Choosing a shock

[r65lsk75c]

After concluding that it's time to replace the original shock on my '87 K75C, I'm left with the difficulty of choosing what to buy. I see shocks from Works, Wilber, Hagon, Progressive and I suppose there are others. I'm an extremely conservative rider and I rarely put on more than 2000 mi. per season. Any recommendations on the most cost effective unit that will restore my confidence in the handling of this bike.

Rick T

[lorazepam]

After concluding that it's time to replace the original shock on my '87 K75C, I'm left with the difficulty of choosing what to buy. I see shocks from Works, Wilber, Hagon, Progressive and I suppose there are others. I'm an extremely conservative rider and I rarely put on more than 2000 mi. per season. Any recommendations on the most cost effective unit that will restore my confidence in the handling of this bike.

Rick T

works or progressive will be the least expensive of the ones listed. You can also check the ibmwr marketplace for a used one. I think it is possible to send out your unit to bruno's in canada, and have it rebuilt, and make it rebuildable. his pricing will be less than a new shock, if I recall correctly.

[barryg]

If you decide on Progressive, get the 420. Does a great job as a shock. I have it on my 87 K100RT and couldn't be happier. The other shocks you mentioned are probably as good or better. They all build a good shock.

[PacWestGS]

Not wanting to get too involved, just rebuild your original shock. Lots of people can do this just look around and find someone. Same for your forks and so on.

If you were not happy with them then definately buy an after-market custom set-up.

But, if you only see seasonal riding and don't crank things through the twisties than stock revalving, oil change and new springs will make you happy again.

HTH

[byker]

If you want to rebuild your stock shock, try Bruno's Machine and Repair in Kitchener Ontario. He did mine and it is just fine. Bruno advertises in the Owners news.

Byker :thumb

[Bruce_C]

I put a Progressive #420 on my '85 K100RT and found it oversprung and underdamped. Also it is probably the best aftermarket shock for the price.
FWIW. Being that you ride so little I would look for a used shock on eBay. You can pick up a good shock for under $50.00
Bruce C
:blah

[deilenberger]

After concluding that it's time to replace the original shock on my '87 K75C, I'm left with the difficulty of choosing what to buy. I see shocks from Works, Wilber, Hagon, Progressive and I suppose there are others. I'm an extremely conservative rider and I rarely put on more than 2000 mi. per season. Any recommendations on the most cost effective unit that will restore my confidence in the handling of this bike.

Rick TYou missed Ohlins.. :)

Whis is pretty much a case of you get what you pay for. I have had the following shocks on a K100RT (close enough to your K75) - and I'll list them in increasing order of goodness:

1. Stock shocks - underdamped when brand new. And oversprung unless you carry a 400lb SO on the back.

2. Progressive steel one - better than stock but not a lot and not rebuildable.

3. Progessive 420 - just didn't do it for me. Felt like a rock, could not adjust it so it worked well for me. A friend bought it - sent it back to Progressive who revalved it and it worked for him.

4. Works Performance - decent shock. Seemed to need rebuilding about every other year - which started to add up.. would loose gas pressure. I finally started rebuilding it myself (had a friend in the dirty-bike business who would let me use his gas recharging kit.)

5. Ohlins - excellent. Expensive. Great shock. Won't go wrong here if price isn't a concern. Ohlins no longer makes the early K bike shock as far as I know - so this one you're gonna have to find used.

6. Wilbers - my current shock. Excellent - as good or IMHO better than the Ohlins. 5 year warranty, made custom to your specs. Priced less then Ohlins but still expensive. I'm running a "full-boat" one (remote reservoir, remote preload adjustment) on my K75S. It is a very nice shock. I can't think of any reason I'd want anything different.

#5 and #6 basically transform the K bike handling. Be hard to describe it any other way. That rather insecure floating feeling you get going around long high-speed sweepers? Gone. "Planted" and "predictable" are the words best describing them.

The Works can provide a decent ride - but not as good as the two most expensive ones... it is probably the most cost effective choice.

I'd also recommend getting Works Performance front fork springs - and spend some time tuning them (changing the crossover point between hard/soft until it suits your riding style.) I would do this no matter which rear shock you pick. Progressive also offers a fork spring - it never seemed to do much for me, where the Works is very obvious what it's doing making it easy to tune.

Ya know - with the right shock - you might find you want to ride more than 2,000 miles a year.. :D

HTH,

[gsmetal]

I am sold on Works Shocks.

I just had one built for my wife's K75 - Works called me on a Thursday to get my wife's height & weight and to learn how she drives (Touring or sport) type of loads she would carry, etc.

I was impressed.

The guy who took care of me ("Memo" is how his name is pronouned) said I would have the shock "next week" and the shock showed up on Tuesday of the following week as promissed. They are in California and I'm in Wisconsin.

THAT'S SERVICE!

By the way, the shock came with all the mounting hardware needed and well protected in the shipping box.

[bmw_rider]

How big a deal is it to replace the front fork springs on an 85K100RT?
I am considering lowering the bike for my inseam challenged son to ride and find the only real way to do so is a short shock and nudging the forks down in the clamps. Thought it might be worth changing out the fork springs as well.

[MCRyder]

Don E. has well summed up the info on K shocks. The Ohlins and Wilburs were too rich for my blood, riding ability, and marriage :rolleyes . I got the Works Performance for my K11RS. It does a better job and has more adjustability than the stocker. For similar price and performance, Hagon shocks are another option. Find info and prices here: http://www.davequinnmotorcycles.com/cgi-bin/webc/home.html

If you opt for a Works Performance your BMW MOA membership get you a 10% discount!

How big a deal is it to replace the front fork springs on an 85K100RT?
I am considering lowering the bike for my inseam challenged son to ride and find the only real way to do so is a short shock and nudging the forks down in the clamps. Thought it might be worth changing out the fork springs as well.

Here's a couple of places that gives guidance on K fork spring installs:http://ibmwr.org/ktech/install-fork-springs.shtml
& http://ibmwr.org/ktech/fork-springs.shtml

I'm an average wrencher and got the job easily done following the directions.

[deilenberger]

How big a deal is it to replace the front fork springs on an 85K100RT?
I am considering lowering the bike for my inseam challenged son to ride and find the only real way to do so is a short shock and nudging the forks down in the clamps. Thought it might be worth changing out the fork springs as well.It isn't a difficult job. With RT bars - it's easier if you remove the bars and lay them back on the tank (well padded of course) - but not absolutely required.

To remove the springs - you must jack the bike up so the wheel is off the ground (floor jack under engine sump works..)

Then find an allen driver (allen that fits a 3/8" ratchet wrench) that will fit the fill bolt in the top cap of the fork (after removing the plastic cap)..

Get a nice tiny pointy screwdriver

Spray some WD40 around where the cap fits in the fork leg - helps break the O ring free

Put the ratchet into the bolt hole - and start turning clockwise while pushing down on the ratchet wrench. The entire cap will turn and move downwards. Once it's down 1/2" or so - look for the wire ring that keeps it from coming out, and use the tiny screwdriver to cock this and then push it out of it's groove so you can remove it.

Remove the ring, then keep turning the cap and release pressure on the wrench - the cap will work it's way up. Don't let it fly off and hit you in the eye..

Once it is out - the spring spacer is first, followed by the spring(s) [may be more than 1 depending on which spring you have] Remove and replace as you want to.

Some hints for lowering the RT..

You should be able to raise the fork tubes up in the triple-clamp about 1/2" or so before they contact the bars..

You can shorten the spacer in the fork tubes if you want to keep the stock springs - I wouldn't take more than about 3/4" off - you want the springs to still be under a bit of compression when the forks are fully extended.

Both of those will lower the front of the bike.

Try to keep the lowering amount the same front-back to keep from upsetting
the bike's suspension geometry.

Oh - 80 series tires will gain you another 1/2" or so. Bridgestone makes some that will fit fine.

HTH,

[r65lsk75c]

I assume that the same procedure will work for my '87 K75C? I used the plastic card and ordered a Wilbers shock - 1/2 inch shorter than stock. If I add Progressive springs to my forks, can I just trim 1/2 inch off the spring spacers and have the front and rear 1/2 in. lower? I don't have more than a quarter of inch or before the fork tubes hit the handlebar, so lowering the front by this method is fairly limited. After making this change, should one alter the volume of fork oil? Is there a sound method for determining the optimum volume of oil?

Thanks,
Rick T

[deilenberger]

I assume that the same procedure will work for my '87 K75C? I used the plastic card and ordered a Wilbers shock - 1/2 inch shorter than stock. If I add Progressive springs to my forks, can I just trim 1/2 inch off the spring spacers and have the front and rear 1/2 in. lower? I don't have more than a quarter of inch or before the fork tubes hit the handlebar, so lowering the front by this method is fairly limited. After making this change, should one alter the volume of fork oil? Is there a sound method for determining the optimum volume of oil?

Thanks,
Rick T
Hmmm.... multiple questions - one paragraph. Easier if you break them out..

1. You CAN lower your front end by shortening the spacer - even with Progressives (if they use spacers - I seem to remember they do..)

2. The shorter spacer has no effect on the oil level/quanity. What can have an effect is the size/diameter/spacing of the spring wire in the portion submerged in the oil. Your best bet is usually to set the level by depth - and Progressive would be the one to tell you what that number should be.

HTH,

[roy]

After concluding that it's time to replace the original shock on my '87 K75C, I'm left with the difficulty of choosing what to buy. I see shocks from Works, Wilber, Hagon, Progressive and I suppose there are others. I'm an extremely conservative rider and I rarely put on more than 2000 mi. per season. Any recommendations on the most cost effective unit that will restore my confidence in the handling of this bike.

Rick T

Rick there is poll in the "campfire" section about a group buy of Wilbers shocks. You may want to add your name to the list if interested.

The thread is: Campfire / poll: Group buy Wilbers Shocks.

I believe Lorazepam (spelling) is in touch with Wilbers at this time so another interested party won't hurt.

[85K100LT]

Hello all,

Have read this shock thread - New to BMW motorcycles 85 K100LT.

I have owned several Honda Goldwings - older GL1100's also ride Dirt bike in the AZ desert.

I just bought an 85 K100LT - Previous Owner had installed a Progressive 420 rear shock at 47,000 miles bike currently has 55,000 miles. PO also kept very detailed records. Front forks were rebuilt at 45,000 miles and 20 w fork oil was used. PO records indicate many adjustmnets to the progressive 420 shock ie sag and dampening. Progressive 420 shock cost around $75 per his records.

I did not like the way this BMW rode with the progressive shock - I adjusted the sag to 1 inch changed the dampening. Did not help - rear suspension felt like a rock no give and felt uncomfortable on the road. Did not feel I had control in cornering. I keep thinking my Goldwings handled better - How could this be a BMW I had to ask myself.


Well Saturday morning I got up and removed the Progressive 420 shock and installed the original BMW shock (PO supplied with bike) this bike is wonderful feels 100 % better with original BMW shock. :heart

I am a big BMW fan and was not 100% sure on their bikes until I made this change. This is my first BMW motorcycle - I have done sport racing with BMW cars 5 series, 3 series and a M3 - currently drive a 1990 535i with manual trans love their cars. :bikes

[deilenberger]

Did the former owner weigh 400lbs?

That's the only reason I can think of to have 20W oil in the front forks. The spec is for 5W - most people find 7.5W satisfactory. With 20W you're riding on a rigid front end.

The way the 420 was setup also hints that the former owner either weighed a ton (or his SO did) or he toured with the kitchen sink hanging off the back of the bike.

I'd suggest:

1. Looking at the front forks - see what springs are in them and how the preload spacers are setup - how much "sag" they have.

2. Changing the front fork oil to something reasonable.

3. Send the 420 back to Progressive and have them look at it. These probably are available with different springs - you might have the heavy load spring on it.

BTW - your bike is a K100RT - there was no LT in 1985..

Best,

[85K100LT]

Don,

Good points -

First I went back and checked my records and the front fork oil used was 15w and yes the springs were changed. The front suspension is setup correct per my riding style and experience.

Not sure of the PO weight but the rear progressive shock made this bike not comfortable to ride and unsafe in my opinion. I am 100 % satisfied with the stock BMW shock in comparision to the progressive shock.

The progressive shock is bad and probaly needs a rebuild to my weight and riding specs - but has only been on the bike for about 6000 miles and the PO did not like it per his records.

I may in the future get this progressive shock rebuilt and retry but for now I am 100% HAPPY!

Yes My bike is a K100RT the LT did not come out until 1987.

Shocks / suspension are very important - this thread has helped me and I hope this added information will help other riders.

Thanks

[wndsrfr]

If the bikes PO only paid $75 for the Progressive rear shock, you can very likely bet it was whipped out. I just put a new 420 on my K75RT and am loving it. However, I did go through an iteration with them to get the spring right--it was originally supplied with the "light" spring per my order since I only weigh 160 and don't ride 2 up or with huge loads. Even so, I was bottoming the shock even with it set up on step #3 on some of the more aggressive bumps around here. Had them switch it to the heavier spring (no charge--Thanks Progressive!) and I couldn't be happier--bike is firm, but not rock hard as you're describing, and has definitely gotten away from that "floating" sensation that the cushy stock BMW shock provided. (BTW--This is a 3/4" shorter shock with the front lowered 3/4" as well by sliding the tubes up in the clamps.) The bike is super responsive now--flicks around the way I want it to versus having to plan ahead to lean it with the stock setup.

[85K100LT]

Yes I will give the Progressive shock a rebuild and try it again - The PO may have bought this used - again this web sites expeience is a valuable tool.

[85K100LT]

I had my Progressive 420 shock rebuilt by Progressive and have reinstalled and rode bike about 10 miles. First Progressive said this was an older 420 series shock in great condition and they were able to rebuild with current parts cost $107.

Well it works great and I will need to get some more riding time to test it futher. The 420 series shocks from Progressive run new approx $400 so I am happy with the rebuild cost and results.

Per my other post about PO paying $75 for this shock I now realize this was in reference to the front fork springs.