope that he would correct them if they feel wrong. but this is pinkbike, so I cant be sure.
I don't think you read my first post...

Compression settings won't affect sag... Compression damping just controls the rate at which the damper can move, not the extent to which it can move.

That said, I usually turn the compression all the way up before I set my sag if I'm trying to do it alone just because it makes the suspension less prone to 'bouncing' as you're sitting there so you would, in theory at least, see less impact from suddle movements like getting back off the bike. If you have someone helping you who'll do the measuring while you're on the bike, it won't make any difference at all though.

Also, on a side note... I typically set my sag slightly high on the rear and slightly short of my target on the front for DH since, once you're actually going downhill there's a weight shift. So, if I'm after say a 30% sag front and rear, I'll set it up as 35% rear and 25% front on flat ground. Then, when I'm on a decline and the weight distribution changes, it balances out to 30/30.

The second post was in response to KTM saying to set the sag with everything already adjusted... which is why I was saying you shouldn't do that as the changing leverage ratio means that adjustments aren't "right" until the sag is set.
flag Nobble
Posted: Jun 2, 2012 at 11:37 Quote
mah bad, i missed that
flag zachrosevt
FL
Posted: Jun 5, 2012 at 4:06 Quote
Ok, I need opinions on a new stem. Trying to buy used to save moolah, found these three potentials in the buy/sell:
Thomson
http://m.pinkbike.com/buysell/1099516/

ODI
http://m.pinkbike.com/buysell/1082519/

Chromag
http://m.pinkbike.com/buysell/1059355/

They're all pretty close in price. I'm looking to get the most for my money (who isn't) and also save weight. Anyone have any strong opinions about any of these? It'll be replacing the OEM Spesh direct mount from my Demo. Thanks y'all
flag captainbringdown
Mod
Posted: Jun 5, 2012 at 6:51 Quote
I swear by thomson products, I assume their DM stem is up there as well. looks great too.
flag downhiller900sl
Posted: Jun 5, 2012 at 6:56 Quote
I think that odi stems really really nice, it's not heavy and it's good looking, any way you can't go wrong with Thomson and it might end up being lighter, so it's up to you

 


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