Suspension Upgrade Time

[Guest russell62]

I finally sold my Multistrada so it's time to burn some money. Unfortunately my plan to get a track bike didn't work out so I'm going to upgrade my 6th gen to handle both commuting and track duties. I spent most of the night, not an exageration, reading the posts on this topic but still have questions.

MY GOAL:

Get the bike to function like a decent sports touring bike on the track without trying to make it something it's not, like a race replica.

A LITTLE ABOUT WHAT I'M WORKING WITH...

I'm 155lbs on a heavy day and tend to push pretty hard. I have never had the stock suspension bottom out on me and honestly it doesn't feel all that crappy. My Multi 620 felt lower grade by comparison.

The fork preload is set halfway between standard (second notch) and the top notch. The shock is set on the 4th setting which is 2 stiffer than standard. Sag has been set by a Racetech rep at a track day and it's good.

It should be noted that I am the 3rd owner of the bike and have no idea who the original was. The original owner had a service manual, which I now have, and the pages covering the rebuilding of the forks shows the obvious sings of use. Page 13-27 has a hand written note that reads "6 x 9" with "540" under it. The "540" is underscored.

Anybody have an idea what those notes might refer to? I wonder if a suspension upgrade has already been made....

SO NOW, WHAT TO DO?

From what I've read, I'm the weight that the bike was designed for. Does that mean I don't need to fool with springs? That would be excellent!

I've read that a compression revalve is a good way to go and am planning to use the Racetech Gold Valves. I've also read that a rebound revalve isn't as important for high speed stuff which is what I'm interested in dialing in. Is that true?

Are Sonic Springs compatible with Gold Valves? I'd like to save money where I can.

I'm also not sure how I feel about Racetech's formula for spring rate. They would like me to have a .95kg fork spring but a lighter than standard shock spring. How can that be?

THREE OPTIONS THAT COME TO MIND:

1) .90kg front springs with compression Gold Valves and a 17kg rear spring (highest Racetech has and I'm trying maintain Honda's balance formula). $390 or $360 if the Sonic's will work.

2) Keep the springs standard and revalve both fork compression and rebound with Gold Valves. $340

3) Just revalve fork compression with Gold Valves. $170

Ok suspension guru's, let's hear it!

[HispanicSlammer]

Well vfr springs are progressive, wound tighter at the bottom end so that they bind up and remove the number of coils that are active, making the spring rate that much higher - to use them with gold valves will mess up the action making high speed damping seem very harsh. gold valves are designed for single rate springs. If you go with Gold vavles you will also have to use lighter fork oil than stock so the stock rebound valves will not do, not unless your willing to put in the time to develop a proper shim stack for the stock shims with lighter wieght oil? In other words one compression gold valve will leave you underdamped on the rebound if you use the recommended 5w oil for goldvavles. If your going to go with Gold vavles then do the whole thing cause it is designed as a complete system springs oil and both vavles.

I did it all myself - its not too difficult to do if you have a garage and a decent set of tools. I have invested in a vice with soft jaws that dont damage the forks, fork seal drivers, a small screwdriver to remove the circlips. metric wrenches and sockets, metric hex drives, perhaps an impact driver if the cassette spins around the oil lock bolt. A lift to put under the header to lift the front wheel, or a front stand under the triple tree.

As far as a shock goes, there is a group buy for a pretty decent 3 way shock in the bargain finder forum you can get it sprung for your wieght! Aftermarket has some good products out there.

[Baileyrock]

First off I think the .95's are WAY too stiff for your weight! That's what I use at 190-200 lbs. I would think .85's max and even that could be a little firm even for the track at your weight. Stocks are .74's front and 15.3 kg rear.

You could use HS's spring rate calculator mod to stiffen your stock springs and save another $100.

At your weight I would think you would be an ideal candidate for a CBR 929 shock swap, this requires a mod to a bracket on the rear sub frame and a spacer for the top of the shock. But it's a far better & fully adjustable shock vs a VFR unit and it's sprung the same as a VFR which could work for you. These can be had for less than $50 on ebay and all you really need is a spacer mod.

You can find the 929 swap in it's own thread or my "vtec shock options "thread in the 6th gen forum. :biggrin:

You can re-shim the stock fork valves, but I would try to find the older CBR showa valves that used the larger ports and use these on the comp side w/re-shimmed stock rebound valves. This is the set-up I'm using on my track vtec. Jamie Daughtry hooked me up with some shim stacks and it worked great! :goofy:

ps I think the 6x9 & 540 in the notes on the manual are the weight of a flat bed trailer he was looking to buy! :fing02:

BR

[AB-Oz]

The first thing I would do is try to work out how many miles are on the front springs, and when was the last time the fork oil was changed?

The second thing I would do would be to pull the forks (the manual says how - as to the How-To's on this forum), check the springs for still within spec, and change the oil out with some new stuff.

Then ride it for a while and see how it feels before shelling out bigger bucks on fork internals...

[JBAXX]

Here's my take:

If you're looking to spend money on suspension upgrades, I would follow Baileyrock's advice to the T. The guy knows what He's talking about.

However, if the bike "doesn't feel all that crappy" as you say, and the sag has been set by a Racetec technician at the track, I would just change the fork oil and ride the pee pee out of it!

The reason I say that is because I have owned several bikes with modded-out, upgraded suspension (Ohlins, Racetec, Traxxion Dynamics), yet when I ride my VFR, I never think about what the suspension is doing - meaning it works pretty well for me the way I have it set up, and it sounds like it works pretty well for you too.

I also own a Superhawk with stock suspension, and all those guys at Superhawkforum gripe about how crappy the suspension is with the wimpy fork springs and flexy forks, but with time spent riding and adjusting the bike to my liking, I've got it working just fine.

So, in summary, if you are having specific issues that you are unable to remedy with the stock suspension, by all means upgrade. On the other hand, if it works, just ride it! :biggrin:

[Guest]

Thanks guys. It took me a while to work through the posts that were referenced and then I had to go take a nap after reading HS's spring rate calculator!

As for the state of my forks, they have over 55k miles on them. I just had new seals and oil done about 3k miles ago.

Here's what I got from it and what I think at this point.

Doing HS's spring mod to make em stiffer is good if I want stiffer springs, which I'm not sure I need, but won't work with the Racetech valves due to the spring still being progressive.

However, per Baileyrock I could use old CBR valves and theoretically combine them with HS's mod to achieve a setup similar to Racetech's for pennies on the dollar right?

I don't think I'm in for a rear shock swap but I'm not above spending the $100 to get a Racetech spring that would match the above setups rate.

Does that make sense or am I going down the wrong path?

Am I just throwing my money away if I don't just step up and do it "right"?

[Guest]

Spend $20 and go to Amazon.com and purchase a copy of Andrew Trevitt's Sportbike Suspension Tuning. Read it front to back before you start any mods. It will give you a great feel for where you're at and where you want to wind up.

Trevitt is a senior editor of Sport Rider magazine.

[Guest]

Spend $20 and go to Amazon.com and purchase a copy of Andrew Trevitt's Sportbike Suspension Tuning. Read it front to back before you start any mods. It will give you a great feel for where you're at and where you want to wind up.

Trevitt is a senior editor of Sport Rider magazine.

Thanks. I'll check it out.

[JamieDaugherty]

From what I've read, I'm the weight that the bike was designed for. Does that mean I don't need to fool with springs? That would be excellent!

Not really. Nobody is perfect because the front does not match the rear. I calculate that you need 0.90kg/mm springs up front (stock is 0.74kg/mm) and a 20.3kg/mm spring out back (stock is 15.3kg/mm!). As you can see, you need much heavier springs.

I've read that a compression revalve is a good way to go and am planning to use the Racetech Gold Valves. I've also read that a rebound revalve isn't as important for high speed stuff which is what I'm interested in dialing in. Is that true?

Correct. I only upgrade the rebound valves for track-only use. Even so, I go with a different shim stack on the stock rebound valves which helps.

Are Sonic Springs compatible with Gold Valves? I'd like to save money where I can.

Absolutely. The valves don't know what brand springs you are using. The most important thing is that the springs are linear rate, which both RaceTech and Sonic are.

I'm also not sure how I feel about Racetech's formula for spring rate. They would like me to have a .95kg fork spring but a lighter than standard shock spring. How can that be?

Yeah, I've been trying to get them to change it. See above for what I use.

THREE OPTIONS THAT COME TO MIND:

1) .90kg front springs with compression Gold Valves and a 17kg rear spring (highest Racetech has and I'm trying maintain Honda's balance formula). $390 or $360 if the Sonic's will work.

2) Keep the springs standard and revalve both fork compression and rebound with Gold Valves. $340

3) Just revalve fork compression with Gold Valves. $170

Ok suspension guru's, let's hear it!

Here is what I would suggest including what I would charge for the work:

Forks - New springs (Sonic is what I install), RT compression valves and new shim stack on stock rebound valves. $305

Shock - New spring and RT valve. $295

Both prices include installation. Something you didn't mention was the rear shock spring - it requires special equipment to remove and install. This might be important in case you were wanting to do the work yourself!

I hope this helps!

[Baileyrock]

I calculate that you need 0.90kg/mm springs up front (stock is 0.74kg/mm) and a 20.3kg/mm spring out back (stock is 15.3kg/mm!). As you can see, you need much heavier springs.

Jamie,

I think something is way off in this rear spring rate calculation, 20kg for a 155 lb guy!!! :ph34r:

Please check your numbers again if you would, I found a 19kg rear to be about perfect for my 190lb azz. :biggrin:

Jamie does great work and he's done good things for me too! :fing02:

BR

[Guest]

From what I've read, I'm the weight that the bike was designed for. Does that mean I don't need to fool with springs? That would be excellent!

Not really. Nobody is perfect because the front does not match the rear. I calculate that you need 0.90kg/mm springs up front (stock is 0.74kg/mm) and a 20.3kg/mm spring out back (stock is 15.3kg/mm!). As you can see, you need much heavier springs.

I've read that a compression revalve is a good way to go and am planning to use the Racetech Gold Valves. I've also read that a rebound revalve isn't as important for high speed stuff which is what I'm interested in dialing in. Is that true?

Correct. I only upgrade the rebound valves for track-only use. Even so, I go with a different shim stack on the stock rebound valves which helps.

Are Sonic Springs compatible with Gold Valves? I'd like to save money where I can.

Absolutely. The valves don't know what brand springs you are using. The most important thing is that the springs are linear rate, which both RaceTech and Sonic are.

I'm also not sure how I feel about Racetech's formula for spring rate. They would like me to have a .95kg fork spring but a lighter than standard shock spring. How can that be?

Yeah, I've been trying to get them to change it. See above for what I use.

THREE OPTIONS THAT COME TO MIND:

1) .90kg front springs with compression Gold Valves and a 17kg rear spring (highest Racetech has and I'm trying maintain Honda's balance formula). $390 or $360 if the Sonic's will work.

2) Keep the springs standard and revalve both fork compression and rebound with Gold Valves. $340

3) Just revalve fork compression with Gold Valves. $170

Ok suspension guru's, let's hear it!

Here is what I would suggest including what I would charge for the work:

Forks - New springs (Sonic is what I install), RT compression valves and new shim stack on stock rebound valves. $305

Shock - New spring and RT valve. $295

Both prices include installation. Something you didn't mention was the rear shock spring - it requires special equipment to remove and install. This might be important in case you were wanting to do the work yourself!

I hope this helps!

Jamie, thanks for the info. Threads by you and Baileyrock are what I'm basing a lot of my decision on.

Ok, I am indeed planning to do the work myself as I never pass up the opportunity to screw up my own bike :biggrin:

So I will probably go with sonic springs and RT compression valves. Can you build me a rebound shim stack that's ready for install and mail it to me?

As for the shock spring, I can't afford the valve job just yet but I can afford a spring. Is the special tool required to remove the shock or the spring? If I can pull the shock without anything special, I'll just have RT swith the spring out since I live close by.

[Baileyrock]

As for the shock spring, I can't afford the valve job just yet but I can afford a spring. Is the special tool required to remove the shock or the spring? If I can pull the shock without anything special, I'll just have RT swith the spring out since I live close by.

I would still recommend the 929 shock swap with stock spring, should be less than a $100 for a fully adjustable rear shock that's sprung the same as the current rear shock that you say feels good to you as is! :unsure:

Ask Jamie if he can set you up with the same comp. valve set-up and shim stacks he did for me and you can install them yourself! :fing02:

[jasonsmith]

so I guess just changing the springs alone up front is not a good idea... Is there a standard valve spring setup that can be purchased and installed or does it take a pile of endless tweaking?

[Baileyrock]

so I guess just changing the springs alone up front is not a good idea... Is there a standard valve spring setup that can be purchased and installed or does it take a pile of endless tweaking?

Actually a spring change alone can be a decent mod depending on how big a change it is.

How much do you weight?

[jasonsmith]

so I guess just changing the springs alone up front is not a good idea... Is there a standard valve spring setup that can be purchased and installed or does it take a pile of endless tweaking?

Actually a spring change alone can be a decent mod depending on how big a change it is.

How much do you weight?

I decided a long time ago that I was going to copy you BR. I vary from 200 to 220lbs a year so was going to go with .95's up front and a 19.5 Elka in the rear. Was hoping to just do the springs in the front but don't wanna stop short just because I'm lazy. Gotta admit though the whole valve thing makes my head spin a bit.

[Guest]

As for the shock spring, I can't afford the valve job just yet but I can afford a spring. Is the special tool required to remove the shock or the spring? If I can pull the shock without anything special, I'll just have RT swith the spring out since I live close by.

I would still recommend the 929 shock swap with stock spring, should be less than a $100 for a fully adjustable rear shock that's sprung the same as the current rear shock that you say feels good to you as is! :unsure:

Ask Jamie if he can set you up with the same comp. valve set-up and shim stacks he did for me and you can install them yourself! :fing02:

I hear ya on the 929 shock but wouldn't that spring be insufficient if I moved to a higher fork spring rate. From what you have said in your other threads, it's important to maintain the balance Honda achieved in the first place.

Also, I read a bit about the 929 shock and it seems like a PITA for my 6th gen. I could probably get someone to do a decent bracket but I read that I'd have to cut and weld under the subframe to get the resevoir to fit. Not really something I want to do.

Are you really against just makeing sure the rear shock spring rate matches the front?

As for the valve/shims Jamie set up for you, aren't they spring rate specific? Meaning I would need a different stack for a lighter spring rate.

[Guest]

Perhaps I've been too hasty regarding the 929 option. I re-read the VTEC shock options thread and a couple things interest me.

I noticed that Jamie was working on manufacturing a bracket for the 954 shock to better fit the 6th gens. My only concern with that is that the 954 is sprung lighter than our stock VTEC shocks.

Jamie, you seem to be the expert regarding the shock modifications. What would be the easiest and best functioning way to go to match a .90 fork spring rate which is what I plan to go with?

Very exciting stuff :unsure:

[Baileyrock]

I hear ya on the 929 shock but wouldn't that spring be insufficient if I moved to a higher fork spring rate. From what you have said in your other threads, it's important to maintain the balance Honda achieved in the first place.

Are you really against just makeing sure the rear shock spring rate matches the front?

As for the valve/shims Jamie set up for you, aren't they spring rate specific? Meaning I would need a different stack for a lighter spring rate.

No, what I'm suggesting based on you saying you like the bike currently is not changing springs on either end and run the 929 shock, the fully adjustable shock would allow much more control of the bikes transitions.

You can and should change out the comp valve to the older large port one I mentioned and have Jamie set you up on shim packs. I still think the .90 front might also be a little stiff for your needs & weight, .90's are 22% stiffer, .85's 15% stiffer and .80 10% stiffer.

I wouldn't want to make to big of a change w/o changing the rear also, 10% maybe 15%. Many people on here just add stiffer front springs and ride, say it feels much better! :fing02:

You can get away with a little softer rear by using the extra comp adjustments to control things, but nothing better than having the ideal springs and bike balance. :goofy:

PS Jamie is smarter than I am on this crap. :unsure:

[Guest]

I hear ya on the 929 shock but wouldn't that spring be insufficient if I moved to a higher fork spring rate. From what you have said in your other threads, it's important to maintain the balance Honda achieved in the first place.

Are you really against just makeing sure the rear shock spring rate matches the front?

As for the valve/shims Jamie set up for you, aren't they spring rate specific? Meaning I would need a different stack for a lighter spring rate.

No, what I'm suggesting based on you saying you like the bike currently is not changing springs on either end and run the 929 shock, the fully adjustable shock would allow much more control of the bikes transitions.

You can and should change out the comp valve to the older large port one I mentioned and have Jamie set you up on shim packs. I still think the .90 front might also be a little stiff for your needs & weight, .90's are 22% stiffer, .85's 15% stiffer and .80 10% stiffer.

I wouldn't want to make to big of a change w/o changing the rear also, 10% maybe 15%. Many people on here just add stiffer front springs and ride, say it feels much better! :wheel:

You can get away with a little softer rear by using the extra comp adjustments to control things, but nothing better than having the ideal springs and bike balance. :fing02:

PS Jamie is smarter than I am on this crap. :fing02:

Well I'm not totally sold on the need for stiffer springs. I did drag my header at the track but I am pretty sure it's because I totally screwed up a corner and chopped the throttle at apex. I figure even stiff springs would have a hard time keeping the bike front hitting with shennanigans like that :goofy:

As such, I've also been thinking about your F4i fork swap. I did a quick check of parts on Ebay and found newish forks, calipers, master cylinder and fender for about $300 at the buy it now prices.

The F4i shocks have a lower spring rate than the VTEC. Since the forks are the same size, and you are suggesting I use the compression valves, I assume I can simply put my VTEC springs in the F4i forks and WHAM! I got me a fancy set of adjustable forks :fing02:

How do (did) you like the F4i setup on your bike? Did the brakes take less lever effort? Do you have an opinion about whether that setup is better than a RT gold valve setup would be in the VTEC's non-adjustable forks?

This combined with a 929/954 swap seems like an interesting idea for about the same cash.

[Baileyrock]

The F4i shocks have a lower spring rate than the VTEC. Since the forks are the same size, and you are suggesting I use the compression valves, I assume I can simply put my VTEC springs in the F4i forks and WHAM! I got me a fancy set of adjustable forks :wheel:

How do (did) you like the F4i setup on your bike? Did the brakes take less lever effort? Do you have an opinion about whether that setup is better than a RT gold valve setup would be in the VTEC's non-adjustable forks?

If I remember correctly F4i forks run .66 kg springs and F4 forks run .74kg(same as VFR)springs. I'm not sure the vtec fork springs will work in the F4i forks as they could be different lengths? :fing02:

The F4i forks are fully adjustable but run the same small port Honda Hmas valves used in the VFR, but if you don't plan on running stiffer springs the stock valves & valving on the f4i forks could work OK for you w/o change. just install some good syn fork oil and add 10cc extra to each leg, this will stiffen the last part of travel and help prevent bottoming under heavy braking. :fing02:

I was very surprised at just how good the F4i forks (with the shim stacks and larger port Showa comp valves that Jamie set me up with) felt, no doubt this is a better set-up than any modded VFR forks.

Brake wise, I ran a radial master cylinder instead of the stock F4i m/s it it works far better. GSXR or R6 stock type radial m/s work well and can be found for decent prices on ebay.

BR

[marid2apterbilt]

The F4i shocks have a lower spring rate than the VTEC. Since the forks are the same size, and you are suggesting I use the compression valves, I assume I can simply put my VTEC springs in the F4i forks and WHAM! I got me a fancy set of adjustable forks

How do (did) you like the F4i setup on your bike? Did the brakes take less lever effort? Do you have an opinion about whether that setup is better than a RT gold valve setup would be in the VTEC's non-adjustable forks?

If I remember correctly F4i forks run .66 kg springs and F4 forks run .74kg(same as VFR)springs. I'm not sure the vtec fork springs will work in the F4i forks as they could be different lengths?

The F4i forks are fully adjustable but run the same small port Honda Hmas valves used in the VFR, but if you don't plan on running stiffer springs the stock valves & valving on the f4i forks could work OK for you w/o change. just install some good syn fork oil and add 10cc extra to each leg, this will stiffen the last part of travel and help prevent bottoming under heavy braking.

I was very surprised at just how good the F4i forks (with the shim stacks and larger port Showa comp valves that Jamie set me up with) felt, no doubt this is a better set-up than any modded VFR forks.

Brake wise, I ran a radial master cylinder instead of the stock F4i m/s it it works far better. GSXR or R6 stock type radial m/s work well and can be found for decent prices on ebay.

BR

I put F4 internals in my VFR forks, I assume the VFR springs will work in the F4 forks by adjusting the size of the spacer needed. PVC pipe can be used for this.. Just a assumption..

[Guest]

I didn't realize the difference between the F4 and F4i forks.

What forks do the "old showa" valves come from?

[Baileyrock]

I didn't realize the difference between the F4 and F4i forks.

The only difference I know of is the difference in spring rates, not sure if they had different shim stacks or not! :laugh:

What forks do the "old showa" valves come from?

I think they were in early F3 forks? :goofy:

[Guest]

I just PM'd Jamie and asked about putting the VTEC springs in the F4i forks. If it's possible, I may go that route and see how the extra tunability works out with the VTEC's stock spring rate. I have to admit I really like the idea of de-linking the brakes which would hopefully get me more stopping power with less lever effort. I would also track down the F3 compression valve you mentioned for that job and maybe get Jamie to build me a rebound shim stack (that's another thing I asked about).

I can always get stiffer springs afterwards if I feel it's still needed.

If that doesn't work, I'll try to track down the F3 compression valve, get the custom rebound shim stack and order a set of .85kg RT springs (Sonic only goes as low as .90kg on their site). I'll also get a matching shock spring or swap to a 929/954 shock depending on Jamie's answer about the bracket.

I hope to be ordering parts, whatever they may be, by next week so I can get this done before the track day season starts again.

[spud786]

at 155 you should be able to make the stock forks work, without money.

I can run 1 ft deep wash board at 100 mph, its stable with modded set up stock forks , sure the rear bottoms alittle , I'm 200 lb Nakid and 65,000 mile so the system has wear

I should note , brand new off the floor vfr , front end diving and rear kicking like crazy under this condition cause forks were way too soft.

the issue with stock set up its too soft, but if you havent even done a oil change and set up, you should atleast try that especially since light weight, unless your gaming for world cup of road race, and want to spend the mula.