Author Topic: air shocks fox\kyb.. you got any info?  (Read 13127 times)

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Offline ghostdancing

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air shocks fox\kyb.. you got any info?
« on: December 28, 2016, 04:14:02 am »
i'm tempted by these vintage aftermarket products.. do they work? are they affordable\durable? pros. and negs? looks like it's  a technical way abandoned\aborted today (at least for offroad motorbikes).. at the end why?

availability and prices today?

i remember there was (in the 90s) an italian small factory named double system, that made some nice air shocks (mainly monoshocks for road racer bikes)..it disappeared some years ago.

Offline John Orchard

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Re: air shocks fox\kyb.. you got any info?
« Reply #1 on: December 28, 2016, 09:23:55 am »
I had the KYB air shocks on my KX250A5, they worked good while it was a 250 but seemed underdamped after I fitted the 400 engine.

They have 3-way adjustable rebound damping; with a low air pressure setting, you compress the shock about 1" and then rotate through the three detents.

They have a low strength spring inside them; they work like a set of late 70's air-assist front forks; changing the oil height changes the rate of compression resistance, changing the air pressure changes both ride-height & spring strength (compression resistance).

I thought they looked cool, not sure if they were as refined as Fox air shocks, as I've never sampled them.  I think I would like to have them in my rear suspension options, if I want serious race stuff I'd go for Ohlins.
Johnny O - Tahition_Red factory rider.

Offline Rossvickicampbell

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Re: air shocks fox\kyb.. you got any info?
« Reply #2 on: December 28, 2016, 11:18:31 am »
depends on what you are after - I had a set of Fox Shox - good when set up and "period correct" however are not as good as a set of modern Ohlins or Works Performance.  So are you after looks or are they for a racer???
1974 Yamaha YZ360B
1980 Honda CR250R - Moto X Fox Replica

Offline Momus

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Re: air shocks fox\kyb.. you got any info?
« Reply #3 on: December 28, 2016, 02:30:51 pm »
Fox airs are bloody good. Their period popularity was no accident. They are fully rebuildable with all seals and the bladders easy to get; as is the comprehensive owners manual. Damping is controlled by a Holley main jet so revalving is a $5 diy if you are mechanical. The best thing about them is the ease of spring rate change.                            I have a set on one bike and am looking for another for my RM370 as a test alternative to Ohlins.
If you love it, lube it.

Offline Slakewell

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Re: air shocks fox\kyb.. you got any info?
« Reply #4 on: December 28, 2016, 03:45:53 pm »
In my current range of shocks , I have KYB air / Fox airs / Ohlins and Gazi they all have interesting features that make them different. Probably the best overall shock for all conditions are the Ohlins. Best for MX on my 77 KTM are the fox airs they seem to load the front tire and gives great feed back so you can carry more corner speed plus they resists big impacts better. They are shit on anything else and hopeless at trail ridding or Vinduro. The KYB look the coolest and fall somewhere in between but have no real stand out feature. The gazi are great as they are easy to buy and set up and have the best traction of any shocks I have used, the rear sticks like glue. They do bottom a bit to easy and kick on big braking bumps.They dont give the good front end feel. 
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle

Offline ghostdancing

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Re: air shocks fox\kyb.. you got any info?
« Reply #5 on: December 28, 2016, 05:59:20 pm »
tnx guys for your opinion and experience; i do not race the bike, it's just because i'm searching a new pair of shocks for my bike, and looks like i have anyway to spend big money to get  something nice: i admit that the correct look is one of the main issue for me.

i also have a muffler pipe clearance problem (right side shock upper mount).. do you know the max outer diameter of the shock body (upper finned section)?


Offline LWC82PE

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Re: air shocks fox\kyb.. you got any info?
« Reply #6 on: December 28, 2016, 06:09:52 pm »
Sounds like you have a KLX?. It is do-able but you just need the taller top mounts like this.
Body OD is 68.40mm

« Last Edit: December 28, 2016, 06:13:22 pm by LWC82PE »
Wanted - 1978 TS185 frame or frame&motor. Frame # TS1852-24007 up to TS1852-39022

Offline ghostdancing

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Re: air shocks fox\kyb.. you got any info?
« Reply #7 on: December 28, 2016, 07:06:39 pm »
nice kawi in this pic.. my bike it's an XT250 with a KLX swingarm (twinshock conversion) and IT250 forks; tnx for the info.. probably the KYB are slight smaller diameter? (it looks so in the pics i have seen in the web..)

Offline Lozza

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Re: air shocks fox\kyb.. you got any info?
« Reply #8 on: December 28, 2016, 07:16:22 pm »
The gazi are great as they are easy to buy and set up and have the best traction of any shocks I have used, the rear sticks like glue. They do bottom a bit to easy and kick on big braking bumps.They dont give the good front end feel.

Sounds  like the spring rate is a bit soft and the rebound damping is not right. No front feel means too much weight on the rear end. Tried dropping the forks through 5mm?
Jesus only loves two strokes

Offline Wasp

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Re: air shocks fox\kyb.. you got any info?
« Reply #9 on: December 29, 2016, 06:55:51 am »
This topic keeps coming up on a nearly monthly basis by the same quality posters that either like posting LOL, or have agendas and have lots of time frequenting multiple forums. I composed this information to help the genuine readers, rather than seeking a confrontation with the experts above. I have set a bit of time aside to help form an opinion. . I have been involved in my capacity as R+D technician for nearly 30 years working and /or designing products for Techno Flex, WP, YSS and Promax. I have designed and improved a quiet few new products over those years. http://store.suspensionshop.org/information/   let me say this, it’s easy to knock products anomalously, but it takes knowledge to create a better product in function and price. I formed this philosophy over the many years in my job:
It’s unwise to pay too much
But it is worse to pay to little
When you pay too much, you
Loose a little money


When you pay too little, you
Sometimes lose everything
Because the thing you have bought
Was incapable of doing the things
It was bought to do

The common law of business balance,
Prohibits paying a little and
Getting a lot, it cannot be done

If you deal with the lowest bidder,
It is well to add something
For the risk you run

And if you do that, you will have
Enough money to pay
For the something better.


This is how we create a product:
First we need to know the demand and trend in that market. Then we can look at numbers  that could be sold on an ongoing basis . (There is no point creating a YZ  B/C shock in multiple numbers  for stock ) .
What is needed to improve that model bike? What is the customer prepared to pay and what does the opposition offer .
Then we can choose from different materials and dimensions.
As a sample we use Evo twin shocks. The materials that we have today to choose from are Aluminium verses steel body, Chrome Silicon verses Piano wire, bladder verses dividing piston, ceramic verses sinter and titanium verses steel or aluminium .
For 80% of long twin shocks 12.5 mm hardened shafts work the best. If you go bigger, you get too much friction on the seals and if you go less they can bend the shafts. In order to make a shock externally adjustable, the shaft needs to be drilled all the way through and that adds considerable cost. Not also are adjustable shocks dearer to produce, you also loose valuable stroke and more things can go wrong  So it’s a bit of a trade-off and at the moment adjusters are the inn thing. The most important adjuster is the rebound. That can be done in various ways. The most proven one is a needle and seat with different needle options. You should have at least 30-60 clicks of adjustment to warrant a big enough window. Unless it’s a self-adjusting high-low speed set up, compression adjusters can add a lot of confusion in setting up a bike. For simplicity reasons they are not always great and necessary. But the market wants them sometimes. Correct rebound damping and the spring to suit the rider’s weight are more important to the average user. The best solution for spring preload adjustment is a lock ring on a thread that gives you seamless choices. A fair bit dearer to produce than clips or cams, but much more user-friendly. Now to the old debate of Alum verses steel bore. Aluminium bodies are far cheaper to produce than steel bores with Alum ends. Aluminium bodies weigh a bit less than steel and can be colored with many options for bling reasons. The downside is they have much more friction and wear out in a shorter period. So for long life and better performance a polished steel bore is the answer. Of course the people that can only offer alum shocks, will deny that. We offer both type, but for the right application and price range. But when you do the Dyno test, you can’t argue with the curve. The Dyno curve on a steel body shock is so much better, they fade much later (because with less friction you get less heat and unnecessary wear) Also the oil on a steel body does not get contaminated (no contamination > no wear> longer life)
 “What shocks to buy? “
As customer I would look for
Good quality steel body
Hyme joints both ends (bearings)
Pricing verses features and finishing quality 
VMX shocks , We don't just sell them - I design and produce them individually for you since 1989.

Offline Momus

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Re: air shocks fox\kyb.. you got any info?
« Reply #10 on: December 29, 2016, 02:14:39 pm »
Wasp, what was the point of that post? It is the same pro forma spiel you periofdically regurgitate. What is your professional opinion of Fox airs?
If you love it, lube it.

Offline Wasp

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Re: air shocks fox\kyb.. you got any info?
« Reply #11 on: December 29, 2016, 07:47:47 pm »
Wasp, what was the point of that post? It is the same pro forma spiel you periofdically regurgitate. What is your professional opinion of Fox airs?

Been corresponding with the Author of the post , all clear and sorted . Thank you for input Mamas.
VMX shocks , We don't just sell them - I design and produce them individually for you since 1989.

Offline TT5 Matt

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Re: air shocks fox\kyb.. you got any info?
« Reply #12 on: December 30, 2016, 01:29:21 am »
I found Walter's words of wisdom very informative and good sound advice without the B.S., ive learnt abit more about shocks I didn't know before

Offline ghostdancing

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Re: air shocks fox\kyb.. you got any info?
« Reply #13 on: December 30, 2016, 03:55:47 am »
..here the autor of the post.. actually i'm looking for a good set of shock for my bike as during the building process i bought a set of that cheap chinese piggyback shocks, just to have some correct lenght shocks and carry out\testing the bike; now i need some "real" shocks.

i dont race the bike, just trail riding,  no agressive\hard driving; the bike is also license plated and got front\rear light (they are period correct units..) as she is my daily drive on pavement too (sorry, there are also passenger footpegs: one of the duties of the bike it's pickup the daughter at school).. but they are small and well hidden..

i searched in the shock market for the best compromise: nice "period" look (forgot to mention that she is a beauty..)and  comfort on small bumps are my needs.

asked to gazi (both gazis, australian and thai), falcon, YSS, work performance.. must say that yss looks the most helpful until now.. Walter of course sells YSS shocks, but his technical point of view is very useful for me.


Offline 80-85 husky

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Re: air shocks fox\kyb.. you got any info?
« Reply #14 on: December 30, 2016, 08:37:37 am »
walter will see you right....