Steering and Handling Discussion.

[400exrider707]

Makes perfect sense to me, very understandable. Thanks for bringing it up to, it was a point I never really thought to mention. I still would really like to know what the actual effect of tire sizes has on the location of the spindle. I think this is also complicated by the fact that nearly every quad is running different camber settings. You could effectively run a camber setting that no matter what size tire you ran, it was always in that imaginary line of the balljoints. Add to that, your castor setting could give you camber gain throughout the travel. I think that this would actually be very difficult to put a "set in stone" definition or number on, but I think it's safe to say for our purposes, its negligible because the contact patch doesn't vary much between the smallest and largest tire a sport quad would genearlly use.

[bradley300]

Originally posted by 400exrider707
Makes perfect sense to me, very understandable. Thanks for bringing it up to, it was a point I never really thought to mention. I still would really like to know what the actual effect of tire sizes has on the location of the spindle.

none really. yes you are rasing the spindle farther from the ground (or closer with smaller tires), but you are doing this to the entire quad, so no change would be felt except you higher (or lower) center of gravity

[400exrider707]

Originally posted by bradley300
none really. yes you are rasing the spindle farther from the ground (or closer with smaller tires), but you are doing this to the entire quad, so no change would be felt except you higher (or lower) center of gravity

With a taller tire, like mentioned before, it moves your contact patch away from the imaginary line that the balljoints create on the arms though. I honestly just dont know the answer to this one, I need to do more research!

[juanki]

hi guys. excelent thread you have here.

i have a question on the set up of my bike.

i have +2+1 dentor caster and camber a-arms and tcs triple rate with compresion only. all this of a 88trx270R

so i have read all i can find on how to fine tune the suspension, i know (or at least i know) what rebound, and compresion is. but havent done anything to the shocks. i never move anything, and i want to do some changes.

what i want to know is how the suspenison would react to the changes.

lets say. what wolud happen if i set the springs to the tallest part of the shock and the compresion to the softest setting?

then if i leave the springs like that and then move the compresion to the harder setting.?

then if i leave the compresion hard and the springs to the bottom of the shocks?

then if i leave the springs on the bottom and put the copresion to the sofftest side?

so i have four scenarios here. i ride both, mx and trails.
when i go mx i change the tires 19 front 18 rear.
when i go trail i use 22 front and rear.
but i've never have change the settings.

also i sent the back shock to revalve and told the guy tha i wanted it set up for mx. so they did. (also the front where set up for mx)

the last q. would be for the rebound. only the rear shock has it so it can be adjusted.
what wolud happend if i put it in the lowest or the highest.

what i'm looking for with this at the end is recomendations or general knowledge. as if..

for mx i recomend hard spring and hard compresion and for trails i recomend soft springs and soft compresion. at the rear the same with rebound. something like this.

thanks

[bradley300]

Originally posted by 400exrider707
With a taller tire, like mentioned before, it moves your contact patch away from the imaginary line that the balljoints create on the arms though. I honestly just dont know the answer to this one, I need to do more research!

i see what you are saying now, the contact patch would be further from the spindle. That in theory would create more feedback thru the bars (think wheel spacers). At the same time tho, bigger tires turn slower so i think and feedback you would gain from having the contact patch such a small amount further from the imaginary line, is automaticly cured, plus some, by using the bigger, less responsive tire

[bradley300]

lets say. what wolud happen if i set the springs to the tallest part of the shock and the compresion to the softest setting?

your shocks would be incredibly soft, and bottom very easy.

you are thinking too much on this one. get your rear sag set before you do anything.
pull up on the grab bar until the quad wants to lift. have a friend measure from the axle to say, a grab bar mounting bolt, call this A measurement. Then sit on the quad with your gear on in a riding position and have your friend take a measurement from the axle to that same grab bar mounting bolt, call this B measurement. subtract B from A to get your rider sag. adjust the preload until the rider sag is 50% of the available travel. then measure the ride height with you on it under the foot peg. then adjust the front ride height to .25 to .5 inches higher than the rear. Now dont ever worry about the preload again. note: i would do this with your MX tires on since the shocks are valved for MX. now when you switch to the bigger tires, i personally wouldnt mess with the ride height. i would go on and play with the compression knob. it takes test and tune time but go 2 or 3 clicks softer until its comfortable for xc. (just record the settings so you can switch back to mx easy). i would go 3 clicks faster on the rebound to start also.

then if i leave the springs like that and then move the compresion to the harder setting.?

the shocks will get stiffer and ride rougher as you raise the compression

then if i leave the compresion hard and the springs to the bottom of the shocks?

they would be incredibly stiff

then if i leave the springs on the bottom and put the copresion to the sofftest side?

somehwere in the middle of the other two scenarios
you dont need to think of the preload adjustments as anything more than a way to adjust the ride height/sag. do not use them to make the ride stiffer or more plush, thats what the compression knob is for

the last q. would be for the rebound. only the rear shock has it so it can be adjusted.

that all depends on how bumpy the terrainis and how fast you ride. typicly the faster you ride and the bumpier the trails, the faster the rebound needs to be and vise versa. your best bet is to start in the middle of the adjustment range. if the rebound is too slow, the rear shock will "pack up" because it cant fully extend back out between bumps and eventually runs out of travel and it will swap the whole rear end back and forth. if the rebound it too fast, the rear end will feel like a pogo stick constantly bouncing straight up, even on smaller bumps

[juanki]

thanks for the reply bradley

i'll do that, so for what i understand the springs are used to set the heigth of the bike and the compresion knobs for changing for stiffer or plusher ride.

if that is so, why there are dual, triple and cuadruple rate springs?

[number52]

Originally posted by juanki
thanks for the reply bradley

i'll do that, so for what i understand the springs are used to set the heigth of the bike and the compresion knobs for changing for stiffer or plusher ride.

if that is so, why there are dual, triple and cuadruple rate springs?

That's correct, the springs are used to hold the bike up and the valving is used to control the springs.

The reason for having multiple spring rates is to create a progressive spring rate or "rising rate" The crossovers control when the next spring takes into effect causing the spring rate to rise when it bottoms out. The crossover height is the most major external adjustment you can change on a shock. Most quad rate shocks have a ZPS spring and are actually a triple rate shock. If you look at the 2nd and 3rd spring you will notice that they are the same length, ID and wire size, which actually makes them the same spring rate, so I would consider these two springs as 1 spring! Mostly a sales gimmick.

[bradley300]

Originally posted by juanki
thanks for the reply bradley

i'll do that, so for what i understand the springs are used to set the heigth of the bike and the compresion knobs for changing for stiffer or plusher ride.

if that is so, why there are dual, triple and quadruple rate springs?

its just shock builders personel preference. shocks are made to get stiffer as they go thru the travel. this is so they can havea smooth ride, and still have bottoming resistance. its called progression. some shock builders use the shims on the inside to tune the correct amount of progression, and some use multiple spring rates to do the same job. it seems the latter is the easier of the two which is why you see so many multi rate springs. but really multi rate or single rate doesnt make a difference as long as the rest of the shock is built around that set up.

thats why people shouldnt say "i'm going with brand X hock because they are tripple rate, and brand Y is only single" because more springs dosent mean it automatcly a better shock.

[bradley300]

Originally posted by number52


Mostly a sales gimmick.

there is actually a purpose to multi rate springs so they are really a gimmick, just a different way of doing things.

now ZPS or SSD is a gimmick. all shocks sag, there isnt a SSD spring needed for that. SSD just makes it sit lower when no one is on it, but the reality is no one rides there quad while they arent on it, and when a person sits on equal shocks that arent SSD, they will sag jus the same