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[rayivers]

I finally got around to installing the optional Fox shock (Podium RC, Fox P/N 997-03-003) on my '14 FX.  It appears to be a very high-quality unit, and is supplied with bushing sets for both the '13 and '14 FX.  If other Zero models use similar shock mounting methods, this info may apply to them as well.

Removing the OEM FastAce shock was easy, except the top bolt had been installed with an ocean of blue Loc-Tite and was head-snapping tight. I got it out with a breaker bar, but should have used heat and an impact driver instead.  The eye bushings were dry and slightly worn, but not too bad. These bushings also serve as  bearings, with shoulders slightly wider than the shock eyes (unlike the Fox setup where nothing should float).

The swingarm end was no trouble - grease both shock Heim joints per the instructions, install the lower bushings/O-rings, tighten to 38 ft/lb, done.  The mounts, bushings, and eye center were solidly clamped together with no play in any direction.

The top mount was another story.  I slid the top eye into the frame and tightened to the recommended 52 ft/lb, but it still moved when the swingarm was lifted, with a clunking noise.  I didn't like this at all.

The instructions call for "minimal free play, with the clamping load applied across the shock bushings by the bolt". Understanding both these things separately but not combined, I called Fox, who told me both top and bottom mounts should be hard clamps, period, with no play whatsoever.  Zero confirmed this.

I measured my frame opening (1.262") and the Fox bushings metal-to-metal (1.252").  I tried two .004" shim washers (better, but still loose), then a very tight-fitting .010" washer which gave a hard clamp at 52 ft/lb, but not at 48 - I bet it will loosen up eventually. The top bolt is a class 10.9, 55 ft/lb max.

This design relies on a small amount of 'crush' for proper tightness, but one look at that frame area makes it pretty clear what kind of force is needed to do that, even with a shim (I doubt I'm getting .002" of crush right now). A 12.9 bolt can do 63 ft/lb and there's over 30mm of extra unused threads for a 10x80 or 10x90 bolt, I may have to go that route if this thing loosens up.

Ray

[Richard230]

Thanks Ray.  That is good information.  If we get enough of these posts we eventually will be able to write our own service manual.   

[rayivers]

Hey, no problem - glad to help if I can.  I usually take a lot of notes when I do stuff anyway, but I feel the Zero info really needs to be shared in light of the no-manuals situation.

It would be interesting if a late-model Zero owner - perhaps one already doing substantial work to the bike anyway - were to strip it down to the frame while another caught everything on HD video.  It would take a lot of work to do and then convert the raw footage into a decent manual, but what a desirable item that would be!  Nothing proprietary, of course - just simple disassembly/assembly.  Since no dealer/NDA relationship exists I don't think it would be a problem, but I'm certainly no expert.

Ray

[rayivers]

Here's a few more details about the Fox shock I forgot to mention, in case anyone's interested - I don't think much (if any) of it's available on the Web:

Eye-to-eye length:  324mm / 12.75"
Reservoir offset angle (Fox calls this 'clocking'): 242° CW / 118° CCW from 12 o'clock
Reservoir offset width from shock centerline: @ 90mm max
Spring: Eibach, @ 500 lb/in single-rate, 8.0" long, 1.88" I.D., (Fox P/N 039-29-213)
Adjustments: Rebound (13 clicks), high-speed compression (24 clicks), low-speed compression (24 clicks), spring preload

I rode it a bit on the street today.  At the recommended initial settings (all 12 clicks CCW from full stop) there's almost no rebound damping, which I'd expect as it's nearly minimum.  The spring feels softer than the OEM 475-585 lb/in spring for the same sag setting, which was great news for me as I only use one battery and weigh 170.

I asked the Fox guy about rebuilding, revalving, and custom springs, and was told to contact Zero each time.  This was NOT what I expected, as a major reason I bought the shock was to have something with support from a big-name US OEM instead of the say-what? FastAce situation.  I guess a suspension shop that handles Fox stuff could do it.

Ray

[Justin Andrews]

Hey, no problem - glad to help if I can.  I usually take a lot of notes when I do stuff anyway, but I feel the Zero info really needs to be shared in light of the no-manuals situation.

It would be interesting if a late-model Zero owner - perhaps one already doing substantial work to the bike anyway - were to strip it down to the frame while another caught everything on HD video.  It would take a lot of work to do and then convert the raw footage into a decent manual, but what a desirable item that would be!  Nothing proprietary, of course - just simple disassembly/assembly.  Since no dealer/NDA relationship exists I don't think it would be a problem, but I'm certainly no expert.

Ray

So, basically a Haynes manual...

[rayivers]

So, basically a Haynes manual...

Yes, pretty much, except no motor & electronics internals.  One of my favorite manuals is a Haynes.

I think Haynes and Clymer may have merged - the Clymer web site uses Haynes E-mail contact addresses.

Ray

[m0t0-ryder]

I asked the Fox guy about rebuilding, revalving, and custom springs, and was told to contact Zero each time.  This was NOT what I expected, as a major reason I bought the shock was to have something with support from a big-name US OEM instead of the say-what? FastAce situation.  I guess a suspension shop that handles Fox stuff could do it.

Ray

If you want suspension tuning for your Zero it is highly recommended to go to a motorcycle suspension shop.
They are in the business of fine tuning bike suspension... irrelevant of make/model.
Find a shop that local racers use and give them a call.

[rayivers]

Find a shop that local racers use and give them a call.

I'll do that.  Hopefully it will work fine as-is, since the spring seems to be pretty close.

Ray

[m0t0-ryder]

You have done a nice job informing on specs and installation of the shock.

I haven't seen anything on suspension setup though. That's why I suggested finding a suspension dealer/shop.
BUT... there are some things you can do to your suspension that may allow you to set it up "for you" before going to a shop and paying their rate.

Every bikes suspension should be set up / optimized for it's owner and riding requirements.
This all starts with setting the sag.
The followed by compression and rebound settings.
Way to much to go into here  but I can provide some links that may help you out with more detail.

Here's some good info from an Aussie company - Your Suspension Shop.
Link --> http://www.suspensionshop.org/tech_suspension_setup.php

Here's a link to Sport Rider on suspension setup.
Link --> http://www.sportrider.com/tech/sportbike-suspension-guide

If you want hard copy here's a nice book from Amazon by Andrew Trevitt (of Sport Rider).
Link --> http://www.amazon.com/Sportbike-Suspension-Tuning-Andrew-Trevitt/dp/1893618455

Good Luck and Good Riding!

[rayivers]

Thanks for those links!  I'm familiar with YSS as I have their G-366 shocks on my 'CR175' bike, and I'll be picking up a Motool Slacker to set up my Fox shock.  As soon as I find some settings that work well I'll post them.

Ray

[rayivers]

A few updates...

As expected, the top of the shock started moving around in the frame & making a clunking noise after ten rides or so.  I replaced the top bolt with an M10x80 12.9 socket-head bolt & two .075"-thick washers (one stainless, one OEM, both coated w/anti-seize) plus a new .010" shim washer between the shock & frame. This bolt/washer setup has about 9mm more thread engagement and the bolt's unthreaded section runs almost to the frame threads, which is about as good as it gets.  I torqued it to 60 ft/lbs - bolt max is 63 - and I'll hope for the best.

The Motool Slacker is amazing!  The remote display makes it very easy for one person to set both the static & race sag (in the riding position), either front or rear (haven't done the front yet). I was wrong about the Fox Eibach spring being close for my 2.8 FX, as it's clearly intended for the 5.7.  I was able to set 30mm of static sag (ballpark OK) but only 72mm of race sag (not nearly enough) at minimum preload.  I believe a 300-500 lb true-progressive spring would be best for my situation, and I'm currently working on some custom spring options and will update if they pan out.

Despite the incorrect spring, I was able to get some fairly decent results under hard acceleration over stutter bumps, decel and cornering not so much. My current settings are rebound 9 clicks CW, high-speed compression 6 clicks, and low-speed compression 11 clicks.

Ray

[Manzanita]

Ray,

I'm curious how you would compare the original FastAce shock to the Fox shock as far as performance. Was the Fast Ace fully adjustable? What about it made you unhappy?

I'm pretty happy with the Fast Ace suspension on my 2014 zero S, but dirt bike riding is definitely more demanding. I had it dialed in by Catalyst Reaction in San Carlos, although I needed to loosen up the rear from their settings to improve the small bump absorption.

Actually, my thought on a aftermarket shock would be just to experiment with lowering the rear and increasing the front rake. The rake is so steep, I'm guessing that the rear can be lowered significantly (30-40mm) and it might improve the handling. So maybe get a cheap ebay shock that is shorter just to see how the swap changes the handling.

It's pretty funny. I used to  have older bikes that were taking up all my time, now I'm looking for things to play around with...

[rayivers]

My impression of the '14 FX FastAce suspension - both front and rear - is that it's sprung for the 5.7 (@ 280 lbs) and a 200+ lb. rider, with damping to match.  In addition, the range of the damping controls is quite narrow.  In the dirt the rear would kick and pack on stutter bumps no matter how I adjusted it, and I would find myself coming into corners too hot and on the front wheel.  I still have the FastAce stuff on my street-only FX and the front of the MX bike, and I'll definitely be trying to improve it as much as possible.  The 43mm forks are rigid and move freely, they just need spring & damping work for my particular needs.

IMO the Fox shock needs no improvement, only a different spring for my situation; it would most likely be perfect as-is for a 5.7.  The adjustments affect what they're supposed to, and their range is very wide.  When the new spring gets here I'll be adding in a bit more race sag to slow the front end down a bit, and reduce the anti-squat force.  I'm also considering a steering damper down the road, after the suspension's sorted.

I've seen some epic fails with the eBay-shock approach, and I would especially not recommend it with the FX's PDS-type setup and very tight clearances up top, plus the clamping issues mentioned earlier in this thread.  It would be nice to have adjustable shock length, but adding a little sag is nearly as good for small changes.

Ray

[rayivers]

I got the new spring, and took it for a test ride yesterday.  What a difference! On the street the rear end just soaks up most bumps rather than pounding into them like before, and in the dirt - wow.  More traction, less wheel hop during acceleration and braking, power slides much easier, and an in-control feeling rather than always on the edge.  It also bottomed (softly) a few times on the worst square-edge stuff, which it never had before - it's good to know I'm finally using all 9" of travel.



The spring is supposedly a triple rate (dual-knee) progressive, 350-450 lb/in.  It looks / feels more like a dual-rate to me, but I don't know for sure.  Sag is now 36mm (static) 92mm (race), much better than the 30/72 with the Fox Eibach 500 lb single-rate spring.  The OEM FastAce shock sag for my 2.8 FX is 22/68 w/1mm preload, which feels like a rock compared to this new setup.

I made up an .012" stainless shim to replace the .010" shim washer. I bent a lip into the front so the shock would pull it in with it, which worked great:



The 12.9 top bolt was again torqued to 60 ft/lb (the threads / frame / washers all looked fine).  The bolt was very hard to get out - 15+ seconds with the impact gun - so I replaced it just to be safe.  I don't think it really needs that much torque with the new shim, but I'd rather it be a bit too tight than loose and chafing.

Ray

[rayivers]

Just a quick update on settings, which I've been using for a while now:

Rebound: 8 clicks CW fm full CCW

Low-speed compression: 8 clicks CW

High-speed compression: 7 clicks CW

A couple of things I've noticed about the Fox shock:

1) Settings below 5 - 6 clicks CW result in little or no damping

2) It seems this shock is set up so that using the same number of clicks in all 3 adjustments works pretty well together.
    Now I try the same number setting in all 3 clickers 1st & then fine-tune as needed, which really simplifies things.

Ray