Before you drop money on machining bodies and revalving and respringing I would really check your setup first.
The moto had 11 inches of travel in the front, so pretty impressive. Perhaps you may be confusing a poor setup for a need that may not be there just yet. One thing you will notice with the Ohlins front shocks is the adjustment range on the compression and rebound is HUGE.
You want to know your baseline before starting anything. I have never owned a moto or taken these raw measurements with one.
The ride height can be controlled by the preload clip on the top spring as well as changing the spring timing with the crossover collar. If you cannot get the adequate ride height adjustment with those it is time to look at running a ZPS spring setup.
If you want someone who can help you revalve and tune these things you should look no farther than our own cannondale27. His prices are unbeatable and the service is the same. He knows these Ohlins shocks quite well.
Here is some nice info and how to on setting the ride height from one of my friends who does suspension consulting:
"Zero preload is a relative term. The only true definition of zero preload is if there is only enough tension on the preload collar to keep the spring it contacts in place. Most top springs, known as tender springs are one of many ways to achieve a low ride height but still have plenty of negative travel, known as suspension drop. This is commonly labeled as sag which is what you guys are thinking of when refering to negative travel. Increasing tension on a very tender spring does not cancel out the "zero preload" label.
Valving should have no bearing on ride height, period. I will always respect other tuners theories but if anyone ever states that they can fix the ride height problem with valving should be disregarded. Proper ride height is determined by spring rate. Also, a machine that is properly sprung will have the same ride height with or without oil in the shocks. Again, if you are relying on the oil to support the machine you are already putting undue pressure on the oil and you haven't even moved yet! Think of the stress on said oil once underway. The oil (or valving) is only there to control the springs. A machine with proper springs on it will have almost no preload when up on a stand and ride perfectly when set-up, although there are certain suspension designs that mandate tension.
Why manufactures use multiple springs on shocks is because of the more tuning options available with that theory. The Honda TRX450 rear OEM shock should never use a dual rate set-up, meaning 2 springs. This is even more important with heavier, faster, or for XC applications. There will of course be those that disagree because they only know what they have experienced, or ridden a "buddy's" machine and then chanted on and on to all that will listen or read that XYZ Brand set-up was no good. The universal theory of modern suspension is to make it work for YOU and only YOU. I have dialed in hundreds of machines thru the years and even when you take 2 riders; same weight, same machine, same components, even the same talent; and they will still have different set-ups on suspension.
The first and single most important adjustment to make is to set the ride height and balance the suspension front & rear. There are those that swear up and down that they have their ride height perfect and as soon as I look at the machine with them sitting on it, it is usually off by alot.
Clean and lube every pivot
If the swingarm (without axle assembly) or a-arms (without the wheels mounted) cannot drop down under their own weight, there is bind that needs to be addressed first.
Take off the belly skid plate
Fill your gas tank
Inflate tires to proper psi (usually 7psi front/5psi rear)
Open up all the valves. Meaning to set all comp adj to full soft and rebound to full fast (or less). Record base settings. Push up and down on bumpers repeatedly to cycle fluid.
Wheel the machine onto a flat surface
Sit on machine with intended gear and mimic usual riding position
Relax and remain still
Have an assistant slowly push down on the front end and far as it will go and allow it to slowly settle into it's natural position.
Repeat for rear
Repeat again front and rear
Relax and remain still
Have the assistant place a ruler (left to right) straight edge side against the underside of the lower frame rail 3-4" in front of the forward motor mount and measure height accordingly. Record.
Still relaxed on machine slowly move your foot off the peg and hold next to motor. Place ruler under frame rail below swingarm pivot bolt and measure height accordingly. Record.
That is your ride height."
ohlins moto shock machined down?
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cannondale27
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QUOTE (joep1219 @ Dec 26 2009, 12:41 AM) <{POST_SNAPBACK}>
is that obtainable with the stock moto front end running 20" fronts and 18" rears? really haven't messed with it much. what started this suspension stuff was last week i brought one of my friends LTR's down to the moto xperts, they seen the moto in the trailer and started asking how i liked it. i replied that i was happy with everything other then i thought that the suspension could be a little more plush! that's when they came up with this idea of getting more upward travel out of the front end by machining the bodies and taking out part of the internal bumpstop, and a revalve and respring.
so what i'm getting at is i don't necessarly want to reinvent the wheel here, i just want close to what i had on my yfz with laegers and PB1"s. i know the revalve and respring will plush it up, but can i get the ride hight lower?
so what i'm getting at is i don't necessarly want to reinvent the wheel here, i just want close to what i had on my yfz with laegers and PB1"s. i know the revalve and respring will plush it up, but can i get the ride hight lower?
that's when they came up with this idea of getting more upward travel out of the front end by machining the bodies and taking out part of the internal bumpstop,
This is what they said that doesnt jive.Removing any of the INTERNAL bumpstop will create downtravel and cause the balljoint binding we all talked about earlier.Yes you would need a new set of springs to get the low ride hieght a ZPS suspension is capable of.Moto shocks springs and valving werent designed to work correctly without preload or at that low of a hieght ZPS is capable of.I would recommend doing like 2000ex said and also try them starting with just enough preload to hold the springs tight.That would be the minimum hieght that Moto shock was designed for.Hopefully your ride hieght will be acceptable with front about 1" higher than rear.Then go from there with shock adjustments.Since you are looking for plush ride I agree with starting on the soft side on all adjustments.Just be careful not to bottom repeatedly so you dont damage anything.
Preload-Ridehieght and small bumps.
Crossover-controls body roll in turns.Gap between top retainer and crossover should be MAX possible with minimum body roll.
Rebound-Set this in a whoops section.You want your wheels especially rear to follow the whoops and not pack up.This also affects body roll,traction and will need to be adjusted depending on course and speed you are going on course.Faster course faster rebound.
Compression-controls bottoming the most.Best is to set it so it just barely bottoms going very slow and plopping off about a 4-5ft jump and landing on a flat or even slight uphill.
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Gibson265R
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QUOTE (cannondale27 @ Dec 26 2009, 12:32 PM) <{POST_SNAPBACK}>
that's when they came up with this idea of getting more upward travel out of the front end by machining the bodies and taking out part of the internal bumpstop,
This is what they said that doesnt jive.Removing any of the INTERNAL bumpstop will create downtravel and cause the balljoint binding we all talked about earlier.Yes you would need a new set of springs to get the low ride hieght a ZPS suspension is capable of.Moto shocks springs and valving werent designed to work correctly without preload or at that low of a hieght ZPS is capable of.I would recommend doing like 2000ex said and also try them starting with just enough preload to hold the springs tight.That would be the minimum hieght that Moto shock was designed for.Hopefully your ride hieght will be acceptable with front about 1" higher than rear.Then go from there with shock adjustments.Since you are looking for plush ride I agree with starting on the soft side on all adjustments.Just be careful not to bottom repeatedly so you dont damage anything.
Preload-Ridehieght and small bumps.
Crossover-controls body roll in turns.Gap between top retainer and crossover should be MAX possible with minimum body roll.
Rebound-Set this in a whoops section.You want your wheels especially rear to follow the whoops and not pack up.This also affects body roll,traction and will need to be adjusted depending on course and speed you are going on course.Faster course faster rebound.
Compression-controls bottoming the most.Best is to set it so it just barely bottoms going very slow and plopping off about a 4-5ft jump and landing on a flat or even slight uphill.
This is what they said that doesnt jive.Removing any of the INTERNAL bumpstop will create downtravel and cause the balljoint binding we all talked about earlier.Yes you would need a new set of springs to get the low ride hieght a ZPS suspension is capable of.Moto shocks springs and valving werent designed to work correctly without preload or at that low of a hieght ZPS is capable of.I would recommend doing like 2000ex said and also try them starting with just enough preload to hold the springs tight.That would be the minimum hieght that Moto shock was designed for.Hopefully your ride hieght will be acceptable with front about 1" higher than rear.Then go from there with shock adjustments.Since you are looking for plush ride I agree with starting on the soft side on all adjustments.Just be careful not to bottom repeatedly so you dont damage anything.
Preload-Ridehieght and small bumps.
Crossover-controls body roll in turns.Gap between top retainer and crossover should be MAX possible with minimum body roll.
Rebound-Set this in a whoops section.You want your wheels especially rear to follow the whoops and not pack up.This also affects body roll,traction and will need to be adjusted depending on course and speed you are going on course.Faster course faster rebound.
Compression-controls bottoming the most.Best is to set it so it just barely bottoms going very slow and plopping off about a 4-5ft jump and landing on a flat or even slight uphill.
when you zps the front end to get it down, you then compress the shocks. so what i'm having a hard time understanding is that when you compress the shocks, and you then hit big rocks, bumps, ect.. don't you loose all your compression travel? won't that just increase my harshness? or is there some kind of happy medium with ride hight and travel with the stock front end? if so what is it? the way that i have it setup now actually works good with deep ruts and big rollers, just not on ruff landings or when the track gets bigger bumps and clumps. i really don't want to start swapping out front ends, i hope i can find what i'm looking for out of the stock moto stuff.
QUOTE (Gibson265R @ Dec 27 2009, 01:42 AM) <{POST_SNAPBACK}>
you should just get a nice aftermarket front end. They are going cheap these days (used). Stock front ends are weak anyway...moto ones are better than a cannibal for example, but are not worth buying. Just pick up a nice set of housers or LSR or walsh if you can find em(walsh that is).
that's not a bad idea, but with funds being limited and me not wanting to start tearing apart a true moto, i would rather not if i don't have to. i'm just looking to get the most out of the factory stuff that i can. i hope by next year i'm racing a new 450 of some sort that i will have no problem tearing apart and building from the ground up. that way i can start to clean my moto up to put in my living room! lol.
QUOTE (joep1219 @ Dec 27 2009, 11:35 AM) <{POST_SNAPBACK}>
when you zps the front end to get it down, you then compress the shocks. so what i'm having a hard time understanding is that when you compress the shocks, and you then hit big rocks, bumps, ect.. don't you loose all your compression travel? won't that just increase my harshness? or is there some kind of happy medium with ride hight and travel with the stock front end? if so what is it? the way that i have it setup now actually works good with deep ruts and big rollers, just not on ruff landings or when the track gets bigger bumps and clumps. i really don't want to start swapping out front ends, i hope i can find what i'm looking for out of the stock moto stuff.
You do not sacrifice travel. The ZPS spring will allow the suspension to compress or sag to the correct or desired ride height. However when you are jumping or hitting holes and whoops you still get the full effect of the travel due to the shock being able to fully extend.
For MX Rear ride height should be anywhere from 6.5??????? - 7.25???????. Front ride height should be anywhere from the same as the rear to 1/2??????? higher. I have found 6.75 inches by the rear and 7 inches at the front to be a happy medium.
It is impossible to have a suspension that will be super plush on the rough stuff then be able to take massive air landings well without changing the setup at all. Suspension is a compromise, and it is the fine tuning that should help you when the track changes. You should have no problem with the proper setup getting the ride you need with this front end.
Follow my advice and start FIRST with setting your ride height correctly. From that point you should be able to fine tune your desired settings by testing it. ONLY do one change at a time so you can see the difference it will make. Write down the settings and note the terrain so you will be able to replicate them at a later date.
Like you said you did not want to recreate the wheel. Before you start plunking down cash, I would take the free route and make sure you have the machine setup correctly.
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cannondale27
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QUOTE (joep1219 @ Dec 27 2009, 10:35 AM) <{POST_SNAPBACK}>
when you zps the front end to get it down, you then compress the shocks. so what i'm having a hard time understanding is that when you compress the shocks, and you then hit big rocks, bumps, ect.. don't you loose all your compression travel? won't that just increase my harshness? or is there some kind of happy medium with ride hight and travel with the stock front end? if so what is it? the way that i have it setup now actually works good with deep ruts and big rollers, just not on ruff landings or when the track gets bigger bumps and clumps. i really don't want to start swapping out front ends, i hope i can find what i'm looking for out of the stock moto stuff.
This is somewhat true with any ZPS setup.The Moto suspension was designed exactly as that compromise you are looking for.Not quite as low ride hieght but plusher because of the little extra ride hieght and still able to take the big hits.The low ride hieghts race quads run have been in and out of style many times in MX.I have noticed they are coming back now.Like Wes said its a compromise thing.I think the Moto Setup is a excellent compromise and fully capable of winning a Pro Race.I do wish they could be setup with Canniboomers joints though.Blackwidows joints do last way better than the stockers and now the bushings can be replaced with Poly bushings so not too bad -vs- aftermarket.
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MX Quad Dad
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QUOTE (2000ex @ Dec 27 2009, 12:19 PM) <{POST_SNAPBACK}>
You do not sacrifice travel. The ZPS spring will allow the suspension to compress or sag to the correct or desired ride height. However when you are jumping or hitting holes and whoops you still get the full effect of the travel due to the shock being able to fully extend.
For MX Rear ride height should be anywhere from 6.5??????? - 7.25???????. Front ride height should be anywhere from the same as the rear to 1/2??????? higher. I have found 6.75 inches by the rear and 7 inches at the front to be a happy medium.
It is impossible to have a suspension that will be super plush on the rough stuff then be able to take massive air landings well without changing the setup at all. Suspension is a compromise, and it is the fine tuning that should help you when the track changes. You should have no problem with the proper setup getting the ride you need with this front end.
Follow my advice and start FIRST with setting your ride height correctly. From that point you should be able to fine tune your desired settings by testing it. ONLY do one change at a time so you can see the difference it will make. Write down the settings and note the terrain so you will be able to replicate them at a later date.
Like you said you did not want to recreate the wheel. Before you start plunking down cash, I would take the free route and make sure you have the machine setup correctly.
For MX Rear ride height should be anywhere from 6.5??????? - 7.25???????. Front ride height should be anywhere from the same as the rear to 1/2??????? higher. I have found 6.75 inches by the rear and 7 inches at the front to be a happy medium.
It is impossible to have a suspension that will be super plush on the rough stuff then be able to take massive air landings well without changing the setup at all. Suspension is a compromise, and it is the fine tuning that should help you when the track changes. You should have no problem with the proper setup getting the ride you need with this front end.
Follow my advice and start FIRST with setting your ride height correctly. From that point you should be able to fine tune your desired settings by testing it. ONLY do one change at a time so you can see the difference it will make. Write down the settings and note the terrain so you will be able to replicate them at a later date.
Like you said you did not want to recreate the wheel. Before you start plunking down cash, I would take the free route and make sure you have the machine setup correctly.
I spent some time trying to setup our Moto for my son who only weighed 130# or a little less maybe. he could get away with a little less ride higth because of his weight and he wasn't one to go for "big air". I never considered my measurement as ride higth, moreso "race sag". I have no ideal where you would measure the 6.5" raer higth.
I ended up taking the springs off the shocks and with the quad on a stand i measured the total travel in an easy to measure piont to point location between the rear axil and sub frame and then between upper ball joint and fender ( I think the factory spec for travel was right on so you could use that if yours is stock). after i got total travel between full extension and comperssed to the bumpstop. I was told by several shock manufactures that race sag should be between 25-33% of total travel. race sag or some call it sag is the differance between fully extended shocks and the measurement you get with the quad on the ground with the rider on the quad. I think they want the riders weight on the pegs. also rider should bounce on the quad and the person measuring should roll the quad back and forth a little (with rider still on) before measuring.
I'm not sure what you have had done to the shocks, but I recomend haveing them serviced and then seting them up right from race sag at about 30%, if you do go for big air or are on a rough track you may want to start closer to the 25% mark. then do a ltile trial and error raise and lower one end or the other. I seem to think the two strokes like the higher front ends and the four strokes seem better closer to level. I would say that the sag differance between the front and rear would be rider preferance on cornering and traction out of the corner but that is just my opinion. you may also want to check toe-in if you change the front much
my opinion on ZPS is that they are completly opposite of what they claim. I had to set my Moto shocks to the lowest setting to even get close to the 25% mark there was absolutlly no preload on the springs. the ZPS uses the tiny soft spring to keep every thing snugg enough. and that little spring uselly has some load on it at full extension when the ride higth is set correctly
27; I think like you said, about the ride higth comming in and out of style, I also think it has a lot to do with the setup that the guy who is winning uses.
MX Quad Dad.
With respect to measuring total travel you must not take the bump stop into account. Measure as if there was nothing there. The bumpstops will compress down to fractions of an inch when at the true bottom of the travel.
You also do not want the riders weight on the pegs when measuring ride height. They want you to bounce up and down and push on front and rear so the suspension "settles" when at that point rider sits on the machine and measurements are taken. You measure the rear height just in front of the footpeg.
To determine the ride height for the front end measure from directly at the forward most area of the chassis where it is still flat, behind the lower a-arm mount is the most common place.
Percentages are great and make sense, however wouldn't it be far easier just to measure at the frame and foot pegs in inches of ride height? That takes less than a minute to do. It is the same thing just much easier to measure and change without having to play around with the actual percentages of travel.
Read the "how to" on correctly measuring ride height earlier in the post to give you a step by step. It was written by a good friend of mine who does professional suspension consulting around the country.
I have just started a book of measurements I am taking for various shocks I have and keeping them on record.....pretty cool to see the differences in manufacturers setups
My moto Ohlins I have which to the best of my knowledge have not been tampered with are exactly 19 inches in length. So according to c27's info in this post, my set must be an early moto shock as all I have read is they are 18.75 inches long. I would venture to guess they just have a spacer in there on the later models.
Also the stroke on these babies is a massive 5.875 inches.
With respect to measuring total travel you must not take the bump stop into account. Measure as if there was nothing there. The bumpstops will compress down to fractions of an inch when at the true bottom of the travel.
You also do not want the riders weight on the pegs when measuring ride height. They want you to bounce up and down and push on front and rear so the suspension "settles" when at that point rider sits on the machine and measurements are taken. You measure the rear height just in front of the footpeg.
To determine the ride height for the front end measure from directly at the forward most area of the chassis where it is still flat, behind the lower a-arm mount is the most common place.
Percentages are great and make sense, however wouldn't it be far easier just to measure at the frame and foot pegs in inches of ride height? That takes less than a minute to do. It is the same thing just much easier to measure and change without having to play around with the actual percentages of travel.
Read the "how to" on correctly measuring ride height earlier in the post to give you a step by step. It was written by a good friend of mine who does professional suspension consulting around the country.
I have just started a book of measurements I am taking for various shocks I have and keeping them on record.....pretty cool to see the differences in manufacturers setups
My moto Ohlins I have which to the best of my knowledge have not been tampered with are exactly 19 inches in length. So according to c27's info in this post, my set must be an early moto shock as all I have read is they are 18.75 inches long. I would venture to guess they just have a spacer in there on the later models.
Also the stroke on these babies is a massive 5.875 inches.