How to adjust non-adjustable forks?

Yeah, that's a hell of a lot of cash to shell out on rebuilding forks, especially for a '92 ST1100. Does anyone reading this have experience with the Progressive springs? at $70 that would be pretty cheap to try. The stock springs look like Progressives the way they are tightly wound on one end and loose on the other. I didn't get any of this bouncing with them, but again they made the bike feel very truckish around curves compared to the Sonics. Maybe they were just worn out after 47k or maybe that's just how they are?
 
There are no options listed on the RaceTech website or in the included instructions anymore. This is the shim list that came with the kit I purchased a couple of weeks ago:

racetech1300.jpg


I hope it works out. I'm not thrilled to see it listed as aggressive/firm in the above PDF.
 
chesthing said:
Maybe they were just worn out after 47k or maybe that's just how they are?
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You could measure the old springs and see if they are still within servicable limits. I doubt they are worn out. I don't have the service limits for an 1100 though.
 
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Regarding oil level - oil is essentially noncompressable while air isn't. Lowering the oil level adds air volume and this allows the fork springs to have a more progressive action than spring rate alone suggests. It makes sense that a stiffer straight rate spring like the Sonic would use less oil/more air vs. the OEM softer progressive spring set-up.

Bel-Ray 7 wt isn't much lighter than Honda's 10wt. If you used a higher oil level than Sonic calls for the action could well have been harsher with the Bel-Ray.
 
chesthing said:
I agree, it's inexcusable that Honda didn't upgrade the ST1300 with adjustable forks - I get why they didn't on the ST1100, hell it came out in 1991.
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A wag once said the best thing about non-adjustable suspension is the rider can't screw up the suspension by adjusting it.
 
Adjustable forks (at least preload) sure would have saved me a lot of hassle. Too bad all ST owners aren't the same weight and liked the same type ride - Honda would be looking pretty smart, instead of pretty cheap.
 
Anybody ever researched replacing the ST1100 (or the ST1300) fork caps with ones that have pre-load adjusters? The standard forks are 41mm and the ABS are 43mm, IIRC. I have a hunch that there are other bikes with the same spec forks that have adjusters that might work. The trick would be the cartridge side where the 'adjuster' would have to work 'around' with the threaded rod. Just a thought ....
 
Just to put closure (finally) on my issues; I ordered and installed a set of Progressive springs - this made the front end softer, with less jack-hammering over light bumps. Sonic took the 2 month old springs back and even refunded postage (outstanding customer service).
I then replaced the fork oil with 5 wt and replaced the stock steering head bearings with CBR tapered bearings. I've also recently replaced the rear spring with a Hyperpro.
This is the ride I've been looking for. The front end doesn't dance over (any size) bumps, ride is incredibly comfortable but still corners like no 630 lb bike has a right to. Damn, what am I going to do with my free time now that my bike is perfect? Audiovox cruise may be next.
 
Food for thought concerning oil level/air volume in forks.

Honda uses a very thin steel tube for a spacer. Sonic uses some rather thick walled plastic electrical conduit. I need to sit down and do the math or get with Professor Archimedes and determine the volume difference of the two spacers. Gut feeling is that the thicker plastic electrical conduit would reduce the air space quite a bit more than the thin steel tube given the same fork oil height.

Y'all's thoughts.

(Y'all is proper english in this part of the country).
 
This discussion is all very good stuff!
I just bought my used '05 St1300, with 40,000 Miles on it. I'm adding it to my already large stable of bikes.
I used to the plush, but firm ride, and outstanding handling of my Buells, so this big Honda is taking me a bit to get used to.
My front forks feel like they are a bit too stiff, and the preload is to low. How are you guys setting the SAG on your front forks?
I see no preload adjustments! Are you shimming your fork springs to get the proper height?
I've been thinking of changing out the fork oil with 7wt, to see if that smooths it out some on the highway, but I certainly don't want to give up any of the bikes ability to handle the twisty stuff either.
Sonic springs seem to be popular here, I've never heard of them, I've used progressive springs in my Harleys, and race tech in my Honda, and Kawasaki sport bikes.
I would like to do a complete rebuild of my forks eventually, with new springs and valving to bring it up to date, and get a little more grin factor from the bike.
Thanks for the info!
 
Fork oil is cheap, try Honda 5 wt then do a mix of 5 and 10 if that's too soft. I raised the forks in the triples 1/4" after going to the 5 wt, as the bike didn't want to turn in or adjust back up after the turn as easily. After all my fiddling I think the bike is as good as I can get it without spending $$$, I'm very satisfied.
 
Had to do a fork seal, so changed the fork oil as well on my 04 ST. It looks like the stock oil was in there, grayish looking stuff with a tint of pink. I put in Bel Ray 10 wt, and geez, the front end feels a ton better! Definitely the old oil was not damping like it should as the front end feels so well tied down now, relative to before. I did sonic springs on my V Strom 1000 this spring, along with the oil and made a huge difference on that bike. Changing the oil on the ST wasn't the same magnitude improvement like I had with doing oil and springs on the Vee, but it made a nice difference that is noticeable. I'll put some springs in later, just didn't want to spend the cash right now, as I also put new brake pads on up front along with replacing my STuck T STat.
 
I would reccomend against progressive springs, I tended to blow thru the softer windings faster when braking and over time seemed to soften up on my SV1000S... ymmv.

I've found straight weight Sonics are best on my St. I used 5wt Silkolene fork oil set at sonics reccomended level and get a firm responsive and controled ride in the canyons. The stock compression valving in the forks is way too stiff and shows up on SoCals not so smooth concreat freeways. It's better than stock but the real fix will be the gold valve kit! Maybe next summer...:D
 
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