Looking To Upgrade Fork Guts. How Far Should I Go?

[1TallTXn]

2002 VFR800 non-ABS 37,000mi

Was looking into rebuilding my forks and was poking around the RaceTech site.

The list of products I'm seeing is as follows

Type 1 Gold Valve Kit – Standard Type 1 Compression Kit, $170

G2-R Gold Valve Kit - G2-R Next Generation Compression Kit, $180

Fork Rebound Gold Valve Kit $170

I'm not going with the race rebound kit

Then of course theres the springs, oil, and bushings that will go along with it.

My question is, Should I go with the compression and rebound kits or just one or the other.

Basic logic tells me I should put them both in there for the best results. Right?

thanks for your input!

[Guest]

Put them both in - along with the correct springs for your weight.

Tell RaceTech to predrill the #55 hole before they ship the GR-2 valves to you. The area where the hole goes is tiny and a real bear to drill. Have them do it for you.

[sckego]

I had my front suspension resprung and installed the Type 1 Gold Valve Kit, per the advice of user JamieDaugherty on this site. I also bought the springs and valve kit through him, and had them installed at a local shop near me. You can read the discussion in this thread for more info...

[1TallTXn]

Believe I'm gonna call Piper Performance in DFW and have a chat.

Oddly enough, RaceTech says I should go to a softer rear spring then stock.

[pres589]

Oddly enough, RaceTech says I should go to a softer rear spring then stock.

I think the rear spring on these bikes, like a lot of motorcycles these days, are sprung with a one size fits all mentality, and part of that size includes two-up riding. If you don't tour a lot or run with a passenger much then software may be better.

Personally I just wish the rear shock was much more heavily damped in both compression and rebound, especially rebound, the spring itself feels about right to me.

[FotoMoto]

If you're going to pay for the labor, it makes more economic sense to have everything done at once.

Warning: any improvement in the front end will only magnify the shocks' short comings.

[1TallTXn]

I think the rear spring on these bikes, like a lot of motorcycles these days, are sprung with a one size fits all mentality, and part of that size includes two-up riding. If you don't tour a lot or run with a passenger much then software may be better.

2-up is not common now, but is in mind. Most frequent duty is commuting duty.

If you're going to pay for the labor, it makes more economic sense to have everything done at once.

Warning: any improvement in the front end will only magnify the shocks' short comings.

I'll most likely do that labor myself, and I don't want to pull it apart again.

The rear is on the to-do list, just waiting for funds. Once funds come around, I'll probably replace the whole unit. But as I said, later.

[Baileyrock]

How much do you weigh?

Don't forget we (VFRD) get a 15% discount at Race Tech! :biggrin:

[1TallTXn]

How much do you weigh?

Don't forget we (VFRD) get a 15% discount at Race Tech! :biggrin:

Sans gear: ~170lbs

oooh! I like discounts! is there a code to punch in for that?

[sckego]

Warning: any improvement in the front end will only magnify the shocks' short comings.

:biggrin:

I had a two-week window between when I had the new front suspension done, and when I got my Wilbers in to put on the rear. It felt reaally odd during those two weeks... stiff front and underdamped rear. All I was doing was commuting, not engaging in any sport stuff, so I figured I'd be OK... but I'm not sure if I would have felt comfortable pushing anything with a mismatched suspension like that. Then again, I'm close to 200 sans gear, so the difference was probably greater for me then it would be for you.

[Trace]

Lots of good advice above, and since I've done the full-on RaceTech deal including the additon of F3 fork guts (for rebound adjustability) I want to add that you need to carefully consider the settings that RT calls for vs. what you use your bike for. [Racing vs. Commuting!!] I went with .95 springs instead of the 1.00s that are typically recommended, and a No. 33 compression stack instead of the more racy and more punishing No. 35 stack that is recommended. I'm 195 and it's goooood! The basic rebound valving is totally dependent on the spring, so you can follow their recommendations on that one. Too much is NOT good!!However, I used a No. 16 stack for rebound instead of the harder [slower) recommended baseline stack of 18, because I can adjust more rebound into my forks if need be via the F3 guts (see picture). So, if you change the spring (duh!) you need to change the rebound valving to prevent a pogostick problem.

Yeah, ask them to drill the #55 hole in the comp valve for you. I've drilled several of them, and I think it's easy to screw up, and you won't need to find that tiny 55 drill.

And you should do everything at once--comp, rebound, springs, a little extra length on the spring spacers (RaceTech provides 'em) to give you more preload range (adjustability without having havnig them screwed all the way in), and bushings and seals. All of it!

Here's what a little extra spacer length allows you to have. I have LOTS of prelaod remaining, in case I should suddenly start dating a 325 lb gal!

Oh....and I have a Penske on the back. It's well worth the price of admission. Sag is easily set for one or two-up (I've premeasured the amount of preload (threads showing) needed for each, and made a handly little flat plastic gage that I keep in the toolbag. Compression is set on 2 (1, soft-6, hard) and rebound is at 50-50 (equal clicks between Hard and Soft). Love it.

[JamieDaugherty]

Sans gear: ~170lbs

oooh! I like discounts! is there a code to punch in for that?

I'd say you should have 0.90kg/mm springs. Stock is 0.74kg/mm, which is certainly too low for you.

I can also hook you with a discount on parts if you like. $150 including shipping. I'd also setup a rebound stack for you with that as well. It's ok to use the stock rebound valves but for best performance with the compression Gold Valves you'll want to adjust the rebound shim stack.

Revalving is not a job for the average mechanic. If you feel comfortable then go for it, if not let me know and I can help you out with the install as well.

[thx1139]

Could anyone post the RT setup instructions for their G2-R compression valves? I have a set of used preload adjustable 20mm valves, but no documentation.

[CornerCarver]

Lots of good advice here already. I did my forks myself with race tech gold valves and F3 fork internals. I played with the shim stacks and settled on the race tech 35 and ported the F3 valves myself. I purchased the F3 forks from ebay for $10 (bent) and used the internals. 0 weight oil and larger ports make for very sure and smooth riding. I push the front end harder than most and Trace has NoFL roads so go with a lighter end of Race Techs set up.

With your 6th gen I would recommend looking for damaged F4 forks and getting the entire set up at once.

I have an agressive street level set up that works great for me. I dont mind the additional harshness when by myself, and it is just right for 2 up riding.

[Trace]

I can also hook you with a discount on parts if you like. $150 including shipping. I'd also setup a rebound stack for you with that as well. It's ok to use the stock rebound valves but for best performance with the compression Gold Valves you'll want to adjust the rebound shim stack.

Jamie knows about what he speaks. He would be a good source of help for someone who isn't familiar with fork guts....IMHO.

Trace has NoFL roads so go with a lighter end of Race Techs set up.

Indeed, which was the thinking behind the .95 springs and the C33 compression stack for my setup.

[soichiro]

The racetech valves are worth every penny. I just did bushings (no wear in 50K miles) seals, and all the race tech stuff. Major improvement. I Highly reccomend it. Do it all once.

[thx1139]

I take it everyone is using the original GoldValves, no one on the G2-Rs ?

[SilverVee]

Lots of good advice above, and since I've done the full-on RaceTech deal including the additon of F3 fork guts (for rebound adjustability) I want to add that you need to carefully consider the settings that RT calls for vs. what you use your bike for. [Racing vs. Commuting!!] I went with .95 springs instead of the 1.00s that are typically recommended, and a No. 33 compression stack instead of the more racy and more punishing No. 35 stack that is recommended. I'm 195 and it's goooood! The basic rebound valving is totally dependent on the spring, so you can follow their recommendations on that one. Too much is NOT good!!However, I used a No. 16 stack for rebound instead of the harder [slower) recommended baseline stack of 18, because I can adjust more rebound into my forks if need be via the F3 guts (see picture). So, if you change the spring (duh!) you need to change the rebound valving to prevent a pogostick problem.

Yeah, ask them to drill the #55 hole in the comp valve for you. I've drilled several of them, and I think it's easy to screw up, and you won't need to find that tiny 55 drill.

And you should do everything at once--comp, rebound, springs, a little extra length on the spring spacers (RaceTech provides 'em) to give you more preload range (adjustability without having havnig them screwed all the way in), and bushings and seals. All of it!

Here's what a little extra spacer length allows you to have. I have LOTS of prelaod remaining, in case I should suddenly start dating a 325 lb gal!

Oh....and I have a Penske on the back. It's well worth the price of admission. Sag is easily set for one or two-up (I've premeasured the amount of preload (threads showing) needed for each, and made a handly little flat plastic gage that I keep in the toolbag. Compression is set on 2 (1, soft-6, hard) and rebound is at 50-50 (equal clicks between Hard and Soft). Love it.

Trace,

Guts from an F3, sounds too good to be true. Does it have to be a specific year in order to fit a 6th Gen?

and are the gold valves and springs the same for the F3 and the VFR (for ordering purposes)?

Adrian

[JamieDaugherty]

Trace has NoFL roads so go with a lighter end of Race Techs set up.

Indeed, which was the thinking behind the .95 springs and the C33 compression stack for my setup.

I'd probably go with a c34 stack with 5wt fluid. Of course, everyone's tastes will vary a little.

[Trace]

Trace,

Guts from an F3, sounds too good to be true. Does it have to be a specific year in order to fit a 6th Gen?

and are the gold valves and springs the same for the F3 and the VFR (for ordering purposes)?

Adrian

For a 6th Gen, it's F4 damper guts, but no specific year as far as I know. [All 6th Gens = F4 = 43mm forks, all 5th Gens = F3 = 41mm forks] It's been a few years since I did all this, but as I recall it's the same RaceTech Gold valves regardless of VFR or F-model forks. You can confirm this by using their selection "tool" on their website. Do it for your year of VFR and then do it for either and an F3 or F4.....you should see that they're the same. I know the springs are all the same...just varying stiffnesses of .90, .95, 1.00.

In the top pic below are shown the VFR guts (upper) and the F3 guts (lower). The F3 stuff shows the rebound adjustment rod. Also, you can see the progressive spring for the VFR and straight-rate RaceTech spring with the F3 stuff. Notice the differing lengths and you can see why you need make a longer spacer with the pipe stock supplied with the springs. As I mentioned in a prior post, I added a little more length to the spacers than needed for *only* the spring length differences, providing me with additional preload adjustment range that's in the picture of my fork top.

This is a closeup of the guts, same pic as above. One of the VFR tubes is obscured by the yardstick.

[Trace]

I'd probably go with a c34 stack with 5wt fluid. Of course, everyone's tastes will vary a little.

This is true. Everyone has differing feel that they're looking for. In my case, I didn't want to end up with a pogo-ing, kidney hammering ride just because I thought it might be "better". I spoke to Luie at RaceTech about my stack choices....and looking over my notes he basically said "our website recommendations are generally for competition setups. So the basic setup [#35 comp and #18 rebound] is pretty stiff. For a street bike on mostly highways, the 34 or 33 comp is fine, and with the .95 spring and adjustable rebound using the F3 parts, a #16 rebound would give you a nice, smooth ride with plenty of rebound control for that spring. You can crank up the adjustment if it's bouncy on rougher pavement." So....that's why I stayed on the conservative side of spring rates and valving, figuring that it would still be fantastically better than the weak Honda stuff. And on their website selection tool (with the access code that you get once you buy the valves), I put in "street rider, amateur" instead of "Nicky Hayden Wannabee" and got similar recommendations.

I think I ended up using 7.5 BelRay fluid. filled to exact OEM height using the Motion fork oil tool. Anyway, after several trips to those famous NC roads and riding two-up, the ziptie tell-tale on my fork tube is still about 1.25 inches away from the lower triple. So...no bottoming with my "softie" .95 spring and "cushy" #33 compression valve!

You know what I hate about working on forks? It's the friggin' endless drool of fork oil that gets all over everything and never seems to be done leaking out of something, somewhere. I hate that oil almost as much as I hate brake fluid....and I REALLY hate that nasty brake fluid! :biggrin:

[thx1139]

For a 6th Gen, it's F4 damper guts, but no specific year as far as I know. [All 6th Gens = F4 = 43mm forks, all 5th Gens = F3 = 41mm forks]

The only difference diameter-wise between 41 and 43mm cartridges is the outer part of the fork cap. You could screw F3 guts into a 43mm tube by changing out that one piece. [and conversely, F4 guts in a 41mm tube.]

One important detail that hasn't been mentioned is the different lengths of the rebound rods, and the respective extended lengths of their cartridges. Notice the F3 rods are shorter, but the top-out springs are located further up on the cartridge bodies. There's potential for trouble here. When assembling a hybrid fork, carefully check that it is topping-out correctly against that spring when extended; otherwise there is nothing preventing the end of the rebound from damaging the bearing in the top of the cartridge at full droop.

[Trace]

The only difference diameter-wise between 41 and 43mm cartridges is the outer part of the fork cap. You could screw F3 guts into a 43mm tube by changing out that one piece. [and conversely, F4 guts in a 41mm tube.]

Ummmm....are you dead-bang positive on this? I agree that it sounds plausible (as a "parts bin engineering change" for the 6th Gen 43mm stuff), but as you can see in my photo, the F3 cap has a longer cast aluminum lower section than the VFR cap. That lower cast portion is part of the whole cap (meaning the upper shiny part and the lower cast part is one piece.). I agree that the actual damper assembly for F3 and F4 could be the same (and definitely meaning the same valves, for sure), but I think you'd need the F3 or F4 cap to make it all work, not just the outer portion of the 5th or 6th VFR cap. So if you're eBaying, you'll want either the F3 or F4 forks for your 5th or 6th Gen, respectively.

Here's a closeup of the two fork tubes, same pic as my earlier post. VFR above, F3 below.

There's potential for trouble here.....there is nothing preventing the end of the rebound from damaging the bearing in the top of the cartridge at full droop.

Just don't do wheelies! :biggrin: :blink: [not true :dry: ]

[thx1139]

...the F3 cap has a longer cast aluminum lower section than the VFR cap.

That's correct; the parts from rebound-adjustable caps and non-adjustable don't match up. I was implying you might take F4 caps and put them on F3 damper rods to get them into a 43mm tube.

I know, next question: "why the hell would I want to scrounge two different sets of broken forks when 43mm F4 guts should be all I need for a gen6..." However; IIRC the F4 damper rods are even shorter than F3, and that might mean cutting down the fork travel a little more than one is prepared to sacrifice.

Ducati, Triumph, Harley, Suzuki, Kawasaki, all used Showa 20mm carts at one time or another and right up into 2009. If a person had the skill, a small lathe and knew what to scavenge, they could build some pretty trick midvalved, aluminum body, 12mm damper rod carts that would literally drop right in to a stock fork. -all from junk! :biggrin:

[JamieDaugherty]

This is true. Everyone has differing feel that they're looking for. In my case, I didn't want to end up with a pogo-ing, kidney hammering ride just because I thought it might be "better".

This isn't necessarily the right way to look at it. Stiffer is not better, that is true, but you also want the damping to be correct. If you go too soft it will be the same as being too stiff. You want a controlled motion from the suspension, too little damping will also knock you around.

Also, thx1139 is spot-on, the cartidges are the same between the CBR600's. In fact, other models also use the same internals, such as the 900RR.