Switching from 0.90s to 0.85 Racetech springs in the front

A few months ago I got my front suspension done up by Racetech. 0.90 springs, gold valves, and new oil were installed. My bike handles much better, but it's a bit stiff, so I'm considering switching to 0.85s. My question is: since the suspension was configured for 0.90 springs, will the valving be compatible with 0.85 springs? I'm thinking I can remove the 0.90s and simply replace them with the 0.85s. Anyone disagree?

Thanks.

You can try removing 10mm of oil height first, 5mm at a time. That will soften it up a bit, not sure if it will be enough though.

The bottom line is, if the springs match your weight and you get good sag numbers with them, then you need to tweak your valving & oil combo till the ride becomes more to your liking.

[image: View Post]SEBSPEED, on 29 June 2010 - 06:34 PM, said:

You can try removing 10mm of oil height first, 5mm at a time. That will soften it up a bit, not sure if it will be enough though.

The bottom line is, if the springs match your weight and you get good sag numbers with them, then you need to tweak your valving & oil combo till the ride becomes more to your liking.


I'm getting 35 mm of rider sag with no preload at all. I can't recall what my free sag number was. Ideally, shouldn't I have at least 1/3 to 1/2 of the preload adjuster turned in to get my ideal sag?

First off how much do you weigh?

Also is your rear shock stock along with a stock spring?

What I found when installing stiffer springs up front (.95's) along with revalving (but not changing the rear at all) was that the front felt somewhat better, but was bouncing off small bumps much more and didn't seem to handle as well. I wasn't really happy! Until I stiffened up the rear also! :fing02:
Turns out that adding stiffer springs to the front only actually screws up many things like the following:
- Front rides higher all the time so turn-in is slowed
- Higher front also loads the already soft rear even more causing the front to do more work because more weigh is transferred to the rear making existing matters worse!
- Throws off the bikes balance because of the same reason(too much rear weight bias)
- Soft rear causes the front to just skim along the road bouncing over bumps instead of absorbing them because the weight is transferred to the soft rear instead!

Once I installed the correct Rear spring it transformed the entire bike and the front started working right again!
See my "Transformed WOW" thread. http://www.vfrdiscus...ransformed-wow/
ps a basic answer to needing a valve change going from a .90 to a .85, NO!


BR

[image: View Post]BaileyRock, on 29 June 2010 - 07:52 PM, said:

First off how much do you weigh?

Also is your rear shock stock along with a stock spring?

What I found when installing stiffer springs up front (.95's) along with revalving (but not changing the rear at all) was that the front felt somewhat better, but was bouncing off small bumps much more and didn't seem to handle as well. I wasn't really happy! Until I stiffened up the rear also! :fing02:
Turns out that adding stiffer springs to the front only actually screws up many things like the following:
- Front rides higher all the time so turn-in is slowed
- Higher front also loads the already soft rear even more causing the front to do more work because more weigh is transferred to the rear making existing matters worse!
- Throws off the bikes balance because of the same reason(too much rear weight bias)
- Soft rear causes the front to just skim along the road bouncing over bumps instead of absorbing them because the weight is transferred to the soft rear instead!

Once I installed the correct Rear spring it transformed the entire bike and the front started working right again!
See my "Transformed WOW" thread. http://www.vfrdiscus...ransformed-wow/
ps a basic answer to needing a valve change going from a .90 to a .85, NO!


BR



Jamie D. rebuilt a stock shock for me with a 1050 #/in spring and gold valves. I started off with a 1200 which was WAY too stiff, but with the 1050, it's perfect. I weigh about 175-180 #s with gear. The bike is dialed in, but sometimes I feel the front a bit too stiff for daily riding. I could live with it as is, but am willing to test out some 0.85s. However, as Seb stated, maybe this could be corrected by removing some oil. I don't know the first thing about adjusting the valving, though.

[image: View Post]jaimev34, on 29 June 2010 - 09:16 PM, said:

Jamie D. rebuilt a stock shock for me with a 1050 #/in spring and gold valves. I started off with a 1200 which was WAY too stiff, but with the 1050, it's perfect. I weigh about 175-180 #s with gear. The bike is dialed in, but sometimes I feel the front a bit too stiff for daily riding. I could live with it as is, but am willing to test out some 0.85s. However, as Seb stated, maybe this could be corrected by removing some oil. I don't know the first thing about adjusting the valving, though.


Yep, a 1200 is way too stiff for your weight, hell the 1050 is kind of stiff for someone weighing only 160 no gear IMO! :huh:

Fork oil level mostly effects the last part of stroke(bottoming) the most, but will have a slight effect overall. I don't know what weight fork oil he used, but maybe light would help?

BR

As I recall, I set your shock up softer than I would prefer (normally I would suggest something higher than the 1050lb/in). Based on that I'd say you seem to like a softer spring setup. Using that logic a set of 0.85kg/mm forks springs should be ok. As for the valving, you are probably ok leaving it alone. Ideally you would make a correction for the change in spring rate but I don't think you would have any troubles leaving it as-is.

[image: View Post]JamieDaugherty, on 30 June 2010 - 04:12 PM, said:

As I recall, I set your shock up softer than I would prefer (normally I would suggest something higher than the 1050lb/in). Based on that I'd say you seem to like a softer spring setup. Using that logic a set of 0.85kg/mm forks springs should be ok. As for the valving, you are probably ok leaving it alone. Ideally you would make a correction for the change in spring rate but I don't think you would have any troubles leaving it as-is.


Thanks, Jamie.

Well, I wouldn't say I like a softer set up, just trying to get appropriate sag numbers. The 1200#/in was way too stiff. I was getting a max sag of 21mm or so with no preload. Now, I'm at 30-ish.

[image: View Post]jaimev34, on 30 June 2010 - 07:27 PM, said:

[image: View Post]JamieDaugherty, on 30 June 2010 - 04:12 PM, said:

As I recall, I set your shock up softer than I would prefer (normally I would suggest something higher than the 1050lb/in). Based on that I'd say you seem to like a softer spring setup. Using that logic a set of 0.85kg/mm forks springs should be ok. As for the valving, you are probably ok leaving it alone. Ideally you would make a correction for the change in spring rate but I don't think you would have any troubles leaving it as-is.


Thanks, Jamie.

Well, I wouldn't say I like a softer set up, just trying to get appropriate sag numbers. The 1200#/in was way too stiff. I was getting a max sag of 21mm or so with no preload. Now, I'm at 30-ish.


Do you have any Free Sag with the new spring? For street use you should have 5-15mm of Free Sag on the rear besides correct Rider Sag.

BR.

[image: View Post]BaileyRock, on 01 July 2010 - 08:19 AM, said:

[image: View Post]jaimev34, on 30 June 2010 - 07:27 PM, said:

[image: View Post]JamieDaugherty, on 30 June 2010 - 04:12 PM, said:

As I recall, I set your shock up softer than I would prefer (normally I would suggest something higher than the 1050lb/in). Based on that I'd say you seem to like a softer spring setup. Using that logic a set of 0.85kg/mm forks springs should be ok. As for the valving, you are probably ok leaving it alone. Ideally you would make a correction for the change in spring rate but I don't think you would have any troubles leaving it as-is.


Thanks, Jamie.

Well, I wouldn't say I like a softer set up, just trying to get appropriate sag numbers. The 1200#/in was way too stiff. I was getting a max sag of 21mm or so with no preload. Now, I'm at 30-ish.


Do you have any Free Sag with the new spring? For street use you should have 5-15mm of Free Sag on the rear besides correct Rider Sag.

BR.


Yes, that was another reason for the 1050 spring. I wasn't getting the free sag number I wanted. All fixed now. I can't remember what I have for free, but at the time it was within the desired range.

[image: View Post]jaimev34, on 01 July 2010 - 08:24 AM, said:

[image: View Post]BaileyRock, on 01 July 2010 - 08:19 AM, said:

[image: View Post]jaimev34, on 30 June 2010 - 07:27 PM, said:

[image: View Post]JamieDaugherty, on 30 June 2010 - 04:12 PM, said:

As I recall, I set your shock up softer than I would prefer (normally I would suggest something higher than the 1050lb/in). Based on that I'd say you seem to like a softer spring setup. Using that logic a set of 0.85kg/mm forks springs should be ok. As for the valving, you are probably ok leaving it alone. Ideally you would make a correction for the change in spring rate but I don't think you would have any troubles leaving it as-is.


Thanks, Jamie.

Well, I wouldn't say I like a softer set up, just trying to get appropriate sag numbers. The 1200#/in was way too stiff. I was getting a max sag of 21mm or so with no preload. Now, I'm at 30-ish.


Do you have any Free Sag with the new spring? For street use you should have 5-15mm of Free Sag on the rear besides correct Rider Sag.

BR.


Yes, that was another reason for the 1050 spring. I wasn't getting the free sag number I wanted. All fixed now. I can't remember what I have for free, but at the time it was within the desired range.



Cool, now you just need to get that front end dialed in. :fing02:

Just got a response from Racetech about switching out my 0.90s for 0.85s. They said they'll send me a pair of 0.85s for my 0.90s free! It's been six months. That's customer service.

Okay, I just checked my front suspension sags and here are the numbers:

My weight (without gear in t-shirt, shorts, and flip flops) = 182 lbs.
Gas tank = a little less than half full
Free sag (bike's weight) = 20mm
Rider sag (bike + me; did 2 measurements [extended and compressed] and averaged them out to account for stiction) = 32mm
Preload adjuster = all the way out. no preload. nada. zippo.

My gear probably weighs about 14 lbs. So my total weight with gear is around 196 lbs. I wonder how my sag numbers would change with gear on. Too hot to try it.

What do you guys think? Should I swap out the springs, or are these numbers good? Today, the suspension didn't feel bad at all. I'm thinking I should leave well enough alone.

Arent the stocker springs ---- .79?

[image: View Post]mello dude, on 03 July 2010 - 10:08 PM, said:

Arent the stocker springs ---- .79?


0.74, if I recall correctly.

Are your new springs progressive or otherwise?? 20 mm free and 32 mm w rider on is a little odd doncha'all think??

[image: View Post]Auspa�ol, on 04 July 2010 - 08:27 AM, said:

Are your new springs progressive or otherwise?? 20 mm free and 32 mm w rider on is a little odd doncha'all think??


Not progressive, I don't think.

I was pondering yesterday that free sag is an odd concept. Think about this: Let's suppose you've got a guy like Brock Lesnar, who walks around at somewhere near 390 lbs. He would probably need some really stiff springs on the VFR. Let's assume they're around 2.0 kg/mm, or whatever the measurement is. How much free sag, if any, will he be able to get out of those springs? Yet those are the springs necessary for the bike to be able to carry his big ass. I doubt the bike would even make the suspension budge on its own. It seems like the stiffer the spring, the lower the free sag, especially at the higher end of the spectrum. So, how important is free sag if there it becomes nonexistant with certain riders?

[image: View Post]jaimev34, on 04 July 2010 - 11:47 AM, said:

I was pondering yesterday that free sag is an odd concept. Think about this: Let's suppose you've got a guy like Brock Lesnar, who walks around at somewhere near 390 lbs. He would probably need some really stiff springs on the VFR. Let's assume they're around 2.0 kg/mm, or whatever the measurement is. How much free sag, if any, will he be able to get out of those springs? Yet those are the springs necessary for the bike to be able to carry his big ass. I doubt the bike would even make the suspension budge on its own. It seems like the stiffer the spring, the lower the free sag, especially at the higher end of the spectrum. So, how important is free sag if there it becomes nonexistant with certain riders?



Exactly, you have hit the nail on the head. I've been blasted on here for stating that free sag doesn't really mean anything, and I'm sure it will happen again. But don't take my word for it..........

http://www.promecha....and_preload.htm

You will note that he identifies three basic problems with using free sag. I personally like #2 where he explains that using free sag and rider sag to determine spring rate will net you the same spring rate for a given rider on a 650lb cruiser and a 160lb GP bike. That's a pretty clear explanation on how free (static) sag doesn't get you where you need to be.

This is just another reason to get with a trusted tuner with experience setting up lots of riders on your particular bike. They will have the data to support their approach and be able to help you dial in your bike to suit your needs/desires.

[image: View Post]JamieDaugherty, on 04 July 2010 - 12:02 PM, said:

[image: View Post]jaimev34, on 04 July 2010 - 11:47 AM, said:

I was pondering yesterday that free sag is an odd concept. Think about this: Let's suppose you've got a guy like Brock Lesnar, who walks around at somewhere near 390 lbs. He would probably need some really stiff springs on the VFR. Let's assume they're around 2.0 kg/mm, or whatever the measurement is. How much free sag, if any, will he be able to get out of those springs? Yet those are the springs necessary for the bike to be able to carry his big ass. I doubt the bike would even make the suspension budge on its own. It seems like the stiffer the spring, the lower the free sag, especially at the higher end of the spectrum. So, how important is free sag if there it becomes nonexistant with certain riders?



Exactly, you have hit the nail on the head. I've been blasted on here for stating that free sag doesn't really mean anything, and I'm sure it will happen again. But don't take my word for it..........

http://www.promecha....and_preload.htm

You will note that he identifies three basic problems with using free sag. I personally like #2 where he explains that using free sag and rider sag to determine spring rate will net you the same spring rate for a given rider on a 650lb cruiser and a 160lb GP bike. That's a pretty clear explanation on how free (static) sag doesn't get you where you need to be.

This is just another reason to get with a trusted tuner with experience setting up lots of riders on your particular bike. They will have the data to support their approach and be able to help you dial in your bike to suit your needs/desires.


One problem with only taking into account rider sag, though, is that two different people with different weights can achieve a desired sag number on the same bike by increasing or reducing preload. Yet one, or neither, may have the correct spring for their weight. For example, I was able to get around 35 mm of rider sag on my stock springs, and I'd probably be able to get 35mm on a set of 0.85s or a set of 0.65s, for that matter.

What do you think about a max rider sag of 32mm on a VFR, without any preload?

[image: View Post]jaimev34, on 04 July 2010 - 12:16 PM, said:

What do you think about a max rider sag of 32mm on a VFR, without any preload?



32mm is perfect. If you want some adjustment I suggest you cutt off 5mm from the spacers. Then you will have to wind in 5mm with the adjusters to get back to where you are now.

[image: View Post]jaimev34, on 04 July 2010 - 12:16 PM, said:

What do you think about a max rider sag of 32mm on a VFR, without any preload?


Maybe a little stiff if you prefer a plusher ride, but it's perfectly within the typical 30-40 mm range (based on the common theory that sag should be 1/4 - 1/3 the fork travel, and fork travel on the VFR = 120 mm). If you often carry a tank-bag or a copilot up the back, then it may be to your advantage to stay as is.

I've never bothered with measuring free sag, although if the set-up has a tad of free sag I can see how it would make the ride less harsh. Obviously you hit the nail on the head in that people outside a certain weight range (over the average weight range) will get no free ("static") sag with springs that give them the right "dynamic" sag. I guess it also depends on the weight of the bike...

In the end, the proof of the pudding is in the handling and if YOU'RE happy with it...

Maybe those measurements you posted that surprised me have to do with them not being progressive. Not that I'd be concerned.

Do you take you're bike to the limit?? I weigh 90 kg and am 195 cm tall... I've pushed my VTEC to the limit at race-tracks and on (public) mountain roads and whilst I agree in that the stock suspension leaves a lot to be desired, mine is stock and has 80,000 km worth of "fatigue" and I haven't been thrown off the bike or had an accident due to suspension issues.

Obviously if you can get her set-up better, the ride will be better... in fact, too hard a suspension may be potentially worse than soft stuff...

Just thinking out loud... I'm a long long way from being an expert... I just like to ride.

Just got back from a 130 mile-long ride today, and the suspension behaved wonderfully. I think I'm finally understanding the whole spring stiffness thing. Going to a softer or harder spring doesn't have as much to do with sag as it has to do with the harshness or plushness of the ride. Preload is simply ride height adjustment. If I were to go down to .85s, my sag would probably increase, but if I don't feel the ride as being harsh now, it's not necessary. However, since I'm not using 100% of my travel, I'm thinking I may cut the spacers a few mm. I have about half an inch of travel that is unused, as measured by a zip tie.

[image: View Post]Auspa�ol, on 04 July 2010 - 01:13 PM, said:

Maybe a little stiff if you prefer a plusher ride, but it's perfectly within the typical 30-40 mm range (based on the common theory that sag should be 1/4 - 1/3 the fork travel, and fork travel on the VFR = 120 mm).


FYI - The VFR800 has 109mm of front wheel travel. Maybe you are thinking of the rear, it's 120mm. If you re-run you numbers using 109mm you'll find that 32mm of rider sag is smack in the middle of the range of 27-36mm.

[image: View Post]jaimev34, on 04 July 2010 - 06:11 PM, said:

However, since I'm not using 100% of my travel, I'm thinking I may cut the spacers a few mm. I have about half an inch of travel that is unused, as measured by a zip tie.



You might try leaving it alone for a while. I find that I don't use all of the travel in a 'typical' ride, yet after a week or so the zip tie is fully pushed back. It's best not to bottom if you can help it. Leaving a bit of travel in reserve for those unforseen big bumps might not be a bad idea.

[image: View Post]JamieDaugherty, on 05 July 2010 - 10:08 AM, said:

[image: View Post]jaimev34, on 04 July 2010 - 06:11 PM, said:

However, since I'm not using 100% of my travel, I'm thinking I may cut the spacers a few mm. I have about half an inch of travel that is unused, as measured by a zip tie.



You might try leaving it alone for a while. I find that I don't use all of the travel in a 'typical' ride, yet after a week or so the zip tie is fully pushed back. It's best not to bottom if you can help it. Leaving a bit of travel in reserve for those unforseen big bumps might not be a bad idea.


Yes, I'm leaving it alone. Yesterday, I opened up one of the forks to see how long the spacer was and what it was made out of. It looks like Racetech used the original metal spacers, and I don't have the equipment to cleanly cut them, so I'm leaving it alone. I leave the zip tie on full time and have noticed that I'm always about 3/4 of an inch away from bottoming out, and I practice high speed stops and have hit big potholes and bumps. I know I can measure the spacer and make a couple or PVC replacement spacers that are about 5mm shorter, but for now, I'll let it be.