fork oil wt

[streetfighter st]

I remember reading something about different wts in the different sides. 91 non abs. I just put new fork seals in and am wondering about what oil I want to put in. I have read a few post on here and there seems to be alot of opinions. Front end has always been a bit soft. I have no idea what springs are in it. Has a 3 in PVC spacer on the left side. I'm considering shortening that so I can put the fork cap on with out living in fear of crossthreading the damn thing. Can I compensate for that with less airspace and thicker oil? Thanks Robin

 

[Catmandu2]

So you have an 1100 ? Seems pretty odd that you would have a preload spacer on the left only. I don't have any experience with 1100's,,, but have do have 3/4" preload spacers on both my ST13's oem springs. They are damped with 5 weight fork oil. There is an old saying that most stock Honda's are over damped and under sprung. If you are having trouble with the left side cap being two tight,,,, perhaps cut it down to 2.5" and fab a matching spacer for the other side. That should stiffen it up a bit. I like the quicker rebound that 5 weight allows. But it's hard to guess what your situation is. Suggest you consult with our other 1100 riders. Is your bike diving under braking,, or collapsing on hard cornering ?? Need more information,,, cheers,, CAt'

 

[Larry Fine]

The left and right forks on 1100s are internally very different, including the oil. You should have a shop manual.

which fork tube is which | ST1100-Suspension

Well i screwed myself up, i have 2 sets of forks torn apart on my bench and i forgot what leg goes where, i know one side is longer but which side is it?

www.st-owners.com

fork oil capacity | ST1100-Suspension

Hi Guys Just been searching to find out the correct capacity of the front forks. I am about to change the seals and will need to replace the fork oil but cant seem to get a direct answer to what the correct capacity for each fork leg is can you advise me. also what the best grade oil for...

www.st-owners.com

 

[John OoSTerhuis]

I suspect you have non-OEM springs. When I installed Progressive Suspension springs on my ‘91 it called for discarding the right OEM spacer and a shorter one (3.25”) on the left side. I cut the ~7” OEM steel spacer down instead of using PVC tubing. I used the Honda spec’d suspension fluid levels per the PS instructions. Changed to Honda 10wt. Firmed things up nicely. FWIW

John

 

[John OoSTerhuis]

Tip on installing the left fork cap against the spring pressure: with the spring out mark the tube and corresponding spot on the cap side when the threads just start to engage. Then with the spring in, line the marks up and screw it in. It helps to have a handmade 17mm hex-bit socket that the hex doesn’t bottom out in the cap recess. BTDT

John

 

[dwalby]

agree with John's assessment of aftermarket springs. If you had the stock left spring and 3" spacer, you wouldn't have to press the fork cap down at all, the spacer would be below the top of the tube.

There's no right or wrong answer on the oil question, too many variables like your weight, the spring rates, your riding style, your personal preference. Since you have no experience or datapoints to go by, try 10w in both forks as an initial starting point and see how you like it.

and regarding installing the cap, I always turn counter-clockwise first to feel the click when the threads mesh, then crank it clockwise with my hand on a ratchet with a 17mm hex drive bit attached to a 4-6" extension. By putting my hand over the ratchet head I can push it down vertically and rotate it a lot with just a little hand movement.

 

[ST1100Y]

Running Hyperpro springs, found OEM 5W too soft, 10W too harsh, settled for 7W I'm very happy with...

 

[streetfighter st]

Well, seeing as how the rear shock is definatly aftermarket, I think the assumption the front springs are would be a good one. I will try the 10 wt oil and see how that rides. At present all I have is a 17 mm allen wrench for the fork caps. I may have to cut a chunk off that to use with a socket, as the ability to push squarely on the cap is just a bit compromised with the alllen wrench. Thanks for the input guys. Ride on.

 

[Al st1100]

I used synthetic ATF, when I had an ST, Synthetic Multi-Vehicle ATF Kinematic Viscosity @ 100°C, cSt (ASTM D-445) 7.6 Kinematic Viscosity . Viscosity is 7.6, right between 5 & 10w fork oil. It has more friction modifiers than fork oil, so hopefully the bushings last longer. I thought the ride was much better.

 

[SMSW]

Front end has always been a bit soft. Can I compensate for that with less airspace and thicker oil? Thanks Robin

The springs support the bike, the oil does little more than slow the relative movement of the wheels to the bike's chassis. Now we run into a semantic problem...what do you mean by soft? If you want a stiffer front end, a heavier oil will do that. If the forks bottom out over bumps, then you need stronger springs. The air trapped in the forks above the oil also acts like a spring, but this effect is usually a fraction of the spring rate. Suspension tuning is a matter of matching both the oil weight and the springs. You start with the springs - measure the bike's sag and adjust the spring rate and/or preload spacers to get the sag set properly (around 1/3 down of the total travel). Then you mess with the oil. Of course, the hardware that restricts the oil flow (and thus the dampening) plays a big part here, which is why folks like RaceTech have their Gold Valves.

 

[Aladinbama]

Based on recommendations I used 10w oil. I think 7 would have been a better choice.
I think this was the first time the oil had been dealt with on mine in the 125,000 miles it's roamed. The oil looked like water, and was just sort of leaking, noy really, but yeah. I knew it needed changing.
I installed Progressive springs and 10w oil. Took a 1,800 mile shake down and I have a completely different bike. I've since changed the bearings. The front is pretty firm - I'd say most would like it, but I'm an old fart enjoying softer things in his old fartedness. I think the stock 5w would have even been ok, but I wished I would have used 7w.
Just my two cents

 

[Larry Fine]

I think the stock 5w would have even been ok, but I wished I would have used 7w.

Dump out half and top off with 5.

 

[Aladinbama]

Dump out half and top off with 5.

lol
If you go that far it would only add a step or two to change it! It's kind of hard to measure the fluid's distance from the top with the forks assembled!

 

[newtonhubcap]

I got away from the oem internals of the suspension and switch over to the Traxxion Cartridge damper system the gives you full adjust of the front end (pre-load, compression and dampening) and switch to 10wt on the oil. Oil can be measure by volume but measuring by fill gap seems to be the preferred method.