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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Killroy on December 14, 2015, 08:42:12 AM
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I'm trying to set the front suspension sag to the specified 45 mm and I have the pre-load all the way backed out and still too stiff.
I have had my 2015 SR for a couple weeks and I am finally getting around to checking the suspension settings. I looked up in the manual and the spec for sag is 45 mm, which is about 28% of the travel spec (159 mm). Funny thing is that they said it was 1/3rd. I followed the procedure, turned the red nut on the top fork all the way counter clockwise and I bounced the bike and put my hands and feet on the controls. I have done this before and I have had pros to this, so I think the springs are just too stiff. The sag is probably less than 30 to 35 m. I even put both rebound and compression all the way soft.
When I'm off the bike and its on its kick stand, it is almost topped out, I even pulled up on the front to verify it was all the way topped out. There is about 4 mm of movement, but that it. I have yet to fully suspend the front wheel
When balance the bike and bounce up and down, its mostly rear suspension movement and the fork does not do much.
I'm 160-165 and I put my gear on for the test.
The rear suspension pre-load/sag is good enough at the stock setting (second positions form full soft).
Any ideas? Anyone adjust there suspension?
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I've done a bunch of work to my '14 FX forks - the specifics are different, but the basic principles are pretty much the same. Mine was too stiff, too harsh, and too frictiony-feeling. I've got a thread about it here, and I'm currently working on an update after my latest mods (I'll try to get it posted today). My forks (stock) had 22mm of static sag and 38mm 'race' (loaded) sag. My 1st attempt at new springs gave me 32S / 67R after the new springs bedded in (worked great, but too much sag) and the latest springs measure out at 24S 44R right now, which will likely be 25S 50R in 3 months (exactly what I was looking for). I set these forks up for the dirt, but they work great on the street - I can hear smaller bumps but not feel them, and braking dive is well-controlled for a "long" (really medium) travel fork.
Have you checked out the Pit Bull steering-stem stands? I'm going to get one of them and modify the stem pin if necessary, the way I've been propping my bike up has gotta stop. :)
Pit Bull front end stands (http://www.pit-bull.com/category/front_stands.html)
If I sent my forks out I'd probably have gotten them back with the same or slightly softer single-rate springs, 5W oil, and clicker adjustments. I'm so glad I didn't do that. There's so much stuff available online to analyze and develop new springs to exactly match your needs - plus there's a ton of people that are curious what's going on inside the Zero Showas (I know I am). Let me know if there's anything I can help with.
Ray
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Thanks for the reply. Should I go to the dealer for softer springs?
I put a zip tie around the fork to see how much travel I was using on the 21 mile ride over the Santa Cruz mountains to work and I only used 61 mm (2.4 in). It did go easy today because the roads were cold, wet and looked icy :o. I don't expect to use all the travel on a commute, but maybe 2/3rds.
I use to have pit bull stands. They are beautiful for $180. If I ever have to work on the forks, I will probably just suspend it from a beam in my garage. I would rather put the money into a windscreen and a fast charger.
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2.4" - wow, not much travel at all (mine will use at least 3" if I hit the front brake medium-hard). This thread has the perfect title. ;)
You could try the dealer - if they're the 'can-do' type they might be of some help in finding springs. You might also try Zero (who will probably tell you to contact a suspension place), and even Showa directly (who will almost certainly tell you to contact Zero, but you might get lucky). By far the easiest - but surely not the cheapest - route would be to just send out your forks for respringing and possibly revalving; a good shop that listens to your needs would likely hook you up, for a price.
Since I knew I'd have to disassemble my forks no matter what, I pulled my springs out and measured them, then went online and found out their rate (there are calculators that determine rate from dimensions, number of coils, and material - I just used standard 'spring wire' for that). Once I had dimensions and rate, I looked around the online suspension shops like Race Tech, Factory Connection, Teknik, etc. to see what they had. Another avenue to pursue are Big Four OEM springs; if one of the suspension shops above carries springs in the correct dimensions for your bike but the rates aren't what you're looking for, you could use their application chart to see what bikes used those springs, check their weights / intended applications / travel etc., then use online OEM parts places to gather part numbers and maybe find an OEM set that worked well. I'm sure you know all this already, but I just wanted to put it out there.
AFAIK no one on this planet had what I needed in stock, so I ended up at Cannon Racecraft for custom springs - but you may have better luck with your well-known fork brand.
Can you really suspend a big bike by the triple clamps? Seems a bit tricky to me, but I've never tried it so I don't know.
Ray
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2.4" - wow, not much travel at all (mine will use at least 3" if I hit the front brake medium-hard). This thread has the perfect title. ;)
You could try the dealer - if they're the 'can-do' type they might be of some help in finding springs. You might also try Zero (who will probably tell you to contact a suspension place), and even Showa directly (who will almost certainly tell you to contact Zero, but you might get lucky). By far the easiest - but surely not the cheapest - route would be to just send out your forks for respringing and possibly revalving; a good shop that listens to your needs would likely hook you up, for a price.
Since I knew I'd have to disassemble my forks no matter what, I pulled my springs out and measured them, then went online and found out their rate (there are calculators that determine rate from dimensions, number of coils, and material - I just used standard 'spring wire' for that). Once I had dimensions and rate, I looked around the online suspension shops like Race Tech, Factory Connection, Teknik, etc. to see what they had. Another avenue to pursue are Big Four OEM springs; if one of the suspension shops above carries springs in the correct dimensions for your bike but the rates aren't what you're looking for, you could use their application chart to see what bikes used those springs, check their weights / intended applications / travel etc., then use online OEM parts places to gather part numbers and maybe find an OEM set that worked well. I'm sure you know all this already, but I just wanted to put it out there.
AFAIK no one on this planet had what I needed in stock, so I ended up at Cannon Racecraft for custom springs - but you may have better luck with your well-known fork brand.
Can you really suspend a big bike by the triple clamps? Seems a bit tricky to me, but I've never tried it so I don't know.
Ray
Yeah, I will try Zero direct first since I already have a contact there and if that does not work I will try a local dealer. I looked around Showa's website and did not find anything useful.
I'm hoping that someone reading this thread will be my exact weight and model year SR and they will link me to the off-the-shelf, inexpensive solution that will be air dropped to me. ;D
Yes, you can suspend the front of the bike by the frame to work on head bearings and the front fork instead of using a stand. I have done it before on other bikes.
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Just curious, what oil level are you running in the front forks? You can try reducing the fork oil level 1" if you are only 160-165 lbs.
You would be surprised to know how much the oil fill affects the actual "spring rate" as the spring rate is a combination of the steel spring and the air spring. Oil doesn't compress, air does, so the more oil you have in the fork, the less air. When the fork compresses, the air pressure really goes up to the point it will not allow you to compress the fork the full stroke (for your light riding weight).
Jerry
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Its a stock fork. I'm not sure what the oil level is. Is there any diagrams and specs on the fork.
I did not think that the fork was pressurized or had any air spring.
Zero customer service has still not gotten back to me, but I only emailed twice. I might have to talk to a dealer. Yuck.
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If the spec is 45mm sag and you cannot adjust the forks to that, it sounds like a dealer warranty issue, period. Why should you be paying to modify the bike if it can't be adjusted per the owners manual? I guess the bigger questions is whether all 2015 SR's are the same as your bike--is your bike bad, or is this a 'feature' of this year/model? Fork internals can certainly be defective.
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Its a stock fork. I'm not sure what the oil level is. Is there any diagrams and specs on the fork.
I would think you would have to get a factory manual to help guide you, or you would google how to set the oil level for a USD fork (in general). I am guessing you have worked on suspensions before and know how to do these kinds of things? It isn't too difficult and the info on the internet is very good.
I did not think that the fork was pressurized or had any air spring.
It is not pressurized at rest. But, when the fork compresses, the air [volume] above the oil gets compressed. Here is a graphic of the work when I was setting up the front suspension on my HD XL1200T:
(http://i93.photobucket.com/albums/l80/spacetiger81/Testing%2058_zpsa6kloguh.jpg) (http://s93.photobucket.com/user/spacetiger81/media/Testing%2058_zpsa6kloguh.jpg.html)
The dotted line represented the front fork (single fork leg) spring performance. You can see the max capacity before bottoming out was 214 lbs. When you add the fork oil, you can see the affect of the oil fill height; the more oil you have, the less air you have, so it gets compressed to higher pressures as the fork compresses. The oem level alone raises the max capacity of a single fork from 214 lbs to 275 lbs - a 61 lb or 21% increase.
You can see if you add too much oil and fill to about 74% oil level (just a little over spec) the fork will not fully compress.
Zero customer service has still not gotten back to me, but I only emailed twice. I might have to talk to a dealer. Yuck.
I don't think a dealer is going to be much help [sadly] as they lack setting up suspension knowledge. You have to talk to someone who knows what they are doing. I was trying to help you see there are options without having to spend money. You just be willing to play with the suspension a bit. If you were close to N. Va, I could help you.
[/quote]
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If the spec is 45mm sag and you cannot adjust the forks to that, it sounds like a dealer warranty issue, period. Why should you be paying to modify the bike if it can't be adjusted per the owners manual? I guess the bigger questions is whether all 2015 SR's are the same as your bike--is your bike bad, or is this a 'feature' of this year/model? Fork internals can certainly be defective.
I would think you can set the sag to factory specs but I suspect the issue is at the other end (setting up the suspension for max capacity for a given rider weight). Setting the sag is a matter of getting the preload spacer length correct for the rider weight. Setting up the suspension at the top end is matter of getting the spring rate right for rider weight and setting the oil level appropriately. [/color]
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I'm trying to set the front suspension sag to the specified 45 mm and I have the pre-load all the way backed out and still too stiff.
I have had my 2015 SR for a couple weeks and I am finally getting around to checking the suspension settings. I looked up in the manual and the spec for sag is 45 mm, which is about 28% of the travel spec (159 mm). Funny thing is that they said it was 1/3rd. I followed the procedure, turned the red nut on the top fork all the way counter clockwise and I bounced the bike and put my hands and feet on the controls. I have done this before and I have had pros to this, so I think the springs are just too stiff. The sag is probably less than 30 to 35 m. I even put both rebound and compression all the way soft.
When I'm off the bike and its on its kick stand, it is almost topped out, I even pulled up on the front to verify it was all the way topped out. There is about 4 mm of movement, but that it. I have yet to fully suspend the front wheel
When balance the bike and bounce up and down, its mostly rear suspension movement and the fork does not do much.
I'm 160-165 and I put my gear on for the test.
The rear suspension pre-load/sag is good enough at the stock setting (second positions form full soft).
Any ideas? Anyone adjust there suspension?
Yeah, 1/3 is a general guide for rider sag, that's why the manual says that. They also say that in the manual, "This adjustment is a recommended guideline; personal riding preference may vary from the specifications given."
The manual also says, "The spring preload must be set to match the weight of the rider. The spring is preloaded for an 180 lb (82 kg) rider.". I assume they mean that the spring rate is for a 180lb rider, but my FX came with three turns of preload, so maybe they actually meant the spring rate, plus the three turns of preload. I'm at about 180lb with no gear on, and my FX(I don't know if they've adjusted the spring rates for the different bike weights) only sags about 35mm with the three turns of preload, I haven't tried with no preload.
I actually like the stock heavier spring rate on the Zero, because Jap bike spring rates are usually for 70kg/155lb riders. I also prefer a heavier spring rate, because I hate it when forks bottom out mechanically, and also use the oil height to prevent that.
The manual also says, "Heavier riders require stiffer spring rates.", so they probably also should have said that "lighter riders require lighter spring rates". As spacetiger has mentioned earlier, you could try lowering the oil height, but this might allow the forks to mechanically bottom out harshly if you ever hit something that uses all the suspension travel. I don't know what the recommended oil height is on these Showa forks, but you could start by measuring the stock height, or measure how much oil comes out. Different(fancy) design fork internals also make the procedure different, and more complex too. Fitting some new softer springs could be easier and quicker. Obviously, a suspension shop should be able to get it sorted, if you'd rather have someone else do it. Labor might be around $50-100, though.
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Thanks for your replys. I understand suspension setup setup, but I have not really worked on a motorcycle fork before.
If I had a shop/factory manual, I would be all over it. Anyone have a link to one?
If I dont hear anything form Zero Service, I will contact the dealer to see if they can help. I agree that its a warranty issue, but I imagine that push back on warranty claimed are common.
The front fender color does not match the "tank", I wonder if they would replace that under warranty.
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I highly doubt they'll accept the springs being too stiff for your weight as a warranty issue. It's a common thing for mass produced bikes; they tell you what the ideal rider weight is, and if you're under or over that, you have to pay for new springs.
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I highly doubt they'll accept the springs being too stiff for your weight as a warranty issue. It's a common thing for mass produced bikes; they tell you what the ideal rider weight is, and if you're under or over that, you have to pay for new springs.
Basically, I agree, but the fork is adjustable, and it seems a 165 pound rider should be in the range of adjustment for preload. I have been very happy with the range of adjustment on my 2014 S both front and rear (Fast Ace). Maybe ask if there is another 2015 SR or S on the showroom floor and verify that other bikes have the same sag with minimum preload for you. That would put them on the spot if indeed your bike is different. Maybe you could at least get a discount on the labor to change springs?
I've gotten very fast customer service and shipping from Rich at sonic springs (http://sonicsprings.com/catalog/about.php (http://sonicsprings.com/catalog/about.php)). I imagine the size is in the range that is common to other bikes, you'd just have to supply him with the dimensions (or have the dealer work with him).
How does the bike feel on a rough road? With all adjustments at minimum, it still rides harsh? That's the real test.
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If the spec is 45mm sag and you cannot adjust the forks to that, it sounds like a dealer warranty issue, period. Why should you be paying to modify the bike if it can't be adjusted per the owners manual? I guess the bigger questions is whether all 2015 SR's are the same as your bike--is your bike bad, or is this a 'feature' of this year/model? Fork internals can certainly be defective.
Went to San Jose BMW (local Zero Dealer)
They said if the fork was not locked up or oil was not leaking out, its not a warranty issue. I think like you, if they bike is not to the factory specification and you are not a extreme case (too fat or too thin), then they should be able to adjust to your weight. If not its a design flaw.
I suggested to check the oil height, but they test rode it, said it was fine and told me to go to a local suspension guy, which has mixed reviews.
I'm going to try contacting Zero again, so far I have sent a couple of emails with no returns.
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After calling Zero, and telling them what happened Nicholas the Customer Service Manager emailed me back.
I asked form some suspension specs and instructions so I could DIY.
He said go to a dealer -ha ha.
He did give me some specs on the Showa fork:
SPRING:
FREE LENGTH: 461.5 mm
OUTER DIAMETER: 36.2 mm
STOCK SPRING RATE: 7.4 N/mm
OIL: SS No. 8
OIL LEVEL: 117 mm - Measured from outer tube end to oil surface (Condition: spring, spring joint, spring collar, seat rubber, slider, fork bolt are removed and dust seal touches axle holder)(I asked for a picture or a diagram, but sorry, none was provided)
I suspended the front end and took the top caps off the fork, but it looks like a fork spring compressor is needed, so I'm going to let Evolution Suspension in San Jose do the work and spec softer springs.
I tried to calculate a spring rate for myself, but there are a lot of unknowns like preload, weight distribution, un-sprung weight, fork angle, ect., so I am going to let the pros do it. They probably just guess it anyway.
Anyone know the rough weight distribution? I was going to put her on the scale. I think I read that the SR is hard to wheely stock because of a lot of weight up front.
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Thanks for the info, and the diagram! Nicholas is a great guy, he's helped me out several times.
At a guess (hey, we're Zero owners, that's what we do!), I imagine the SR is close to 50F/50R, and very likely within the range of 45F/55R to 55F/45R. My 2.8 dirt bike is 44F/56R, which is no help at all. :)
If you contact the suspension shop armed with a few numbers and some specific suggestions, they'll probably appreciate it and possibly do a better job for you, regardless of what actually ends up going into the bike. So, for what it's worth - if this were my SR, with the sag numbers and ride quality mentioned previously in this thread, these are the fork springs I'd have made for it:
460mm long, 36.2mm O.D. dual-rate springs: slightly shorter for less preload; I wish I knew what minimum preload Showa uses
Spring travel @ 203mm (8.0"): my OEM FX springs had @ 10.5" travel for nominal 9" fork travel
Initial rate 5.71 N/mm (32.6 lb/in): laden 'race' sag should increase from @ 33mm to @ 45mm depending on preload; static sag TBD
Final rate 7.18 N/mm (41.0 lb/in): this may still be a bit stiff, but will definitely control brake dive
Rate-transition 'knee' 65mm (2.56"): this gives @ 20mm additional upward travel at the initial rate, for more compliance & smoothness
Obviously any or all of these can be tweaked as needed. There might well be something similar available from one of the suspension places too, I don't know.
Showa SS-8 suspension fluid is pretty thick (36.47 cSt @ 40C, at the heavy end of the '10W' oils). Showa SS-7 might work better for you (16.44 cSt).
Ray
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If you need custom springs, I recommend Factory Connection. Using my cr500 for supermoto with my fat butt requires custom wound fork springs. They made me drop in springs for $20 more than the normal in stock. Drooped right in.
I know other places do this too, but they were fast and treated me right. I will buy from them again.
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I went to a local suspension shop and they said that that spring was OK, but the internal pre-load spacer was too much.
So, he cut off 25 mm off the pre-load spacer. Now the total sag is ~40mm which is much better the original 25 mm.
One thing we notice is that fork travel is more like 152 mm (6") that the 159 mm (6.25") that is on the website.
The spring rate is probably suspect too.
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To verify your spring rate, add a ziptie to the the fork tube. Make sure it is snug so it stays in the place it was last pushed too. Once the zip tie is on the fork tube, you push it up to rest it against the upper fork.
Bike sag: lift the front fork off the ground and measure the gap (ziptie to fork gap) created by the front weight of the bike.
Rider sag: Now push ziptie back up the fork, then sit on the bike and raise your feet so all of your weight is carried through the suspension. Then carefully dismount and put kickstand down. Measure the gap (ziptie to fork) created by your weight. Add this gap measurement to the bike sag measurement, this is the total sag. This measurement should be around 25% of the working range of the front suspension. Now that is a rule of thumb, it can be higher or lower than 25%. It depends on what is happening when you are loading up the suspension (upper rend).
Checking the upper end by using the zip tie. After riding, check the location of the ziptie, the gap from the fork to the ziptie. Lets say the measurement is 5". Then you would know the total max travel used was 5" + bike sag measurement. That total measurement should never equal the total suspension travel amount (6", I think based on your posting). If it equal, then you are bottoming out. You would need to increase the preload and see if this keeps you from bottoming out. If you use max preload and are till bottoming out, You will need stronger springs. If you find you are only using 75% to 80% of the max suspension travel, you can reduce the preload spacer length some or you can live with this. If you are only using ~50% or less of the suspension travel, your springs are probably too stiff. You should swap springs to a lower rate spring.
Hopefully, some helpful guides.
Jerry