Finally blew a fork seal.. Need a couple of questions answered
I have 2003 M1000 adjustable showas on my bike
1) Whats the oil level measurement in mm from top of fork
2) Its it with the fork compressed?
3) Does the spring need to be installed before measuring the fork oil level?
I have a fork oil level tool so and I know its 7.5wt oil for my fork. Just cant remember the above.
Thanks in advance
Make sure to clean the sliders and wet-sand the dings with 1200 paper and WD-40 so the new seals will live longer.
1) 120mm is a good start.
2) Yes, fork compressed.
3) No spring for oil level.
So..this is where I get confused. It seems like they keep changing the spec on us. I was able to look at a factory chart from today when I boughy my fork seals and it say 95mm from top for the M1000. Thats a lot stiffer than 120mm. When I look at the S2R1000 service manual and it says 105mm from top.
What the hell! Arent these all the same fork?
Quote from: EEL on February 23, 2011, 04:29:14 PM
So..this is where I get confused. It seems like they keep changing the spec on us. I was able to look at a factory chart from today when I boughy my fork seals and it say 95mm from top for the M1000. Thats a lot stiffer than 120mm. When I look at the S2R1000 service manual and it says 105mm from top.
What the hell! Arent these all the same fork?
They play with the oil level to avoid bottoming with light springs.
If your bike is sprung correctly for your weight you need less oil.
trust Speeddog.
Shoulda asked before.... what springs do you have, and how much do you weigh?
stock m1000 springs (They are progressive). I weigh 175 w/ gear. I've heard that most bikes are springed stock for 150.
Not sure if it matters but i've probably got about the same amount of weight pulled off from the bike from all the mods.
Wondering if its a wash.
Not if you have clip ons.
No clipons.
Not in a long time. But doesnt sag change w/ fork oil level and preload? . How does that help me set the oil level in the fork?
Quote from: EEL on February 23, 2011, 06:36:43 PM
Not in a long time. But doesnt sag change w/ fork oil level and preload? . How does that help me set the oil level in the fork?
Sag does not change with oil level. It will change with preload.
What we're trying to determine is if you have the correct springs for your weight. If you do then you can safely use the oil level Speeddog gave you.
If you don't, then a lower oil level may cause you to bottom out. If you have a lot of preload on the springs the bike will ride harshly regardless of oil level.
I've got a set of used S4 springs that would be quite a bit better for ya than those stock dual-rate jobbies.
Dont have the bucks for that right now. But i've never bottomed out on the fork yet and ( my zip tie tells me I have about an inch at the bottom) Preload is pretty weak actually. I have about 4 lines showing.
Quote from: EEL on February 23, 2011, 10:05:49 PM
Dont have the bucks for that right now. But i've never bottomed out on the fork yet and ( my zip tie tells me I have about an inch at the bottom) Preload is pretty weak actually. I have about 4 lines showing.
What is your sag number?
You'll never get closer to the bottom of the travel than that with the stock oil level.
I'll measure and get back to you guys.
Rider Sag 39mm. I had set it to 30% of fork travel. Per the M1000 owners manual fork travel was 130mm
Do you typically ride at a spirited pace, or are you a putt-about commuter/long distance tourer kinda guy? That makes a difference, too. If you're one of the latter types you might be as well off with stock or near stock springs and factory oil levels. Do you often ride two-up? If so, you might want to err toward stiffer springs but softer damping, especially on compression.
Most folks I know who ride at a more spirited pace are most comfortable at 25 to 30mm of front end sag for a street ride. I can't imagine needing more than 25mm of rebound for any bike on paved roads! Less is common for the rear. I use 0 to 10 mm.
I concur with Speeddog's fork oil level if the bike is correctly sprung. You won't hurt yourself with the recommended factory settings, but the bike will never handle well with them, either, in all probability. Ducati tend to underspring fronts in my experience, at least for most American (i.e. FAT like me) riders.
Be careful adding spring spacers to hit sag targets. Excessive preload to make the sag work is sometimes worse than riding with the bike undersprung, as it can limit suspension travel if the spring binds.
Ask Speeddog what he want's for the more substantial springs before you decide you can't afford them. They might be really cheap!?!
Cloner
ABQ, NM
OK. I'll start by saying that I'm not trying to be argumentative here. I'm just trying to make sense of these comments
1) Its been said that ducati springs are calibrated for a 150 rider. If I told you I was 120 pounds. Would the stock springs be too stiff?
2) I've been doing some digging (racetech site) suspension gurus say 25% to 33% for fork travel. The higher percentage being for street conditions. Why is everyone telling me otherwise when it contradicts this statement
3) These forks are off a ducati monster 1000. If an m1000 is 416 lbs dry (stock) (per spec manual) and my S2R 800 is 381lbs dry (stock) per spec manual. Then were talking about a 35 lb difference. On the bike.
I have boomtubes and a shorai battery, and pods. That together shaves easily another 10 lbs (Its probably more but I'll be conservative.). Putting the s2r dry weight at probably around 371 lbs.
That's a 45lbs difference between what the forks were sprung for and what they are currently loaded with. Simple question, why is everyone saying they are still undersprung? Its like saying I could be a 120lb rider and I would need to stiffen up the springs. I just don't get it.
I'm sure my thinking is wrong somewhere but I'm one of those people who needs it to make sense in their head first before I move forward. Someone explain where my reasoning is wrong.
Because you're basing your conclusions on propaganda and we're basing our recommendations to you on real world experience.
I'm done now.
Good luck.
I didnt realize racetech didnt know what they were talking about.
Quote from: EEL on February 25, 2011, 02:33:49 PM
I didnt realize racetech didnt know what they were talking about.
You're assuming we don't. I was referring to the Ducati info.
It so happens Racetech has some bad info with regards to Monster rear springs...again from real world experience. The amount of travel to use up with sag is generic and follows the conventional wisdom, but not necessarily gospel...because....\/ \/ \/ \/
Suspension is partially preference. There are many fact You were looking for an oil level originally with no complaint of the way your bike was working.
I don't happen to agree with Cloner about only using 10% of rear travel with sag. If it works for him that's great. I use 25%...it works for me.
There are too many factors that affect suspension for there to be any hard and fast rules...everything is a guideline
I suggest you buy the oil level tool, measure before you take them off to drain them, and set them at the same level.
My 41 mm Showa forks have a 115mm travel. 25% to 33% is 28.75mm to 37.95mm static sag (bike plus rider, accounting for stiction). As I said, I've always used 25mm to 30mm as a baseline.
Your forks you say have 130 mm of travel. That's 32.5mm to 42.9 mm of static sag. If you're more comfortable starting at 32.5mm, feel free. It's your ass.
I gave you numbers I've used for the last 30 years. I believe that anyone I've ridden with would tell you I ride at a rather brisk pace, so I choose to set my suspensions up on the firm side so that I can feel what's happening beneath me. I've also raced bikes since the late '80s, so take that for what it's worth.
Since you're perusing Racetech's website, maybe take their word for it. Column "Front mm" in the answer to question 3 tells you that for roadracing use 25mm to 30mm static sag and for street bikes use 30mm to 35mm. Their 30 to 35mm number is generic, but it falls toward the low end of your percent targets, so what's the problem. These are, as with any suspension set-up, starting numbers. If it doesn't feel right, you adjust (if you know what it's supposed to feel like). The big thing to avoid is bottoming. Topping can generally be avoided via rebound damping on all but the roughest surfaces.
I should have clarified that the 0 to 10mm I recommended for the rear is what the folks at Racetech call "Free Sag", which is bike less rider. (not 10% static sag, Nate....10mm free! I like my bikes stiff, but not THAT stiff! ;D) They recommend 0 to 5 mm for roadrace and street use. They further recommend a static sag (bike plus rider, accounting for stiction) of 25 to 30mm or 30 to 35mm for race and street riding respectively.
If you're into Racetech, call them and have them run a calculation for you and your bike (as they don't have the S2R in their online database). They'll do it free of charge. That will tell you whether your bike is undersprung, oversprung, or correctly sprung! Why guess when the answer can be had for free without experimentation.
I didn't say your bike is undersprung....I said Ducati's are undersprung for fat folks like me. I didn't see where you said you're 120 pounds......Midget. ;D
Have fun. Be careful. If you disassemble your forks, keep everything SQUEEKY CLEAN! Modern cartridges hate grit.
I think you're asking the right questions, for what it's worth. If you don't understand the answers you're given, keep asking questions. Eventually you'll either "get it", or you'll discover that the person answering is full of crap. In this case, I know that DP and Speeddog aren't full of crap, but I also don't believe that the answers you've been given here and the guidelines from Racetech are terribly far apart. I learned most of what I know about suspension from the folks at Racetech, so I trust them more than most folks in that business....again, for what that's worth.
Quote from: Cloner on February 25, 2011, 04:14:50 PM
<snip>
I should have clarified that the 0 to 10mm I recommended for the rear is what the folks at Racetech call "Free Sag", which is bike less rider. (not 10% static sag, Nate....10mm free! I like my bikes stiff, but not THAT stiff! ;D) They recommend 0 to 5 mm for roadrace and street use. They further recommend a static sag (bike plus rider, accounting for stiction) of 25 to 30mm or 30 to 35mm for race and street riding respectively.
<snip>
That makes more sense...but to be honest with stock suspension components I pay more attention to static sag. Lack of free sag is usually only an indicator that static sag has been reached with too much preload, or you're working with a light bike and heavy rider.
Didn't realize this thread was going to get so 'advanced'. [laugh]
At 175 lb geared, you would benefit from proper springs.
Not "OMFG!!! you'll crash if you don't get proper springs!!!" by any means, but you would be better off.
If you were 120 lbs, I'd say the OEM springs are a bit too stiff.
I've had a number of customers in the 200-230 lb range running around on stock suspension.
They weren't crashing right and left.
But the nearly universal feedback after I resprung their bikes was "I wish I had done that a long time ago!".
OEM S4 springs are about 0.86, I'm about 175 geared up and I think they're pretty good.
I have about 3/4" unused travel in normal riding, the roads here in CA are pretty decent.
I like having that amount left unused, it's a bit of a safety margin for a whopper bump.
S2R1k forks have dual rate springs, initial rate is about 0.58, and it jumps to 0.79 at about half travel.
You can get the static sag to a good number, but then you'll not use full travel.
The static sag numbers are guidelines.
Track setups are a bit easier to define, because you're mainly looking at laptimes and tire wear to judge how well the suspension is working.