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zooman72

"Budget" fork options - cost/ benefit analysis?

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zooman72

Ok, picked up a 2015 FZ 07 back in June after riding one again for a local Yamaha demo truck event (3 year in a row).  Wanted a change of pace from my 2012 Stryker (still love it and keeping it), and having just turned 46 (with almost 30 years of riding), I wanted to ride something sporty again before I get too old (lots of sore spots anymore, with new ones every year).  Love the bike, with the 2 obvious exceptions: engine braking and front suspension/ fork dive.  Promised the wife I would keep this latest bike and its upgrades within a certain budget, so I am working within a certain framework.  Bike came with stock exhaust and an EJK, but still too much engine braking for me, so I will get it flashed (probably by Hordpower) shortly - this is the easy decision, and not too expensive.  The bigger (and more annoying, honestly) issue is what to do with the front forks and the pathetic brake dive.  I mostly ride to commute to work and bomb around the Erie Canal here in Western New York.

 

Added preload caps from Ebay, set to an additional 15mm of preload, and with the rear shock preload at position "7", the ride is actually not too bad - for reference, I am 6'1" (185cm) and around 215 lbs (98 kg) in gear.  I am around 1.5" (38mm) of "sag" front and rear I think - difficult to be precise without a "helper".  I know from copious amounts of reading here (seriously, like 2 weeks worth) that I probably "need" new fork springs (0.95 kg/mm), and that, coupled with new "thicker" fork oil, would be the lowest cost option. 

 

I guess it comes down to 3 things, keeping in mind I simply want to greatly reduce the brake dive up front:

1. Can new springs and fork oil be done without removing the forks?

2. Does anyone have a simple fork oil recommendation for my specs (i.e. "just buy this brand and weight")?

3. Would it be "necessary" to also use the Cogent DDC's to get what I want?

 

Option 1 is obviously only around $100, but I would probably have to grab a front triple tree stand (and 21mm pin) for an additional $80 or so - did the preload caps with the bike jacked up on a 3-ton car jack and make-shift plank, and almost lost it to gravity.  I have not come across a thread where the front fork oil was replaced with the forks still on the bike, so I am afraid that it is not possible/ advisable, but wanted to check.  With this being my first sport bike in 2 decades, I am not sure I will "need" or appreciate what an additional $100-200 or so will get me, and want to keep it simple and inexpensive.  I am also looking into an inexpensive exhaust option (it is too weird and quiet coming off my Stryker with V&H pipes), with the possibility of the K-Tech Razor Lite rear shock next spring, and the wife is getting suspicious - although it probably doesn't help that I keep my notes in view on my desk at home!

 

OK, so all that said, in addition to Matt@pattonme, Zoran@TWF, and Terry@Norwest, any advice/ words of wisdom from the assembled crowd?  Sorry in advance for yet another fork/ front suspension thread, but I selfishly wanted a bit of specificity...

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mossrider

Having owned and tried to maintain and ride as many as 15 clunker bikes at one time I used to cut some corners at times to save time and money. I have put springs in forks after syphoning off as much fluid as possible and replacing it with the same amount of whatever fluid I wanted to run.  This can be done with the forks in place generally. 

 

Disclaimer: While not ideal it works. I know there are better ways and I'm not endorsing not using professional assistance or established practices but you asked. 

 

P.S. I'd take the forks off and do emulators too and get rid of the damn toilet paper rolls on the fork tubes. Just sayin.

 

Edited by mossrider
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zooman72
2 hours ago, mossrider said:

Having owned and tried to maintain and ride as many as 15 clunker bikes at one time I used to cut some corners at times to save time and money. I have put springs in forks after syphoning off as much fluid as possible and replacing it with the same amount of whatever fluid I wanted to run.  This can be done with the forks in place generally. 

 

Disclaimer: While not ideal it works. I know there are better ways and I'm not endorsing not using professional assistance or established practices but you asked. 

 

P.S. I'd take the forks off and do emulators too and get rid of the damn toilet paper rolls on the fork tubes. Just sayin.

 

Thanks for the reply mossrider - and no need for the disclaimer, as I know I am pushing it with regards to what is ideal vs. "quick and dirty".  I was wondering if I did siphon off as much of the OE fork oil and then replace it, would it be necessary to prime the damper rods?   While I have owned several motorcycles, I have never altered front forks, and I don't know what I don't know - i.e. ignorance so far has been relative bliss.  Mind you, it has been 2 decades since I owned a sportbike, and only riding cruisers, where my weight was a better match for the components.

 

Also, I have read here that the Cogent DDC's are "better" than emulators, and would honestly only add them if the spring and oil swap was not sufficient enough to reduce the brake dive to acceptable levels.  When riding other bikes back in May and June before I bought the FZ 07, I never noticed the brake dive as such a stark concern - riding an R3, Ninja 400 & 650, FJ-09, Z900rs, etc.  That and the engine breaking really bother me now...

Edited by zooman72

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mossrider
Just now, zooman72 said:

Thanks for the reply mossrider - and no need for the disclaimer, as I know I am pushing it with regards to what is ideal vs. "quick and dirty".  I was wondering if I did siphon off as much of the OE fork oil and then replace it, would it be necessary to prime the damper rods?   While I have owned several motorcycles, I have never altered front forks, and I don't know what I don't know - i.e. ignorance so far has been relative bliss.  Mind you, it has been 2 decades since I owned a sportbike, and only riding cruisers, where my weight was a better match for the components.

 

Also, I have read here that the Cogent DDC's are "better" than emulators, and would honestly only add them if the spring and oil swap was not sufficient enough to reduce the brake dive to acceptable levels.  When riding other bikes back in May and June before I bought the FZ 07, I never noticed the brake dive as such a stark concern - riding an R3, Ninja 400 & 650, FJ-09, Z900rs, etc.  That and the engine breaking really bother me now...

After replacing what oil I could with forks in place, I spooged the tube slowly a couple strokes before buttoning it up then forcefully a couple times before riding off to make sure nothing binds or bonks. This will also serve to prime the dampers as you say. Of course the fluid is a mix of old and new, 10 and 20wt what ever but for day to day use it won't matter and you can do another fluid change whenever you want, it's virtually free in this fashion to keep fresh fluid in them. 

 

As for emul's. I've no first hand experience with the ddc's but they appear to be of similar construction and function to those I do have experience with, half dozen sets of Gold Valves and several sets of Chinese knock offs. Pick your favorite and go with it. I know the GV's are top notch, the knock offs were ok, I hear good things about the ddc's.  Of course the forks need to come off for installation and modification. Get help here if you've never pulled a fork apart unless you are patient and capable with hand tools.

 

The engine  braking. Apapt to it or get used to it. A flash will help but costs money. A slipper clutch virtually eliminates it but costs big money.  I learned to rev match and delay downshifts, or in other words adapted to it. Costs nothing.

 

The front end dive gets much better with a fork upgrade. Much of the diving problem is softly sprung and under damped rear shock allowing the rear to rise and over pitch on the brakes. Upgrading the shock finishes the fix, as it were.  Just understand that cheap means good enough and top shelf costs money.

😊

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zooman72

I am leaning towards swapping out the fork oil without removing the forks, just have to find the right tool to remove the oil easily - might be a bit tedious with the commonly available fork oil-level syringe.  Currently looking for another syringe-type tool that will allow me to track how much I am removing, so that I can put that same amount back, just in a different viscosity.

 

The DDC's are $180, so not exactly "cheap" or "budget", and I am questioning whether I need them to realize full anti-dive properties in the fork or not - they do seem to be relatively easy to install though.  I do agree that replacing the rear shock will also help the front, but it is just not in the early budget.

 

The Hordpower flash is "only" $225, and I was thinking of selling the EJK to recoup some of that.  I had my Stryker flashed thru Ivan's Performance Tuning, and it was/ is an excellent improvement for that bike, so I am already "sold" on the flash, plus it should help with a bit of front end dive by easing the off-throttle transition (i.e. delete the closed throttle fuel cut). 

 

My grandfather was a mechanic and an engineer (military-trained), and while a little bit rubbed off (I can do quite a bit I guess), I am only looking to do enough to improve my daily commute comfort.  If money and time were no object, I would simply spend $400-$800 in parts (front fork only - plus a kick-ass rear shock) and pay a local, qualified mechanic to install, or send it off to Matt.  Then again, if money were no object, I would be riding a Ducati X-Diavel and Monster, plus a few others come to mind...  :)

 

Thanks again mossrider, I appreciate the advice and comments...

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djfz07

I'd suggest just removing the front forks for oil change/spring swap.  It's really not difficult at all.  I've recently pulled my forks a bunch of times installing an Ohlins cartridge kit and experimenting with spring rates and oil levels.  Fork removal is a 5 minute job for me now.  Much easier to work on the forks, get most of the oil out, and you can be accurate with the oil level.  Also easier to pump the fork to prime it with the new oil.  Not sure what the factory oil level is (I think they go by fluid volume than level) but I'd just measure it before you dumped the oil.  I use a Motion Pro fork oil tool.  https://www.amazon.com/Motion-Pro-08-0121-Fork-Level/dp/B000GZPCYI

 

 

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zooman72
1 hour ago, djfz07 said:

I'd suggest just removing the front forks for oil change/spring swap.  It's really not difficult at all.  I've recently pulled my forks a bunch of times installing an Ohlins cartridge kit and experimenting with spring rates and oil levels.  Fork removal is a 5 minute job for me now.  Much easier to work on the forks, get most of the oil out, and you can be accurate with the oil level.  Also easier to pump the fork to prime it with the new oil.  Not sure what the factory oil level is (I think they go by fluid volume than level) but I'd just measure it before you dumped the oil.  I use a Motion Pro fork oil tool.  https://www.amazon.com/Motion-Pro-08-0121-Fork-Level/dp/B000GZPCYI

 

 

Yeah, I have been going back and forth on this issue, and am slowly coming around to (or the resignation of) the fact it would be better to take them off and completely change out the oil.  Checking Matt's chart on oil viscosity, it appears that Maxima 15W fork oil will provide 46 cSt@40C, which is close to recommended via the "front fork sticky" in this subforum, and it is readily available locally.

 

I guess that leaves me with two remaining issues: 

 

1.  Do I go with 0.92 or 0.95 kg/mm springs?  I am 208 lbs lately, so 215+ lbs in gear, and not all spring brands are available in 0.92 kg/mm.  I keep reading that going from 0.87 to 0.92 may not be worth it, and yet some of the spring rate calculators recommend 0.90!

 

2.  Do I "need" to include the Cogent DDC valves, seeing as I am looking to only greatly reduce brake dive at this time?  I have noticed an improvement in reduced brake dive (although not enough) with just the preload caps, but cranking them up enough to reduce dive significantly reduces sag too much, and also reduces ride quality of course...

 

Thanks for the advice, and I intend to use a fork oil level "gauge".

Edited by zooman72

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djfz07

I'm 6/2, 220 lbs with gear and I'm currently running a .95 and .90 (effectively .925) spring with zero preload and my sag numbers are just within spec (slightly less than I'd prefer for the street at about 32mm in the front).  I'm playing with the idea of running slightly softer springs with added preload just so I can tune it to get in the 35-40mm range for the street.  In regards to brake dive, it's reduced so much that it's not really an issue.  The dive is still there, but it doesn't feel like it's slamming forward anymore.  Tested this with the compression setting set to zero so it was mainly the spring alone resisting the braking force. Adding compression helps to slow the motion further. 

 

I don't have any experience with the Cogent or Gold valves but I've heard they're a good alternative to full cartridges.  

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zooman72
6 hours ago, djfz07 said:

I'm 6/2, 220 lbs with gear and I'm currently running a .95 and .90 (effectively .925) spring with zero preload and my sag numbers are just within spec (slightly less than I'd prefer for the street at about 32mm in the front).  I'm playing with the idea of running slightly softer springs with added preload just so I can tune it to get in the 35-40mm range for the street.  In regards to brake dive, it's reduced so much that it's not really an issue.  The dive is still there, but it doesn't feel like it's slamming forward anymore.  Tested this with the compression setting set to zero so it was mainly the spring alone resisting the braking force. Adding compression helps to slow the motion further. 

 

I don't have any experience with the Cogent or Gold valves but I've heard they're a good alternative to full cartridges.  

Interesting, and your experience/ insight is much appreciated - thanks!

 

3 questions:

 

1.  Are you running the firmer springs with stock oil, or did you swap it out for thicker?  The reason I ask is that I assumed that I would have to increase viscosity as previously noted/ advised  in the front fork "sticky", but I like to ride through November here in WNY, and it is below 40 degrees F in the mornings.  I am concerned the thicker fork oil at that temp will be slightly problematic in the late fall, and was wondering whether it would be worth it to go with much thinner oil and the Cogent DDC's.  The nice thing is that I still have the option of trying springs first (with or without new oil), see what it feels like and how it acts when braking, and adjust.  Adding the Cogent DDC's (and thinner oil) would not be difficult to install later if I did not like what the springs/ oil did alone - I was hoping someone already went through this scenario (i.e. piecemeal change), and they may have and I skimmed over it....🤔

 

2. Are you stating that you are having issues obtaining proper sag with the 0.925 spring rate?  I already have the preload caps, so can probably "survive" the 0.925 rate being a little "light" - and I am assuming that when you state "zero preload", you are referring to "zero additional preload past O.E".  I am also failing to find 0.925 rate springs, even though I could have sworn I saw them previously, so unless I mix two springs like you did, this would be a moot point I suppose, but possibly significant... 🤨

 

3. When you are referring to "compression setting set to zero" - do you actually have preload caps installed, or something else?  I also though most preload caps available to us impart some measure of preload over stock, usually 7-10mm, and so even with them backed out all the way, there would still be more preload then just the plain fork caps offered with the spacers below....

Edited by zooman72

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FZ07R WaNaB

My forks were set up by Matt which included him wrenching on my bike too. I initially had .90 springs with a mixture of 10w and 15w oil. For a brief time I had Bitubo cartridges which didn't work out well, so I went back to conventional springs but this time I went with a .90 and a .95 and the oil combo. This has been the perfect setup! The ride over both small and large bumps is dramatically better than both stock or the .90 springs. You will not have to worry about dive either. For the combo of the oils, you might want to ask Matt but it was close to 50/50.

 

Having seen the forks removed 3 times, I will be the first to say, that it's no big deal at all. You just need a headlift front stand and a fork oil level guage.

 

 

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topazsparrow
1 minute ago, FZ07R WaNaB said:

My forks were set up by Matt which included him wrenching on my bike too. I initially had .90 springs with a mixture of 10w and 15w oil. For a brief time I had Bitubo cartridges which didn't work out well, so I went back to conventional springs but this time I went with a .90 and a .95 and the oil combo. This has been the perfect setup! The ride over both small and large bumps is dramatically better than both stock or the .90 springs. You will not have to worry about dive either. For the combo of the oils, you might want to ask Matt but it was close to 50/50.

 

Having seen the forks removed 3 times, I will be the first to say, that it's no big deal at all. You just need a headlift front stand and a fork oil level guage.

 

 

My buddy and I just took for the forks out this weekend, we just hung it off the ceiling with some tie down straps. Works good.

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djfz07

I'm running the Ohlins NIX-22 cartridges (compression valve modified by pattome).  It's adjustable for compression, rebound, and preload.  With the .95 and .90 springs, I have the preload adjusters all the way out and my front sag is right about 32mm.  I'm happy with how the bike feels but I'd like to try a softer spring to get my sag in the 35-40mm range. 

 

This setup would be very different than what you're planning but I wanted to give you an idea of what the spring rate feels like as we are close in height and weight.  Having ridden the bike with the compression turned all the way out (almost no hydraulic help from the compression valve) the brake dive was much better than stock. Maxima 5w is the fluid I'm using but it's what was recommended by pattonme for my specific setup. 

 

 

 

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zooman72
22 minutes ago, FZ07R WaNaB said:

My forks were set up by Matt which included him wrenching on my bike too. I initially had .90 springs with a mixture of 10w and 15w oil. For a brief time I had Bitubo cartridges which didn't work out well, so I went back to conventional springs but this time I went with a .90 and a .95 and the oil combo. This has been the perfect setup! The ride over both small and large bumps is dramatically better than both stock or the .90 springs. You will not have to worry about dive either. For the combo of the oils, you might want to ask Matt but it was close to 50/50.

 

Having seen the forks removed 3 times, I will be the first to say, that it's no big deal at all. You just need a headlift front stand and a fork oil level guage.

 

 

OK, that is two members here with mixed springs - thanks for the info!  What is your weight in gear if I may ask?  I am planning to grab a Venom headlift stand, and will have to reach out to Matt to see what he advises, and if I can grab the spring and oil from him.

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zooman72
26 minutes ago, topazsparrow said:

My buddy and I just took for the forks out this weekend, we just hung it off the ceiling with some tie down straps. Works good.

Thanks for the advice though, but unfortunately I don't have a good spot to hang the front of the bike from.  I was thinking I might try the jack stands under frame sliders trick, but with a Venom stand under $70 (plus $8 for the 21mm pin), I might as well "spring for it"....😆

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zooman72
24 minutes ago, djfz07 said:

I'm running the Ohlins NIX-22 cartridges (compression valve modified by pattome).  It's adjustable for compression, rebound, and preload.  With the .95 and .90 springs, I have the preload adjusters all the way out and my front sag is right about 32mm.  I'm happy with how the bike feels but I'd like to try a softer spring to get my sag in the 35-40mm range. 

 

This setup would be very different than what you're planning but I wanted to give you an idea of what the spring rate feels like as we are close in height and weight.  Having ridden the bike with the compression turned all the way out (almost no hydraulic help from the compression valve) the brake dive was much better than stock. Maxima 5w is the fluid I'm using but it's what was recommended by pattonme for my specific setup. 

 

 

 

Ah, that makes sense now, thanks for clarifying, and color me jealous....

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pattonme
On 8/11/2018 at 8:22 PM, zooman72 said:

Added preload caps from Ebay, set to an additional 15mm of preload, and with the rear shock preload at position "7", the ride is actually not too bad - for reference, I am 6'1" (185cm) and around 215 lbs (98 kg) in gear.  I am around 1.5" (38mm) of "sag" front and rear 

 

I guess it comes down to 3 things, keeping in mind I simply want to greatly reduce the brake dive up front:

1. Can new springs and fork oil be done without removing the forks?

2. Does anyone have a simple fork oil recommendation for my specs (i.e. "just buy this brand and weight")?

3. Would it be "necessary" to also use the Cogent DDC's to get what I want?

 

If it's worth doing, just do it right. Use an A-frame ladder and some straps and hang the bike by the frame for handlebars if you're really desperate. Otherwise buy a set of stands.

 

1. no, not really and anyway you want those new, properly  sized bushings, right?

2. https://sites.google.com/site/forksbymatt/resources/oil-list pick something between 36-46cSt@40. When it gets cold you'll probably want something at the low end of the range, if it stays hot (SCal, AZ, TX etc) the higher end.

3. no. First try the oil and opt. spring change. If it's not to your liking then you can spend more money.

 

You have about 0.88kg/mm springs so at 215lb you can still get away with using them. What is your bike sag? Are you really using the stock spacers un-cut with the new caps? How thick are the new caps from the base plate to the underside of the lip? Cutting the OE metal spacer is a PITA, so just go get some 1" PVC from the hardware store and you can experiment easily and cheaply.

 

The NIX-22 comes with about 10mm (7+) of built-in preload. So I guess @djfz07 will want a set of 9's. You can get 0.92kg/mm springs, it's called 9.0N/mm and european sources generally mark them as such. Mixing neighboring rates is just fine. In your case maybe you install one 0.95kg/mm and a stocker if you like.

Edited by pattonme
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zooman72
4 hours ago, pattonme said:

 

If it's worth doing, just do it right. Use an A-frame ladder and some straps and hang the bike by the frame for handlebars if you're really desperate. Otherwise buy a set of stands.

 

1. no, not really and anyway you want those new, properly  sized bushings, right?

2. https://sites.google.com/site/forksbymatt/resources/oil-list pick something between 36-46cSt@40. When it gets cold you'll probably want something at the low end of the range, if it stays hot (SCal, AZ, TX etc) the higher end.

3. no. First try the oil and opt. spring change. If it's not to your liking then you can spend more money.

 

You have about 0.88kg/mm springs so at 215lb you can still get away with using them. What is your bike sag? Are you really using the stock spacers un-cut with the new caps? How thick are the new caps from the base plate to the underside of the lip? Cutting the OE metal spacer is a PITA, so just go get some 1" PVC from the hardware store and you can experiment easily and cheaply.

 

The NIX-22 comes with about 10mm (7+) of built-in preload. So I guess @djfz07 will want a set of 9's. You can get 0.92kg/mm springs, it's called 9.0N/mm and european sources generally mark them as such. Mixing neighboring rates is just fine. In your case maybe you install one 0.95kg/mm and a stocker if you like.

Ah, thank you for commenting Matt - although now I am a bit perplexed, so let's see:

 

1. Yes, I have seen the other makeshift options, and even tried one myself (wasn't great), but since my 24 y.o. son is not around much, it is usually me working by myself, so I will be grabbing a Venom headlift stand (already have the rear one).

 

2. My impression from reading that thread was that it was not a guarantee that the bushings in question were bad (or incorrect from O.E.), and that it would require one to split the forks.  Since I have never worked on forks before, and was not sure how serious this issue might be, I planned to bypass it for now.

 

3. Yeah, I initially planned on Maxima 15 W (46 cSt@40C) since it is readily available locally, and most of my riding is done from May - October between 50 - 90F, and only occasionally in the cold mornings below 40F in April (too much salt residue here in Western NY) and November.  However, I considered Ohlins 10W (01314-01) (40cSt@40C) as a potential compromise, but it a bit rare (even online), and I find firmer forks more to my liking.  @FZ07R WaNaB stated that you mixed 10W and 15W for his - what was the final cSt@40C rating?

 

4. Yeah, have decided the Cogent DDC's are probably not needed at this time, with some of the above reports and others stating that the fork and oil change was enough to counteract the heavy brake dive.  I really don't experience much of an issue with the front or rear, except when braking, but again, I am coming off of riding cruisers for the last 20+ years, so my ignorance is probably significant.

 

5. My initial sag estimates are probably way off (tried to do it by myself with no assistance), and when my oldest son comes over I plan on doing it right.  I estimate my rear at 35mm+ (O.E. rear shock preload set to 7), but my front is probably only 20mm or so.  I have the Fast Gear adjusters (off of Ebay, and found in the preload cap thread), and they are stating 10mm initial/ minimum with 20mm maximum - and yes, I am using the stock spacers uncut (is that bad?), with the adjusters at 50%, so I assumed I had added 15mm (0.6") of additional preload over stock.  It definitely firmed up the front (maybe a bit too much?), but brake dive was still too much for me (of course).  I did not take any measurements before installing the caps, but I would estimate 12-15mm from the base plate to the lip.

 

6. Well, I love learning stuff, and I did not know that the 9.0N/mm = 0.925kg/mm.  What springs would you recommend at the 9.0N/mm?  After @FZ07R WaNaB posted his experience (with your installation), I considered installing one of each spring (0.90kg/mm and 0.95kg/mm = 0.925 effective rate) and focusing on the fork oil.  It now appears that I could also use a pair of 9.0N/mm as well, correct?  If so, are they both equal options, meaning it is of no benefit one way or the other?  It appears that when using various spring rate calculators, that I am right between the 0.90 and 0.95 rate.

 

7. Thanks again for popping in - can I purchase the springs (and oil?) through you?  🙂

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pattonme

I mixed Maxima 10 (165/150) and 15 (235/150) with 150ml of the thinner for somewhere close to 43.

https://www.widman.biz/English/Calculators/Mixtures.html

 

If you've been riding cruisers, aren't you used to brake dive by now and consider it "usual and customary"? :)

 

The OE cap is about 20mm thick between the bottom surface and the lip. I am not familiar with the Fast Gear's dimensions. I would be surprised if from fully backed out to max turned in is much over 10mm.

 

Sure you can get springs from me. But at this juncture you need to first determine BOTH rider and non-rider sag values at both ends. Then we can have a further conversation about springs.

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zooman72
31 minutes ago, pattonme said:

I mixed Maxima 10 (165/150) and 15 (235/150) with 150ml of the thinner for somewhere close to 43.

https://www.widman.biz/English/Calculators/Mixtures.html

 

If you've been riding cruisers, aren't you used to brake dive by now and consider it "usual and customary"? :)

 

The OE cap is about 20mm thick between the bottom surface and the lip. I am not familiar with the Fast Gear's dimensions. I would be surprised if from fully backed out to max turned in is much over 10mm.

 

Sure you can get springs from me. But at this juncture you need to first determine BOTH rider and non-rider sag values at both ends. Then we can have a further conversation about springs.

OK, so would the Ohlins 01314-01 10W (40cSt@40C) or Torco RFF 15W (43.4cSt@40C) be easy enough to substitute for your Maxima mix, especially since I am hoping for a "one and done" scenario at this point?  Or could you provide a mixed oil with the springs perhaps?

 

Actually, my 2012 Stryker (which I still ride) has quite good forks for such a stretched out "chopperish" cruiser (little if any front dive, very controlled), and my problem was that the rear was too stiff initially.  This is presumably due to it being initially set up for a heavier type of rider on a 1300cc machine - quite unlike the featherweight FZ-07.  My previous cruiser bike was a 2003 Honda Magna (loved that V-4!), and it had a slight brake dive, but nothing objectionable.  I have now had 6 motorcycles in my adulthood, and none have had suspension this poor for my size, even my little old 1986 Kawasaki 454 LTD, although I was "littler" back then too!

 

Not sure about the preload caps' specifics, but it definitely made a difference in front end feel.  Unfortunately, it only reduced the significant brake dive by about 30% or so, and I may have too little sag as a result.

 

I will try to find out the sag values this evening when my oldest son comes home (just moved back to the area from Philly, and it is nice to have an extra set of hands), and then post them here.  Thanks again!

 

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zooman72

OK Matt, here are the updated sag measures:

 

Front: 9.5mm unloaded sag & 22mm loaded sag - w/ preload adj. at 50% (15mm added?)

Rear: 6.5mm unloaded sag and 40mm loaded sag - w/ O.E. shock preload at 7/9

 

Looks like I can survive with the rear shock until next spring (or longer?), but would need to back out all added preload from added fork adj. caps to get back close to recommended front sag range.  O.E. springs without preload caps would appear to be close, so the 9.0N/ 0.925kg/mm springs would be the choice over the 0.95kg/mm springs, correct?  Oh, and with the Ohlins or Torco oil I noted above to improve damping?

 

What do you think?

 

Edit: I should have noted that I think I was at 1.5" (38mm) before the adj. preload caps were installed, and again, that was an estimate - my first post here was unclear...

Edited by zooman72

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pattonme

Pick any oil solution you like. Good luck finding the Torco and the Ohlins price will probably take your breath away. I don't ship oil except in rare cases since it's a pain, heavy, and I only buy specific items in 1L bottles (super thin cartridge oil). Otherwise I buy it by the 5 gallon pail. Just buy the 2 bottles of Maxima and you'll have plenty to play mix-master with down the road.

 

Measure your new caps and cut a new PVC spacer so you end up with 10mm of preload.built-in. 

length from top of spring to top of tube (fully extended) - thickness of cap + 10mm - any washers.

 

Remeasure sag.

Your shock spring rate is off but livable for the moment. The whole unit needs to get replaced anyway...

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zooman72
6 hours ago, pattonme said:

Pick any oil solution you like. Good luck finding the Torco and the Ohlins price will probably take your breath away. I don't ship oil except in rare cases since it's a pain, heavy, and I only buy specific items in 1L bottles (super thin cartridge oil). Otherwise I buy it by the 5 gallon pail. Just buy the 2 bottles of Maxima and you'll have plenty to play mix-master with down the road.

 

Measure your new caps and cut a new PVC spacer so you end up with 10mm of preload.built-in. 

length from top of spring to top of tube (fully extended) - thickness of cap + 10mm - any washers.

 

Remeasure sag.

Your shock spring rate is off but livable for the moment. The whole unit needs to get replaced anyway...

Yeah, I can get both the Ohlins and Torco online, but you are right - probably just easier to mix my own via the readily-available Maxima.  The Ohlins was quite expensive for what it is, so no loss not using it.

 

Since I was quite close on my rear sag estimate (only off 2mm), I think my initial front preload estimate of 38-40mm (without O.E. non-adjustable caps) was close to actual too.

 

I will back out the preload spacers all the way and remeasure for now (just to see what it gets me), grab the headlift stand (from Amazon or Ebay) and 21mm pin, and will send you a PM for the springs.  

 

I am thinking of replacing the O.E. rear shock in the spring, and am looking at the K-Tech Razor-R Lite for around $500 and the Hagon M62092 for around $380 (not sure what shipping is with no U.S. distributor anymore).  Of course, if you have any ideas and updates from the rear shock thread sticky, I will be all ears.  I am just thinking of attacking one half of the bike at a time for now....

 

  

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zooman72

OK, backed out the fork preload spacers all the way (still 10mm of preload? - at least according to product listing), and front sag is now 19 unloaded and 29 loaded - quite a difference!  Comfort is fine (better even), but brake dive is terrible, hence the need for new springs and oil. 

 

It appears that when I install the new springs I will also have to install the shorter spacers as you (Matt) have noted - only question is how much shorter I will have to make the new spacers to still have sufficient adjustability in the preload caps.  At least 1" PVC is cheap!

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zooman72

OK, time for a long overdue update!

 

To answer my original question - no, it is not possible (or wise) to try to change fork springs and oil without removing the forks.  So, that is just what I did, and taking my sweet old time, it took me about 90 minutes in total.

 

I did have to purchase a few items of course: Sonic springs (0.95kg/mm rate from Stoltec Moto), 15W Maxima fork oil (only 1 shop out of 6 in my area had it in stock!), and a Venom headlift stand (w/ pin kit #2 from Amazon - had to wait for them to come back in stock).

 

No pics, but to rundown: no issues (watched the British gent on Youtube with the fork spring replacement tutorial), but did have to decide on/ estimate the new fork spacer measurement since I already had adjustable fork caps from Ebay.  After noting my previous measurements (see above), and noting the Sonic Springs are 5mm shorter than the O.E. springs, I took an additional 10mm off of the new PVC spacers (included with the new springs.  This means that my new spacers were 140mm (down from stock 150mm), and coupled with the 5mm deduction in spring length, left me with a preload reduction of 15mm from stock.

 

With the adjustable caps screwed in to 1/6 travel (2.5 - 3.0 mm additional preload), my sag for the front is 32mm, which matches the back (with the "new" Penske 8900e shock I picked up here from another member, with a 675 lbs. Hyperco spring).  In my little seat time the difference is quite significant.  The front no longer has the "lose" brake dive and is much more controlled without being too stiff over various road issues.  The rear is much more firm, and not harsh, and combined with the front spring and oil upgrade, the pitching forward that was so pronounced before is much improved.  I also still have plenty of adjustment left if I want to stiffen things up.

 

All in all, thanks to Matt@pattonme for his help here and in PM's, and to the others that replied to this thread.  It is a real shame that Yamaha went so inexpensive with the suspension on the FZ-07, and now the only thing left for me is to send the ECU in for a flash to get rid of that annoying closed throttle fuel shutoff...  :)

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