Fork Swap now fork spring issues

[Guest]

So when I purchased my bike it had L fork Lowers in the G triple tree. After talking to Steve and realizing how much this can change the steering geometry I wanted to I recently acquired a ton of Suzuki crap which included forks. I found a good looking set of G forks that were on a L that was bobbed out. I took the forks apart put in new seals, fresh 241ml of 10W fork oil. then the springs shocked me they seemed like a short pair of progressive springs with a 5' PVC spacer. I will get photos up tonight with measurements but wanted some input on these and what you guys think about this set up. I wanted to change back to G lowers for the salty monk brake upgrade and I went ahead and installed these forks so I can get the brakes bled. but I am now thinking these are lowering springs for the forks which I do not want I guess. I did not measure the fork sag because of the issue I don't know how much fork sag do you need? I will upload photos later and we can figure this out if I need to change these out or if I don't need to

[Steve]

... then the springs shocked me they seemed like a short pair of progressive springs with a 5' PVC spacer.

I'm sure you meant 5 inches, rather than 5 feet, but that's OK.
In many bikes, the stock springs were progressively-wound, but that does not make them Progressive (brand name) springs. Springs from the Progressive Suspension company use thicker wire than Suzuki did, but you might not notice that unless you actually measure the wire or have one of each spring for comparison.

The use of a spacer is very common, that way you can use one spring for many models and just change the length of the spacer.

I wanted to change back to G lowers for the salty monk brake upgrade ...

I was not aware that the Salty Monk upgrade did not work with L forks. I guess the angle of the caliper would be a bit different, so it makes sense, but had not thought of that before.

... but I am now thinking these are lowering springs for the forks which I do not want I guess.

Before you assume that they are 'special' springs, compare the length with the specification in the manual. As mentioned earlier, it is not unusual to have a spacer to fill the length of the fork tube.

I did not measure the fork sag because of the issue I don't know how much fork sag do you need?

The generally-accepted amount of fork sag is 20-25% of available travel. Most of our forks have between 5 and 6 inches of travel, so you are looking for sag in the 1 to 1.5" range. Remember that sag is the difference in fork length from fully extended (bike on centerstand is a good way to measure) and 'riding length' with you on the bike, gas tank full, gear on, etc.

You will obviously need help measuring the fork when you are on the bike, so make it easy on your helper. Just measure from the bottom of the lower triple to the top of the dust boot.

.

[mmattockx]

The generally-accepted amount of fork sag is 20-25% of available travel.

On these softly suspended old bikes 25% laden sag (ie - with rider in full gear on board) works very well as a starting point for the front end.

You will obviously need help measuring the fork when you are on the bike, so make it easy on your helper. Just measure from the bottom of the lower triple to the top of the dust boot.

Very sound advice. OP, as Steve says, there is no need to worry about a preload spacer as most all bikes use them. My 82 1100E uses 54mm spacers with modified Progressive Suspension fork springs so you aren't out in the wilderness very far with yours.


Mark

[850 Combat]

You can put a zip tie on the fork tube and see how far up the wiper pushes it to measure sag.

[RichDesmond]

Sag (and static preload) is hard to be exact on with progressive springs. Depends on the rates of the soft and hard section, and where the transition point is.
Given that there's a PVC spacer in there it's likely that they are Progressive brand springs, which mean they are a lot better than stock. I'd start with 20mm of static preload and work from there. If your total sag is between 30-35mm then your good to go.

As a side note, with straight rate springs of the proper rate, 28% of actual travel is a good starting point for sag.

[Gs1000g]

Sorry for the delayed response, got home from lake today and did some measuring, with 10.5psi in each fork I have 2.189" of travel on the forks. The fork seal boot to the triple tree is 7 1/4" on length. So I guess I have too much sag? Thanks for the quick replies I didn't take any photos because I don't really want to take apart the forks and take the springs out for just photos but I will if need be I will but not preferred

[Gs1000g]

Today I took the forks back apart, measured the spring, it's a stock spring with a 4.5" PVC spacer. With this being my
options I have a bucket of forks so I'm going to take them apart and see if any have aftermarket springs, if they do I will swap them out and go from there. Thanks for the help again

[Gs1000g]

Got my new sonic springs delivered and installed today I'm right at 34mm of sag, I would do a test ride but now I have to figure out why my brakes are not working btw thanks for the phone call and great customer service Rich!!

[dantodd]

Got my new sonic springs delivered and installed today I'm right at 34mm of sag, I would do a test ride but now I have to figure out why my brakes are not working btw thanks for the phone call and great customer service Rich!!

Is that 34mm with spacers or without? I just placed an order and was wondering what I'm in for.

[Gs1000g]

Is that 34mm with spacers or without? I just placed an order and was wondering what I'm in for.

They are quick and easy Dan, its with the spacers installed. According to the directions you want roughly 1/2" of preload with spacers installed.
Basically you install the springs with washers, then take the supplied PVC pipe and insert into the fork tube, mark the top of the PVC flush with the tube.
Measure your fork caps and cut spacer accordingly so that you have said 1/2" of preload (springs compressed 1/2") with caps fully installed
measure Sag again and if you are between 30-35mm of sag you are good to go according to rich, it sounds more complicated than it really is, took me about 20 minutes after I figured out that my calipers were not zeroed.

[mmattockx]

Got my new sonic springs delivered and installed today I'm right at 34mm of sag, I would do a test ride but now I have to figure out why my brakes are not working btw thanks for the phone call and great customer service Rich!!

That 34mm is with the rider in full gear on board?


Mark

[dantodd]

They are quick and easy Dan, its with the spacers installed. According to the directions you want roughly 1/2" of preload with spacers installed.
Basically you install the springs with washers, then take the supplied PVC pipe and insert into the fork tube, mark the top of the PVC flush with the tube.
Measure your fork caps and cut spacer accordingly so that you have said 1/2" of preload (springs compressed 1/2") with caps fully installed
measure Sag again and if you are between 30-35mm of sag you are good to go according to rich, it sounds more complicated than it really is, took me about 20 minutes after I figured out that my calipers were not zeroed.

Thanks. I'm excited. My forks nearly bottom out every time I get in the front brakes.

[Gs1000g]

yes its 34mm with me sitting on the bike and a full tank of gas

[dantodd]

yes its 34mm with me sitting on the bike and a full tank of gas

Morning or evening?

[Gs1000g]

Depends if I have taken my morning leak or not....
update: I went riding about 150 miles today on a lot of Ozarks curvy roads. The difference with the proper forks and new sonic springs are astonishing, it's a completely different bike. Handling, bumps, and vibrations are all completely different then before. I would of pushed the bike a lot more but the Mrs was on the back and she doesn't appreciate that.