[FactoryCostcoDH]

Ok, here's my scenario. I weigh 145 pounds with gear and I'm running an 8.75x2.75 DHX 5.0 on my big hit. Right now I have it sprung at 500 pounds with 150 PSI in the chamber, and what I believe is stock oil in the reservoir. The bottom out adjustment is cranked all the way up and the propedal is about half way.

I know for a fact that the shock isn't broken in any way, but I am still having trouble bottoming out. The funny thing is that 75% of time i'm bottoming riding gnarly solid rock garden/lava flow on the local DH rather than any FR style drops and jumps in the area. So at the moment I am unsure whether I want to buy a new/more dampened shock, or buy heavier oil for my DHX and hope it becomes much stiffer.

Therefore, my question to all you monkey's is:
-If I buy a new shock, what shock should I go with? I hear avy's are very dampened, but do you think a double barrel can be set up the same way just for the sake of having the choice of extra adjustments?
-Should I keep my shock and get heavier oil or possibly re-shim it if that isn't too hard to do? And what weight oil should I use? Is stock 5wt or 7.5wt? I can get oil even heavier than 10wt at the local motorcyle shop, if needed.

just remember that your advice will be on my riding style not your own, so plushness isn't as much of a concern to me as the plowability. Any help will be greatly appreciated though.

 

[Luckybikes]

500lbs spring sounds high to me. When i rode my Bighit i ran a 450 on mine and weighed 160. Something seems out of whack in your set up.

 

[FactoryCostcoDH]

Forgot to mention, changing spring rates isn't much of an option for me either, because at the moment I'm only running about 20% sag and I don't plan on going with any less

 

[DirtyMike]

I would personally suggest instead of buying a new shock, Send it to PUSH. Let them custom build the DHX for you and your riding style. Good stuff coming from them, havent heard of anyone not happy with there work

 

[Udi]

Something is VERY wrong somewhere.

Just to double check:
- Bighit (8.x" travel setting?). What year model?
- 145lb rider with gear
- 500lb spring
- 150psi
- Propedal = ?

Something is amiss. I weigh in identically to you, and when I rode a bighit (DHX5) I ran a 300-350lb spring. With the 350 I would have had around 33-34% sag. No bottoming out issues.

 

[FactoryCostcoDH]

500lbs spring sounds high to me. When i rode my Bighit i ran a 450 on mine and weighed 160. Something seems out of whack in your set up.

It sounds wrong, until you see the local trails in person and the speeds you can acquire on them with good stiff suspension. It's all plow riding for most of the decent riding here.

 

[DirtyMike]

Something is VERY wrong somewhere.

Just to double check:
- Bighit (8.x" travel setting?). What year model?
- 145lb rider with gear
- 500lb spring
- 150psi
- Propedal = ?

Something is amiss. I weigh in identically to you, and when I rode a bighit (DHX5) I ran a 300-350lb spring. With the 350 I would have had around 33-34% sag. No bottoming out issues.

Im thinking something is wrong with the shock itself, maybe air in the oil side or something like that

 

[FactoryCostcoDH]

Something is VERY wrong somewhere.

Just to double check:
- Bighit (8.x" travel setting?). What year model?
- 145lb rider with gear
- 500lb spring
- 150psi
- Propedal = ?

Something is amiss. I weigh in identically to you, and when I rode a bighit (DHX5) I ran a 300-350lb spring. With the 350 I would have had around 33-34% sag. No bottoming out issues.

I can assure you, nothing is wrong with the shock. It performs WONDERFULLY... until I really start pushing it hard... and even then it's still good, it just happens to be bottoming.

It's an 03 comp with a big link

 

[Udi]

For your bodyweight that is VERY oversprung and that's why there's evidently something wrong here if you're bottoming out. Have you calculated how much sag you're getting out of interest?

Are you sure the shock is actually using all its travel? Not coil binding, or contacting the frame/link at any point?

 

[SKYWAYBUZZ]

oil's beat up, new oil.

 

[FactoryCostcoDH]

The trail has gnalry ledged rocks and G-outs, probably similar in force values as 4-8 foot drops to flat, except that the energy spikes and you continue bouncing your way down the trail. My last crash involved me bottoming both ends (05 888rc custom valved sprung for a 170 lb rider) 3 times in a row causing my back wheel to gradually raise up placing me in a nose manual until I flipped over the bars. The suspension is fine.

 

[FactoryCostcoDH]

For your bodyweight that is VERY oversprung and that's why there's evidently something wrong here if you're bottoming out. Have you calculated how much sag you're getting out of interest?

Are you sure the shock is actually using all its travel? Not coil binding, or contacting the frame/link at any point?

thats what I was looking for. I am using full travel, but I believe I'm only compressing 2" when I sit on the bike. what spring rate would you propose?

 

[FactoryCostcoDH]

Sorry, I thought you said undersprung. Nevermind then. At the moment I'm thinking I might just go for heavier oil.

Anyone here in SoCal is free to ride my bike if they want to see for themselves that nothing's wrong with the shock. Come check it out if you want. It's more just the trail and my desire for speed.

 

[DirtyMike]

The trail has gnalry ledged rocks and G-outs, probably similar in force values as 4-8 foot drops to flat, except that the energy spikes and you continue bouncing your way down the trail. My last crash involved me bottoming both ends (05 888rc custom valved sprung for a 170 lb rider) 3 times in a row causing my back wheel to gradually raise up placing me in a nose manual until I flipped over the bars. The suspension is fine.

Slow your rebound a bit

 

[NY_Star]

What the problem sounds like to me is your rear shock is packing up. this means that the rebound is to slow. the shock is not recovering from each hit so that it goes farther and farther into the travel with out coming out each time. This is why it is not bottoming on the big hits but it is on the repetitive stutter bumps. I would try to back out the rebound before you go and buy a new spring.
Max

 

[jamesdc]

I have the same problem with my 5.0, it bottoms way to easily with the correct sag and the shock is fine, i think it might just be a fox thing and i'm about to give up on it and buy a roco.

 

[Udi]

Well to get the correct 33% sag you really should be running a 350lb spring, 400lb at the highest. But if you are bottoming out with a 500 that's obviously not an option. It seriously doesn't make sense though, that's why I asked if you're sure the shock is actually using all of its travel and that you're not mistaking "not using all the travel" for "bottoming out". Not using all the travel could be for many reasons - being oversprung, or like I asked - frame/shock contact or coil bind. Only you can check those things.

Anyway if you're sure none of that is an issue, and if you just want a heap more damping (and more ramp-up) try something control valved. 5th Element or Swinger 6-way should give you what you're chasing. Most newer shocks are headed in the direction of providing less damping, and ones that still give a lot (like the CCDB) don't really have anything to provide position sensitive compression damping like the old CVT/SPV shocks.

You can run heavier oil in the DHX too but they aren't very heavily damped shocks by default. That said, 10wt silkolene RSF (or 15 if available) + max pressure + heavy propedal should leave you with an adequately heavily damped shock.

Given your body weight and the bike though, this really is crazy talk so I genuinely believe something else is amiss here.

 

[FactoryCostcoDH]

It was more of a HA issue at that moment when my forks were completely bottomed and still had force running through them. It's nowhere near pogostick-like but it is set fairly quick. However both the front and rear are balanced

 

[FactoryCostcoDH]

Ok so I might try 15 wt and start with the bottom out at 0 and work my way up. I know it sounds crazy, but I am 100% sure I'm not packing up and that the shock is working fine. sure its possible the oil might be worn out a little but it shouldn't create as much of a difference that I am talking about. The performance is flawless, just too soft

 

[DirtyMike]

You would be amazed how good a shock will feel with bad oil will feel at some points, yet will still bottomout and not function properly on big stuff. How many miles would you say you have on this shock.

 

[FactoryCostcoDH]

I've had it for about 6 months, and I only ride about 1-2 a week on average, sometimes less due to school.

 

[DirtyMike]

Shouldnt be worn yet then, Personally I still think that if your going to be changing and fine tuning this, send it tp push, its cheaper than getting an entirely new shock, and they already know what to do to make it do what you want. I mean fine tuning yourself is kinda fun, but can be a general pain in the A%% so let the guys who know do it for you, there order questionaire is pretty specific, talks about riding style riding weight everything...... I think thats your best bet

 

[cheetaprowlerDH]

i have ridden FactoryCostcoDH's bike countless times, and if anyone can remeber the little video we made earlier this year, his bike was the bike being put through its paces on literally 80% of the video by the two of us.

i weigh about 178-180 with gear and ride his bike AND my old cheeta down the same trails all of the time. i have had bottoming issues the same as him, but just as he said, it ONLY acts up on the high speed rock... when i say high speed over these gardens, i mean literally pushing yourself to keep from losing yourself off the back of bike, even on a rock eating monster like my cheeta was...

a little slower trails with gnarlier rocks, 10' drops and stutter bumps/whoops are nothing for this shock, it eats everything up, but due to the nature of the trail that it virtually always bottoms out on, i'm surprised that it happens like that.
i was literally right behing Cory when he last crashed and saw exactly how it happened, he was in a good position on the bike, but all of the sudden he was up on his nose and then on his face...
the problem section consists of about 4 consecutive 1'-1.5' ledges that have downhill sloped landings and lead up to eachother with about 10' or less in between... you hit these going problably around 20-25mph and they are easy to flow into and are not punishing on any shock BUT his! i'm as stumped as he is, i know my riding style is different and i feel that i flick the bike alot different than he does into sections like these, but that shock gives me the same problem...

but one thing to consider though Cory, you DO have a 24" wheel in the back...
but yes, the shock is very problematic back there.

 

[slowracer]

i've seen quite a few bikes with similar problems on the dhx5. what i have tried and worked it the past could be due to three things, first its oversprung, 2nd rebound is too slow (packing up) or the shock is overdamped.

u can try a softer spring that actually is recommended for ur weight.

make the rebound faster.

reduce the pressure and make the bottom out chamber bigger ie make the shock more linear. reason being that the bottom out adjuster at full closed, it makes the dhx ramp up really early i.e. 50-60% into shaft travel. this will give a feeling of harsh bottom out. also at 150 psi for ur weight its waaay to high. on our team bikes we found that given the same setting and riders weight, its easier to puncture the rear tire at 150psi in dhx chamber compared to 100-120psi. so the pressure makes a lot of difference in terms of plushness. so maybe what u feel as harsh bottom out isnt a harsh bottom but an overdamped with/without a too progressive shock setup.

just my thoughts.

 

[cheetaprowlerDH]

to me everything that you guys have been saying about the shock make perfect sense, but performance-wise, i have personally bottomed that shock hard enough to be scared for the rest of the bikes components. the true-bottom where you can hear what sounds like metal to metal.

the bike doesnt feel oversprung to me OR look oversprung when cory rides it.
i spend hours reviewing footage that we have in one of my classes while putting together a movie and i can watch the suspension go through its paces and either bottom or get 90% of the way there... everything looks smooth over perpendicular-to-the-trail ruts, drop landings, loose rock, and corners. but one thing i notice is that on one of the clips that we have in our vid. i watch myself launch into the section after the section that bottoms the shock(both cosist of essentially the same terrain, the bottom one is just 3x as long), and i see the shock compress from the back and then buck ME forward! i recovered from it obviously, but i remember that moment and know i felt the shock bottom on a very small, but very fast drop off.

its mystifying to me...

 

[cheetaprowlerDH]

^^ and to add,^^
ive never had these experiences on the much softer sprung Romic on my old cheeta... but i do know the bikes were obviously drastically different...

 

[davet]

When I first started reading this thread I was convinced that there was just something wrong with your shock, possibly it had low air at one time and cavitated. This could still be part of the problem.

As you described the symptoms a bit more, I think you might be getting some compression spiking. The fact that you're getting it on the really faster chundery sections reminded me that it was exactly what I used to get on my DHX 5.0 too. It's not bottoming, rather spiking. I had my shock serviced by a local guy that's a bit of a suspension whiz, I talked to him about this and he said it was actually common. He drilled out the holes in the piston or valve a wee bit and said that would do the trick. He also said that's one of the differences in the Push piston as well.

Whatever he did made a huge difference. I thought the shock was plush before, it's silky smooth now with no evidence of spiking.

With that theory in mind, putting thicker oil in will just make it worse.

Send it to Push.

 

[DirtyMike]

Send it to Push.

 

[FactoryCostcoDH]

Sorry to say it, but Bryce, your talking about something totally different than I am. It's not the chunderry stuff that's getting me. The shock is plenty plush. It's the extended compressions like the ledges we mentioned. More of a hard G-out than a spike. Try to imagine yourself riding super deep whoops out in the desert but they're too far apart to skip across the tops of them. However you still want to go fast, so what do you do? Stiffen your suspension. The bike will definately track straighter. The hit is inevitable, but it is nevertheless a fun trail.

This probably isn't going to register for some people and I find that it rarely does, but I would rather sacrifice the couch-like ride for the ability to just point, shoot, and just bulldoze the snot out of any rock garden I choose. but thats just me

 

[FactoryCostcoDH]

just to clear something up, I had a lighter spring on my bike before I bought the 500 lb'er

 

[toodles]

Stupid question but I have to ask - you absolutely sure you're bottoming the shock and not getting frame contact on something? Chain not too short?

Running 20% sag and bottoming too often is pretty messed up. I've spent a fair bit of time working on shocks and forks and that sounds terribly amiss. Running it oversprung isn't going to help with what is essentially a damping and progressiveness issue.

 

[miuan]

Take the spring out, put it back together w/o it and test bounce it several times to make sure it has to be the shock bottoming out.

 

[ZUMBI]

If the shock is ok I would try putting on a bigger anti bottom bumper like on an Avalanche. The ones on the DHX are very thin.From the setup You are writing it seems that You really plow over everything very hard.

 

[FactoryCostcoDH]

When I first put on the DHX when I bought it, I bounced around on the bike without the spring. No frame contact.

And it's not that I'm bottoming TOO often, it's just the fact that I would like to have the capability on a few of my local trails to go faster and not have to worry about eating $hit. Even though I am running very little sag, it is balnced with the front end of the bike, which I got from a 170 lb rider. So I only wanted to know what option would be better as far as heavier dampening. The spring rate is right where I want it.

It all sounds very illogical, but given the circumstances and that they're the only DH runs within riding distance from my house, I don't mind to sacrifice all small bump compliance. I know I sound like an idiot, but I know how I would like my bike to ride.

I'll have to get a few pictures of the trail when I get the chance, so you guys can at least have an idea what I'm talking about. One's fairly twisty covered in lots of good sized loose rock, and the other is all straight aways and wide sweepers over solid lava flow. On the main rock garden you would probably be going 30-40 mph if you let off the brakes completely.

And thanks for the suggestion zumbi, I might have to look into that

 

[Fonzie18]

slow down!

 

[miuan]

Basically there are 5 options left for you:
Replace your shock with a Swinger 6W or 5th with compression adjustments and see what it does.
If this doesn't work, choose an even higher spring rate.
If this doesn't work, choose a frame with more travel.
If this doesn't work, slow down, like Fonzie18 said.
If nothing works for you, just quit riding your bike, it feels too dangerous anyway

 

[NY_Star]

It may be that the shaft speeds are to high and that you are getting a hydraulic spike in the fluid.

 

[cheetaprowlerDH]

If the shock is ok I would try putting on a bigger anti bottom bumper like on an Avalanche. The ones on the DHX are very thin.From the setup You are writing it seems that You really plow over everything very hard.

this may be why my Romic doesnt ramp like crazy on this trail, I put a 1" bottom out bumper on it and have never had major problems like this...
i know its a totally different shock, but the bumper makes sense... thats the first thing i noticed and mentioned to FCDH when he got his shock...


he wants an Avy in the first place, so he's probably just going to get that, i doubt he'll send it to PUSH even though its an awesome idea and i wish i had a chance to do it...

 

[General Lee]

Just a suggestion; but suspension set-up is a compromise. if it feels great everywhere but on certain kinds of terrain at high speed then I would suggest getting used to it (or slowing down if its not a race). Bottoming out has been given a bad rap. A plush set-up with 33% sag is going to bottom out hard now and again--possibly often, in fact--and is essentially the compromise for having it set up properly for the other 90% of the track you are on.

Someone suggested putting a bigger bottom out bumper on and I agree. I swapped the dhx bumper for a 5th element one when i rode a 224(they bottom out really hard) and it did a lot to help reduce that aweful metal-to-metal feeling. If nothing else, I no longer fely like i was ripping the back of my bike off.

I'm from the school of suspension set-up that says get it right for cornering and the majority of the track and find a way to deal with the other bits. On some tracks I'll go full speed in some sections only a few times other than a race run because I know the bike is going to bottom out like a ton of bricks. Also, your riding technique can go a long way in making up for shock performance in certain situations. It is possible that you are bottoming out hard becasue you are not being as 'light' on your bike as you could be.

Some impacts will bottom out a shock even if it is grossly oversrung; no getting around it. you could address the problem with a damping adjustment but then your suspension will under-perform on the rest of the trail. So, if in fact you have the bike over-sprung I'd try a lighter spring as well. chances are you will bottom just as hard in the places you are now and the bike might feel even better everywhere else.

Again, the word to keep in mind is compromise.

 

[Huck Banzai]

At your size, with that spring you should not be bottoming it.

At my size (245) with a 500 on a VPF (granted diff suspension, but has a higher leverage if anything) I rarely see bottom (1-2x a big ride/mountain day) with ZERO compression/propedal clicks, and the bottom out half way in.

Something IS wrong with the shock!(or u r really 300lbs)