Author Topic: Rear shock, time for replacement?  (Read 315 times)

Offline kevinu

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Rear shock, time for replacement?
« on: May 18, 2020, 03:28:01 PM »
I have recently felt the rear shock hit bottom, once when crossing a cattle guard and then when crossing a rough section of road, both at ~60 mph.  Is there and adjustment for its travel, or is it time for a new one?
  • Alpine, Texas
  • 1994 K75

Offline The Mighty Gryphon

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Re: Rear shock, time for replacement?
« Reply #1 on: May 18, 2020, 03:58:15 PM »
Is it the OEM shock that came with the bike?  If so, it probably reached the end of it's useful life sometime in the last Millenium. 

There are replacements out there specific to the K bike.  One of the most cost effective is the YSS.  I have had one on my 16V K100RS for two years and can't find anything to complain about.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE
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Offline Chaos

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  • Mars needs women!
Re: Rear shock, time for replacement?
« Reply #2 on: May 18, 2020, 04:10:15 PM »
check the shock for oil leaks, sure sigh it's toast.  And what TMG said. 
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
2012 Ural 2WD sidecar (BMW's bastard step child)
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Offline TriSpark

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Re: Rear shock, time for replacement?
« Reply #3 on: May 18, 2020, 06:01:31 PM »
My K75 came with an old Koni shock and the rubber bumper on the shaft had rotted away, allowing it to bottom out on even the smallest bumps. It was rough to ride and almost kicked me off a few times, so the insides were probably knackered too. I tossed it and fitted a Progressive shock, and everything is good. It was cheaper to replace the whole thing than send the Koni off to Ikon to have it rebuilt.
  • Chattanooga TN
  • Red 1987 K75s

Offline Past-my-Prime

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Re: Rear shock, time for replacement?
« Reply #4 on: May 18, 2020, 11:21:38 PM »
The stock shock has adjustment for load; if you have a medium/heavy load and on the lowest setting it might bottom out. I'd go for a higher setting. There is a ring at the top of the shock and should be a tool in your tool kit for adjusting. Once you look at it, it's obvious.

If that doesn't help, I guess you're looking at investment time!
  • North Shore of Lake Superior
  • BRICK: 1989 K75 RT - Rocinante; NONBRICK: 2007 F650 GS Dakar - not yet named

Offline K1300S

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Re: Rear shock, time for replacement?
« Reply #5 on: May 19, 2020, 09:52:35 AM »
Is it the OEM shock that came with the bike?  If so, it probably reached the end of it's useful life sometime in the last Millenium. 

There are replacements out there specific to the K bike.  One of the most cost effective is the YSS.  I have had one on my 16V K100RS for two years and can't find anything to complain about.

what he said!
Project Thread "K75s Midlife Refresh"
http://www.motobrick.com/index.php/topic,7810.0.html

Offline Laitch

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Re: Rear shock, time for replacement?
« Reply #6 on: May 19, 2020, 10:29:31 AM »
I have recently felt the rear shock hit bottom, once when crossing a cattle guard . . .  at ~60  mph. . .
That seems like a senior moment writ large.  :laughing4-giggles:
  • Along the Ridley in Vermont.
  • 1995 K75 79,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline jjefferies

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Re: Rear shock, time for replacement?
« Reply #7 on: May 23, 2020, 02:24:54 AM »
Hi guys, I'm restoring what I thought was a K75C but now it's down to being a K75. But it has a Koni shock on the rear, and I have a Progressive, 3 BMW stds and something that looks like it came off a later model K11 or something bigger than a K75. Problem is that none of them are showing issues like leaking. Well can't really tell until they're on the bike and I've bounced it around a bit. BUT they all suffer from the rubber bumper disintegrating. Perhaps that's understandable as the bike itself sat in the weather for a few years out in the Avenues in S.F.  But is it possible to obtain the bumpers themselves?  Checked on having the Progressive renewed. The fellow down at Catalyst Reaction Suspension Tuning, was of the opinion that Progressive is at the lower end and that buying a new one would make the most sense. He may be right but I find the idea of tossing 5 rear shocks which appear to be functioning a bit annoying. is that the emotion? Or abusive to my wallet.

Does anyone sell the rubber bumpers? Is this a case where special tools etc make the change out of the rubber more expensive than just buying a new one? I know we're only talking USD $300. here but still. It's money that could be used to make the bike ...prettier?

Offline The Mighty Gryphon

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Re: Rear shock, time for replacement?
« Reply #8 on: May 23, 2020, 09:30:00 AM »
Maybe you should try a search engine on the interweb.  There are people out there selling parts for aftermarket shocks.  I have Works Performance and Fox Twin Clickers on my bikes and have no problem finding parts suppliers.  If the shock is rebuildable, someone is selling parts.  If you can't find the exact bumper for your shock, it should be possible to use one from another company as long as the shaft diameter is the same.  Fox bumpers go for about $12-15.

You should be able to change the bumper yourself in about an hour.  You will need a spring compressor.  I got mine at eBay for about $25.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue, '89 K100RS Special edition White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too
'89 K100RS SE

Offline Laitch

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Re: Rear shock, time for replacement?
« Reply #9 on: May 23, 2020, 09:51:53 AM »
Hi guys, I'm restoring what I thought was a K75C but now it's down to being a K75.
It's a K75C if it has a rear drum brake. How about posting a photo of it?
  • Along the Ridley in Vermont.
  • 1995 K75 79,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline jjefferies

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Re: Rear shock, time for replacement?
« Reply #10 on: May 24, 2020, 01:15:25 AM »
Laitch said: It's a K75C if it has a rear drum brake. How about posting a photo of it?
Well, that's a piece if info that's managed to get past me. So it's not a K75C. Must be a std then. I'f I can upload it here's a photo. The red in the background is my K75 with R100RT fairing and 162,000 miles on it.

* 20200512_153327.jpg (62.56 kB . 768x432 - viewed 59 times)

Offline Laitch

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Re: Rear shock, time for replacement?
« Reply #11 on: May 24, 2020, 01:22:57 AM »
So it's not a K75C. Must be a std then.
Fer gawdsake sake! Quit the hypothesizing and drop the last seven digits in this VIN checker and settle it once and for all, maybe. :laughing4-giggles:
  • Along the Ridley in Vermont.
  • 1995 K75 79,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline jjefferies

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Re: Rear shock, time for replacement?
« Reply #12 on: May 24, 2020, 01:30:20 AM »
Maybe you should try a search engine on the interweb.  There are people out there selling parts for aftermarket shocks.  I have Works Performance and Fox Twin Clickers on my bikes and have no problem finding parts suppliers.  If the shock is rebuildable, someone is selling parts.  If you can't find the exact bumper for your shock, it should be possible to use one from another company as long as the shaft diameter is the same.  Fox bumpers go for about $12-15.

You should be able to change the bumper yourself in about an hour.  You will need a spring compressor.  I got mine at eBay for about $25.
I must not be searching correctly then. When I made up the search string if I include the word "Progressive" I get all sorts of hits on progressive springs but not on the shock made by Progressive. There's an art to searching and I'm sure in the future there will be an art to selecting the name of your company to make it stand out. My main bike has a Works Performance, but I'm hoping to be able to use one of the existing 5 rear shocks that I've acquired along with this bike. And the parts I'm seeing are more to do with the mounting bolt eyelets than parts for the shock itself. I'll keep trying but if you have a magic search string I'd appreciate learning of it.
best regards
J.Jefferies

Offline Laitch

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Re: Rear shock, time for replacement?
« Reply #13 on: May 24, 2020, 01:34:34 AM »
I must not be searching correctly then. When I made up the search string if I include the word "Progressive" There's an art to searching
There's a tutorial about searching on this site; in fact, it's among the pinned topics at the top of this section. If English is your first language, you're all set.
  • Along the Ridley in Vermont.
  • 1995 K75 79,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline jjefferies

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Re: Rear shock, time for replacement?
« Reply #14 on: May 24, 2020, 01:38:21 AM »
Fer gawdsake sake! Quit the hypothesizing and drop the last seven digits in this VIN checker and settle it once and for all, maybe. :laughing4-giggles:
As you say "MAYBE". The VIN number shows it as a K75C. It has a rear disk brake. Not a drum.  Among the several issues is that I also have a parts K75 bike which I have been cannibalizing. And it's rear end and tranny were gone before I got it. So after 30 years purity is a bit muddied.

Offline Laitch

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Re: Rear shock, time for replacement?
« Reply #15 on: May 24, 2020, 01:52:51 AM »
And it's rear end and tranny were gone before I got it. So after 30 years purity is a bit muddied.
It's not a C any more.  177381 Not even the handlebar is a C-bar. It's purity isn't muddied; it's flat-out impure boohoo but it's your baby though, looking for adventure and whatever comes its way. Here's some history. It's close enough to accurate.
Anyway, I'm a big fan of compliance and you complied.  icon_cheers   Thanks for the photo and info update.
  • Along the Ridley in Vermont.
  • 1995 K75 79,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

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