RaceTech Gold Valve Emulators and Springs...

supertux1

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Postman delivered relief for my shoulders and back:



So I've been scouring the threads trying to find out where to start tuning with the RaceTech Gold Valve Emulators. The install isn't a big deal and I have no problem drilling stuff. [emoji1]

I weigh about 200 lbs all geared up, and sometimes ride with a lot of cargo weight, so I ordered the .90kg springs to go with the RaceTech Gold Valve. I rounded up.

I figure I'm going to use a 15wt oil as that seems to be the standard recommendation from RT and from what I read elsewhere. I found this on Amazon and using a comparison chart it seems to be a 'real' 15wt:



I'll have to figure out the correct preload spacer length when I get the adjustable fork caps and get a chance to measure the stock components next to the new stuff...

A couple of NC700 questions:

1. How much should the NC forks compress with the rider on?

I have it in my mind from general suspension tuning literature that it is about 1/4 to 1/3 of the total travel, which would be 30 to 40mm on the NC's 137mm fork travel.

2. With the RaceTech Gold Valve, I have been given a blue spring and a yellow spring (stiffer) to control the compression dampening rate. RT says 2-5 turns preload on these springs. What is everyone here using?

3. To control rebound, I have the option of drilling two extra holes in the valve. Do you guys go with 2,3 or 4?

4. Will the bike explode and the world end if I just put the stuff in as given?

That is: yellow spring, 2 turns preload, 2 holes in the valve, 120mm 15wt oil.

Thanks! Can't wait to install these things!
 
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DirtFlier

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Suspension mods are always trial & error no matter what they provide for guidelines. Be prepared to get into the forks again and again.
 

rippin209

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I'd say install as is and after 3 to 5k miles if your not completely satisfied start adjusting
 

supertux1

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Well I did a study of the fork spring / suspension in its static state.

Honda says it has 137mm of travel according to the service manual.

Free Sag: When the bike is sitting all by itself, with just the weight of my accessories, the front fork is compressed 47mm, or %37 of 137mm.

Rider Sag: When I sit on the bike with my gear on, (+200 pounds) that turns into 67mm, or
%47.



These numbers seem high to me... I don't recall ever bottoming out the front but as I understand it, the spring is really stiff in the last third or so.
Has anyone else measured?

Good thing I got the stiffer spring, I'm hoping it will improve the ride.
 
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bamamate

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I did the lighter spring (yellow?) with ~2-3 turns. It isn't exactly a precise method of count the turns after the spring makes good contact. I drilled 3 holes. If I remember correctly from a convo 670cc had with RT, generally people feel no difference from 2-3 holes so go 2 or go 4. I'd start with 2 and see how you like it. You can always drill more holes. Hard to un-drill them. I'm going to move to 4 holes for more relief on the square bumps. I believe RT sent 670cc an even lighter spring for a more cushy ride.

As for preload, I'm on stock springs and just cut the spacers approximately the same amount that the gold valves added. Been too lazy to actually check if that was correct or not. Been thinking about getting the RT springs since I've beefed up over the past year from 165 to 195.

I went with Maxima 10wt oil. Trying a 50/50 mix of 5wt/10wt next. Note: 16oz wasn't quite enough for both forks to get to the RT recommended level.
 

supertux1

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I did the lighter spring (yellow?) with ~2-3 turns. It isn't exactly a precise method of count the turns after the spring makes good contact. I drilled 3 holes. If I remember correctly from a convo 670cc had with RT, generally people feel no difference from 2-3 holes so go 2 or go 4. I'd start with 2 and see how you like it. You can always drill more holes. Hard to un-drill them. I'm going to move to 4 holes for more relief on the square bumps. I believe RT sent 670cc an even lighter spring for a more cushy ride.

As for preload, I'm on stock springs and just cut the spacers approximately the same amount that the gold valves added. Been too lazy to actually check if that was correct or not. Been thinking about getting the RT springs since I've beefed up over the past year from 165 to 195.

I went with Maxima 10wt oil. Trying a 50/50 mix of 5wt/10wt next. Note: 16oz wasn't quite enough for both forks to get to the RT recommended level.
I believe the blue spring is the lighter one. The exact 'installed' spring length at 2-3 turns can be calculated if the thread pitch of the bolt is known... in my hand it looks like a M4 coarse thread at .7mm per turn... so whatever the free spring length is minus 1.4 to 2.1mm? I could be wrong, I haven't taken them out of the bag yet...

I think mother Honda makes this bike for tall skinny people...

I think getting the correct spring for my weight is going to make a big difference, so I can go with minimal preload and have more of the spring to work with. I think just that with the stock RT valve settings will give a good baseline to make adjustments from.

By the way, the yellow installed spring length (right from the package) is 26.7mm on one and 27.5mm on the other so you definitely have to set them up the first time...
 

mike5100

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Well I did a study of the fork spring / suspension in its static state.

Honda says it has 137mm of travel according to the service manual.

Free Sag: When the bike is sitting all by itself, with just the weight of my accessories, the front fork is compressed 47mm, or %37 of 137mm.

Rider Sag: When I sit on the bike with my gear on, (+200 pounds) that turns into 67mm, or
%47.



These numbers seem high to me... I don't recall ever bottoming out the front but as I understand it, the spring is really stiff in the last third or so.
Has anyone else measured?

Good thing I got the stiffer spring, I'm hoping it will improve the ride.
Yes - I got similarly high figures for the sag with the standard 2016 forks. I weight 180lbs and the ride of the 2016 bike compared to my previous '12 and '14 NC bikes was appalling. The forks jittered about so much I couldn't use the mirrors and they were so rough in bumpy corners it was IMHO dangerous causing me to stand the bike up and run wide.
FWIW I discovered that the progressive spring fitted to the 2016 bike is different from that used in the earlier forks, and I think the early part of the spring movement is too light. This means that much of the 'gentle' travel is used up simply with the rider sitting on the bike and you are straight into the hard wound section of the spring leading to a very harsh ride. Also I am not convinced by the new Showa dual bending valve technology. No-one seems to know how it works - even suspension specialists - but if it's a cheap version of an emulator then the problem must surely be that it's a one size fits all. All emulators allow substantial adjustment for the rider weight and the type of riding that is aimed for - the new Showa technology allows no adjustment.
Finally I spent a lot of time researching what the 'travel' is on the front forks and to cut a long story short I believe the theoretical travel measured along the fork on the 2016 bike is in fact 150mm (The 137mm quoted in my service manual is I believe the amount of vertical travel available to the front axle).
Hence I have aimed at 50mm of sag with me on the bike and have got fairly close with 0.85 Ktech springs although I suspect that .80 might be slightly better and Ktech have said they will swap them if I wish. In the meantime I have got a decent ride with the Ractech emulators using the lighter blue preload springs with 2 turns and by drilling out the two undrilled holes on the emulator plates. However I used a smaller drill size than the 3mm predrilled holes and I may drill them out to match as the low compression damping could do with being a smidge softer. And I aim to try one turn less on the racetech preload just to soften the high speed bumps a touch. So far I don't get any weaving or wallowing so I think I have a bit to play with, but there are so many variables and it's not like the back end, to fiddle around with the front means a partial strip and rebuild so the temptation is to change several variables at once which would probably be a big mistake.
Mike
 

670cc

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What Bamamate said.

I started with the lighter of the two emulator springs shipped with the GVEs, and later switched to an even lighter "silver" spring. I believe I'm running 10wt Belray oil. I have drilled the two extra holes in the GVE.

You might say I have mine set too soft, but i think I've got it pretty close to my liking. With the starting recommended settings, the compression damping was stiff enough that I couldn't get any fork action over sharp bumps. Almost no fork travel was being utilized. What is the point of 5+ inches of travel if the forks won't move? So I continued to lighten up the damping to where I think the forks are fairly compliant without getting mushy.

I guess it depends on the load on the bike, what ride you're looking for, and what your typical road conditions might be.
 
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supertux1

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Yes - I got similarly high figures for the sag with the standard 2016 forks. I weight 180lbs and the ride of the 2016 bike compared to my previous '12 and '14 NC bikes was appalling. The forks jittered about so much I couldn't use the mirrors and they were so rough in bumpy corners it was IMHO dangerous causing me to stand the bike up and run wide.
FWIW I discovered that the progressive spring fitted to the 2016 bike is different from that used in the earlier forks, and I think the early part of the spring movement is too light. This means that much of the 'gentle' travel is used up simply with the rider sitting on the bike and you are straight into the hard wound section of the spring leading to a very harsh ride. Also I am not convinced by the new Showa dual bending valve technology. No-one seems to know how it works - even suspension specialists - but if it's a cheap version of an emulator then the problem must surely be that it's a one size fits all. All emulators allow substantial adjustment for the rider weight and the type of riding that is aimed for - the new Showa technology allows no adjustment.
Finally I spent a lot of time researching what the 'travel' is on the front forks and to cut a long story short I believe the theoretical travel measured along the fork on the 2016 bike is in fact 150mm (The 137mm quoted in my service manual is I believe the amount of vertical travel available to the front axle).
Hence I have aimed at 50mm of sag with me on the bike and have got fairly close with 0.85 Ktech springs although I suspect that .80 might be slightly better and Ktech have said they will swap them if I wish. In the meantime I have got a decent ride with the Ractech emulators using the lighter blue preload springs with 2 turns and by drilling out the two undrilled holes on the emulator plates. However I used a smaller drill size than the 3mm predrilled holes and I may drill them out to match as the low compression damping could do with being a smidge softer. And I aim to try one turn less on the racetech preload just to soften the high speed bumps a touch. So far I don't get any weaving or wallowing so I think I have a bit to play with, but there are so many variables and it's not like the back end, to fiddle around with the front means a partial strip and rebuild so the temptation is to change several variables at once which would probably be a big mistake.
Mike
This was exactly the kind of data I was looking for, thanks.

I think Honda tried to address previous complaints to their single low-rate compression/rebound design with a progressive spring in the newer models.

It's the cheapest way they could 'improve' the suspension -for their targeted demographic of skinny lightweight people-, but if you fall out of that goldilocks weight zone it actually makes things worse by putting you into the stiff rate all the time while reducing overall travel available, and messes with the rake/geometry of the bike a bit.

I could correct the rake/geometry and make the bike sit higher by installing a longer preload spacer, so steering is where it should be, but
uh oh, that further compresses the spring into it's stiff rate. :(

I believe that single rate springs are better and that 'progression' -or resistance to bottoming out at the top end-, comes from the compression of the air above the oil and is controlled by the oil level, not the spring. (Gas is naturally progressive.) But all this costs money and even more to be adjustable, so we get the cheap stuff. It's better than the fork tube being filled with rocks, I guess. (maybe)

I weigh pretty close to you, but even more all geared up and with a backpack + stuff, so I think I'll be okay with the .90kg and if not it's an easy swap.

Do you know how much your spring can compress before all the coils are touching each other? (Measure/calculate the space between the coils?)

I think the 'theoretical' suspension travel could be as much as 180mm as that is the distance of the chrome between the fork seal and the lower triple tree clamp.
(I'm pretty sure that the hard parts near the radiator would be colliding at less than that though.)

We don't get the SHOWA dual bending valve on the 2016's in USA (or the LED headlight, sigh.) Have you taken it out and looked at it?
I assume it sucks because there's no advertised adjustability and Honda didn't jack up the MSRP for it etc...

RT documentation for the valve says 'Note that Touring Riders may prefer the Softer 40lb/in spring at 3-5 turns', but this assumes 'HONDA VF700-1100 V-4 Models using SHOWA 37/39/41mm Forks.'

I was warned that the suspension on the NC left much to be desired. I guess even more so for the 2016 with its soft progressive spring. The more you know!
 

MZ5

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I think Honda tried to address previous complaints to their single low-rate compression/rebound design with a progressive spring in the newer models.
FYI-- The NCX has always had progressive-rate springs in the forks, as have most (all?) Hondas for a very long time.
 

supertux1

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FYI-- The NCX has always had progressive-rate springs in the forks, as have most (all?) Hondas for a very long time.
Oh really!? Yes, I see from the 2012 manual that it shows a progressive spring... so I guess that's how they address the non valve piston.

So I measured the RT .90kg single rate springs I have calculated the travel.

They are 340mm long with 28 coils/spaces. The wire is 4.95mm thick, and the spaces are 7.05mm wide.

After the math is done, this spring can compress approximately 200mm before the coils touch each other. Well past the maximum travel allowed by the frame. (180mm max, probably less.)

Also, to move it this far would require 200mm x .90kg = 180kg, or 396 pounds. A 200 pound force (me sitting directly on it) would move it halfway. Inside the fork tube there will be additional resistance from the compressed air above the oil. I think this will work good.
 
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mike5100

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This was exactly the kind of data I was looking for, thanks.

I think Honda tried to address previous complaints to their single low-rate compression/rebound design with a progressive spring in the newer models.

It's the cheapest way they could 'improve' the suspension -for their targeted demographic of skinny lightweight people-, but if you fall out of that goldilocks weight zone it actually makes things worse by putting you into the stiff rate all the time while reducing overall travel available, and messes with the rake/geometry of the bike a bit.

I could correct the rake/geometry and make the bike sit higher by installing a longer preload spacer, so steering is where it should be, but
uh oh, that further compresses the spring into it's stiff rate. :(

I believe that single rate springs are better and that 'progression' -or resistance to bottoming out at the top end-, comes from the compression of the air above the oil and is controlled by the oil level, not the spring. (Gas is naturally progressive.) But all this costs money and even more to be adjustable, so we get the cheap stuff. It's better than the fork tube being filled with rocks, I guess. (maybe)

I weigh pretty close to you, but even more all geared up and with a backpack + stuff, so I think I'll be okay with the .90kg and if not it's an easy swap.

Do you know how much your spring can compress before all the coils are touching each other? (Measure/calculate the space between the coils?)

I think the 'theoretical' suspension travel could be as much as 180mm as that is the distance of the chrome between the fork seal and the lower triple tree clamp.
(I'm pretty sure that the hard parts near the radiator would be colliding at less than that though.)

We don't get the SHOWA dual bending valve on the 2016's in USA (or the LED headlight, sigh.) Have you taken it out and looked at it?
I assume it sucks because there's no advertised adjustability and Honda didn't jack up the MSRP for it etc...

RT documentation for the valve says 'Note that Touring Riders may prefer the Softer 40lb/in spring at 3-5 turns', but this assumes 'HONDA VF700-1100 V-4 Models using SHOWA 37/39/41mm Forks.'

I was warned that the suspension on the NC left much to be desired. I guess even more so for the 2016 with its soft progressive spring. The more you know!
Ah yes I forgot that you guys didn't get the Showa fork. Well this next comment is going to be controversial then. Be careful what you wish for, as I found the previous (ie your current) front suspension ideal. When I bought the new Showa DBVS equipped bike I had to learn a lot about suspension in general, and got very little help from two specialist shops that knew nothing about the DBVS and weren't really that interested in sorting a budget dual purpose bike. I am glad it forced me into this learning curve but it has of course made me 'picky' and now I'm never satisfied that I have got it right.
Anyway just to pick up a couple of your points.
I think the maximum theoretical travel is 150mm. IIRC with the wheel out and the oil and springs out, the difference between forks fully compressed and fully extended was 140mm so I reckoned there was a 10mm bump stop spring in there, making 150mm altogether. My reasoning for deciding that the 137mm was the vertical axle travel is a) that's what they are quoting for the back and b) I found some Honda scooter specs where they quoted front wheel suspension in terms of 'cushion stroke' which to me seems like a measurement made along the fork stanchion. And I think if the 137mm was a cushion stroke measurement they would have said so.

It's very time consuming and expensive to get the springs front and back correct for the type of riding you want to do. In Europe all the supplier err on the side of stiffness as they assume that we want to make our bikes handle like the best sportsbikes - you may find it more realistic in the USA where suspension shops are perhaps more used to people wanting a softer ride. My Wilbers rear shock came with a 170N spring which was obviously too hard as I couldn't get the sag measurement anywhere near. The have swapped it for a 160 but my calculations show that it really should be down around 130 to give the ride I want. The suspension specialist who did the RT emulators for me put in .90 springs (and that's what both KTech and Racetech said was right). It wasn't and the .85 springs have helped but the .8s will be better if I can be bothered to change them. Which is an easy job by the way. - maybe half an hour providing the springs are the same length. Unfortunately the only spring Ktech do in a .8 is 30mm shorter so I would have to mess around with new spacers and changing oil levels, which is why I will probably just fiddle with the emulators for now.

Oh yeah - by the way - here's what I am aiming for in front and rear sag.
1/3 of available travel with me sitting on the bike in normal riding gear and no luggage (99% of my riding time)
So that suggests 50mm front and rear.
However after trawling lots of sites it seems clear that the bike should settle more at the rear than the front when you get on - so the sag of the bike under its own weight at the front should be 32mm (+18 when you get on) and at the back should be 14mm (+36 when you get on)
Only if you can get close to those figures with the springs and any preload adjusters or front spacers will fiddling with damping adjustments make any appreciable difference. IMHO
Mike
 

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There is a "Rebound Spring", the service manual doesn't mention it's free length, but it looks about 1/8th the length of the damping rod (err, "fork piston") going by the photos in the manual (not the drawings).
 

rippin209

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There is a "Rebound Spring", the service manual doesn't mention it's free length, but it looks about 1/8th the length of the damping rod (err, "fork piston") going by the photos in the manual (not the drawings).
I didn't take any measurements but here is a pic of the stock parts (for scale at least)
 

supertux1

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Well I need a few more parts and probably won't get to this until riding season starts in a month or so.

No point in installing stuff and not being able to test ride it. I will have a rear shock as well, probably a Nitron R2 or similar.

I'll post back here with measurements and data when I start taking stuff apart.
 

DirtFlier

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[...In Europe all the supplier err on the side of stiffness as they assume that we want to make our bikes handle like the best sportsbikes - you may find it more realistic in the USA where suspension shops are perhaps more used to people wanting a softer ride...Mike]

Most shops in the US also assume you want a stiffer ride! If allowed to give suspension preferences to a shop, I've found it works best if you say TOURING.
 

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Would definitely drill 4 holes. 2 passes with a drill. You don't want any restrictions in the flow of oil so the emulator is actually controlling compression dampening. Esp since your complaint is about being beaten up.


Sent from my iPhone using Tapatalk
 

showkey

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If you follow race tech initial setup and install instructions, they will get you to a good starting point. After that, valve settings, oil type, weight and quantity and different spring combinations and sag settings all equal dozens of combinations that can get you to the same or similar level of suspension comfort and performance.
 
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