Seat post springs question

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Toymaster
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Joined: Mon May 01, 2006 11:59 am

Seat post springs question

#1

Post by Toymaster » Sat Oct 09, 2004 1:05 am

Description: Is there a 'missing spring' I don't know about?

New to the board but have owned my baby[62 FLH pan] for .. 28 yrs.. Surprised
I have a question about the seat springs..
I had a Mustang seat on for a few years due to bad bushings and springs on the seat post..
Recently decided to go with the solo seat again..

I replaced the bushing [top only.. bottom one is hard to do without the HD 'tool']
The springs I got from NOSparts.com... it's the 6 spring set..
I also have a true HD set of the 3 lower springs..
[I prefer the 'real thing' when I can]
the 3 lower springs seem right..
The upper springs that go into the seat post of my original, came out in pieces, so I can't compare them with the new..]
I have put the 1" 'recoil spring' at the top.. [between the plunger locknut, and the seat post rod..]
Then, in the seat post, [on 'top' of the seat post rod, inside the seat post] I put one 3" Auxiliary Spring [top one] and one 2 7/16" Auxiliary Spring.. [bottom one]
Now, all the references I have show that as correct, BUT.. there is 'room' at the top of the seat post rod and the auxiliary springs [about 2"? of 'empty space'?] when the lower rod adjustment is made[11 1/2"]
Is there a 'missing spring' I don't know about?
It seems to me that that a spring is missing that should take up that 'space'?
Thanks in advance for any help!..
Charlie
Cool



Andy
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Re: Seat post springs question

#2

Post by Andy » Sun Oct 10, 2004 6:52 am

I had the same problem with my 49. It takes some trial and error with the springs, add the extra spring and try it. The seat tension can be made with various resistance depending on the riders weight.

Toymaster
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Re: Seat post springs question

#3

Post by Toymaster » Mon Oct 11, 2004 5:33 pm

Thanks for the reply,Andy!
Yes, those are the diagrams [and similar] that I am using for reference..
The prob is that there's about 1" of 'space' in the 'seat post' after the proper springs are all in place and the tension on the lowers set at 11.5"
Here's what springs I have installed, top to bottom:

Inside seat post, [above the rod]:
The 3335-30 aux spring =3"
The 186-10 aux spring = 2 7/16"

Between the 'plunger nut' and the top of the 'seat rod' [on the seat rod SHAFT part]:
3133-30 recoil spring =1"

Then below the 'plunger nut' [on the rod:
3128-31 'cushion spring' = 3"
'spring guide collar'
3129-31 cushion spring = 2 3/4"
'spring guide collar'
3128-31 'cushion spring' = 3"
spring tension adjusting nut, lock nut,..etc

With the spring tension on the lowers adjusted to 11.5", there's about 1" of SPACE that is above the 'seat post rod' inside the seat post, after all the proper springs are installed, and tension is set..
That just doesn't sound right to me? Surprised
I would think the idea is to have the lighter 'auxiliary springs' counter balance the heavier 'cushion springs'?
Those aux springs shouldn't just bounce around inside there?

The above is the problem.. as clear as I can make it..
I don't really want to just start putting springs in it..
It SEEMS that the addition of one 'recoil spring [1"] inside the seat post above the seat post rod would rectify it.. Cool
Call me a stickler for detail I guess..
Going to try the above, if I don't get reply from this post..
Thanks!
Charlie

kell
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Re: Seat post springs question

#4

Post by kell » Mon Oct 11, 2004 8:23 pm

Been a while but I vaguely recollect that one set of springs doesn't come into action until the post compresses somewhat... I guess that is the "auxiliary" springs. That may happen as soon as you sit on it, or only at bumps, I don't know. But if your springs are not strong enough then your idea of filling up the empty space the auxiliary has when unloaded is just as good as any other. You don't have to stick with "stock," particularly where seat post springs are concerned. I and others have bought springs from a commercial supplier ASRaymond or RSRaymond I think the name is, they are on the web and have a catalog they will send you too, though I had to wait forever to get mine.
Especially if you are a heavy guy/passenger or have changed the lever arm length of the t-bar (as in my case), even heavy duty springs supplied by HD or aftermarket may not suffice. And then there's the price difference between the bike market and industrial suppliers of the same materials, like springs, bearings, and so forth... always better to go with an industrial supply house than to pay HD aftermarket prices. Of course in the case of springs there is an extra complication in that you have to know the spring constant to select the spring you want. I just leaned my weight on the stock springs and measured how far they compressed, then got something stiffer from ASRaymond.
Good luck with it and let us know how it goes.

Andy
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Re: Seat post springs question

#5

Post by Andy » Tue Oct 12, 2004 11:48 pm

Just checking my seat, it seems there is some play in the springs before resistance is felt. I don't think it's critical, but there isn't any pre-load on the springs without a rider on the seat. I think you have the correct setting on your seat.

dereborn
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Re: Seat post springs question

#6

Post by dereborn » Wed Oct 13, 2004 1:00 am

I t-h-i-n-k I heard something somewhere about valve springs used in this area?? Not at all correct, of course, but an old "custom" trick that seems pretty clever to me. Anyone who knows more 'bout this?

mbskeam
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Re: Seat post springs question

#7

Post by mbskeam » Wed Oct 13, 2004 4:45 am

hello, when I first got mine up and running I used springs that are from the packaging equipment that I build. well that worked for almost 9 years, but I found this place called ebay . perhaps you have heard of it.............I got a new set of springs for the pogo.it used to ride like a tractor, now its like a caddy. man what a diff. they made. and the springs in the top part do not fill it up all the way, there is same space up there.
mbskeam

Toymaster
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Re: Seat post springs question

#8

Post by Toymaster » Wed Oct 13, 2004 5:34 am

Thanks all for the help!.. Cool
So the general consensus is that there IS a 'dead space' in the top of the post when it is at rest.. [seems odd tho?..]
I do have all new springs for it..[that was part of the problem.. the old top springs were all broken and wedged in top of the seat post.. so I really couldn't measure/compare them]
I have given it some thought here, as to why the dead space might be in there..
My first thought was that one of the the lower springs could be cut a bit to make it so there's no space there.. [and to lower the seat a bit?.. ] This makes sense at first glance..
But... further pondering I flashed on the idea that the design/engineering is such that the lower springs have to have a certain amount of 'weight/compression' on them [BEFORE the upper auxiliary springs come into play] for maximum effect? [only way I can account for the empty space!..] This also makes a certain amount of sense..
I am going to try a few variations [ including the empty spaced 'proper' way] and see what happens..
I'll post the results after I do it..
Thanks again all!
Charlie Cool

Billy
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Re: Seat post springs question

#9

Post by Billy » Wed Oct 13, 2004 8:52 am

Dereborn, I have 2 Chevy V-8 valve springs on my pogo [outside] It rides great!! Floats like a Caddy.
I'm 235 lbs. & it used to bottom-out. Not anymore. ;D
I was gonna do it proper, after I break the 'New motor in',
Someone liked them, & said it added character ;D
So for now they will stay. Till I get the other stuff together. This is on my FlatHead.
Toymaster, I also have a gap in the spring stack on the stick.
45" Flatty valve springs are about the right size for the po-go stick..

VintageTwin
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Re: Seat post springs question

#10

Post by VintageTwin » Wed Oct 13, 2004 1:49 pm

You want I should take a pix of my spring post and you can match it up to what you have? Springs are loaded full time, none rack loose back and forth. Hurry up with a request, my rigid is progressing past the point of no return. ;D
Dereborn- I think the 1" re-coil spring that slips over the exposed top end of the post is an outer valve spring, but actually all I've seen are cad plated, so maybe their not.

Toymaster
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Re: Seat post springs question

#11

Post by Toymaster » Wed Oct 13, 2004 5:04 pm

Hmm 4 say a gap in the post... and my common sense still says no there shouldn't be [which is what prompted this post initially]
Plumber, a pic certainly would be helpful, but I would need the upper [auxiliary springs/recoil spring] area inside the post more than the lower 3 compression springs [ I know that those 3 are correct..]
Also, you mention 'the 1" 'recoil' spring that slides over the exposed top end of the post'? Can you elaborate more on that?
I put the recoil spring BETWEEN the 'plunger nut' and the seat post rod, [on the seat post rod, but inside the seat post above the nut] which is as it is in all the diagrams I have seen.. It makes sense for it to go there, so as to absorb 'recoil' [hence it's name] and soften it from slamming upward during a fast rise [weight unloading]
My 1" recoil spring is NOS and looks parkerized.. as are the 3 compression springs... I believe it's the auxiliary springs that are no longer available NOS.. I got repops..
There are 2 auxiliary springs only right? [I did read somewhere that there were 3.. all diagrams I have seen indicate 2 only?]

Total of 6 springs? From top down:
2 aux [1- 3" and 1- 2 7/16" ]
1 recoil [1"] placed BETWEEN the plunger nut, and the top of the seat rod on the rod] inside the post
3 compression [1- 5 1/8" 1- 2 3/4" 1- 5 1/8" with the guide collars between]

Keep the thoughts and ideas coming.. they are much appreciated and food for thought!
I also can take a pic of how I have it set up now, if anyone is interested.. didn't install it yet.. working on the Tbar..
We'll get it right yet!..
Thanks again! Cool
Charlie

VintageTwin
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Re: Seat post springs question

#12

Post by VintageTwin » Wed Oct 13, 2004 11:04 pm

I'll take a couple. One close up of the top and the other of the whole thing. Be a day or so The re-coil spring "looks" like an outer valve spring, but the one I saw was cad, not rusted bare metal from outta somebodys head.

Toymaster
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Re: Seat post springs question

#13

Post by Toymaster » Thu Oct 14, 2004 3:37 am

Thanks! Cool
I'll be lookin for the pics..
Charlie

kell
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Re: Seat post springs question

#14

Post by kell » Thu Oct 14, 2004 7:23 pm

I think the reason stock springs have a gap in the aux is so that you start out with a relatively soft spring and then under heavy loads (like a bump) it gets stiffer. So you have a more comfortable ride until the road gets rough and then the stiffer springs kick in.

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Re: Seat post springs question

#15

Post by PanPal » Thu Oct 21, 2004 4:16 pm

Not stock, but I remembered reading info on a seat post shock that fits inside the frame tube. I found it in American Iron Magazine last night. Sold buy Kustom Culture Motorcycles. (650) 871 8333. It looks like something that would work well, but it does not look like the original.

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