Front forks what you should know= progressive

[jasonm.]

Hello everyone, I have had my 87 Venture w/progressive springs for 20+ years. The info below can help everyone. But describes my 87. I see online the recommendation here , the recommendation of the 5.5" spec. w/o springs and compressed . This is the MAX. oil you should have. As this spec is given for 95% of their spring kits. And not all bikes are the same. The people at Progressive along with their instructions state, this is a MAX. spec. Again ...this is a maximum spec. The Progressive springs are so robust they take up much more volume than OEM. Using 10wt. the 5.5" or 409 cc resulted in a harsh ride and is way too much oil. Simply, if you do not weigh 300# solo. This is too much oil. There is no reaon to go to 15wt. because having progressives is similar to a higher air pressure w/stock springs. My '87, I toyed with 1/2 to 1" spacer size and 10 or 15wt oil. And different oil levels. I have an oil level suction tool. Which you can make w/small hollow brass tubing w/hose and a mighty vac. or buy one for approx. $20. Static sag with you on the bike is key. My goal 2.25" sag. Having just a 1/2" spacer required more oil and I could change the sag with oil volume... thus removing air within the fork and creating an "air spring" situation. Remember oil cannot be compressed...but air can be. And less volume of air results in a higher resistance to compression and less air means quicker resistance. Meaning you will not bottom and have some anti dive properties. But the ride was not best on rough roads. I now have 1" spacer with approx. 360cc of 10 wt.... 2 things...if your sag is less than 2" you need to remove oil or size of spacer. 2nd you should not be putting in 409cc oil. Others here will disagree about the amount of oil in 1st gen. But law of physics says you are starting with less available volume with the new springs. ...but check the "sag" with a zip tie and putting it on the center stand after, again sag is the key... Lastly, if you are not comfortable putting the bike on the center stand again and again...get a helper...Cheers

[Rosie1965]

I've been thinking of making some changes. I have the progressives and one up ride is pretty good. Two up is where the front seems light and too rough on rough roads, it seems around here that's all we have:confused24:.

I have 5w oil in my magna forks and like it, but I'm 175 lbs. and bike is lighter too. Would be interesting to hear what others have tried to turn their first gen into a cadillac.

[Money Venture]

This is an upgrade I want to do this winter. I am 280 and ride 2-up most of the time. What settings do you recommend when I get ready to do this? Thanks.

[jasonm.]

This is an upgrade I want to do this winter. I am 280 and ride 2-up most of the time. What settings do you recommend when I get ready to do this? Thanks.

the "sag" is mostly determined riding solo...as a passanger puts 90% weight on the rear. If you still have the anti-dive active on your 86-93. Then my suggestions will get you close. The biggest hassle is adding or removing oil. Removing is easier..but not presice. You need to be careful putting the fork caps on. As cross-threading is very easy. I suggest "marking" the caps with a sharpie or paint. And watch it as you loosen the cap. At what point is the cap totally "free". That helps you find your starting point. I read some say a "light" feeling. That usually means not enough sag. The Venture has 5.5" of travel...so sag 2 to 2.5" gives plenty of available travel to handle the vast majority of roads...PS- I have my anti-dive on a switch. Only use it on the interstate.

Edited May 25, 2014 by jasonm.

[Money Venture]

How exactly do the anti-dives work? Do they stop the flow of oil preventing the forks from compressing?

[jasonm.]

Yes, on the 1300 there is a relay in the fairing. That triggers the solenoids. I simply put the ground wire on a switch. As I have had both 1200 and 1300 models. The 1200's the system is totally based upon brake pressure. Most find it does little to really control dive but weakens the actually braking potential. Some swap the brake hose bolts and eliminate it all together...which is something I did on my 1200. I could actually feel the brakes and the lever to front brake was more responsive.

[frankd]

Jason,

 

Thanks for your recommendations. While I was replacing a fork seal, I also decided to install Progressive springs. I installed them on my 83 30 years ago, but they're pretty stiff and I didn't want the 89 anywhere near that stiff (yes, I've got too much oil in the 83). When I set up the 89, I used a 7/8" spacer, and 360cc of 10wt. oil. I have about 2" of sag. The oil measured 9.5" down from the top of the forks.

 

The bike rides just a bit harsher than the OEM setup, but after about 10 miles it was hard to notice. When I got to a curvy road (2 up), something that I wasn't prepared for was how much more precisely it steers. Even my wife noticed how much better it was. I'll measure the sag again after the springs have time to settle.

 

Frank D.

[jasonm.]

Always glad someone tried what works for me. Having one of those fork oil level "suckers" now(both being the same level). I measured my oil level completely assembled on the center stand after a ride and sitting for 30 minutes. Both sides at 15" using the sucker. I suspect yours is similar. Only changes I have made since the last post was 70/30 10wt. - 15wt. oil . I know it sounds odd. REASON> Honestly with my bike once in a while over mild changes in the surface feeling a VERY slight pogo...meaning only lasted a split second. And rebound damping slightly less than perfect. Someone said add oil . I did not do that as that would raise ride height and harshness. 15wt would totally eliminate this but this also causes compression damping go up and ride would be harsher than I like. Thus the result I have listed 70/30 10wt/15wt. works to my liking. Unfortunately no one makes a 12wt. oil I am not a putter as my saddlebag trim will testify. I have also done a "fork alignment". Which has resulted in minimal fork stiction. I presently have a commander2 rear tire with Dunlop E3 front. Handling is razor sharp and stable at all speeds. From 2 to 112mph

Edited January 15, 2016 by jasonm.

[Patmac6075]

Very interested in your post Jason, and thank you for doing the research & results.

Three things I'd like to know,

1. What size are you? I'm 5'9" and just over 200...I'm looking for a starting point

2. Are you measuring down from the top of the chrome fork tube?

3. Back in the day we just used plain motor oil...is that still acceptable? 10w/40 20w/50...ect, BTW, I rarely test the limits of my bike...so foaming would very unlikely.

Looking at ordering spring in a couple days.

[jasonm.]

with all my gear on..(1)I am 190#. I have tested my VR for 25+ years. So I have experimented. (2) With caps removed and on center stand I measure down from the top with springs in ... . (3) 10w40 is WAY TOO HEAVY for forks. You are passing oil thru damping holes, Flow is the key.. If it's too heavy it's just too stiff. Yamaha calls for 10wt which flows like water compared to 10w40. I did a complicated orifice test and found 0w20 Mobil1 does work very similar to 15wt. I have used 0W20 with good success. Sounds odd but true, motor oil will foam in forks as it passes thru the damping orifices at the bottom due to air in the oil until you have done at least a few hundred miles. Sounds odd but true. Fork oil has anti-foam additives that really work. For many years my wife was always been on the back. Now she cannot(bad back). Presently I now ride solo 99% of the time I have gone with traditional oils....10wt or 15wt. BUT I have done something no one else has. After removing the caps 20 years ago I proceeded using a drill press ... I drilled and tapped my caps for an allen bolt> 6mm- 1.0, and using 25mm long bolts like the engine case bolts. And sealed with copper washer allows me to replace oil quickly and set height with the "sucker tool". Yes, holes must be dead straight and centered. I have the big allen like the manual calls for, but now I never need to remove caps for normal oil change service. One of my best mods. Along with standard brakes ...not unified and FJ1200 calipers and a dozen other little things....I have no reason to sell this ever. Next mod is increasing rotor size. Doing test rides at Americade I realized even with other people saying put on R1 calipers and stronger pads... the slowing power is not there when you are past 75mph. You need Mechanical Leverage. Our bikes front rotors are only 282mm FYI.... 298 mm R1 pre-2004 and 320mm FJR 1300 rotors fit. Just need to make caliper bracket. Which I have experience at....cheers

Edited January 17, 2016 by jasonm.