king vs fox vs ???

[fabr]

 Read this. Thanks to Pirate4X4

 http://www.pirate4x4.com/tech/billavista/PR-Airshox/index.html

NOW I see!

[trans man]

Read this. Thanks to Pirate4X4

 http://www.pirate4x4.com/tech/billavista/PR-Airshox/index.html

NOW I see!

There is ALOT of damn good info there!!!

[dsrace]

that is some great info fabbr thanks for posting it! I particularly like the spread sheet! I posted pics of the fox shock tear down a while back in the susp section.  I do already understand what the article is saying and the principals behind the fox 2.0 and even the 2.5 airs this is why I pre-fer them to the coils myself. I just don't under stand what is not believed or understood or what some are looking for as far as info on trans problem is?

in a nut shell the king shock was assembled a$$ backwards right from the factory and the nut that holds it all together unscrewed not ripped off, and poof new roman candle.

with the valving installed backwards from king the ride was a lot like walking into a gravel pit pond, first few steps shallow- progressive next one 20' drop and flat on its face! so he/we added pressure to keep him up to enjoy in some way the rest of the trip till the shock went roman candle!

[fabr]

It's just educational chatter. I read that article a long time ago and forgot all about it. DDuh.

[BDKW1]

bdkw1 let me ask you this then, I used to have a 900ninja mini and had to run 380 psi on fox 2.0's to get my desired ride with 2-200lb men, while at ls. that rail was under 800lbs wet with only 20"s travel all 4 corners, how could that be? when you set your shocks how much do you give up at normal ride height, like 33% 28% etc etc?

Whats your motion ratio and angle on the shocks. I did a rail with a Mazda rotary mounted mid ship. It had fox 2.0 X 14" air shocks on the rear. They were mounted almost at the end of the arm an laid over to get 20" of travel. They needed 400#'s of air the get it to sit right. We also had to put extra oil in them, I forget how much.
 
A little good info from Todd at Fox (Tinman) http://www.race-dezert.com/forum/showthread.php/82610-air-shock-pressures??

[dsrace]

they were 8.5 fox 2.0, mounted 3"s in from the end and layed over to get 20" travel at the wheel on the front. here is a pic. they did there job and rode pretty smooth with at that pressure. thanks for the link I'll check it out. I also had an 824lb rail with 24" wheel travel with a 10" stroke 2.0 fox of course that had just a touch more psi for the same ride with no limiting straps up front.

[BDKW1]

they were 8.5 fox 2.0, mounted 3"s in from the end and layed over to get 20" travel at the wheel on the front.

There in lies your problem. Way to high of motion ratio. Over 2-1 gets really difficult. Had you used a 10" shock you would have been a lot better of. 12" would have been even better. It's not just the spring rate but the valving also.

[BDKW1]

Oh yeah, fork Fox and King, It's all about the BK Racing shocks......
 

 

 

[fabr]

There in lies your problem. Way to high of motion ratio. Over 2-1 gets really difficult. Had you used a 10" shock you would have been a lot better of. 12" would have been even better. It's not just the spring rate but the valving also.

I gotta agree. We all learn over time tho.   

[tenaja]

they were 8.5 fox 2.0, mounted 3"s in from the end and layed over to get  20" travel at the wheel on the front.

There in lies your problem. Way to high of motion ratio. Over 2-1 gets really difficult. Had you used a 10" shock you would have been a lot better of. 12" would have been even better. It's not just the spring rate but the valving also.

I don't see what the "problem" is here. I've read the whole thread and seen you guys trying to calculate the spring force on the a-arm, but what's the problem?

And I do understand it might get more tricky to valve a shock at high ratios, but rear bike shocks have like a 4:1 ratio, and they are revalved all the time. Is valving them on the high-ratio buggy tricky just because the shock mfr.'s don't have disks with the same resolution (larger difference between each shim) as what's available for a rear shock (small differences between shim sizes)?

[fabr]

I think it's the utter lack of readily available info on HOW to properly tune the things may be more the issue in addition to what you said.

[dsrace]

There in lies your problem. Way to high of motion ratio. Over 2-1 gets really difficult. Had you used a 10" shock you would have been a lot better of. 12" would have been even better. It's not just the spring rate but the valving also.

no problem and that's my point, there was no problem! both of those rode great, it's all in the way you valve them! but at that angle you do need more pressure to set ride height which with more pressure comes more heat, more heat shocks fade but at a 2-1 ratio the shock actually runs cooler that at 1.2 or 1.5-1 in personal experience now on my designs! more wheel stroke and less shock stroke. this may not be the norm but it works when set properly.

those two were origanal designs.  my front ends have changed, the shock is damn near 90* at full bump but I still run a 2-1 stroke!  the shock doesn't get as warm in the fronts only on a rear or mid ship rail!

[dsrace]

I don't see what the "problem" is here. I've read the whole thread and seen you guys trying to calculate the spring force on the a-arm, but what's the problem?

And I do understand it might get more tricky to valve a shock at high ratios, but rear bike shocks have like a 4:1 ratio, and they are revalved all the time. Is valving them on the high-ratio buggy tricky just because the shock mfr.'s don't have disks with the same resolution (larger difference between each shim) as what's available for a rear shock (small differences between shim sizes)?

bottom line is it can be done but you have to start with a quality product with good customer support and a shock that was atleast assembled correct in the first place!   I am only talking about the front ends.   yes it does get more tricky for high ratio's.

[dsrace]

Oh yeah, fork Fox and King, It's all about the BK Racing shocks......
 

never used them, is that a 16" stroke shock?  are they comparable in price? hope it was assembled right the first time!   

[dsrace]

I think it's the utter lack of readily available info on HOW to properly tune the things may be more the issue in addition to what you said.

at this point tuning them is more trial and error but more info would be great!   of course starting with a shock that was properly assembled is a plus!  this was my point in the beginning. I am not saying that fox is better than king in the grand scheme of things just that I believe fox offers more tunability for people such as myself but since I have not tuned king shocks I guess I will never know for sure.

I do have to say this, my rail has 26" of wheel travel using a 10" fox 2.0 and that is why I had to valve it 60/2-1, 70/2-1 would be better with my front end weight, but with an additional 30cc oil it's working and there's room for a 12".  24" with a 10" or 12" stoke is better and easier to tune. staying 2-1 or under is better but playing in the higher relm can be done.  would it work for long distance desert racing, no, does it work for sand and dirt tracks, so far after 3 years. I haven't had it 10' plus off the ground on sand but I have on dirt. landed flat on the other side, 8 consecutive jumps in 2 hours! did I feel it youbetcha! the landing wasn't bad though. solely from personal experience , I would recommend a 2.5 fox for the higher ratios.

the chart that fabbr posted and the math that fabbr and bdwk1 posted will get you to a starting point only (imo) but to find that sweet spot for each individual app takes trial and error!