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[pennjon]

Spoke to a reliable source today  and found out the suspension components would be sourced from a  different supplier in the future.  I can't recall exactly.......... it was either Showa or Kayaba.   He never mentioned  when this would be implemented .   I guess we'll have to wait and see.

[Richard230]

I would be happy if a new suspension supplier was chosen, if only because replacement parts will be easier to locate and maintenance easier to perform.  But I am slowly getting to appreciate the Fast Ace suspension components more than I originally did.  Mine seem to be working better now that they have almost 4000 miles on them.  It seemed to take a long time for the seals to break-in and they are working at least as well as most "name-brand" suspension components do on your typical IC models.  But the forks are still tough to work on to do something like oil replacement and you won't find too many shops that have Fast Ace parts in stock or have technicians with the knowledge to work on them.  So going with the mainstream will probably be an improvement for Zero's customers in the long run.

[NoiseBoy]

I have actually been quite impressed by the fast ace stuff and im comparing to high end WP forks and shock.  Its not as good as that but for cheap eastern stuff it seems to be compliant enough.  I suspect a lot of the finer jolts people experience isnt unusually high stiction but actually that what there is is not being hidden by engine vibration.

[Richard230]

The problem that I have with my 2012 S is that when going around a bumpy corner over 50 mph the bike develops a "hinge in the middle" and starts weaving.  I don't know if this is because of the frame design or because of the suspension components - or both. I would anticipate that the 2013 bike should have greatly improved stability though, due to the improvements made to both the frame and suspension..

[Marshm]

Since weight is so important, especially for electric and dirt riding, I wonder if they will look into the air forks or shocks.  Using air as a spring instead of a heavy steel spring sounds neat if you can make it work.  I thought a couple of the 450's from the major manufacturers went that route already with the forks.  So the technology is already there, but I have not followed it to see if it worked out well or not. 

I do think it is important for Zero to put effort into the bike as well as the electric system.  To truely go head to head with existing motorcycles, you need to have the handling performance comparable.  Looks like the 2013's took a big step to that goal.  I still find it hard to believe they would even try a motor that was not completely sealed up.  That has to be a guaranteed failure.  Maybe it was the best they could do at the time with what manpower they had, or something.  It doesn't inspire confidence that they know about motorcycles though.  Makes me think they live in the sunny climate of S Cal and don't know about things like mud, but they should have sand down there and that can destroy machinery as well as mud.  I even read the battery pack top was open on top on the mx model.  That would quickly fill with water where I ride.  So things like that make me scared to buy one.  The 2013's might be changing my mind, they look more refined, and hey they sealed the motor.  Some engineer on the mechanical side must know what they are doing down there.  So congrats to Zero on making improvements.  New suspension just might have made me put down a deposite since suspension is super important for dirt riding and I have been looking at that FX.  You know what, Zero does make changes, thats impressive how they get it done compared to the company I work for.  So I believe they can and might do it. 

[amahoser]

The problem that I have with my 2012 S is that when going around a bumpy corner over 50 mph the bike develops a "hinge in the middle" and starts weaving. .....

I am NOT a suspension expert by any stretch of the imagination so I can only relate your experience to my personal experience. I have a 2000 Kawaaski Concours that I used to use on long motorcycle camping trips. For those long rides, I load up both saddlebags and top case with camping gear. I also have a huge rear seat bag that gets stuffed. I put a ton of gear for those trips on my bike. If I forget to adjust the suspension, the bike develops a high speed wobble like you describe when I hit a mid corner bump.... even a slight bump. I end up cranking up the preload and rebound adjusters on the rear shock and the wobble disappears. With the bike unload for normal riding, I soften up the settings for a more comfortable ride.

Of course every bike is different and I am sure the suspension geometry has a lot to do with it but if I was in your shoes, I would do a full suspension adjust. Preload CAN be adjusted on your front forks by increasing or decreasing the size of a spacer on top of the fork springs as I do not believe that the ZERO has external preload adjusters on the forks. There are plenty of guides on how to properly adjust suspension on the internet. Either do it yourself or pay a competent suspension shop to do it for you. But I'll bet you can dial out that weave with a bit more rebound damping.

I'll bet that the issue is the rear shock's preload and damping. But I would see if I can adjust both ends so it it proper for your weight and riding style.

Also, check your steering stem bearings. With the front wheel off the ground and the bike centered,  push slightly on one handlebar, let the front end drop to the steering stop. If the handlebar bounces against the steering stop, your stem bearings are loose. if it stops before hitting the steering stop, your stem bearings are too tight.  Also, while the front end is off the ground, slowly turn the handle bar. It should be smooth with no rough spots. If you find a rough spot, it MIGHT be a cable (throttle or brake) or wire harness  hitting something. Try and reroute the cable or wire harness so the action is smooth or temporarily disconnect the offending cable or wire harness... try turning the handlebar again... if there is still a rough spot, your stem bearings may be worn. Usually, the stem bearing wears a rough spot very near the center of the steering arc. You'll need to replace the bearings.

Form my personal experience though, a high speed wobble on bumps can usually be attributed to the rear suspension.  But it never hurts to do a full suspension adjust. If none of those things fix the problem, check your swing arm bearings (remove rear shock  and make sure there is minimal play and that the action is smooth). Even wheel bearings have been the culprit for a high speed wobble.

I've had a couple of bikes with the same wobble on bump issue you described and I have been able to dial it out with suspension settings or bearing preload...

Jose Soriano

[Richard230]

Thanks Jose, I am aware of all of your recommendations.  I have my suspension set to Zero's recommendations for my weight.  I don't think the problem is the suspension settings, but that a frame swingarm bolt, connecting the two sides of the frame at the pivot, does not exist as it does on just about every other motorcycle chassis. Without this connection, I believe that the frame/swingarm junction is subject to bending when stressed side-to-side.  Also the Zero S's geometry is very radical, apparently even more radical than a Triumph sportbike, according to BIKE magazine and its light weight probably doesn't help much either to stabilize the chassis when hitting a bump.  I agree that the steering head bearings could use a little tightening up, but I lack the tool to remove the steering stem bolt that would allow me to access the adjusting ring.  I would like to install a steering damper but I don't know of any aftermarket damper that would work on the Zero's forks. So right now I just slow down when cornering.

However, I do plan to take my bike to one of our local suspension experts and have it adjusted professionally.  That is certainly worth a try and probably won't cost more than $100 for an hour of labor. Adjusting suspension by yourself is very time consuming, not easy and rarely produces good results.

I understand what you are saying about adjusting the rear shock preload, having done a lot of camping touring on my motorcycles, but I don't think that is the problem here as I never carry much extra weight on my Zero.

[BSDThw]

Also the Zero's geometry is very radical,

I test rode the 2012 S and own a DS and it is a big difference. I like the DS geometry much more.

The S tend to wobble, this will only happen at my DS if I have a soft front suspension setting together with load on the back.

My dealer confirmed the nicer DS geometry after he has ridden my DS.

[trikester]

My 2012 DS handles better than my 2010 DS. I expect that my 2013 FX, when I get it, will be an improvement over both of those earlier year's DS bikes and I would think that will go for the 2013 DS as well.

Trikester

[amahoser]

......I understand what you are saying about adjusting the rear shock preload, having done a lot of camping touring on my motorcycles, but I don't think that is the problem here as I never carry much extra weight on my Zero.

What I meant when I brought up my Concours wasn't about carrying extra weight, it was improper suspension settings for the weight. If your damping is set too soft, (especially the rear suspension) that's where I have seen the mid corner weave. Proper Preload will help keep the suspension up in in its optimum position but rebound and compression damping will control that weave. The weave... usually... is your rear shock bouncing up and down after a bump while you are leaned over. Rebound should fix that...

It may be a suspension/swingarm design flaw, but I highly doubt it....

Jose Soriano

[Richard230]

I did get my suspension adjusted by a professional yesterday - see my thread under the 2012 forum.

I was told that the front fork could use more preload (which is something that requires more work than I wanted to do) and that the rear shock could be replaced by something much better to obtain optimum handling. (I think this comment is mostly due to the rebound dial needing to be maxed out on the shock.)

Here are the settings recommended by Zero that I was using and which resulted in a weave when hitting a bump when cornering above 50 mph:

Fork compression: 8 clicks out
Fork rebound: 8 clicks out
Preloaded shock spring length: 141mm (spring free length is 145mm long)
Shock compression: 14 clicks out
Shock rebound: 1 click out

And here are the settings resulting from a visit to the local suspension experts:

Fork compression:  3 clicks out
Fork rebound:  2 turns out
Preloaded shock spring length:  137 mm
Shock rebound: 1 click out
Shock compression:  4 clicks out

I haven't tried any tricky corners yet, but I do note that these new settings make the bike feel more stable when cornering quickly around street intersections, but also make the ride noticeably more harsh over small pavement imperfections.  I guess you can't have  both comfort and good handling.