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Discussion Starter · #1 ·
Hi guys,

So a little while ago I bought a cheap '99 SV650 with the idea to make it a track bike. It has some 'upgrades' like GSXR brakes, a Hyperpro rear spring and (possibly) some hyperpro linear springs in the front.

Now, my streetbike is a 2009 Fireblade, so for that reason I'm probably spoiled and like to upgrade my front suspension a little more. Now I've orderd some cheapo emulators on Ebay a few days ago and really tried to dig into the subject, but there's still a few things I cant figure out.

I found the following to be very helpfull:

Drill out the existing two lower sets of holes(4 holes total) out to 7/16 of an inch which runs a bit over 11mm. The reason to drill out existing holes so they dont work any more. 10-11mm is what works good. emulator will control damping from here.

Rebound is controled only by weight of oil (typically 20wt is most common), you have to choose one brand and stick with it,you can change weight of oil but dont change brand. you get more consistent results. every suspension shop chooses oil they work with and do valving accordingly.that way they know exactly where they are and consistency is there.
2.5-3 turns is normal range on emulators used.

The rebound hole is the little hole up on top of the damper rod, block it off by brazing, welding.
Some use JB Weld to fill it. rebound will be controlled by rebound hole in emulator.


However, I still have a few questions:

  • On the forum I've read some differences in the Gen1 and Gen2 forks. Now I'm aware they were built by different companies, but do the steps mentioned above differ from either Gen? I can't find the post anymore but somewhere I believe I read that for one Gen you need to cut the spacers, and for the other you do not?
  • If cutting the spacers is a requirement, do I just cut the length of the actual emulator off?
  • Like I stated, my springs are possible upgraded progressive springs, are there extra things I would need to take in consideration, or is it better to change them out for a linear set?
  • In the statement mentioned above 20wt is mentioned, is this most common, even for the knockoff Harley emulators?
  • In this post it says not to reinstall the bottom out cone when using emulators. Unfortunately this is the only post I found saying this, so asking if this is actually necessary. And if so, what this part actually looks like, unfortunately the pictures in the post are no longer loading :(
Well, that was quite a write up, sorry about that. English is not my native language btw, so forgive me if I may not understand the first time you explain :)
 

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I think you need to keep the bottom out cone that the damper rod seats into. The cone has a larger dia. than the end of the damper rod which spreads the load inside bottom legs?
Have not heard of anyone excluding that cone.
 

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very big dumb
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  • On the forum I've read some differences in the Gen1 and Gen2 forks. Now I'm aware they were built by different companies, but do the steps mentioned above differ from either Gen? I can't find the post anymore but somewhere I believe I read that for one Gen you need to cut the spacers, and for the other you do not?
    • the damper rod modification is the same. need to get emulators appropriate to your forks though (the shape of the seat on the rod is different)
  • If cutting the spacers is a requirement, do I just cut the length of the actual emulator off?
    • yes. however it works better when you follow the measurement procedure rather than just cutting the height of the emulator body. who knows how well the guy before you measured...
  • Like I stated, my springs are possible upgraded progressive springs, are there extra things I would need to take in consideration, or is it better to change them out for a linear set?
    • progressive is a compromise in performance at a constant weight, but a little benefit if you keep changing weight. straight rate is a compromise the other way. if you're tracking, you definitely want straight rate
  • In the statement mentioned above 20wt is mentioned, is this most common, even for the knockoff Harley emulators?
    • there are people running down to 7.5 and up to 20wt. try 15 or 20 and if it's too slow change out. make sure to leave yourself the correct airgap (measured with emulator and oil in, spring out, forks collapsed, 120mm from the top)
  • In this postit says not to reinstall the bottom out cone when using emulators. Unfortunately this is the only post I found saying this, so asking if this is actually necessary. And if so, what this part actually looks like, unfortunately the pictures in the post are no longer loading :(
    • bottom out cone should stay. on a 1g it's the little while cap that's in the fork. you can see it sticking out on the left of the fork upper
      56030


since you're gonna have them apart, you should probably do bushings/seals etc. as well as check the legs for straightness (no sense in building a crooked set lol)
 

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Discussion Starter · #4 ·
  • On the forum I've read some differences in the Gen1 and Gen2 forks. Now I'm aware they were built by different companies, but do the steps mentioned above differ from either Gen? I can't find the post anymore but somewhere I believe I read that for one Gen you need to cut the spacers, and for the other you do not?
    • the damper rod modification is the same. need to get emulators appropriate to your forks though (the shape of the seat on the rod is different)
  • If cutting the spacers is a requirement, do I just cut the length of the actual emulator off?
    • yes. however it works better when you follow the measurement procedure rather than just cutting the height of the emulator body. who knows how well the guy before you measured...
  • Like I stated, my springs are possible upgraded progressive springs, are there extra things I would need to take in consideration, or is it better to change them out for a linear set?
    • progressive is a compromise in performance at a constant weight, but a little benefit if you keep changing weight. straight rate is a compromise the other way. if you're tracking, you definitely want straight rate
  • In the statement mentioned above 20wt is mentioned, is this most common, even for the knockoff Harley emulators?
    • there are people running down to 7.5 and up to 20wt. try 15 or 20 and if it's too slow change out. make sure to leave yourself the correct airgap (measured with emulator and oil in, spring out, forks collapsed, 120mm from the top)
  • In this postit says not to reinstall the bottom out cone when using emulators. Unfortunately this is the only post I found saying this, so asking if this is actually necessary. And if so, what this part actually looks like, unfortunately the pictures in the post are no longer loading :(
    • bottom out cone should stay. on a 1g it's the little while cap that's in the fork. you can see it sticking out on the left of the fork upper View attachment 56030


since you're gonna have them apart, you should probably do bushings/seals etc. as well as check the legs for straightness (no sense in building a crooked set lol)
Wow, thanks! This is great information. As for the appropriate emulators, i ordered these knock-offs. Not sure if they'll be ok for my Gen1 then?

Good to know that progressive springs are a compromise for the track, I will see if I can order the correct linear for my weight.

Great video btw, will absolutely check if they're bent beforehand. I will probably need a sealdriver for changing the forkseals right, or is there a trick I'm missing?

I also saw that a few people will replace their normal spacers for something like PVC. Is there a reason for this? Since the spacers will be shorter it's fine to cut them right?
 

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You can make your own seal driver, easy. Here are two videos of different seal drivers. One thing that really helps is having an extra large washer like the one that sits on top of the upper bushing. Makes it easy to drive home the upper bushing and seal without damaging the seal.


You can cut the spacer you have or use pvc as a spacer
 

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Discussion Starter · #6 ·
You can make your own seal driver, easy. Here are two videos of different seal drivers. One thing that really helps is having an extra large washer like the one that sits on top of the upper bushing. Makes it easy to drive home the upper bushing and seal without damaging the seal.


You can cut the spacer you have or use pvc as a spacer
Thanks, those are great examples of easy and cheap sealdrivers! Not entirely sure what you mean with the extra large washer though. Do you mean that it's convenient to have an extra washer to use in combination with the sealdriver?

something like this: (excuse my drawing skills)

....|.........|...
....|.........|... <---- fork stanchion
....|.........|...
....|.........|...
...||||||||||||||.. <--- pvc sealdriver
...||||||||||||||..
...||||||||||||||..
...||||||||||||||..
.=======. <--- (extra) washer
|########| <--- seal
....|............|.. <--- fork leg
....|............|..
 

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Yes, in combination with the seal driver. It makes it easy driving in the upper bushing and seal straight without damaging both.
....|.........|...
....|.........|... <---- fork stanchion
....|.........|...
....|.........|...
...||||||||||||||.. <--- pvc sealdriver
...||||||||||||||..
...||||||||||||||..
...||||||||||||||..
.=======. <--- (extra) washer used to drive upper bushing, seal
|########| <--- seal
======= washer
xxxxxxxxx upper bushing
....|............|.. <--- fork leg
....|............|..
 

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very big dumb
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I also saw that a few people will replace their normal spacers for something like PVC. Is there a reason for this? Since the spacers will be shorter it's fine to cut them right?
USUALLY aftermarket springs are shorter than stock. so you wouldnt cut the existing spacer, youd need to make a longer one.
it doesnt matter wtf the spacers are made from. they really arent that stressed. pvc is easier to cut for most people ;)
 

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Discussion Starter · #9 ·
Yes, in combination with the seal driver. It makes it easy driving in the upper bushing and seal straight without damaging both.
....|.........|...
....|.........|... <---- fork stanchion
....|.........|...
....|.........|...
...||||||||||||||.. <--- pvc sealdriver
...||||||||||||||..
...||||||||||||||..
...||||||||||||||..
.=======. <--- (extra) washer used to drive upper bushing, seal
|########| <--- seal
======= washer
xxxxxxxxx upper bushing
....|............|.. <--- fork leg
....|............|..
Thanks! Hopefully I can get my hands on one
 

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Discussion Starter · #10 ·
USUALLY aftermarket springs are shorter than stock. so you wouldnt cut the existing spacer, youd need to make a longer one.
it doesnt matter wtf the spacers are made from. they really arent that stressed. pvc is easier to cut for most people ;)
Ah, that makes sense. Seems like I have to learn about setting sag at least in order to determine the spacer length
 

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This post here is highly relevant to my current struggles--glad you posted it.

First, to be of some help. Here is a picture of the one of the Oil Locks from a gen1. They sit in the bottom of the fork stanchion, and help with the final ~10mm of travel to help the fork out from bottoming out metal to metal. There's the little metal spring--that I honestly can't figure out the purpose of, maybe aligning the damper rod--and the plastic piece. In order to remove this piece, you need to separate the stanchion from the fork lower. I believe the gen2 oil locks are metal. If your seals are not leaking, it's not actually necessary to split the stanchion from the fork lower to install the emulators unless you also want to remove the oil locks. It's probably a good idea to replace the seals though if you haven't done it yet.

56031


Snipping Mad8v's image from above incase it helps make it more clear..
56033


So I'm currently going through a 2001 650S that I bought this summer and did my first two track days on. I knew there had been work done to the forks, but I had no clue what. And yesterday and today have been full of surprises and a lot of research. One of the things I found in the box of parts I had been given was these oil locks--so I assumed I'd find the Traxxion Dynamics damper rods and a RaceTech emulator inside--especially because the box of spare parts was a Traxxion box. Traxxion recommends removing the oil lock as you mentioned in the above post, but I didn't see anywhere that RaceTech does. Well, when I got into the internals I found that I've got the stock damper with holes bored to 10mm and rebound hole welded shut with the fork oil locks removed. I also found 0.90 springs which are probably a good bit too heavy for me according to Sonic Spring's tables since I'm 160lb.

Then I was looking at the emulator and getting confused. I was thinking it must be a RaceTech with the softest silver spring on it set to zero preload. But then I discovered that there were knockoffs, and now I'm betting that it is one of those.

56032


I'm still confused on why the rebound hole is supposed to be welded up. My understanding is that the only path for oil flow on rebound then is for blow-by around the damper seal. But it seems to be universally stated as the right thing to do on these SV650's with emulators, so I'm not going to argue it.

I filled up with 15W oil with a 130mm air gap. I think I'm going to pull them back off the bike and do a double check that I have the emulators properly adjusted and take a lot more photos. I should probably also make a decision on keeping the 0.90 springs or ordering more weight appropriate ones. Honestly, the front end felt fantastic to me; however, I probably just don't know what a well-tuned suspension actually feels like. I also need to make a decision on whether or not to re-install the oil locks. I'm honestly thinking no. I have had major headaches with those things getting stuck when driving new seals (Suzuki Bandit has the same part) that I'd prefer to eliminate them from my life if I don't need them. I haven't bottomed out yet on some pretty shitty roads, but maybe that's because of the heavier springs.

I'm not trying to hijack your post! I just think it sounds like you're planning to set the forks up the same way that mine are, and it's been the only thing on my brain the last 48 hours.
 

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Ok peoples, two things.

#1. This site has a search function

#2. It has a FAQ sub-forum

Everything being discussed here already has literally thousands of posts on this site, with all the info you need.

For example:


Long thread, but if you take the time to read it you'll actually know how damper rod forks work and have a good idea what to do with yours.
 

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There is a difference between 1st Gen and 2nd Gen bikes on how to set up the emulators. According to this and other threads:
• 1st Gen: 20wt fork oil, rebound holes closed
• 2nd Gen: 15wt fork oil, rebound holes closed but can stay open for street use

As far as your spring rate is concerned, it should be fine:
FRONT
• 1st Gen: 160-190 lbs rider - 0.85 kg/mm
• 2nd Gen: 155-190 lbs rider - 0.90 kg/mm spring rate (Stock 1st Gen has 0.71, 2nd Gen has 0.67)
REAR
160 - 190 lbs Rider - 500 lb/in - 8.95 kg/mm spring rate
(Stock 1st Gen has 510 lb/in, 2nd Gen has 430 lb/in)
 

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Ok peoples, two things.

#1. This site has a search function
#2. It has a FAQ sub-forum
Rich--I wasn't trying to be obtuse and clutter up an over-discussed subject by chiming in without researching it first. There is just hardly anything that comes up if you search Suzuki's term "oil lock". There is even less that relates to removing the oil lock when working with anything but the Traxxion damper rod replacement. However, "Bottom Out Cone" brought me to this thread: hydraulic bottom out cone (oil stop) question (front forks), and the following two answers are good enough for me to ditch them.

56034

56036


I also do not know if there is any way to tell a difference from the knock-off valve emulator from a RaceTech one with the #26 silver spring. I was hoping maybe there was something obvious I was missing, so I don't end up buying a $180 replacement for a component I already have. From my research I have two guesses as to how it could potentially be done:
1. Remove the spring and test the spring rate, which I do not have the capacity to do. I have a set of yellow RaceTech springs from another bike I could compare it to, but that's it.
2. Count the bleed holes on the emulator piston. I think the RaceTech emulators for the SV650 come with 2 bleed holes in the default configuration. I think the "Harley 41mm emulator" knockoffs come with a single hole. I've got a single hole.

And in regards to sealing the rebound hole--I know that the commonly recommended solution is to close it up. I accept that because people much smarter than me say that is what should be done, they've done it, and the results speak for themselves. But when you read through Racetech's article on Emulators and How They Work, knowing that they emphasize that one of the primary benefits of the emulator is to separate compression from rebound damping... I must have stared at this image for 30 minutes trying to work out how the fluid could move after removing it's primary flow path. Apparently the blow-by on the damper rod seal is quite substantial. The picture below makes it sound like it must be passed the check valves, but SV tribal knowledge indicates the fluid is actually moving passed the damper seal. It makes it seem like a worthwhile upgrade to the stock SV forks (without emulators) would be sealing up the rebound hole regardless of anything else if that's the case.

56037

As far as your spring rate is concerned, it should be fine:
FRONT
• 1st Gen: 160-190 lbs rider - 0.85 kg/mm
• 2nd Gen: 155-190 lbs rider - 0.90 kg/mm spring rate (Stock 1st Gen has 0.71, 2nd Gen has 0.67)
REAR
160 - 190 lbs Rider - 500 lb/in - 8.95 kg/mm spring rate
(Stock 1st Gen has 510 lb/in, 2nd Gen has 430 lb/in)
If this was in response to my post (please disregard it if it wasn't), my worry was that I have a first gen, and the recommendation on the Sonic Springs table indicates that I should have a lighter spring. However, with gear and everything, and given the fact that I'm essentially a novice at anything but highway pavement pounding, I can't imagine I'd realize the difference between 0.90 and 0.85 springs at 160lbs before breakfast and gear.

56038


Again, sorry to derail this. I know you guys are probably sick of seeing the same question pop up for at least 14 years now, but there are still some answers that aren't simple to find. I've been reading through the older threads--I promise, and I'm super grateful to be able to use this website as a resource and to all of you that have contributed to it.
 

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I agree with you that certain intricacies are hard to figure out from the many threads on this subject. This is not the same as yet another oil/oil filter thread.
It also seems to me the recommend fork spring rate on the Sonic Springs chart has changed in the last couple of years.
I'm 190lb with gear and was told to get a 0.90 kg/mm spring three years ago. I think it's great for good streets/track, but a bit stiff for NYCs pothole strewn roads. These days I'd probably opt for a 0.85 spring.
 

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I agree with you that certain intricacies are hard to figure out from the many threads on this subject. This is not the same as yet another oil/oil filter thread.
It also seems to me the recommend fork spring rate on the Sonic Springs chart has changed in the last couple of years.
I'm 190lb with gear and was told to get a 0.90 kg/mm spring three years ago. I think it's great for good streets/track, but a bit stiff for NYCs pothole strewn roads. These days I'd probably opt for a 0.85 spring.
What you're feeling there isn't spring rate, it's high speed compression damping. Do you have emulators, and if so how are they set up?

FYI, Sonic Springs changed ownership in April '19. I sold it to Jamie Daugherty. Really good guy, and very knowledgeable. But any two suspension guys are going to have slightly different ways of doing things.
 

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There is a difference between 1st Gen and 2nd Gen bikes on how to set up the emulators. According to this and other threads:
• 1st Gen: 20wt fork oil, rebound holes closed
• 2nd Gen: 15wt fork oil, rebound holes closed but can stay open for street use

As far as your spring rate is concerned, it should be fine:
FRONT
• 1st Gen: 160-190 lbs rider - 0.85 kg/mm
• 2nd Gen: 155-190 lbs rider - 0.90 kg/mm spring rate (Stock 1st Gen has 0.71, 2nd Gen has 0.67)
REAR
160 - 190 lbs Rider - 500 lb/in - 8.95 kg/mm spring rate
(Stock 1st Gen has 510 lb/in, 2nd Gen has 430 lb/in)
There really isn't a reason for a fork spring rate difference between 1st and 2nd gens. Where there might be a difference is S vs. naked, because the lower bars on the S mean the rider's weight is a bit more forward. Not much in it though, only matters if you're on the edge between rates.

On the rear, there's a major difference because the linkage ratio is different between 1st and 2nd gens. Desired shock spring rate for an average 180lb rider is going to be around 480 for a 2nd gen but 600 for a 1st gen.
 

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Discussion Starter · #19 ·
First of all, thank you all for helping me out with info, much appreciated. I have to agree with Matt that I too have some difficulties of reading the many threads that are already on this subject and try and make it sensible for my situation. Can I ask for a little vote on the bottom out cone/oil lock?

Leave it in, or take it out? Like I stated, I have a 1st gen which will be used on the track only. And if I take it out, the homemade spacer will have to become even longer I reckon?
 
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