[Viv92]

I have a few suspension questions...

I have an Izimu with a DHX 5 shock. I'm pretty impressed with it in most ways but I don't feel like I can get the shock to feel right. I'm running a 300lb spring, which is pretty much on the money for what TF suggest for my weight. I get about 33% sag sitting down with my weight on the seat. In any case I'm definitely not running too soft a spring but it still feels like the shock blows through it's travel too fast, especially in the mid/late travel. It's a falling rate frame, so this makes sense, but there must be a way to get around this issue.

I'm running the DHX with the bottom out 2.5 turns in (half a turn from full bottom out resistance) with 180psi in the boost valve. It doesn't bottom out too much but it still after multiple hard hits or harsh landings It doesn't feel great. It's fairly good I guess, but I think it could be better. The DHX just doesn't feel like it has as much control as the Boxxers I have on the front. It rides too far into the travel and unbalances the bike. I have the Boxxers on 5->4 clicks of compression (set it on 5, then move to 4, feels way different to 3->4) and floodgate about half a turn from fully open. They ride higher in the travel and don't bob or dive around too much. Basically there isn't any more I can do with the stock DHX and the adjustments it has.


Possible improvements could be:

Get the shock tuned to the bike (PUSH)- I got the frame second hand and the shock may be a standard DHX retrofitted as I think the frames came stock with Swingers.

Vivid- can get these in tunes for regressive rate bikes, but it looks like you have to buy the shock then get the parts for the tune then get the tune done which would cost a bit more. Shock itself is fairly cheap and sounds pretty adjustable. Sound like they have some serious durability issues though, big minus. Name of shock fits my name well which is a definite plus.

BOS- I've thought about it. It's a lot of money, and sounds like it doesn't play that well with standard forks. I don't want to buy a BOS fork and shock.

CCDB/Elka- not really available where I am, not much support, not really good options at all.

Sooo... any thoughts? Sorry for the massive post.

Or I could just ride the damn thing.

 

[Bicyclist]

Is your Boxxer set up too firm, thus throwing the balance towards the rear? Those things come with retardedly stiff springs stock. Maybe you're running too much LSC in front, and need to balance it out with a bit more Propedal?

 

[Viv92]

Is your Boxxer set up too firm, thus throwing the balance towards the rear? Those things come with retardedly stiff springs stock. Maybe you're running too much LSC in front, and need to balance it out with a bit more Propedal?

I've got a soft spring in the Boxxer and I'm around 75kg, so that should be about right (RS recommends mediums but I know that is way off).

The propedal doesn't seem to have all that much influence on the shock. I mean I can tell the difference, but it doesn't fix the problem at all.

 

[Sov]

Yeah it certainly sounds like you're after a stable feel with 180psi and 2.5 turns of bottom out but at those settings, the shock is going to be harsh. IMHO the DHX is never really going to be a stable shock, especially compared to a Boxxer with heaps of LSC. I reckon the Boxxer feels like it has a really agressive blow off in compression (a tight knee point) whereas the DHX feels like it's more linear.

I reckon you'd be better off dropping the reservoir pressure down to improve compliance. 130-150psi should give a nice compromise between control and bump gobbling (on my DHX at least - it's one of the older ones with the 75psi min setting) If you're bottoming too much then wind in the bottom out adjuster all the way or look at getting a firmer spring.

The other thing to play with is the rebound damping. When you're running loads of compression damping you can speed up the rebound quite a bit. This will help it ride higher as well. Just make sure that front end is balanced in rebound as well (or a touch quicker.)

But yeah, I wouldn't worry about picking up another shock. The rear end just follows the front around. Get the forkss dialled cos that's what really matters, and find a nice 'compromise' setting for the rear.

 

[Kanye West]

Cane Creek and Elka probably both provide excellent support, but I could see shipping being an issue. The Morewood team ran the Cane Creeks and loved them.

My best suggestion would be an Avalanche. They can make a frame with a non-favorable leverage curve feel VERY good with the amount of oil they can flow and the levels of compression they can achieve.

 

[Viv92]

Cane Creek and Elka probably both provide excellent support, but I could see shipping being an issue. The Morewood team ran the Cane Creeks and loved them.

My best suggestion would be an Avalanche. They can make a frame with a non-favorable leverage curve feel VERY good with the amount of oil they can flow and the levels of compression they can achieve.

I'm in Australia...


Oh yeah and what's all this stuff about higher oil flow being better?

Don't you want the oil flow restricted a certain amount (ie damping...)?

 

[top_dog]

What is it with Avalanche people always going on about how much oil an Avy can flow?

I would have thought that an Avy with high 'levels of compression' would flow less oil than one with low 'levels of compression', thus making the mega flow rates that Avy's have (reputedly) a moot point.

 

[P.T.W]

For sure go spend hundreds on a new shock......but they wont help either as they have adjustable rebound just like your dhx.......just sayn

 

[Kanye West]

Christ.....

I don't even ride an Avy. I sold mine because it was overdamped for my particular frame. The frame I had BEFORE that was a falling rate design that the Avy made a BIG improvement upon. I do not consider myself an "Avy people" person.

The damping/oil flow thing: More oil flow is better because it doesn't spike at higher shaft speeds and repeated hits like a DHX - you can run more low speed damping and still have the shock accommodate higher shaft speeds without spiking or binding or bucking or whatever. That is characteristic of any high quality damper: Avy, CC/Ohlins, BOS. Even PUSH would be doing that with bored out compression piston and resy pistons. Any kind of "works" stuff is basically doing modifications to make the damper flow more oil and having a greater dynamic range (think BlackBox). That can also lead to dampers that are more sensitive to smaller inputs.

Viv - The point is that you get a damper where you can run as much damping as you need to without the damper being overwhelmed by the shaft speeds. Low leverage falling rate frames generate high shaft speeds and easier bottom-outs, and they benefit from such things. Make sense?

 

[djamgils]

sag shouldnt be measured while sitting down. Do you sit down while downhilling?

My experience is that some frames/linkages just need more LSC then others. And for those that need more LSC the DHX isnt a good option in its stock form.
The socom is one of those bikes that need more LSC in my experience and for me only the Bos Stoy worked good on the Socom.
Now I am on a Supreme DH and altough I really like the bos on it I think that a vivid or maybe even a dhx would work well.

It might be a possibility to accept that the DHX doesnt have enough LSC and set the boxxer accordingly. So you at least have a bike that is balanced front and rear. It might not be ideal but maybe better then big front and rear differences.

 

[ozzemale]

sag shouldnt be measured while sitting down. Do you sit down while downhilling?

My experience is that some frames/linkages just need more LSC then others. And for those that need more LSC the DHX isnt a good option in its stock form.
The socom is one of those bikes that need more LSC in my experience and for me only the Bos Stoy worked good on the Socom.
Now I am on a Supreme DH and altough I really like the bos on it I think that a vivid or maybe even a dhx would work well.

It might be a possibility to accept that the DHX doesnt have enough LSC and set the boxxer accordingly. So you at least have a bike that is balanced front and rear. It might not be ideal but maybe better then big front and rear differences.

yeah agreed.
sag should be measured on a slope with an attack riding position (ie: the position you should be mostly in whilst racing/travelling down the hill)

Viv guaranteed win with a bos shock. I'm gonna get up the gold coast in about two weeks time with some shocks etc... Might be worth while trying one out. It sounds like you could be one of the possible candidates. i know you think it's a lot of money but wait till you try it.

nicho

 

[Viv92]

Christ.....
Viv - The point is that you get a damper where you can run as much damping as you need to without the damper being overwhelmed by the shaft speeds. Low leverage falling rate frames generate high shaft speeds and easier bottom-outs, and they benefit from such things. Make sense?

Yep, makes a lot of sense. Cheers.

sag shouldnt be measured while sitting down. Do you sit down while downhilling?

My experience is that some frames/linkages just need more LSC then others. And for those that need more LSC the DHX isnt a good option in its stock form.
The socom is one of those bikes that need more LSC in my experience and for me only the Bos Stoy worked good on the Socom.
Now I am on a Supreme DH and altough I really like the bos on it I think that a vivid or maybe even a dhx would work well.

It might be a possibility to accept that the DHX doesnt have enough LSC and set the boxxer accordingly. So you at least have a bike that is balanced front and rear. It might not be ideal but maybe better then big front and rear differences.

I've given the Boxxer a shot with half a click less compression (setting it to 3 then moving to 4, rather than 5 ---> 4). It did definitely feel more balanced but then it suffered the same sort of problems. I'd rather my fork be dialled and the rear end feel worse than compromising both. Maybe if I closed the gate a little it would help... Anyway the next race is in 3 weeks time so I'll see how I go running it with less LSC on the front.

With regards to sitting sag, that was basically to illustrate that my spring rate is definitely not too soft, in fact it's more likely the opposite but going any lower won't help.




Has anyone had their DHX pushed? I have a few questions as to what they actually do. Does it add some low speed comp to the shock or no? And do they tune it to match the rate of your frame? (ie harder damping at the end of the stroke on a regressive rate)

 

[buckoW]

Has anyone had their DHX pushed? I have a few questions as to what they actually do. Does it add some low speed comp to the shock or no? And do they tune it to match the rate of your frame? (ie harder damping at the end of the stroke on a regressive rate)

I have a bunch of tuned DHXs and it changes everything. I would get it Pushed and explain to them exactly what you just explained here. I have a DHX with completely different compression than stock and it works excellent. The DHX chassis is a good platform to start with and then get it tuned to your needs.

 

[Viv92]

I have a bunch of tuned DHXs and it changes everything. I would get it Pushed and explain to them exactly what you just explained here. I have a DHX with completely different compression than stock and it works excellent. The DHX chassis is a good platform to start with and then get it tuned to your needs.

OK thanks. How long was the turnaround for your push stuff?

Also how accurately did you feel that they got it compared to what you asked for? I'm a bit dubious about getting something tuned then having basically no adjustments for it if it's not quite right.

nicho, pm'ing ya

 

[top_dog]

Yo Viv, if your bike takes a 3" shock and 22x8 hardware (or Nicho wants to facilitate), and you can get yourself relatively near to my house, I'll lend you my shock for some runs. You can do back to backs and see how much better the BOS is on a single pivot. Night and day.

 

[Viv92]

Yo Viv, if your bike takes a 3" shock and 22x8 hardware (or Nicho wants to facilitate), and you can get yourself relatively near to my house, I'll lend you my shock for some runs. You can do back to backs and see how much better the BOS is on a single pivot. Night and day.

Yeah it's 3", not sure on what sort of hardware it runs.

Any good spots for runs near caboolture? How close is mapo to you? I might be hitting it soon. I honestly didn't mind the DHX there though, its the flatter, more bermed/groomed tracks it feels worse on.

 

[P.T.W]

I have a few suspension questions...

I have an Izimu with a DHX 5 shock. I'm pretty impressed with it in most ways but I don't feel like I can get the shock to feel right. I'm running a 300lb spring, which is pretty much on the money for what TF suggest for my weight. I get about 33% sag sitting down with my weight on the seat. In any case I'm definitely not running too soft a spring but it still feels like the shock blows through it's travel too fast, especially in the mid/late travel. It's a falling rate frame, so this makes sense, but there must be a way to get around this issue.

I'm running the DHX with the bottom out 2.5 turns in (half a turn from full bottom out resistance) with 180psi in the boost valve. It doesn't bottom out too much but it still after multiple hard hits or harsh landings It doesn't feel great. It's fairly good I guess, but I think it could be better. The DHX just doesn't feel like it has as much control as the Boxxers I have on the front. It rides too far into the travel and unbalances the bike. I have the Boxxers on 5->4 clicks of compression (set it on 5, then move to 4, feels way different to 3->4) and floodgate about half a turn from fully open. They ride higher in the travel and don't bob or dive around too much. Basically there isn't any more I can do with the stock DHX and the adjustments it has.


Possible improvements could be:

Get the shock tuned to the bike (PUSH)- I got the frame second hand and the shock may be a standard DHX retrofitted as I think the frames came stock with Swingers.

Vivid- can get these in tunes for regressive rate bikes, but it looks like you have to buy the shock then get the parts for the tune then get the tune done which would cost a bit more. Shock itself is fairly cheap and sounds pretty adjustable. Sound like they have some serious durability issues though, big minus. Name of shock fits my name well which is a definite plus.

BOS- I've thought about it. It's a lot of money, and sounds like it doesn't play that well with standard forks. I don't want to buy a BOS fork and shock.

CCDB/Elka- not really available where I am, not much support, not really good options at all.

Sooo... any thoughts? Sorry for the massive post.

Or I could just ride the damn thing.

Why is that Sov an i are the ony ones who've mentioned rebound ?????

 

[Viv92]

Harsh hits meant single harsh hits. Sorry, wasn't too clear on that.

 

[P.T.W]

What position do you have the shock shuttle in???
Is it possable to move it to a slacker position???
If so... Try a slacker position with less sag to give the same static b/b height(as steeper with more sag), this will move the rear suspension further away from the regressive part of the travel an into a more linear maybe progressive part..and allowing more positive travel for those big hits.
Just an idea

 

[buckoW]

What position do you have the shock shuttle in???
Is it possable to move it to a slacker position???
If so... Try a slacker position with less sag to give the same static b/b height(as steeper with more sag), this will move the rear suspension further away from the regressive part of the travel an into a more linear maybe progressive part..and allowing more positive travel for those big hits.
Just an idea

he said the rear is not riding high enough nor very stable feeling so putting more weight on the rear of the bike will make this worse. It seems like it will only exaggerate the problem. He just needs a compression tune on his current shock or a new shock with more compression.

Is the fork slammed? That could help getting some weight over the front and giving the rear an easier time compared to the fork.

 

[Viv92]

he said the rear is not riding high enough nor very stable feeling so putting more weight on the rear of the bike will make this worse. It seems like it will only exaggerate the problem. He just needs a compression tune on his current shock or a new shock with more compression.

Is the fork slammed? That could help getting some weight over the front and giving the rear an easier time compared to the fork.

Fork isn't slammed but it's 3mm off. Not going to make a wild difference. It's in the middle position in the shock shuttle. I don't really want to try the lower setting as of yet, I'm running 175mm hones and the bike feels slack enough already.

 

[Sov]

Might be worth trying a 350lb spring with less reservoir pressure if you haven't already. Lower pressure to keep it supple in the initial stroke but a higher spring rate to help it ride higher and resist bottoming.

TFtuned says that a 300lb spring rate is spot on for your 75kg weight (with gear?) but I would imagine that the calculator assumes a constant leverage ratio. For a digressive bike I think that it would make sense to run a slightly higher spring rate. And how do you know that your 300lb spring isn't on the low end of the tolerance range? It could be 270lb/in...

Did you measure sag with the res pressure set to 180psi? Compression damping shouldn't really affect your sag in theory but the DHX gets a bit sticky at high pressures. What sag do you get at the minimum recommended pressure?

 

[P.T.W]

he said the rear is not riding high enough nor very stable feeling so putting more weight on the rear of the bike will make this worse. It seems like it will only exaggerate the problem. He just needs a compression tune on his current shock or a new shock with more compression.

Is the fork slammed? That could help getting some weight over the front and giving the rear an easier time compared to the fork.

Fork isn't slammed but it's 3mm off. Not going to make a wild difference. It's in the middle position in the shock shuttle. I don't really want to try the lower setting as of yet, I'm running 175mm hones and the bike feels slack enough already.

Nooo you guys arn't getting me
Ok Viv(this is for example...the numbers are just estimates)your running your Izimu's shuttle in the middle position with 60mm of sag measured at the b/b giving you a sagged b/b height of 270mm.
Try moving your shuttle to the slack position which will lower your sagged b/b height by 20mm....then add preload to your spring to reduce your sag by the 20mm that it was lowered. If you do this you arn't altering the static geo of your bike as the b/b height is the same(your just running less sag)
This will make the bike ride in a different(less regressive) part of the suspension,,,also leaving you with more positive travel to use up on those big hits.
A push tune or a new shock costs money...all playing with your settings costs is time. It might not work...but hey if it does it was free

 

[broke(n)]

As you're in Oz it would be worth having a look at Tekin which is based in Melbourne (I think).

They will re-valve your DHX so it will work just the way you like it. They will particularly solve the tendancy for DHX's to blow through their travel. Turn around is fast if you want it to be.

They happily altered the initial shim stack they put in my shock free of charge when it wasn't exactly what I wanted (it was for a home made frame so they were kind of guestimating what would be required...)

 

[Harry BarnOwl]

Stock DHX's are pants, get it PUSHed and it's a whole new shock, the difference is unbelievable. Or get a vivid.

 

[buckoW]

Nooo you guys arn't getting me
Ok Viv(this is for example...the numbers are just estimates)your running your Izimu's shuttle in the middle position with 60mm of sag measured at the b/b giving you a sagged b/b height of 270mm.
Try moving your shuttle to the slack position which will lower your sagged b/b height by 20mm....then add preload to your spring to reduce your sag by the 20mm that it was lowered. If you do this you arn't altering the static geo of your bike as the b/b height is the same(your just running less sag)
This will make the bike ride in a different(less regressive) part of the suspension,,,also leaving you with more positive travel to use up on those big hits.
A push tune or a new shock costs money...all playing with your settings costs is time. It might not work...but hey if it does it was free

I understood but still think that the farther forward (Lower bb) he runs the shock mount the more the bike will be falling rate at the end of the travel. If anything he needs to slide the front shock mount to the rear which will be lower (raise the bb) to get the single pivot design to be more progressive.

I still think a shim tune for a falling rate design will be the best bet. Then you can lower the bb all you want without the negative effects.

 

[Steve M]

Nooo you guys arn't getting me
Ok Viv(this is for example...the numbers are just estimates)your running your Izimu's shuttle in the middle position with 60mm of sag measured at the b/b giving you a sagged b/b height of 270mm.
Try moving your shuttle to the slack position which will lower your sagged b/b height by 20mm....then add preload to your spring to reduce your sag by the 20mm that it was lowered. If you do this you arn't altering the static geo of your bike as the b/b height is the same(your just running less sag)
This will make the bike ride in a different(less regressive) part of the suspension,,,also leaving you with more positive travel to use up on those big hits.
A push tune or a new shock costs money...all playing with your settings costs is time. It might not work...but hey if it does it was free

haha, you've got your wires crossed. If the BB height is the same, the rate at that point will be much the same, since the swingarm will be at the same position. In fact, if he wanted to make it less regressive (you do realise the bike goes from linear to regressive right, not the other way around?) he'd raise the BB up with the shock shuttle and run more sag so that the shock mounting point was down lower as well as further back.

In either case, it sounds like you need a better compression tune. The whole "doesn't flow enough oil" thing is a crock of ****.

 

[slowitdown]

Yeah it certainly sounds like you're after a stable feel with 180psi and 2.5 turns of bottom out but at those settings, the shock is going to be harsh. IMHO the DHX is never really going to be a stable shock, especially compared to a Boxxer with heaps of LSC. I reckon the Boxxer feels like it has a really agressive blow off in compression (a tight knee point) whereas the DHX feels like it's more linear.

I reckon you'd be better off dropping the reservoir pressure down to improve compliance. 130-150psi should give a nice compromise between control and bump gobbling (on my DHX at least - it's one of the older ones with the 75psi min setting) If you're bottoming too much then wind in the bottom out adjuster all the way or look at getting a firmer spring.

The other thing to play with is the rebound damping. When you're running loads of compression damping you can speed up the rebound quite a bit. This will help it ride higher as well. Just make sure that front end is balanced in rebound as well (or a touch quicker.)

But yeah, I wouldn't worry about picking up another shock. The rear end just follows the front around. Get the forkss dialled cos that's what really matters, and find a nice 'compromise' setting for the rear.

great answer.

 

[RedOne]

I replaced the DHX on my 08 Izimu with a pushed Marzocchi Roco.
Feels really nice, great compression damping, easy to set up.