Topic: Progressive suspension shock and fork springs install

[78CB750CAFE]

I picked myself a $59 bike lift at Pep Boys on black friday, and now it's time to start all my winter projects
First up is a complete suspension revamp with RaceTech and Progressive Suspension goodies.

I got a screaming ebay deal on these shocks from Z1:
A set of Progressive 12 Series Gas Charged Rear Shocks.
13.0" Eye-to-Clevis.
Black body, Chrome Springs, Black Shroud Caps.

Progressive part numbers:
12-1204B
12-1367C 95/140 springs


I have them loosely installed right now since I need a few more spacers to fine tune the alignment and chain clearance.

My first question is this:

How much clearance should I have from the drive chain? I am running fresh 630 sprockets and chain and I have about 5mm from the chain pins to the shock body, is this sufficient? The progressive shock is much stouter then either the stock shocks or other aftermarket ones I had because the springs are MUCH longer.

#2:

Do the shocks have to be PERFECTLY vertical? It seems my last ones weren't and still worked just fine slightly toed out. I am trying to get this set up as dialed as possible, and I would like to know if anyone has any input on tolerances, before I drive myself nuts machining .25mm spacers and crap.

#3

Who wants to by my last set of shocks (shown below, brand/model escapes me...) with about 1500 miles on them for cheap ?


relevant info:

1978 CB 750K
stock swingarm stripped of all brackets and junk
NO chainguard
stock front sprocket size, 38-41t rear sprockets
630 O ring chain

pix to come soon...

[dramsell]

I am interested.  Can you tell me more and send pics?

Dave R

[78CB750CAFE]

I am interested.  Can you tell me more and send pics?

Dave R

I am guessing you are interested in the other shocks, here is a pic of them boxed

I will take $50 shipped, and I will get the brand/ model later.

[78CB750CAFE]

here are the Progressive Suspension shocks mounted

[78CB750CAFE]

chain side clearance

[MCRider]

snip
My first question is this:

How much clearance should I have from the drive chain? I am running fresh 630 sprockets and chain and I have about 5mm from the chain pins to the shock body, is this sufficient? The progressive shock is much stouter then either the stock shocks or other aftermarket ones I had because the springs are MUCH longer.

#2:

Do the shocks have to be PERFECTLY vertical? It seems my last ones weren't and still worked just fine slightly toed out. I am trying to get this set up as dialed as possible, and I would like to know if anyone has any input on tolerances, before I drive myself nuts machining .25mm spacers and crap.

#3
snip

On the tilted question, They should be straight up and down, if for no other reason than aesthetics. You'll be working the rubber in the top and bottom mounts in a way that was not intended. Doesn't mean it won't work though. Would be interesting to take the springs off, mount the shocks and then watch how much they rotate in the rubber as the swingarm goes up and down. If its not scary... But it might be, especially at the top of the travel.

Why aren't they vertical, are they for a different model?

[greenjeans]

If Dramsell passes on the shocks - I got $50 burning a hole in my pocket....

Are they 13"  centers as well or 13.5" ??

Lemme know, I can paypal or what ever you prefer

[78CB750CAFE]

both shocks are 13" centers.

As far as the alignment, I am talking about a minuscule amount off of vertical, it may even just be perceived, as I have yet to hit it with a plumb bob or anything. I am still working out the spacing/mounting. The clevis end is a few mm wider then its mount and I am just trying to get correct spacers to get it just right without deforming the clevis end when tightening. Also with the lower part of the shock body being significantly thicker then stock I have to spacer out the top mount to give myself adequate clearance for the chain.

I am off to the hardware store for a variety of 10mm id washers in stainless and brass, and tonight I will experiment with spacing.

[scondon]

  When I installed my Progressive shocks I noticed the same thing. The cleavis was wider than the swingarm and I ended up putting washers in the gap. Because the shocks were already touching the chaingaurd I put the washers/spacers on the outside which left the shocks slightly "toed" out. I toyed with the idea of adding spacers up on the shoulders but decided that I didn't want any portion of the eye hanging off unsupported. 20,000 miles and no uneven wear at the eyes or wear on the piston.

   To be honest I had forgotten all about this detail until reading this post, which is to say I haven't been looking at my bike thinking "#$%*, my shocks look splayed out". As MCRider points out I think you'll be OK as long as you please yourself.

[mlinder]

I used washers when I installed my progressives, too.

[mrosso]

What is the purpose of those flimsy plastic caps on Progressive shocks? Can you just discard those and run without them?

[scunny]

just a thought about your clearance issue. is the clevis end off centre, looks from the pics as tho it is. swap shocks over and you will have more clearance. but I could be wrong, it's happened before

[MCRider]

What is the purpose of those flimsy plastic caps on Progressive shocks? Can you just discard those and run without them?

When there is weight on the shock most of the shaft will be shielded from the elements by that cap.

Besides being a dust cover, and perhaps more importantly, its the place where the sticker goes. 

[78CB750CAFE]

It seems I have gotten a few thicker grade 10 washers that fill the gap and straighten the shafts up just right.
While I was at the local hardware I also got some grade 10 bolts for the lower mount, but I am having trouble finding a high quality acorn cap style nut for the top mount ( my stock ones are showing their age), anyone have a lead on good cap nuts (10mm 25)

Pix coming of finished shocks, next step is the rebuild of the forks w/ Progressive Suspension springs, RaceTech valve emulators, and all new Honda seals and whatnot.
Anyone out there with any advice regarding drilling the damper rods for this application??

[egar]

750cafe,

No to highjack the thread, but is that bedliner on your tank? I love the look. Please hook me up...

[Really?]

TAS sells the acorn nut and washer.

[A Grove]

It seems I have gotten a few thicker grade 10 washers that fill the gap and straighten the shafts up just right.
While I was at the local hardware I also got some grade 10 bolts for the lower mount, but I am having trouble finding a high quality acorn cap style nut for the top mount ( my stock ones are showing their age), anyone have a lead on good cap nuts (10mm 25)

Pix coming of finished shocks, next step is the rebuild of the forks w/ Progressive Suspension springs, RaceTech valve emulators, and all new Honda seals and whatnot.
Anyone out there with any advice regarding drilling the damper rods for this application??

Details on the RaceTech valve emulators?  I'm looking to re-vamp my suspension and want to make it as modern/best as I can.  Is this the way to go?  Do they make them for 550's as well?

I love your rid, its very unique, and badasss.  Keep it up

[78CB750CAFE]

Yup, Rhino Liner on tank, seat and headlight bucket.

On to the old shocks for those who are interested...

NDI brand, 13" c to c, dual rate springs, FC 508C seems to be the model #. I payed around $85 + shipping last year, I will take $50 shipped continental US, if outside US, email me your address and I will find out a shipping cost and adjust price accordingly.

[ev0lution7]

are you putting in new fork springs??

[78CB750CAFE]

Thanks all for the advice, comments and compliments.
Giga- Kewl, I will get on getting some from them

evo7- yup, Progressive Suspension fork springs as well

Agrove- you install the valve emulator jammies, drill big holes in your damping rods so they flow more oil then the emulator, then magically your bike handles like a factory GP bike (I wish). So the cartridge emulator is just an adjustable valve that takes over the damping control duties the damper rod used to do.
Also, I am pretty sure your 550 would run the same valve emulators, they are pretty much just made for different fork inner diameters. Check RaceTech or Bike Bandits site for a fitment chart, they will set ya back between $125-175 depending where ya get 'em.

[A Grove]

So, is there much information around to back-up the vavle emulators? AKA will it improve the ride quality well enough to notice a difference?  Thanks for the info, tho.  I'll have to check into them more..

[MCRider]

So, is there much information around to back-up the vavle emulators? AKA will it improve the ride quality well enough to notice a difference?  Thanks for the info, tho.  I'll have to check into them more..

Besides the awards and accolades they present on their website RaceTech.com, I can attest personally. Having put them in my 88HawkGT, which had a beefy fork, but not a cartridge style. IT makes a HUGE difference in ride quality, controlling braking dive, and all around coolness.

[MCRider]

Here's a Q/A from Race-Tech
Q: I have a bike with damping rod type forks. I have heard that Gold Valve® Cartridge Emulators® are the greatest thing since sliced bread. Why?
A: Old fashioned damping rods while inexpensive to manufacture have major limitations. To create compression damping, oil is shoved through a hole or holes. Shoving oil through holes creates very little resistance to flow at low vertical wheel velocities as when hitting a dip or gully or applying the front brakes. This allows the forks to shoot through the travel fairly easily, diving or bottomming in these situations. On the other hand when the wheel hits something square edge, especially at speed, it needs a lot of oil to pass through the damping holes very quickly. Unfortunately the nature of shoving oil through holes is that as the wheel velocity increases the damping force increases with the square of the velocity. In other words if you double the velocity you get four times the force. This means the hole basically "hydraulic locks" resulting in a harsh spike. Damping rods give the worst of both worlds, they are both too mushy and too harsh at the same time.

An Emulator® is a valve that sits on top of the damping rod and is held in place with the main spring. To install them we simply remove the damping rods and drill out the existing compression damping holes so they are so large they do not create any appreciable damping. Then during reassembly we simply drop the Emulator® on top of the damping rod. The Emulator® creates the compression damping of a state-of-the-art cartridge fork. The ride is both firmer and plusher than the damping rod and is completely tuneable. Sliced bread is good, Emulators® are better.

[A Grove]

Thanks MC!  I'll most likely be adding these to my new build, mine-as-well hit all the key points and make it ride as nice as possible, 'eh?   Report back, 78CB750CAFE, once you've had a chance to "review" them.

[78CB750CAFE]

Well...
It may be a while till I have test ride info, it's cold and the bike is still in pieces as I rebuild the whole front end. I have the triple trees baking in my oven right now to cure the engine paint I used on them, and I am about to repaint the lower fork legs. In a day or two I should have my All Balls roller bearing headset and all new stock replacement bolts from my local Honda shop (Coleman's Power Sports shout out!  HOLLA ) so I can bolt it all together nicely. Next I need to find someone with a good drill press to do the damper rod holes and on to the brakes.
I really need to snap some progress shots of the front end work, and finally post a close up of the stainless adapter I had made for the 2 Bros race can I am running. Do ya think a pic of my bike in pieces will hurt my votes in the BOTM competition  ?