zps shock advantages ???

[markvette]

we will be getting our 03 moto soon
( hopefully ) we ran an 02 for 3 months and done real well. we have been told to go with zps shocks on the 03. josh my son is a pretty agressive rider and will jump almost anything on a track. the moto's stock ohlins seem to do real good there but suffer in the corners and the whoops. i have been told by many riders that the zps really shine in these areas. i talked to a local suspension shop about revalving and making the ohlins zps but he advised me against it. he said the zps were more for AX racing and not MX. he works mostly on bikes and i think he's full of crap. so tell me the advantages of the zps shocks for moto cross racing.

[AlaskaSpeed]

I'll chime in a bit here, keep in mind that this was my first season racing MX. I ran Elkas with SSD(same as ZPS) for a year on my 400ex and then this season on my Speed.

ZPS allows you to adjust your ride height and your quad sits lower giving you more stability in the corners. All I know is wide and low equals stable.

The shocks still give you full travel, not sure of why they are better in the whoops; like I said....new to this whole thing.

I have PEP ZPS shocks on order and actually will never buy anything but ZPS style for MX.......JIM

[markvette]

we are new to mx too, i pretty much knew the zps helped out in the corners because of the lower ride height. another thing the suspension shop told me was that we would hate them on a rutted track in the straights. now i need to figure out if i want to revalve the ohlins or buy elkas. i talked to a guy that had his ohlins revalved and he paid $1000 for all three but i can get the three elkas for about $1500. probably get the elkas so we can put the stock ohlins back on when we sell the quad in 6 monts. thanks for the advice

[86atc250r]

Yep, the main advantage to ZPS shocks is the adjustability of the ride height.

One problem this brings up though is it makes springing and valving critical. If they're not right, the performance of the shock will suffer, this will be especially evident in the whoops - I have yet to have a set of shocks (except maybe my current set) that have worked better in the whoops than the stockers (on my 400ex before they were worn out) believe it or not & I've practically owned them all - Axis, Elka, PEP, Ohlins, TCS, etc...

While you do retain full travel with "ZPS" style shocks, it's important to remember that for the ZPS portion of the travel, you are basically relying on the valving only since there is essentially no spring rate there until this portion of travel is used up.

This means that ZPS shocks must be sprung heavier than standard shocks, which can then cause ride quality problems. This also causes issues with rebound damping - so as you can see, zps shocks have some unique requirements that make them tricky to tune.

FWIW, I pretty much run exclusively with zps shocks for flat track, MX and my main racing, XC... Still searching for the perfect setup, but slowly and expensively getting there...

As far as ruts go, if you're running in ruts that cause frame to ground clearance problems, you find swingarm to ground problems faster, so it's not really that big an issue from what I've found, even in XC racing. In fact, I've found that ZPS shocks work especially well in rutted out conditions since they allow for better front tire to ground tracking, providing more steering (given you're running a decent damper)....

[cannondale27]

I agree with everything posted so far except for "Ohlins were bad in whoops" I have moto front it actually works better in the whoops than the zps the reason is the front bumper and framewont dig in cause it is higher.Comp.and rebound adjustments seem to have more effect on Ohlins than P.E.P.
PEP are a ball and spring arrangement in front which actually is very adjustable problem is it has to be taken apart to do it.If you go to nationals Wayne owner of PEP will be there to revalve them right there for you.If I were a B level serious national mx racer or higher PEP zps would be my pick.

[86atc250r]

You kinda confused me with a couple statements

I never said the Ohlins were bad in the whoops - just that they are not as good as my stock 400EX setup was (in the whoops - other conditions are a different story). Actually, it wasn't an apples to apples comparison since I can't try the Ohlins bolted on the 400EX (since the rear shock won't work). So for my Ohlins comparison I was comparing my 400EX to my Cannibal... While the Cannibal works fairly well, it didn't work quite as well as the 400.

Now comparing a Moto front end is another apples to oranges comparison since they are a 19" setup & can't be tried on either bike without also changing front ends.

If the ZPS setup was hammering the ground with the frame, it's one of those setup issues I was talking about with "ZPS" style shocks - although "ZPS" will take up some of your travel when hitting whoops, they should be sprung to handle the conditions you're riding/racing in, setup is more critical on a ZPS shock than a regular shock.

One thing that can be tried if your ZPS setup is not working in the whoops is to raise the ride height - which only takes a couple minutes and can be done at trackside with no tools for the front and a hammer/punch or screwdriver for the rear. Raising the ride height can make dramatic handling differences, especially if the spring rate on the "ZPS" shocks is too low.

PEP and Ohlins use similar adjustment mechanisms for compression adjustment - PEP's, in theory, should have more adjustment because of the larger shafts being used (PEP ZPS use 5/8" shafts, the Olhins used on the moto front are a 9/16" shaft). This is because the compression adjuster is on the reservoir and regulates the fluid being displaced by the shock shaft into the reservoir.

Given you're comparing 19" shock to 19" shock, the shock that displaces more fluid into the reservoir per unit of shock travel, should offer more adjustment. This would be the shock with the larger shaft.

As far as revalving - Yes PEP uses a check ball and spring setup that must be disassembled to be revalved. However, I don't know of anyone that can revalve a shim stack shock without disassembling either.

[markvette]

in my original post i stated that the stock ohlins did not fair well in the whoops and that i had been told that the zps did better.

[cannondale27]

Wow,
For serious mx (you have to decide how serious you are)PEP zps.
Atc 250r I was replying to the first post not you.As for the raising the ride height for whoops the big advantage of zps is the low height raising it would take away that advantage.The shaft diameter is for strength yes it would be displacing morefluid but the dia.of hole in shaft,needle,rebound valving and jet size if it has one can all be changed to easily change this if you are talking rebound.Compression its the valving and the actual valve.I am sure that wayne could make the PEP as EXTERNALLY adjustable as the Ohlins I just havent seen it.My Ohlins if I adjust the rebound clicker tight and push down it will take all day to come back up all the way out it springs back like a pogostick.Compression it can be soft as a caddilac or so stiff you litterally cant move it even jumping on front bumper.Yes I know that adjusting the rebound with clicker and not the valving effects the overall valving.I also hate hoses on shocks they like to break.THERE IS NO SUCH THING AS A PERFECT SHOCK FOR EVERYONE.I am not a serious MX'er and like the plush ride and external adjustability of Ohlins.If I was the ride height and the fact Wayne is at all nationals and is the best in the business would definitly be PEP.I sure hope I didnt tick you off some way I really admire your work in the mapping field and help you give everyone.

[Cannibal440]

I noticed the same thing when I added the Blaze Ohlins to my Cannibal. I know this is not exactly the same thing but with the dual rate springs there is a bit more dive. It took a while to get used to and alot of fiddling with the compression adjustment and preload/crossover, but now I dont really notice it. I can imagine that with a ZPS shock the dive must be quite noticeable.

[airtime]

i have run pep zps shocks for over three years on mx tracks. the biggest problems i've seen with pep zps shocks is someone buying a used quad with pep zps shocks and not having the shocks revavled or sprung for their weight and riding style. i just installed pep zps shocks on my 03"cannible with lonstar +3 a-arms and there is no front end dive when i hit the brakes. the zps shocks actually reduce front end wheelies when you are hard on the gas. my cdale does not roll in corners either. if you are hitting your bumper when your going through the whoops then obviuosly your bike is setting too low and needs to be raised. when you call wayne at pep to ordered your pep shocks, you will understand why almost every pro mx rider uses them. he wants to know what nerf bar you are using, what class of rider you are (skill level), swing arm length, a-arm manufactor and width, tire size and type, body weight, etc... i have never had a set of pep's that were not set up right when i got them in. beware of ordering shocks from a company that just wants to know what type of bike you ride and how much you weigh. both my quads ride plush. it's not the ability of a shock to take a hard landing (no shock is desiegned to handle coming up short on a jump) but the abililty to ride over the rough stuff and keep you and the tires on the ground. i have blasted down several rough straightawys in fourth gear and never felt anything other than a few small bumps, where as my friend was getting beat to death with stiff shocks that did not bottom out when he cased that big double. one last thing, be honest when you order shocks, pro shocks are set up way soft for a beginner. beginner shocks are set up stiffer. nothing wrong with axis or elka shocks, but if they are not set up for the individual person they will not handle right either.