Race Tech Fork Rebuild
by Brian McCoy
The VFR (86/87 vintage) can be made a VERY capable bike with not a whole lot of money, well, capable as far as the handling goes. Those long, thin front suspenders were drastically undersprung even when they were brand-new rolling off the show-room floor. About the best place to start with any front end upgrades is http://www.race-tech.com/ - here you can do some research on spring rates, gold valve emulators, and even shoot off an e-mail to the guys who do suspension for a living. The basic upgrade will involve a set of springs, a Gold Valve Emulator, fresh fork seals, possibly some new fork bushings and some fresh fork oil. Once you have those few items, it's time to start doing the work.
Follow your Honda Service manual (or Clymer/Haynes if you're using one of those) to remove the front wheel, front fender, brake calipers, and clip-ons. Before loosening the forks themselves, you should loosen the top fork cap (trust me, this is a MUCH easier job with the forks still on the bike). Just loosen it, don't remove it. At this point, it's ok to remove your forks. If you're going to let a shop do the work, then all you need to do is go drop your forks off (I did this, I'm a wuss - ok, not really.. I had a broken left wrist and 2nd degree separated right shoulder). If you're willing and able to do some, if not all of the work yourself, then you'll need a few of the following items:
Bench Vise w/AL clamps (I used wood without much problem)
30mm (?? not sure what the fork cap size is) wrench to remove the fork cap
oil drain pan
lots of rags
6mm alan (long wrench with 1/2" adapter for an impact preferable)
* impact (air or electric)
(*) Impact only needed if you don't have Honda tool # ? to hold the dampening rod - otherwise it'll spin (webmaster's note: see Tips section). You CAN take the empty forks to a dealer to have the dampening rod removed, or just plain skip this step - though that's not advisable.
Clamp the fork in the vise (clamp the area the axle goes through, not the tabs that hold the calipers!!) and loosen the fork cap the rest of the way. Careful though, because the springs may be under load and shoot the cap across your garage. Once the cap is off, pull the spring out and let it sit in your oil catch pan. Remove the fork from the vise
and pour the oil into the catch can. You'll want to pump the fork to get all the oil out. I tend to leave my forks sitting upside down on a pile of old rags, leaned against a corner, so everything can drain. While one's draining, repeat the process on the other. Now, the only thing holding your forks together is the dampening rod. That's held in the fork with the 6mm alan nut accessible from the fork bottom. If you've an impact, you're set - just impact it out, and the dampening rod will fall out of the fork. The reason we're removing this item is to drill open some holes that are already existent, this will shift ALL the dampening to the Gold Valve Emulator, and will help with more consistent tuning.
Race Tech should have the site and spacing you need to drill available (I didn't do my VFR forks, so sorry for the sketchy info. All this was covered by Don Zielke in print in 98 sometime - hopefully he writes to augment this article). At this point, you CAN stop from dismantlin your forks the rest of the way, but all the hard work has been done. If you clamp the fork in the vise again, you can slide-hammer (just pull on the slider) the seal out and separate the tube from the fork leg. Sounds like a good time to take a close look at your sliders and make sure they aren't nicked, or pot-marked. That's the main reason fork-seals fail. It's also a VERY good idea to take a look at the bushings on the fork-tube. Chances are it's 13~14 years old, and has seen it's life expectancy. It's Teflon coated (er, ok - the new ones are, I assume they were back then aswell), so be careful with things like wrenches, screwdrivers and other hard bits in the area. You'll want to look for worn spots, or metal flakes imbedded in the coating. If that's there, time to replace (actually, if you notice a line worn in the coating, chances are pretty good that the fork tube is bent.) When installing the new fork-seals, cover the end of the fork with a piece of saran wrap, or a
plastic bag and some oil (fork), this will help the seal slide over the groves and keep from damaging the seal. You should take every opportunity to clean the interior of your forks, as the more dirt and grime, the worse it's going to perform, I like Kerosene as it's cheap, works wonderfully and is readily available.
With the bushings inspected, and new fork seals ready to be installed, start to reassemble your fork tube. We're going to re-attach the damping rod (which you should have drilled about 3~4 holes in, deburred the holes, and cleaned ALL of the metal shavings from) first. Actually, first is putting the slider back in the fork-leg, being careful not to ding your new bushings. Slide that all the way in (the fork seals will be seated later). Gently drop the dampening rod into the fork, and align it so the 6mm alan screw's holding it at the bottom, and tighten that the same way you loosened it (impact, with the Honda tool, or at a shop). Next is the fork seals.. you might have access to a set of purpose built drivers, if so, that's great.. the rest of us will use a piece of PVC pipe that fits over the tube and inside the bottom... tap on the pipe/drive gently, rotating the whole assembly so you don't get the seal to twisted. When it's fully seated, you'll likely hear a change in sound as you tap on the driver.
From this point, we're back to the really easy stuff (if you take your forks to a shop for the previous, it'll be like $50 all said and done). Set the Gold Valve Emulators per Race Techs instructions, and gently slide it down the tube (I have a custom bent coat-hanger that helps the job go a lot smoother). Then start adding oil (again, that weight will be per Race Techs instructions.. I think someone mentioned 20wt at one time for the VFR forks - it's 10wt for F2 forks, and I'm having success with 12.5 wt on F2 forks and being 230lbs). Make sure you pump the forks while you're adding oil.. it should be a smooth pull and push, no gurgling sounds from escaping air... Don't worry to much about being precise at this time because you're going to let your forks sit for about 10 minutes, then pump somemore just to be 100% certain that you have all the air out of them. I, personally, measure the height of the oil (instead of volume), just because it's easier. Grab your trusty ruler that has marks in MM, and lower it in to the factory specs (BEFORE putting in the springs, and AFTER installing the Emulators). I suspect you know how to measure, so no more here - just get both forks as absolutely close to one another as possible (within a mm if you can
do it). Once the oil is added, then you can drop in the springs, and some new spacers (Race Tech has directions on how to cut these.. it's usually the length of the original spacer minus the height of the emulator, adding the difference of the new springs.. might not be any difference - and you can always use that to modify the ride later on if needed). Carefully thread the caps back on and reinstall the forks in the reverse order of uninstall. The fork caps shouldn't be torqued down very hard, so be careful there....
That's the basics - I recommend watching Race Techs suspension video (even though it focuses on USD cartridge forks), for a little familiarity on the insides of forks. If you're not comfortable with the procedures, get someone else to help and watch them do the work. It's not really that hard, but you do need some special tools, and maybe a bit more than beginner wrenching skills. If all else fails, e-mail the VFR list - someone there will be able to help you..
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