Progressive Shock questions (several of them)

[Westone]

Hi everybody. I own a '88 K75 for 3 months now and have it running the best it has since I got it. Recently I noticed it came with a Progressive shock, which from what I read is a good thing compared to the stock shock. Not really knowing anything about shocks, I have a few questions.

The bike has 91,000 miles and I don't know how long the Progressive has been on there. Plus, not having any K bike experience prior to this bike, I don't have any reference for how this bike is handling. It could be great for an '88 K75, or there could be room for improvement, I don't know. The Progressive has a rubber stop at the top of the shaft for when it bottoms out, and it is cracked, dry rotted and appears hardened from exposure.

How can I tell if the shock itself is worn out? And if it needs it, is it serviceable or does it just get replaced? And what tool(s) are used to adjust the pre-load on the spring? I assume if I'm going two up with gear on a road trip I might want to dial in some extra preload, and I might otherwise want to experiment with it to see how different settings affect the handling.

Also, the shock has a air nipple at the bottom, and the text on the label of the shock makes reference to nitrogen. Is the pressure something that needs checking occasionally, or just leave it alone.

Thanks for the help on this.

[johnny]

greetings westone...

there are lotts o progressive shocks... posting up the shock part number and some photos will get you the right answers faster than anything...

j o

[mathias]

I too had a surprise finding a Progressive shock on the K75S that I bought a month ago.
At first it was unclear which model it is, since it isn't one of the current ones on their website. Then I noticed some numbers scratched in by hand on top of the cap by the piston. It turns out it's a 420, which checks out when comparing it to pictures online.
The numbers on top are:

420-100
20-1400

If anyone knows what the lower numbers are, I'd love to know. I'm guessing it's the stiffness specs of the spring.
This far I'm not in love with this shock. It seems way too heavily sprung - even at preload backed way off I can't get it to deflect much under my weight, around 165lbs. The ride is fairly harsh (seems like something named 420 should be anything but harsh!).
Also, the 5-position damping adjustment MAY be broken, it doesn't click between the positions, it just rotates freely. Can anyone confirm if this is normal?

[Westone]

greetings westone...

there are lotts o progressive shocks... posting up the shock part number and some photos will get you the right answers faster than anything...

j o

Yeah, I can see how knowing what we are talking about would help LOL. After removing the hard case these numbers are visible on the spring: 1188 250/310. A quick Google located basic specs about the shock. Picture attached.

[Westone]

Have not been able to locate a series or model number on the shock itself. It is still mounted on the bike and may be where I cannot see it. A little more digging with Google images and I think what it may be is a 465 series 1101.

[johnny]

oem instructions...

i would set the ride height then move on to the rebound... heavy steering can usually be fixt by raising the rear ride height... if you are wallering in the twisties you can try maximum rebound...

if you can enter this curve hot... trailbrake to the apex... whack the throttle on exit... and live through it... you may have it dialed in and all in the world is good...

j o

[Westone]

Awesome! Thanks to you for pointing me to the correct info Johnny. I'm glad to have this shock on the bike. Don't recall the seller ever saying anything about it.

[Lawrence]

Why not get the needed info from the horse's mouth?  I.e. contact Progressive Suspension.  It's not like the business disappeared or anything.

[Westone]

If anybody needs me, I'll be over in the Lieberry catching up on my reading.

[mathias]

That look a lot like the same shock that I have, the 420.



They are in upside-down, probably to fit better around the luggage racks. The numbers in your picture are probably the specs for that specific spring, I don't see those numbers on mine.
Could you check something for me on your bike? Does the setting for the damper (1-5) move in discrete clicks, or does it rotate continuously between the settings? I suspect mine is broken.

[Westone]

I'll have to check it. We're having a severe thunderstorm system move through at the moment, so give me a little time. The instructions do stipulate to only rotate the damper clockwise.

So yours is installed upside down as well? I don't know the top from the bottom, but from pictures had begun to suspect mine is upside down. I can't see any reason for it to be that way. It looks like it would fit either way.

[cy7878]

You got the good stuff.   420 or 465 is definitely better than the 412 that I have. 

[Westone]

Could you check something for me on your bike? Does the setting for the damper (1-5) move in discrete clicks, or does it rotate continuously between the settings? I suspect mine is broken.

Okay I just checked the damper adjustment on mine and it does not click, it simply turns smoothly and can be left at any position on or between the numbers.