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turtlecreek

Cbr F4 Shock In Place Of Vfr Shock

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What a great day Saturday was! I found time to get two major mods completed and both seem to really help.

1st, I was able to install an F4 shock in place of the VFR's original. This is EXTEMELY EASY as the shocks are only 1/2" different in total length. I did not have to fabricate any brackets. I did have to drill some holes in the battery box to tie rap the reservoir to, add 1/2" of shim/washers to the top tie to get the height correct, but that was all. The exchange took 20 minutes MAX.

One other note is that I did revalve and add a 950 spring to it through aftershock as the original spring was old. total cost was $40 on ebay for the shock plus $300 to aftershock, or $340 total for a 'internals are new' shock with rebound and compression adjustment.

Being that I am 250lbs necked, I really needed a stronger spring and this has fit the bill!! My SAG was 50mm and is now 25mm with more preload left! The bike definitely handles much nicer now and holds the lines in the curve much easier. I was having issues everything feeling loose in turns and I believe it was simply the rear end swaying on the weak (for my wt) spring. All that is gone now.

overall length difference of .5"

f4vsvfrshock.jpg

where I mounted my reservoir

reservoirmount.jpg

While I was under there, I threw on a catless header too. I don't notice a lot of volume difference, but I believe I am feeling the front end lift much easier now. I don't have a dyno, so that is my only test at this point. I am still using coyze's map and it seems to be running just fine too. Apparantly, he has developed the super map! I still plan on gutting my exhaust sometime in the near future and once this is complete, I will try Tinymind's map and see if it runs better/worse on my setup.

I also weighed all the parts I have removed and swapped and I am down 20lbs so far on my bike. Not bad!

deadweight

deadweight.jpg

new and improved!

nowshecanbreath.jpg

now she can breath!

5thvs6thgen.jpg

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Guest 767fixer

if anyone else wants to do it i have a good shape cbr F4 shock :D

Cool mods. i like the exhaust work

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Hey turtle, Welcome to 2003! :P I'm pretty sure I pioneered both of these mods to the VTEC. IMHO, the headers are a waste if you don't open the rest of the exhaust. I ran the F4i spring towards the max and I was about 170lbs at the time.

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Guest 767fixer
Cool stuff Dale, but a .500" shorter shock? That's not a good thing unless you want to drop/lower the bike which I doubt you would want to do. :unsure:

You will screw up the handling of the in a major way without compensating for this shorter shock, 5mm is a big change and your talking 12.5mm. If anything you would want a slightly longer shock to improve turn-in, the shorter shock will slow steering a huge amount. You will not like it!

Also that .500 is doubled or tripled in read ride height by the rocker ratio of the rear suspension, I'm guessing it will lower the rear of the bike by 1-1 1/2 ". :unsure:

didnt you do the same and just make a spacer to compensate for the shorter length?

that didnt sound right????? :unsure: smile.gif

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didnt you do the same and just make a spacer to compensate for the shorter length?

that didnt sound right????? :goofy: smile.gif

I missed where he added 1/2" of washers! :beer: Never mind my post! :goofy:

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According to the pic, that's not a 1/2 inch difference. Looks to me about 3-4mm which is still too short but if he's been riding it with WAY too much sag all this time, it will still feel better. Throw a couple of washers on the top of the upper bracket and you'll be good to go.

Edit: see he's all ready done that. Life will be good.

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Well, I read the whole post, and I think he's out loving life with his new shock right now!! :thumbsup:

I just hope he doesn't get too happy and bottom that resevoir out on his chainguard... that could be bad... or just a bad angle on the camera? :goofy:

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Well, I read the whole post, and I think he's out loving life with his new shock right now!! :thumbsup:

I just hope he doesn't get too happy and bottom that resevoir out on his chainguard... that could be bad... or just a bad angle on the camera? :goofy:

It probably won't hit. My res is mounted further forward than that attached to the sub frame and it doesn't seem to hit

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thanks to all the input. u have to love this place as people actually read what you post, and think about issues you might have missed and try to help out!

here are the sag numbers I put in a spread sheet 'now' was prior to mod, 'future' is after mod:

what '-5' doesn't really mean anything. it is just a base line number in 'mm' that i was using to see where i was heading I am actually 8mm biased to the rear from what i 'think' is the factory 'ideal'. not great, i know, but the springs have improved the ride so much i dont care!

as you will see, the 'original' condition of the bike with me on it was actually 'close' to what a normal rider sees from the factory regarding front to rear bias.

but with me on it (now) it was basically doing a 18mm wheelie!! with the .95s on front and 950 on rear, things are still a little rearward balanced, but it is much more improved over my (now) ride....

front sag fork height rear sag rear height front to back difference

factory setup 35 43 30 0 -5

original (w/ me) 55 44 50 0 -6

now (pre mod) 15 50 50 15 13

future (post mod) 15 50 25 0 3

(oops, spacing isn't working on the post like it is in the edit section....so i just attached tiny xls file.)

regarding reservoir, i am glad to hear that yours is forward jeremy and yet still no issue. i was definitely concerned about this, but could not figure out where else to put it as the hydraulic line is only so long.....

i know someone might mention that 7mm down on front is issue, but unfortunately, i am not sure what to do about it at this time. i may try cutting my spacers in my forks some to see if i can 'unload' the spring some as my adjustment screw is out about 15mm and i still have minimal sag in front. i don't exactly understand this with my weight, but it is what it is.

my_sag_settings.xls

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I am thinking of changing my 99 VFR over to the 929 or F4i shocks. Main advantage is compression damping adjustable? The F4i needs heavier springs and revalving but is closer in height, whereas the 929 is shorter but spring is correct weight. I also have an almost new CBR1100xx shock but that looks like the VFR shock, so not worth changing probably. I had a Works Perf shock on the 100xx when I had and it was great but I don't want to spend the $750 on the VFR.

MikeG

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I am thinking of changing my 99 VFR over to the 929 or F4i shocks. Main advantage is compression damping adjustable? The F4i needs heavier springs and revalving but is closer in height, whereas the 929 is shorter but spring is correct weight. I also have an almost new CBR1100xx shock but that looks like the VFR shock, so not worth changing probably. I had a Works Perf shock on the 100xx when I had and it was great but I don't want to spend the $750 on the VFR.

MikeG

I would go with the 929 shock if I were you. You'll get compression damping and you can easily add spacers to make it the right height. The F4i shock would work too, but then you would have to get a new spring for it.

The CBR-XX shock is also shorter than the 5th gen stock, but it's rated for about 100 lbs more than the VFR spring. So, if you're on the heavy side or do a lot of two-up riding, it might be the way to go. Of course, you can just get a heavier spring for the F4i or 929 shock too. :blink:

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Congrats Dale, suspension mods rawk. I recently got a 929 for 5ht gen. Now all I need are new springs & valves for the front and I'll be all set for the Fall meet.

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so far I gathered from this is that and F4i shock conversion is easier than a 929 shock conversion, and the benefits are similiar. Right?

On the issue of spring, could we fit the original 5th gen spring into the F4i shock?

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so far I gathered from this is that and F4i shock conversion is easier than a 929 shock conversion, and the benefits are similiar. Right?

On the issue of spring, could we fit the original 5th gen spring into the F4i shock?

This is a Vtec shock option, IMO the 929 shock is the best swap for the 5th gen and has the same spring rate as the VFR.

btw the vfr spring will not work on either the F4i or 929 shock.

also the cbr 1100xx shock runs a stiffer spring( I think a 17 kg) and with bolt into either, but if I'm not mistaken it's like 1/4" shorter than a 5th gen and 1/4" longer than a 6th gen. and only has the same adjustments as the stock VFR shock.

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what BR said....

i am 250lb so i knew i had to respring and revalve anyways and on a 6th gen, it is almost a 'drop in' (just add the 1/4"-1/2" stack of washers and mount the remote reservoir)

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I have a line on a F4i shock for my 5th Gen (2001 model). Will I be able to add shims to adjust for the length difference?

And if I do go with the recommendation of some of you, for the CBR 929 shock, would I have to shim the top end?

Grateful for inputs, especially from guys that have done this mod.

Edited by Throttlestop

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I have a line on a F4i shock for my 5th Gen (2001 model). Will I be able to add shims to adjust for the length difference?

And if I do go with the recommendation of some of you, for the CBR 929 shock, would I have to shim the top end?

Grateful for inputs, especially from guys that have done this mod.

http://www.vfrdiscussion.com/forum/index.p...mp;hl=929+shock

do a search on '929 shock' for other posts.

you will have to shim...too much for just a simple stack of washers though.

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Are the basics the same for a 3rd gen as well? F4i/929??

Thanks...

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Come alive THREAD!! The problem I see using these f3/f4 shocks.... found said problem after I ordered 2 of them ... Is that the preload adjuster is at the bottom where you cant adjust it??? Ill be reselling those and install the 929 one.

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Come alive THREAD!! The problem I see using these f3/f4 shocks.... found said problem after I ordered 2 of them ... Is that the preload adjuster is at the bottom where you cant adjust it??? Ill be reselling those and install the 929 one.

Is the adjuster hidden by the bottom linkage? Is it something else?

TBH I really don't mind if it's difficult to set; I'd only set it once and be done with anyway...

Also, what is the difference between an F4 shock with red spring and an F4 shock with yellow?

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no difference in the shocks...

if you look at the 1st post pictures, you will see the black adjuster. it is difficult to get to. like you said, if you set it and forget it, fine...otherwise, you might want to consider something else. i have tried to set it with spanner, but haven't spent a lot of time on it and didn't have success. once i get the bike out of my garage (no room to manuever) i'll see if i can do it.

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I wouldn't recommend using Cozye's map with Catless headers unless you richen the whole map. Cozye's map is much richer than stock, but still probably not rich enough for catless. Tinymind's map is in the download's section.

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I wouldn't recommend using Cozye's map with Catless headers unless you richen the whole map. Cozye's map is much richer than stock, but still probably not rich enough for catless. Tinymind's map is in the download's section.

this is a shock thread and that was a random post.....but since you did it....i have run cozye's map for 2 years now....stinks to high heavens because it is VERY rich....no problem running with catless....oh, and she runs like a scalded dog too....i have not tried Jasons, but meant to....having no issues with cozyes, i just never got around to it.

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Better a little rich than lean. Safer that way and less drivability problems.

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