Guys I need help.

here is the situation. i have a Nightster. I picked up a set of Progresive fork springs for it. i got the ones listed on their website #11-1527. these are listed for just about all the sporties. i am in the middle of installing them and have become more confused than ever. i am soooo confused about figuring out the correct spacer length.

the instructions have install notes for each bike. however they do not have the nightster listed. i called progressive yesterday afternoon and the guy said to just use the notes and procedure listed for the 1200C. Okay, cool, easy, not!

The note listed in the instructions for the 1200C is #5 which states, "Spacer required is furnished with the springs." The spacer that is furninshed is 3" long. They guy said I will need to calculate the preload per the instructions and cut the spacer accordingly. Okay, still easy. The instructions state, Calculating Pre-load: "...you will need to determine if you need a spacer and length it must be. Most motorcycles need between 3/4" and 1" of pre-load. As a rough rule of thumb, the fork spring or fork spring and spacer combination should be at least flush (or above) the top of the fork tube with the forks fully extended. This is true for most motorcycles because their fork caps are between 3/4-1" long meaning they will screw into the fork tube the same distance."

Okay, seems straight forward. I'll need to cut the spacer and I'll be good to go.

Well here is the issue:

Ths stock springs, washer, and spacer measure 22 5/8" total. The stock spacer is 7 7/8" long. When I removed the fork cap the spacer stuck out of the top of the fork tube about 3-4". Not flush with the top of the tube like the progressive directions make it sound like it should be.

The progressive spring, washer and spacer measure out to be 21 5/8". The spacer is only 3" long. When this set-up is in the fork tube, the top of the spacer only sticks out the top of the fork tube 3/4".

The stock set-up is about 1" longer in length.

This is why I am confused. If the stock set-up leaves the spacer about 3" out of the fork tube, and needs to be compressed that much (approx 4" and produces lots of preload).

why do I need to cut the replacement spacer 3/4" when it will only produce about 1.5" of pre-load?

If I cut the spacer, I will only be cutting 3/4" off of it to make it flush with the top of the tube (per the instructions), so it will end up being approx 2 1/4". Others on this board have said they cut their spacer and only ended up using 3/4" for the spacer, not 2 1/4".

the install note stating "spacer required is furnished with springs" make me think I just use the whole spacer and not to cut it, but everyone says I do need to cut it.

Should I use the whole replacement spacer and just compress 1.5" or not?

Did HD change the internals of the fork on the Nightster?

Of course, Progressive was closed when I ran into the problems, and my bike is unrideable.


Please help, sorry for the long post

 

I'm just guessing here but the new springs being stiffer probibly don't need as much preload, if you have the recomended 3/4 to 1" using the full spacer I would put it together like that, you will know right away as soon as you put some weight on it if it is too stiff or sags down too much.

 

in order to get the recommended pre-load of 3/4-1" I will need to cut the spacer about 3/4". that would leave about a 2 1/4" spacer. others on this board have said their spacer ended up being about 3/4". why would mine end up being so much longer?

 

Idon't know why but if your only 3/4" too long with the full spacer I would try to put it together that way, dont force anything when tightening up the cap. Try it like that, if it is way too stiff take it apart and start cutting the spacer 1/2" at a time and re-assemble until it feels right.

 

Correct me if I'm wrong, but I think the Nightster has shorter fork tubes than the customs and are the same as those on the low model so I would presume that you would be using the lowering springs as std. hgt. for the nightster vs. std. hgt springs. I'm running std. hgt. progressives on my 1200C with a 3" spacer and have approx. 1" of spacer showing before pushing the caps down. One of the differences in the lowering springs is they have additional rebound springs in the bottom where the damper tube is and spacers.

 

I ran into pretty much the same problem as you. I did my springs last weekend. I did NOT cut the spacer at all ('06 883 Custom) and my front end is stiff....very stiff. I weigh 150lbs. I used 11.5oz of Bel Ray 15W. I ordered some Amsoil 10W which should be here either today or Monday. I'm gonna replace the 15W w/ 10W on Monday. I'm gonna cut the spacer down to even w/ the tubes (right now, it was sticking 3/4" above the tubes) and go from there. If its still too stiff, I'll try reducing the spacer by 1/2" and try again....and repeat if needed.
Keep us updated w/ what you wind up doing and how it works out for you. Good luck.

 

I'm going to do mine in a week or two, but everything I read fromguys that replaced them on sportsters is use 9 oz of 15 wt fork oil messure the oil in the tube and it should be no less that 5 1/2 inches from the top of the tube to the top of the oil. cut or leave the pvcpipe to make it 3/4 of of inch above the fork tube for pre load. that's the way I' going to try it. (hope it works out)

 

That's exactly what I read too before doing mine....but it didnt turn out that way. With the springs out, forks fully compressed and 9oz of oil, it was closer to 10" from the top of the tubes. The manual says to add 11.5oz. Even w/ 11.5oz, I still wasnt close to the recommended 5-6" from the top of the tubes.

 

so how much oil did you finally put in? just to have it when I get ready to do this.

 

I wound up using 11.6 like the manual suggested. I called the HD dealership and spoke to one of the service guys who runs Progressive springs in his bike...he said he runs 11.6 in his too. I'm thinking it may be too much for me though. It was suggested to me by sombody else (roughly my same size) to use 10oz of 10W.....so that's what I'm gonna try.