motion ratio vs leverage [Archive]

wilkin250r

09-03-2003, 04:08 AM

Originally posted by Pappy
ok...so offset rims dont affect the shock enough for a spring change but it will affect the valving? or is it just the crossovers that may need tweaking?

I would imagine it to be the other way around. I'm obviously not a shock expert, but I have a pretty decent knowledge of physics.

Obviously your shocks react differently to different forces. If you slowly compress your shocks, you are fighting ONLY the spring rate, and not the valving. If you QUICKLY compress your shocks, you are fighting BOTH the spring rate AND the valving. The valving only affects high velocity changes.

The offset rims will affect the leverage of your quad as it rolls in the corners and sidways bumps. Usually, these types of actions don't compress the shock very quickly, so the valving doesn't have a big impact, they are controled entirely by the spring rate. By adjusting the crossover, you are adjusting how your quad reacts to low-speed shock compression.

If anything, you would need to change your spring rate before it would affect your valving.

Pappy

09-03-2003, 04:17 AM

Originally posted by wilkin250r

The offset rims will affect the leverage of your quad as it rolls in the corners and sidways bumps. Usually, these types of actions don't compress the shock very quickly, so the valving doesn't have a big impact, they are controled entirely by the spring rate. By adjusting the crossover, you are adjusting how your quad reacts to low-speed shock compression.

well when i ride i dont usually go straight...so based on the info you posted an offset rim WILL affect the shock during the normal course of riding a quad.

wilkin250r

09-03-2003, 04:46 AM

Yes, I've said it all along. Offset rims WILL affect your shocks, just not in the way that many people are thinking, certainly not the same way as longer a-arms.

In all reality, the change isn't very much. Think about it, you aren't changing your valving, you're not changing your springs, you're just adjusting the crossover. We're not exactly talking about a drastic change.

Pappy

09-03-2003, 04:50 AM

that would reaffirm what silverfox posted about being able to tell a difference in her shocks with the wider offset rims.

wilkin250r

09-03-2003, 05:03 AM

No doubt. The original question that started this whole thing was if offset rims are the same as longer a-arms. If the question had been, do offset rims have ANY effect, the answer would have been different.

Pappy

09-03-2003, 05:04 AM

Originally posted by wilkin250r
No doubt. The original question that started this whole thing was if offset rims are the same as longer a-arms. If the question had been, do offset rims have ANY effect, the answer would have been different.

i agree. but sometimes all the techno mumbo jumbo dont mean jack in the real world:p

wilkin250r

09-03-2003, 05:07 AM

Originally posted by Pappy
i agree. but sometimes all the techno mumbo jumbo dont mean jack in the real world:p

Increase the high-speed rebound damping? You mean, twist that little knobby-thing next to the springy-thing?

86atc250r

09-03-2003, 05:49 AM

The width provided by the offset wheels will allow you to corner harder - thereby increasing the load *you* can put on the shocks from cornering before overturning - but that's a totally indirect change & the topic of the original discussion was direct - i.e. control arms vs offset and their effects on the shock leverage ratio.

Control arms will do the same, as well as leverage against the shock more per unit of wheel travel, causing the need for additional spring rate and more firm valving.

In my experience racing MX and Flat track with reversed and normal wheels - the difference in body roll is not typically detectable and is negated by the increased cornering power offered by the additional width... Suspension action from hitting bumps/jumps in the trail or track is not affected by offset changes.

I have affirmed this by hitting jumps on my home track I was very familiar with & knew exactly how my quad reacted - the results, no change in landings with reversed or not reversed wheels - however, I did fold an upper control arm after a particular jump on the offset wheels & bent several tie rods (just from landing).

Cornering stability improved with offset wheels & no increases in dive were immediately detectable in a given corner unless that corner was pushed harder.

Remember that offset wheels will cause additional component stress, will lower your confidence level in the rough (i.e. slow you down), and increase your chances of bent tie-rods, wrist injury, and increase the likelihood of a crash when the terrain becomes rough.

Heavily offset wheels should only be used in places where you won't experience much rough that will put stress on components and/or your hands and wrists.

Personally, I like a mix of technical data and (mumbo jumbo to some) and real world testing. Sometimes real world testing will expose things that were not accounted for, but if your tech data is good, real world testing just affirms it.

Also the bad thing about "real world" testing only is many times your "seat of the pants dyno" gives false reports & the person doing the testing does it in a less than controlled manner. Many times, this "real world testing" is then recounted here on the forums as fact, then bad info is propagated & those without the background to know better don't know what to believe...

It seems to me that some here want to believe that offset wheels affect shock load in a significant manner so badly that they'll latch on to any excuse - which is fine, believe as you wish - myself and others have tried to present the facts as clearly as possible....

Predator36

09-03-2003, 06:04 AM

Originally posted by bleupoud
an offset wheel will not change the motion ratio. It won't do a difference in bump and jump. But it will change the leverage ratio.
So it will do a little difference in cornering and sideway bump. The valving and spring rate usualy stay the same but you must play with the cross over

Please explain the differance between "motion ratio" and "leverage" I would like both the technical and the down to earth explanation.

Note: I am not challanging you in any way. I just think it would be easier to understand if we all understand the terminology and how it is being used here.

09-03-2003, 06:08 AM

Originally posted by Rico
I believe this new member is a shock technician and not someone talkin outa their butt.

Welcome to the site....:)

LMFAO :D

I just got this vision of Jim Carey typing with his bunghole.:devil: :D

Welcome bleupoud

Maybe we can get this info and put this one behind us (without a closed thread :rolleyes: )

nakomis0

09-03-2003, 06:17 AM

I wish somebody would shoot this tread. Even if I didnt want to look at it I gotta see it. Its in the Suspension Forum like 2 times, and in the open forum like 3 times.

I'm glad I dont care as much as you all. I like what Rico said awhile back... " I just ride the darn thing.":ermm: :)

86atc250r

09-03-2003, 06:29 AM

If you don't like these threads, stay out of them. We don't want/need posts like your clogging the discussion.

Some people are not interested in how or why their quad handles, just like some are not interested in engine building - however you don't see many come into engine building threads and complaining about the info being shared.

Bottom line - ignore if you don't want to read about, think about, or improve your handling.

SlapNutz

09-03-2003, 06:37 AM

thise is rong fromum 4 this toopic,, :cuss:

bleupoud

09-03-2003, 06:39 AM

Motion ratio : Relation between wheel travel and shaft travel on the shock. ex: you have 10 inch of wheel travel and 5 inch of shaft travel. Divide 10 by 5 (10/5) = 2 : 1 motion ratio

Leverage ratio : Mechanical advantage; how the force is translated to the shock from the wheel. Try to hold a hamer horisontal by the middle of the handle and after that at the end of the handle ....

But a lot of the force will be absorb by spindle and knuckle so the shock will not be affected by this a lot.

wilkin250r

09-03-2003, 06:40 AM

Originally posted by Predator36
Please explain the differance between "motion ratio" and "leverage" I would like both the technical and the down to earth explanation.

Note: I am not challanging you in any way. I just think it would be easier to understand if we all understand the terminology and how it is being used here.

The motion ratio is how far the wheel moves vs how much the shock moves.

Imagine a really long 10 ft wrench on a stubborn bolt. The far end of the wrench moves more than the close end, so the motion ratio isn't the same. The farther it moves, the more force it will exert on the bolt. (in case you haven't figured, the bolt is like your shocks in this example)

Now picture your typical dual a-arm setup. Imagine that you have a set of lug nut bolts that are 10 ft long. As you move your wheel hub up 5 inches, the far end of your 10ft lug nuts also move 5 inches. The motion ratio is the same. Remember the wrench? The far end moved more, the motion ratio wasn't the same.

09-03-2003, 06:40 AM

So puttin on offset wheels will not make any difference in how the shock works???? That's what i've gathered from what little i have read in these threads???

09-03-2003, 06:42 AM

Then read more, and u'll get it:)

09-03-2003, 06:44 AM

Originally posted by Curt
Then read more, and u'll get it:)

I'm not waddin thru 60 pages of arguements an BS.

It seems to me that if you extend your wheel farther away from the shock it will take less leverage to compress the shock, which means the shocks would feel softer..maybe just a tiny bit but it would make it softer... seems pretty logical to me..:confused:

wilkin250r

09-03-2003, 06:48 AM

Originally posted by Rico
So puttin on offset wheels will not make any difference in how the shock works???? That's what i've gathered from what little i have read in these threads???

I think there are only a handful of people that will be able to tell the difference in how the shocks perform. Yes, most people will be able to tell the difference in stability, but only a handful can feel how it affects the shocks.

Almost everybody would be able to tell how longer a-arms affect the shocks. Longer arms can turn your shocks into mush.

09-03-2003, 06:49 AM

Well sometimes the easiest things can be mistaken or done wrong. Go with what you think is right, if youre wrong, then youre wrong. I really dont care, I just ride the freakin machines:blah:

Looks to me we try more at proving each other wrong and stating facts rather then trying to get better on the quads themselves. If half the ppl here would ride as much as they talk, We'd be overflowing with pros:D :p

wilkin250r

09-03-2003, 06:50 AM

Castor-426ex

09-03-2003, 06:50 AM

i know the true answer but its a secret

86atc250r

09-03-2003, 07:02 AM

It seems to me that if you extend your wheel farther away from the shock it will take less leverage to compress the shock, which means the shocks would feel softer..maybe just a tiny bit but it would make it softer... seems pretty logical to me..

That's the reason you *should* wade thru the posts - you'd learn why something that seems logical on the surface is maybe not so logical.

Wilkin250R is right - very few people can "feel" the difference. Differences will not come from where you expect them to i.e. the greater distance from the wheel to the shock leveraging upon the shock. The differences come from how the weight transfers as you corner (and not when you hit bumps) - these differences will be very small - negligible when going from something like a 4/1 to a 3/2 wheel...

Differences from control arm changes will be noticible to an average enthusiast.

That was the original question - do offset wheels affect the shocks the same as extended control arms - the answer is a resounding "NO".

Somewhere along the line - maybe to save face, the question became "Do offset wheels affect shocks in any way what-so-ever, no matter how small". The answer to that is "yes", of course - practically any change you make to the chassis will affect the way suspension reacts in some manner...

Pappy

09-03-2003, 07:10 AM

Originally posted by 86atc250r

Somewhere along the line - maybe to save face, the question became "Do offset wheels affect shocks in any way what-so-ever, no matter how small". The answer to that is "yes", of course - practically any change you make to the chassis will affect the way suspension reacts in some manner...

who's face are we saving...?

oh thats right...jeff's face:rolleyes: not!!!

jeff is a big boy and can more then handle himself. maybe you have mistaken genuine intellectual curiosity for saving face. ill ask questions till the moon falls from the sky....thats how you learn.

as far as the real world? you lost 3/4 of the site when you went technical...lmao i appreciate it though...even if i dont fully understand it all. but...im man enough to say i dont know it all;)

wilkin250r

09-03-2003, 07:26 AM

Getting technical was the only way to properly explain it.

Be thankful he didn't bust out the equations. I think that would have lost everybody :cool:

09-03-2003, 07:33 AM

Originally posted by Rico
I'm not waddin thru 60 pages of arguements an BS.

It seems to me that if you extend your wheel farther away from the shock it will take less leverage to compress the shock, which means the shocks would feel softer..maybe just a tiny bit but it would make it softer... seems pretty logical to me..:confused:

Hopefully this one wont have all the BS in it (please help :) )

Your thought is not too far off but when you intro the spindle and second pivot point (top a-arm) it changes things.

Sorry that I cant offer much more than that, but thats why I have an interest in this thread or topic.

09-03-2003, 07:34 AM

Admin

09-03-2003, 07:37 AM

Well, because I am not an expert on Motion ratio and leverage ratio, I have contacted 5 shock manufacturers and shock rebuilders today to get their insight on this Issue.

Basically, I have found that wider offset wheel does not affect the Motion ratio, but does affect the leverage ratio. But, the affect on the leverage ratio is so small that most riders won't notice it. If a rider does notice it, then changing the crossovers or shock springs could compensate for it, but these changes are for the extreme circumstance. The change in offset from a 4x1 to a 1x4 would only be 3" and is very minimal in the affect it will have on the leverage ratio.

The handling of the quad would be affected the most with the wider offset. The wider offset will increase the bump steer and lead to the premature wear of Ball Joints, spindles, bearing, and etc..

Pappy

09-03-2003, 07:40 AM

dont get me wrong...gabe is a smart mofo. but when the majority of people read what he posts they click to another post before they are done reading it. i dont...i read every word he types.

is he perfect? nope is any one here? nope

but i think that some matuirity is called for when an issue of any importance is being debated. you cant take it personal if someone takes an oppisite side of an issue.

im still re reading about the affects of offset on the suspension from the other thread for christ sakes:p

and now its leverage and motion:ermm: :mad:

86atc250r

09-03-2003, 07:45 AM

Questions are good, honest inquisitiveness is even better - However, as time passed, it seemed some took it fairly personally and began shifting the topic from it's original question to "does offset affect shocks in any way what-so-ever". Shifting focus like that is a way of not admitting one was mistaken and takes away from the discussion.

It was not brought up to start a flame war- it was brought up to bring attention to the fact that people were shifting focus from the original topic no matter what their motives.

Not to harp on it, but in the case of Jeff, during the discussion, he guaranteed me that if I stuck a 10' pole on the end of the spindle, it would be easy to lift and compress the suspension - I called his bluff & posted the results - he offered nothing but insults in the form of one liner arguments and smiley icons.

If the technical explanations lost 3/4 of the site, that's not a good reflection on the condition of the boards, is it. Personally I'll give more merit any day to a well written explanation with technical data to back it up than to that of someone saying "I felt a difference".

If someone doesn't have the attention span to read a little about the topic they're wanting to learn about (and skim over the BS posts) - they're going to have a rough time in life. I'm sorry if I tend to be wordy - but I try to explain things thoroughly as possible to stay clear of confusion.

I'd love to hear more of what bleupoud has to say. I don't claim to know it all - heck if that were the case I wouldn't have went thru 6 sets of high end shocks in the last 3 years and still no rears that I'm really satisfied with - but what I do know, I'll attempt to share and help others understand.

Anyone that knows me personally knows that if they ask a question I don't know the answer to, I'll tell them straight up, they also know I'll help with anything I can & I don't play the games of giving bad info or playing dumb, even to competitors that run the same classes.

09-03-2003, 07:48 AM

Originally posted by Pappy
who's face are we saving...?

oh thats right...jeff's face:rolleyes: not!!!

jeff is a big boy and can more then handle himself. maybe you have mistaken genuine intellectual curiosity for saving face. ill ask questions till the moon falls from the sky....thats how you learn.

as far as the real world? you lost 3/4 of the site when you went technical...lmao i appreciate it though...even if i dont fully understand it all. but...im man enough to say i dont know it all;)

Hang on here it goes :)

Kenny I believe you in what your saying and understand you 100% but I also know that not everyone who has flamed these threads is as genuine.

Ok now save face, or whatever face, or any other inuendos would be better if not posted in the thread casue all the BS (as rico so well put it) in both directions is only clouding a very interesting and important issue.

Lets all find a way to forget who said what and who mis spoke or who thinks what and just stick to the basic subject that this has grown into, what is the affect of offset on the suspension and how does it compare to other things (feel free to correct me here if you like :) ).

Now for losing 3/4 of the site, well thats a whole other issue. :D I think that once this thread gets moving in the right direction those who seriously want to lean could or shlould ask questions so they can answer the ramaining 95% of the 3/4's that will continue to ask the same basic questions in various new forms till eternity and never find this thread because they are too lazy, special, important or just refuse to perform a search. Maybe the last part wasnt fair as I should have included that they may just want to talk to someone on the forum. :rolleyes:

Guys lets keep it clean and moving in the right direction this time, PLEASE :)

09-03-2003, 08:11 AM

So what are we tryin to figure out here? The question has been changed about 5 times..from leverage, to ratio, to falatio, to wheel offset, to spring and crossover changing. I think i'm gonna pull off my shocks and put on 1 inch angle iron and be done with it...:confused2

I think most people including myself are a little confused now and gabe pointed it out pretty good. The real question has changed and been modified so many times that we finally are getting real results from shock companies but we've lost track of what the he11 is goin on from the beginning....:huh :confused:

Pappy

09-03-2003, 08:19 AM

i think the topic moved for a reason. once a level of information reaches a point it leads to more questions and more info.

i dont give good got dam how smart someone is...if they cant see past petty issues then they need help.

i normally ignore most of the BS...maybe thats why for me the thread progressed to new info on how offsets affect the handling and such. i guess for the rest of ya it didnt.

im out....ill contact suspension companies and hit the books for information. when you fellas put aside the who's right who's wrong stuff lemme know:mad:

wilkin250r

09-03-2003, 08:19 AM

So basically, we presented so much information that we lost the question?

09-03-2003, 08:35 AM

Originally posted by wilkin250r
So basically, we presented so much information that we lost the question?

I think so....LMAO

09-03-2003, 08:36 AM

Originally posted by 440EX4me
Hang on here it goes :)

:rolleyes:

:D

09-03-2003, 08:36 AM

Originally posted by wilkin250r
So basically, we presented so much information that we lost the question?

LOL seems like the question needs to be questioned ;)

09-03-2003, 08:43 AM

Originally posted by EXriders Admin
The change in offset from a 4x1 to a 1x4 would only be 3" and is very minimal in the affect it will have on the leverage ratio.

here within his post is the best description & answer concerning the leverage issue ....agree or not ?

wilkin250r

09-03-2003, 08:43 AM

Originally posted by 440EX4me
LOL seems like the question needs to be questioned ;)

Well, that's fine, as long as it doesn't still need to be answered. :)

exman

09-03-2003, 08:47 AM

i think its a good forum, i ahev read them all and defently learned alot about this shock issue. Now if I can just decide what arms and shock setup to go with sons 300ex..he is MX'n any suggestions

AtvMxRider

09-03-2003, 09:23 AM

What's the best slip-on for a 400ex?............:ermm:

Guy400

09-03-2003, 02:16 PM

I really hope this thread stays on topic because we all can learn from it. I agree with several others that the original question metamorphosized into something different. The original question of wheel offset affecting shocks was interpreted differently by different people. Gabe, myself and a couple others interpreted this as wheel offset vs. shock dampening in and of itself, meaning we were looking at a controlled experiment. Does wheel offset affect shock dampening, period. To answer this specific question you can only take two factors into account, wheel offset and the result on the shock. The assumption has to be made in order to keep the data controlled that all other factors are at the zero point. What I'm trying to say is that if someone asked "Does adding a slice of cheese to a hamburger make it any taller?" we've got to assume that the bun thickness and hamburger patty thickness are at a constant. The original question then turned into does wheel offset affect handling in all situations. Some argued this point while others were still arguing the first variation of the question. When you look at wheel offsets and how it affects handling during the dynamics of cornering, bumpsteer, suspension articulation, etc. then the discussion becomes much more broad. Now we could argue about a whole slew of events that occur during riding. How does tire roll or sidewall stiffness affect overall handling? How does temporary a-arm or spindle deformation affect handling? How does that 1/1,000,000th of an inch of play in the balljoint affect handling? The answer to most of those questions is negligible but nonetheless play a role in handling.

I hope I didn't add any fuel or a spark to potential flames:ermm: I can learn from these discussions as much as anyone else.

09-03-2003, 02:58 PM

I hope I didn't add any fuel or a spark to potential flames I can learn from these discussions as much as anyone else.

Same here but I am wondering that with all the attention :) in these threads if anyone with the answers would have the courage to answer????????

Bad Habit

09-03-2003, 03:40 PM

Originally posted by 440EX4me
Same here but I am wondering that with all the attention :) in these threads if anyone with the answers would have the courage to answer????????

I have to ask, do we need to have the answer???
Now hang on, let me explain where I'm coming from. (Or at least stall long enough to put on my flame proof coat.:D )
The related threads on this subject have provided an enormous amount of hard information on front end suspension from all view points, it's there just filter out all the flames and finger pointing. All of that information now needs to be absorbed and seriously thought about. Once all the info is tabulated in our heads, we will be miles ahead of where we were at before all of this. I'm sure more than a few will have a lot better understanding of those wishbone looking thingys on the front end and how they are affected by changes, conditions, terrain etc. As long as this gets people to start thinking more about it, they will start making educated decisions on their own what will work for them. It might not be right to another members eyes, but that doesn't matter I don't think. There does not necessarily have to be a correct, definitive answer.

Take all the shock manufacturers for example. If there was one and only one absolute correct way to build a shock, all the companies would be identical. But they're not. Why, because everyone of them has a slightly different view on what makes the best design. I don't want to start the "who makes the best shock" thread, but I think this helps illustrate my point.

SGA

09-03-2003, 05:04 PM

Well, I for one have learned alot about front end set up from these threads.
I found this on the net, which to me is kinda like these threads. Some people are missing the big picture here.(Read the fine print at the bottom of the sign) http://www.imagestation.com/picture/sraid77/pbb4f622e7239b48cf59b483c5b8a86e2/fb3085ed.jpg

SGA

09-03-2003, 05:14 PM

Oh yeah, big news! Check out this pic while I tell ya about it!
http://www.imagestation.com/picture/sraid77/pcf9ea6d143d6b0a0e3307591b0d46e39/fb3ce576.jpg
No, im not dating her, BUT I JUST SAVED ALOTTA MONEY ON MY CAR INSURANCE!:blah: ;)

09-03-2003, 11:36 PM

Originally posted by 440EX4me
Hopefully this one wont have all the BS in it (please help :) )

SGA

09-04-2003, 04:41 AM

Everyones so serious, I was just trying to lighten the mood david.:)

spincr4hire

09-04-2003, 04:58 AM

Originally posted by SGA
Everyones so serious, I was just trying to lighten the mood david.:)

LMAO, that was great...:p

wilkin250r

09-04-2003, 08:50 AM

I think we cleared up the original question, as well as some of the new questions that arose since then. I believe that anybody that HAS read through the entire history knows that offset wheels are NOT the same as extended a-arms, but they WILL have an effect on overall handling and suspension characteristics.

If I'm wrong, and there are some that still don't understand, please correct me and we'll try to help. I don't want anybody coming out of this topic still confused. (even though there are those of us that are MORE confused than before :) )

I think the only thing left to explain is the fine details of exactly what aspects offset wheels will affect, to what degree, and how to compensate. In reality, these questions and aspects are different for every riding style, and I don't think there are any easy answers.