All over the place...Maxim/Seca build

[Jeff0133]

Then I rebuilt the forks, put them in the tree, got the swing arm in...Rear wheel temporarily.
Put the engine in...Not without a fight..
It appears that, the bottom mount was modified at some point so the bolt doesn't line up with the left side mount. So I put on the middle bolt and the upper mounts for now.

 

[Jeff0133]

I wanted to put it together roughly to get an idea of the stance. The R6 shock is shorter than stock but I already knew that.
So I am going to fabricate an extension from the top of the frame down to the shock, also I want to have it attach a little lower on the swing harm...I find that it sits high on there and I think that it will be in a straighter line pushing against the frame if I drop it a little.

 

[Jeff0133]

Been mulching over my swingarm/shock for a couple of days...
This is how it sits...just mocked-up.

I wonder if I leave it as it is with an extension to the frame mount. Or go a little lower on the swing arm...
(FORGIVE THE DRAWING IT WAS DONE A SHIFTY APP...)

Or....really go all out on mods

Looking for opinions, comments,outrage,insults...

 

[16VGTIDave]

Looking for opinions, comments,outrage,insults...

Hrmmm... Where to start? From the end, of course!

Crazy Qbekker! What are you thinking? Put down that bottle of 50, go eat some Poutine to sober up, and get your toque on straight! - Does that take care of the outrage and insults you were looking for?

When looking at the shock positioning, consider its position with the suspension fully compressed. The shock should never be allowed to go "over center" or strange things will happen. I'd guess that the stock position is likely the best position, but you should remove the spring and test it to be sure. Then there is the question of the spring rate and valving of the shock. Was it setup for a direct connection (like it is currently mounted) or a linkage suspension?

 

[Jeff0133]

It is an R6 suspension so intented for linkage as it stands almost upright in the R6 setup.
Not too worried about the spring as it is barely used and was used on a bit heavier bike than the Little 400...And it is fully adjustable.

As for the over-center part....That I what I was worried about when using the stock mounting point on my swing arm. Also...My electrical tray will sit flush on the frame rails and i am pretty sure that as-is the shock will contact the tray under compression and that would suck big time.
As for the insults part...Twas artful.

 

[Jeff0133]

I used a Seca rear wheel to do my mock-up...But maybe if try the Maxim rear wheel....Maybe that would drop enough for me to use the stock mounting point...

 

[Jeff0133]

Today,...With time to lose and swing arms laying around the garage...

Decided to get creative...

Chopped off the top end, repaired the gouge left n'y the removal, kept part of the posts for what is next...

 

[Jeff0133]

Built a mount for the shock, with gussets.

 

[Jeff0133]

Then mounted the R6 shock, still have fab-up the top mount, although am still pondering if I'll use the R6 shock as I find it is soft but haven't ajusted the preload on it yet.

 

[Jeff0133]

Now bare in mind this is just a trial...But I had fun modifying/fabricating the swing arm.
I might end up using a Seca NOS rear shock that I have stashed in the garage...We'll see how it goes

 

[BBS360]

Looks cool. There's much less shock travel now vs swingarm travel so you'll probably want all the preload that shock can give you.

 

[Jeff0133]

Looks cool. There's much less shock travel now vs swingarm travel so you'll probably want all the preload that shock can give you.

Yep...just what I noticed when I took the bike off the centerstand....almost bottomed out....the angle in which it sits and without the leverage of the dog bone linkage it was designed with makes it soft or is it just a matter of force vectors applying more force on the shock in this setup....
Well...maybe I can use another swing arm I have laying around to try something else...or get the linkage and figure something out.
But hey...this is the part I like about building stuff, creating,fabrication,trial/error....
Thanks for your comments gents.

 

[16VGTIDave]

Preload won't be enough, a much stronger spring is required. And that will necessitate revalving the shock as well. If a linkage suspension (like I have) were installed, that shock and spring combo may be close enough to work, but there is no way it will work direct acting. The stock shock, or a different shock designed for direct action will be a better choice. But I'm not even sure that the stock shock would be strong enough as it wasn't designed to work with the suspension ratios as currently designed.

I know enough about suspension design to know I don't know much...

 

[Jeff0133]

Preload won't be enough, a much stronger spring is required. And that will necessitate revalving the shock as well. If a linkage suspension (like I have) were installed, that shock and spring combo may be close enough to work, but there is no way it will work direct acting. The stock shock, or a different shock designed for direct action will be a better choice. But I'm not even sure that the stock shock would be strong enough as it wasn't designed to work with the suspension ratios as currently designed.

I know enough about suspension design to know I don't know much...

Yep just what I thought...the R6 shock is not made to take direct load and even less....levered load like what I did...went back to physics 101 and realized that the position of the mount as it is now multiplies the load...so I might try the stock shock just for the hell of it but I have doubts...ah well, all in good fun I guess.
Still makes for interesting thought experiments though...

 

[Jeff0133]

So I tried the stock shock on the modified swing arm...And guess what...It bottomed out when I took the centerstand out...So I guess my swing arm acts as a lever....And the 400 pounds of the bike multiply by an X factor of the lenght of the swing arm with the pivot point acting as the Fulcrum....
So back to the stock swing arm.
Now I know that the stock shock Works...
What I wanted to know is...Could I keep my Fully adjustable R6 shock with it...
I put it Up using the clevis on its Side to pinch the frame and try...Took the centerstand out and it kept Up...sat on it and it kept...Bounced on the bike and could NOT from the life of me get it to bottom-out..
So happy Days!...I get to use my R6 shock. All that remains now is to fab-up the mounts.
Here it is mocked-up...With the Maxim wheel which I think I like more...

 

[16VGTIDave]

Keep an eye on the chain path. You will find that you can't raise the rear much before the chain will rub on the swingarm pivot when the suspension is extended. Using 17/38 sprockets will help slightly with clearance, but may cause frustrations with the Seca gearing by lowering the engine RPMs about 500. And you may find that with the chain adjusted for enough slack, that it rubs on the frame just above the center stand. I had to make a chain tensioner to deal with the slack.

And both the center and side stands may need lengthening...

 

[Jeff0133]

I will be using 15 front and 40 rear JT sprockets, thanks for the pointers on the chain clearance, I will keep that in mind when fabricating the mounts for the shock so as to adjust clearance

 

[16VGTIDave]

40T rear sprocket? I was not aware of such a thing. Got a part number?

 

[Jeff0133]

40T rear sprocket? I was not aware of such a thing. Got a part number?

Here you go

 

[16VGTIDave]

I just looked on jtsprockets.com and the JTR840 sprocket is only available in 35 and 38 teeth sizes. Not sure where that sprocket is actually from, but it doesn't look to be a genuine JT sprocket...