Fork rebuild advice

Happy 4th all,

In the next week or 2, I'll be digging into a fork rebuild on the 86 700. Both forks are leaking badly, and the front now sags a bit. The front end is very soft now and needs attention. I've never pulled a set of forks apart so not sure what I'm going to find. The right fork holds 5 lbs of air but the left only holds air for about 5 minutes. I'm sure most of the fluid has leaked out as well.

I've watched a few videos on YouTube on Honda fork rebuilds, but none specifically on an 86 VFR set that has air and TRAC . Has anyone dug into a set of these and have any advice on how to correctly service these?

The 86 is almost completed. Once forks are done, I'll add new tires and coolant hoses. That should be it.

Thanks in advance for any help.

 

There's nothing too exotic in there. The hardest part is likely undoing the socket bolt in the base of the forks and I can recommend you use a rattle gun while the fork is still assembled to break that loose (drain the fluid out of the drain port first).
Think about replacing the bushings as well as the seals.
Protect your new seals by slipping a bit of plastic bag over the tube end when you slide them over. You'll need something to drive the new seal into place, a long piece of PVC pipe that just fits over the stanchion is pretty good. I use a bit of red rubber grease on the new seal and dust seal.
Set the fork oil level (153mm) with the springs out and the fork fully compressed and pumped up an down a few times. Pay attention to which way up the springs should be (taper down or read the manual).
Get a new copper sealing washer for the socket bolt or anneal the old one red hot and quench to make it pliable again.

 

Hi, why not head over to the new VFRDiscussion, join and then download the service manual for your bike. It's free.

The site is here:
https://vfrdiscussion.nl/index.php

 

Thanks for the link. I already have the hardcopy of the Honda Service Manual and its instructions on disassembly are fairly clear and straightforward. I was just looking for advice from anyone who has done the job and what, if any difficulties they encountered with servicing them.

 

Terry pretty much nailed it.

The stock springs are woefully too weak, if that is what's still in there. Definitely consider going to Sonic Springs and getting something appropriate. You won't be modifying or making the bike "unoriginal" if that is a concern.

You got this. It's a pretty satisfying do-it-yourself job.

 

Thanks, Capt, it's been an enjoyable experience so far. I'm looking forward to the fork rebuild.

I've considered changing out the stock springs and I checked out Progressive Springs as a replacement. They offer a one trick pony with a progressive rate. I see Sonic offers several levels of stiffness. Any particular level and fluid weight you suggest from Sonic?

 

Thanks Terry. Your recommendations are appreciated and will be followed. The factory service manual doesn't include tips like these. That's the kind of information that can only come from seasoned owners like all of you. Thanks again.

 

If you were looking to "modernise" the insides of the fork, I can heartly recommend the Racetech Cartridge Emulator plus some new springs, I used 0.9kg/mm. From the outside there will no sign that anything has been changed but the fork action will be 100% better than stock.

 

+1 on Terry's emulator advice. I do it on all of my damper rod forks. BIG difference and not a big jump in technical ability. If you have a vice and a drill, you can do it.

I didn't immediately mention it cuz I always recommend to go "while you're there" on everything and didn't want to dissuade you from springs,.which are a must do imo

Stick to straight rate springs also imo
How much do.you weigh

Oh, also, YSS make Emulators called PD valves which are the same concept and a better value. I have usex them twice now.

RaceTech prices have jumped immensely.

 

Thanks for the advice Terry. I'm definitely going with new springs, and I'll check out the emulators. Looking at Amsoil Shock Therapy #10 Medium for shock oil.

 

Thanks for the advice, Capt.

I'm going to do it right the first time, so I'm going to do whatever is necessary while they are apart. I'd rather win it in the first, than the ninth. I think the straight rate springs are more suited for me as well. I'll check out the PD valves as well.

I'm 225-230 in street clothes and 6'2". I'm a little big for the VFR but I make it work.

 

I'm looking at doing my forks soon too. Both Racetech and Sonic have fork spring rate calculators and for your weight Racetech says 1.11 kg/mm springs and Sonic 1.0 kg/mm. I don't see springs listed on the Sonic site for the 86/87 VFR unless I'm missing something. The highest rate spring that Racetech lists is .95 kg/mm but keep in mind the stock rate is 0.49 kg/mm. Lol

 

Thanks for the tip on the PD valves, looks like they're $119 versus $199 for the Racetech valves!

 

Good luck with the procedure, guys. At some point if you could share some photos, it would be greatly appreciated! Thanks!

 

If you get stuck at the first hurdle (removing the bottom bolts), the absolute best way to get them out is to use an air-powered impact wrench. Electric might also work. (Make sure it's in reverse...)

But don't compress the forks to assist with removing the bolts. Compressing the forks mechanically relieves any external pressure that might be acting against the cartridge valve body to keep it from spinning within the cartridge. (The bottom bolt threads into the valve body, not the cartridge per se.) Pulling the forks apart should, in theory, provide that extra friction necessary to keep the valve body (and thus, the bolt) from spinning.

Ciao,

JZH

 

I always use an 8mm drill bit and drill the heads off the screws in the bottom, saves a lot of messing around and takes minutes

 

This guy is looking at an 86 VFR so it has damper rod forks. I expect that the pulling up advice is probably not needed. If you pull up, the topout springs will be applying upward pressure to the damper rod. If you push down, the main springs will be pushing down and also pushing the damper rod base into the fork bottom. Pushing down sounds like it creates more fricion in this case.

 

Hey Bazza, I'm not sure how soon I'll get to it but I'll definitely take some pictures. I did order a PD valve, but haven't heard back from Sonic about springs for the 86/87 VFR. If I don't hear anything back I'll just order Racetech springs.

 

Yes, I should have mentioned that I was referring to cartridge forks, Terry!

Ciao,

JZH

 

Last time I jacked up my front I just used my scissors jack under the exhaust pipes. Like this - when I was changing out the front tire on one of my Blue bikes.

I wonder if this would work OK for doing forks or would it not be stable enough? I used a paddock stand on the rear to keep the bike upright.