How to install new fork springs

[HispanicSlammer]

Installing Race Tech Springs

I am a rather heavy guy. I come in about 220lbs and dropping :D ! I found that my bike is bouncy - from mostly the front. Last year I changed the fork oil and that seemed to help with the front end diving under braking but the bike is still bouncy. In order for me to get a smooth ride I would have to take off some preload, however in tight twisties it would wallow.The sag was set at 42mm for my trip across country so I could get a smooth ride. I would crank up the preload to a line or 2 showing and get my sag to around 32mm for the tight stuff but then it would get bouncy on the rough roads. So I bought some stiffer springs from race tech to remedy this.

Race tech has an interactive website that will help you determine what kind of suspension pieces you need for your weight and riding style. I used the site to determine the correct spring rate I should use.The Race Tech website Calculated 1.0 kg/mm for me, compare that to the OEM springs which are 0.75 kg/mm. The 98VFR has softer springs than the VTEC.

http://www.race-tech.com

Here is a graph they include in the kit.

The bike has a curb weight of (516lbs) + Rider (220lbs) + Equipment (helm, suit, clothes, tank-bag) (16lbs) = 752lbs

I used a jack to support the bike while I removed the old springs.

I unscrewed the fork caps with a socket and then lowered the jack slow enough to get at the spacers, cap, washers and springs.

The instructions have some complicated details on how to find the correct spacer size. The Race Tech kit came with an aluminum tube for spacers, washers, 2 springs, instructions, and a bunch of stickers.

The Race tech springs are 1 1/2" shorter than the OEM springs and they are not progressive wound, (they don't get tighter at the bottom like the OEM) just strait wound.

I just measured the old springs minus the new spring length, then measured the old spacer and added the difference in spring length to that number (see the pad) and cut off new spacers. Everything was actually 1/16" shorter so I just rounded up and then remembered when I made my cut lines.

I cut off a small portion on the top because the ends were not square then I cut the pipe to length.

I used the first cut to measure the second spacer

Side by side comparison

You can see the thicker and shorter windings of the Race tech springs compared to the OEM springs.

To finish up I put in the new springs, put the old washers back on, the new spacers, and shims, then I screwed the caps back on. There was some oil loss when I took the old ones out, but very little I let them drip off into the tube when I removed them.

When I put the caps back on I measured the sag at the same settings I had the old springs at. (27mm) is what I came up with. The old one were set at 35mm and I could not get them to sag any less than that. I cranked off 3 lines of preload and the sag came to within 35mm of sag where I like it.

I took the bike out for a short ride and lo and behold its a stiffer ride! :goof: no seriously no more bounciness like before. I still have not ridden on a bumpy road at speed yet but it feels much more stable!

[HispanicSlammer]

I should point out that 1.0 kg/mm springs are the stiffest spring they sell.

[Guest afterburn]

Miguel, maybe you can help me here a little. I put in Hyperpro spings front and back this winter, and I just had an oppertunity to test them.

I set them to the default settings as recommended by Hyperpro, which are the same defaults as the Honda default for my VFR750.

Sag is measured 30mm at this setting.

When riding it, it feels very hard, especially on them hard snappy bumps.

Imo, it could be 2 things: 1) spring pre-load is too hard, or 2) due to temperatures still being around freezing making the oil thicker, the dampers are still not optimal.

The bike handles great, no bouncing or weaving in corners, but I did have short (once back and forth) tankslapper accellerating HARD over a bump trying to pass a few cars.

Any idea of where I should start to look?

[HispanicSlammer]

Tankslapper?  Perhaps your geometry is too far forward and your getting oversteer,  take some preload off the back, get a more neutral feel.  30mm is too high for street riding everything I have read has 32mm as the upper limit for street sag,  maybe of you set it to around 35mm  you will get a better feel.  Just make small adjustments until you get the feel you want.

[Guest afterburn]

Not a real tankslapper, just once back and forth. Full trottle accellerating over a short bump. Geometry is standard VFR. No raised back or dropped front.

Seems springs need some brake in time too, since it's getting a lot better now. Still, I'm going to give it a click less next time I'm taking my baby out.

[Guest afterburn]

BTW: do you set it to 35mm back and front?

[HispanicSlammer]

Yea like I said in the first post 35mm.

[Guest meat sac]

Hey Miguel,

Any update on the Race tech springs? How are they treatin' ya? This mod is still on my list - right after Sergeant releases the 02 VFR seat later this month. I also noticed Race tech didn't have any info for the V-tec VFRs.

[HispanicSlammer]

I rode up the canyon Saturday the bike does not take as much effort thru the hard turns, not as bumpy as it was going over rough stuff.  I also have the Ohlins now so my ride is so smooth now,  the only thing is I still have to dial the shock in a bit, its almost right but still playing with it.

I am running about 35mm of sag up front and 30mm in back so it is jacked up higher in the back, a 2mm shim back there too.  So the bike steers very quick, sometimes when I downshift I get some rear wheel hop so I think i might need to soften up the rebound compression a little. When I crank on the throttle hard its smooth.  The suspension is very tight now,  90 mph feels like 70 used to feel.

So far I have been able to push it fast on some smooth sweepers at about 70-90 mph and it feels very smooth, but have not had some really tight stuff yet so I dont know if Its dialed in all the way yet.

[HispanicSlammer]

If you are installing a higher rate set of springs I would also recommend re-valving the dampers.  

I did not do so and instead used new fork oil and had a very harsh ride.  The heavier springs don't allow as much fork movement it takes more force to move the forks up and down.  With that being said I changed to the 5w honda ss7 oil in place of the ss8 10w oil that is standard for the 98 vfr.  After riding the bike about 20 miles of rough roads and twisties, It soaks up bumps much better.  I did not re-valve at all, just a lighter weight oil.  I think I will ride it for a while and decide later weather or not to get the cartridges re-valved.  

To explain what what happening by harsh ride I mean that the fork springs were sort of being rendered useless by over-damping, sort as if the fork was welded in place and did not move at all.  The lighter oil is allowing the springs to work, absorb a bump and keep the tire on the road, the greater spring strength handles the shock better, no wallowing.  I think I have it dialed in perfect now, in combination with my Ohlins shock I have a very sweet ride now!

[Guest Randy]

Re: VFR tankslapper. I had one major incident with my bike. Less than 1 year old so everything was stock-springs etc and still in like new condition. I was riding on a very rough secondary road with no traffic and fooling around in second gear.

I hit w.o.t in second and at the same time hit a patch of very rippled road-wow big time tank slapper no crash but close. I suspect the cause was I was very close to pulling a wheellie and at the same time my front wheel hit a big bump also and this made the front wheel very light. Just wanted to mention that if the conditions are right the normally stable VFR (98) can do a major tankslapper if ridden like an idiot-even with stock springs etc.

[Guest stevnmd]

Thanks so much for the writeup, HispanicSlammer.  I just got my new springs from RaceTech in yesterday and hopefully will get them installed, along with RaceTech oil, this weekend.  This how-to will definitely be printed and with me in the garage.  RaceTech's instructions leave a bit to be desired.  

[ULEWZ]

Thanks so much for the writeup, HispanicSlammer. ?I just got my new springs from RaceTech in yesterday and hopefully will get them installed, along with RaceTech oil, this weekend. ?This how-to will definitely be printed and with me in the garage. ?RaceTech's instructions leave a bit to be desired. ?

Just make sure everything is clean and dust free. After you have done it once it will be a walk in the park. I bought a set of long allen sockets and an impact wrench to get the lower bolt out, but that is not necessary to do a spring swap.  :wheel:

[BoulderGeek]

My first point to make is that I do not wish to step on any toes or contradict what has been written here.  This is an excellent starting guide.

I have had confusion in reading all of the guides and install information regarding replacement of the fork springs.  My spring replacement is now done, and I wanted to jot a few notes to the community, as there are some new members who will likely want to do the same thing.

I got a set of Race Tech .95kg/mm springs (the 1.0 springs were on backorder too long). Since my 1993 VFR is claimed at 476lbs, and I am 200lbs, my thumbnail sketch was that Miguel's 1.0 springs were supporting ~50lbs more than my rider and bike weight. And with his notes that his front end was a tad stiff, I figured the .95s would be an acceptable compromise without an excessive waiting period to get them.

Again following Miguel's lead, I ordered the Race Tech 5 weight low-friction suspension fluid.  They sold me two quarts, which was one too many.  You need less than one quart (.95 liter) for a full replacement on a 1990-93 at least.

My confusion stemmed from most guides (Clymer, Race Tech, VFRD and other board posts) saying that complete disassembly was required to do a good job.  When I did my old 650 Seca springs, I just  drained the forks, pumped them out, and replaced the springs (being careful not to lose an eye on the pressurized end cap).  I was skeptical that complete fork removal was necessary, and hesitant because I didn't want to introduce stiction and binding in my properly aligned forks.

I drained the fork oil with the bike supporting its own weight via the drain plug on the aft side of each fork lower.  I collected the fluid and poured into a completely non-scientific graduated container (a Classico spaghetti sauce jar that had ounce markings. I got roughtly 22 ounces from the two legs collectively.

Placing the bike on teh center stand,and following Miguel's advice, I took my Jeep's jack and placed it under the mounting bracket for one of the exhaust headers, just aft of the lower engine cowl.  I only lifted enough to get the front wheel off of the ground about an inch.

I removed the top caps and fitted a straightened wire coat hanger around the damping rod, inferior to the damping rod nut.  Thanks very much to whomever suggested this.  Without this step, I would have lost the damping rod down the fork leg after removing the top cap assembly.  This is an important step, and following it will save your day.

On each fork leg, one at a time, I  pulled the springs and washers out. I used the wire to draw back the damping rod and cartridge along its range of motion, and turned the front wheel outboard while draining the last bits of oil from each leg (i.e. the left fork leg turned left to drain completely with gravity and damping rod action).

I measured the difference between old spring and new, and cut a spacer from the aluminum tubing to just that delta.  I kept the original spacer washers, plus the four new ones in my spring kit, so I guess I got another 3mm of preload that way.  I filed the spacer edges smooth and got all the shavings wiped off.

I replaced the fork drain bolts, and measured out the proper volume of suspension fluid according to my Honda Service Manual.  I used the figure for the Canadian version, just from my unscientific observation that their machines come with slightly more performance spec than US models.  My fork fluid volume was 390cc per leg (I measured in milliliters, hopefully the density difference of the oil won't give volumetric skew).  This is somewhere around 13.5 ounces per leg, which shows that my 11 ounces recovered had left each leg low.  Perhaps this is compensation for more spring mass of a longer OEM spring, perhaps not.

I pumped the damping rod and cartridge a few times, until uniform resistance was displayed.  Then I reassembled, now with race Tech's washers and my custom spacer.  The washers bound on my fork tube in each leg, so I had to remove the washers and slightly file them down with a mill bastard file.  Then I used 220 grit sandpaper to deburr.  Just a little bit of filing and sanding and they popped right down.

I backed eack preload screw out on the top caps, inspected the O-rings, and reinstalled the top caps.  It required a lot of downforce now to get the caps threaded up.  I was concerned about not being able to feel a cross thread, but I seem to have gotten them threaded properly.

I adjusted preload down to two lines showing.  I took a test ride, and the feel was much better, though now a tad stiff.  Backing out to the third preload line seems to make a nice balance.

So, my end result was a spring and oil change, without fork or wheel removal,in about 2 hours.  Next time I could have it done in 50 minutes or so.   YMMV.

:cool:

[dude]

Has anyone installed the progressive fork springs in their 5th gen? I would be interested in any feedback on this one guys/gals.

Thx

Gary

[fallzboater]

I just did the Race Tech springs install myself, here are a few notes. I'm about 190 lb without gear, and I ordered the 0.95 springs, which I also noticed were the same part number as for many other Honda models with conventional (non-inverted) forks, including my Hawk GT and older CBR and VFR models with 41mm forks.

You'll need a 24mm socket to get the caps off. Loosen the clip-ons first, and cover the tank with a thick towel at least so you won't ding it when you slip. :^( Back the preload screws out, jack the front of the bike up, and push down on the caps as you unscrew them to reduce the chances of buggering up the last thread when they release. Not much force is required.

With the caps off, drop the front of the bike until the fork bottoms. You'll need two 14mm open-end wrenches to separate the top cap from the damper rod on each side. After that you can pull out the spacers and springs with your fingers. When you're not watching and the damper rods slide down inside the forks, you'll need needle-nose pliers to pull them back up.

With the springs out, measure the oil level by dipping a tape measure into the tubes. Mine was low (~175mm) so I added 7wt oil to bring it up to 120mm. I'll change it next time, when I figure out what to do with the valving. I dropped the springs in, measured the top cap height, and went through the process of calculating the spacer length from scratch, but I'll save you the trouble. With three lines showing on the preload spacers, 85mm spacers (15mm shorter than stock) worked out perfectily. I put it all together, and without touching the preload caps, got 21mm of bike sag, and 35mm of total sag with rider (and full tank of gas). If the springs settle at all, I should be able to take care of it with the preload adjusters. Note that 5 gallons of fuel weighs about 40 lb, so keep that in mind when measuring your sag.

I was a bit dissapointed in the Race Tech kit. The instructions were a bit hard to follow for a first-timer since they apply to every bike they make a kit for. The springs, washers, and spacers all fit in 41mm forks, so they don't really locate ideally in 43mm forks. They give you plenty of aluminum tube for cutting spacers (enough to screw up once and make a second set), but the ends weren't cut real straight, so you'll want to make a clean cut to start with. They sure give you plenty of stickers, though.

Riding impressions will have to wait until tomorrow!

Edited October 25, 2005 by fallzboater

[HispanicSlammer]

fixed the photos

[fallzboater]

Riding impressions will have to wait until tomorrow!

<{POST_SNAPBACK}>

I took the long way in to work this morning, but it was a bit cool and foggy, so I didn't push too hard. As others have said, there is significantly less brake dive. Also, the bike seemed less sensitive to my sometimes ham-fisted (I'm working on it!) throttle and brake control in corners. Should be much better when I get a chance to wick it up a bit. Slightly harsher on washboard pavement, but not objectionably so. Next I'll have to play around with the f-r ride heights a bit.

One thing I noticed on the Race Tech spec sheets is that the Hawk GT (400 lb) stock springs are 0.71, and they're considered too light for that bike. The VFR is over 100 lb (25%) heavier, yet the stock springs are 0.74, only 4% stiffer. Not sure how they measure those though, since the stock springs are progressively wound.

Proper rate springs are probably the best $100 you can spend on your bike, and this is an extremely easy mod. :thumbsup:

[Jmmymc750]

Thanks for this Miguel. Put in some Sonic Springs (1.0) tonight after work in under an hour. Got the springs very cheap from Jamie Daugherty. Now if my 929 shock with heavier spring will just show up...the USPS tracking number says "out for delivery", but its 715pm!

Thanks again Miguel, and thanks to BaileyRock, too!