Suspension Questions

[Laney]

I need help figuring out what’s wrong with my KRS, but hopefully suspension knowledge is somewhat universal, and this is the right forum to pose this question.

 

My KRS has Ohlins front and rear, and the stock steering dampener. I put the Ohlins on about a year and a half ago, and they have about 25K on them. The steering dampener’s seen 35K.

 

My RS was in the shop for almost 9 weeks, and today was the first day I took it out to play after doing the engine break-in miles and subsequent oil change over the last few weeks. (OK, TWO oil changes, but I'm being extra good. )

 

Around town it wasn’t so obvious, but on the freeways and in the canyons, the suspension is (for me) brutally harsh. The front end feels like crap -- it negatively affects the handling in corners, and I got beat to death riding it on the freeway to and from the good roads.

 

The rear shock has a preload adjustment, plus compression and rebound damping. The rear preload is at the minimum. My experience with changing the compression and rebound damping settings in the past was that changes were mostly in handling – it was either grossly squishy, or different levels of better than grossly squishy, until you hit “GOOD.” I never felt anything terribly harsh from changing those settings, just varying levels of control. I set both compression and rebound damping to just a little less than halfway. I’ve never changed the front shock setting – the only thing I could change is preload, and I don’t weigh enough to need more than the factory setting.

 

The only things I can think of are – the front shock’s gone bad somehow, or the steering dampener’s got some problem, or the front shock preload got cranked up so some big guy tech could test ride it while it was in the shop. I don’t remember what the front shock looked like before, but I looked at it today and there’s about an inch and a half of threads below the two adjustment nuts that push up on the spring. It may have always been that way, but I’m not certain.

 

Any suggestions on where and how to check any of the front end stuff? I’m planning to take the bike to Torrey, but I’d never survive 5 days with it the way it is now.

[EffBee]

Laney, let's assume they didn't mess with your preload at the dealer. Therefore, harshness can only come from one of two things. Either the compression damping is too high, or the rebound damping is too high.

 

If it's the first, it's easy to understand. If it's the latter, you may be asking yourself how could rebound damping affect the compression stroke of a shock? It can because if rebound damping is too high, then after your shock compresses on a bump, it does not have the time to extend from a compressed position quickly enough before the next bump. Eventually, the shock gets shorter and shorter (this is called "packing down") and as it shortens it gets stiffer and stiffer because the spring is more and more compressed.

 

First, I would re-set the sag in the garage. If anyone DID mess with the spring preload, that would tell you.

 

Next, I would back the rebound damping out even further and start there. If it still feels harsh, back the compression damping out and slowly bring in the rebound. In the meantime, make an appointment ASAP with Stig Petterson at Petterson Pro Suspension in Anaheim/Santa Ana. See if they can get you in quickly. If you fix the problem yourself, you can cancel the appointment. But if you can't, then take the shocks to Stig for a rebuild.

[Art..]

Did you check the tire pressure when you got the bike back from the dealer?

 

I know - stupid question, but I've seen dealers put 50PSI++ in some tires.

[Laney]

Laney, let's assume they didn't mess with your preload at the dealer.

 

It seems as if it would be too much work to change preload on the front shock -- that's why I'm wondering what other options there are if that's not what caused the change.

 

I was planning to call PPS today -- I bought the shocks from them -- but I know they're not always there. I'm hoping I can resolve this quickly, if not this bike isn't going to Torrey.

 

I did check the tire pressures, and rechecked before I left in the morning. I wish it could've been something so simple!

[russell_bynum]

Just give me a week with it. I'm sure it's all that "riding like a girl" stuff you do that's causing the problem.

 

 

<running for cover>

 

I liked Fernando's advice.

[JerryMather]

Mine is a little stiff too. I called Stig the other day and he told me to mark the nuts on the front shock and then back them off by two turns to see if that helps. I did it last night and will test ride it this morning.

Let us know what it takes to correct your problem.

[JonathanE]

Let's see if I understand the back ground of your suspension changes:

 

You left your bike in the shop for several weeks while they worked on something other than your suspension. When you got the bike back, the suspension had changed in a major way, for the worse.

 

You might want to verify that the serial numbers on your shocks hasn't changed.

[Tool Man]

Laney, Fernando hit the nail on the head.

 

I doubt anyone at the shop touched your suspension settings. Tech's don't care about your suspension when they take it out for a test ride...they're checking the work "they" did. However, you don't mention if the bike felt fine when you took it in 9 weeks ago and now it's completely different.

 

Do exactly as Fenando suggested before worrying about where your damping is set. You should set your ride height first, then adjust the damping to your liking/needs. Don't refer to "factory" settings for adjustments. How does the factory know what you weigh? They don't, so factory settings don't exsist as far as I'm concerned when setting up suspension. I am assuming you have the correct spring installed as you have not complained or felt this condition before.

 

After you have achieved your desired ride height, again do exactly as Fernando suggests. Start low on the damping adjustmemnt knob, maybe 10 from full soft and work up from there. I doubt you would go past the halfway setting of 24 clicks to achieve correct damping for your weight and spring. I could be wrong, but I don't think you have independent rebound and compression damping on that shock set. Most Ohlins for BMW's have one damping ring which controls both rebound and compression.

 

Your steering damper will not effect how the front suspension is reacting in a vertical movement. You can remove and you'd never notice as it serves another purpose which is not suspension movement related.

 

I'm not convinced your shocks need rebuilding. I doubt you have abused the suspension and the milage isn't that high. Usually the first thing to go are the damping rod seals which would weep fluid down the damping rod much like a fork seal would, being very visible. There is a slight possibility the internal seals on the damping piston have swelled causing some frictional resistance along it's internal bore.

 

Again, to echo Fernando's advice if the changes we offer do not improve the performance, Stig can have a look inside to see what's going on.

 

Good luck Laney and post back your results.

[Laney]

However, you don't mention if the bike felt fine when you took it in 9 weeks ago and now it's completely different.

You're right...

Just before its last trip to the shop in June I rode the RS to Torrey. It felt rock-solidly-perfect throughout that trip – even when I hit that frost heave in Zion. When I brought it home, it wouldn’t start again, so the next time it left the garage was on a tow truck.

 

I didn’t think the steering dampener had anything to do with up and down travel, I just mentioned it because the first time I did anything to the bike after its return in August, I found one of Motolight wires had somehow been caught under the extended part of the steering dampener, and it was under a lot of tension as the wire was pulling upward. I assume it was like that from the time I rode it home until I found it – three or four days. I can’t believe the wire didn’t give up!

 

There are three adjustments on the rear shock, and just one – preload -- on the front.

 

I checked my receipts this morning, and the shocks are newer than I remember – just over 15K, and I’m probably not terribly brutal. Sheesh, how tough could anyone that rides like a girl be on a pair of shocks?

 

I talked to Stig Petterson and he can’t tell me anything unless I have the shock(s) removed and delivered to him. It’s unlikely that’d be possible between now and when I’d planned to leave for Torrey – I had them installed at Irv Seaver’s and they had the bike for a long time – two days, I think -- trying to get things installed right. I don’t know they’d have the big block of time to do that now, and also don’t know if the big block of money required would be a worthwhile investment.

 

Sometimes I wonder if I’m just supposed to sell this bike and get it out of my life.

[BFish]

Mine is a little stiff too. I called Stig the other day and he told me to mark the nuts

 

that's gotta hurt

[Tool Man]

You left your bike in the shop for several weeks while they worked on something other than your suspension. When you got the bike back, the suspension had changed in a major way, for the worse.

You might want to verify that the serial numbers on your shocks hasn't changed.

 

I tried not to go down that path but since you started it....I had the same thought. I would hope that's not the case.

 

Jerry....by the nuts Stig is referring to...doesn't he mean the adjusting collar and the lock ring collar for setting preload???? Two turns would be a starting point and maybe change the ride hieght by about .125 or 3mm which isn't alot. You might want to back off the damping by two-three clicks as well.

 

Laney, feel free to PM me if you have trouble.

[Laney]

I tried not to go down that path but since you started it....I had the same thought. I would hope that's not the case.

 

I went out to the parking lot at lunch and took a look – at least the front shock looks too dirty to be anything but the original. It would have been cleaner, at least in spots, if it had been handled and replaced, wouldn’t it?

 

What’s the likelihood either shock was partially removed to take the engine out? I saw the bike while it was engineless, and don’t remember any shock stuff hanging out, but the compression damping adjustment reservoir appears to have been moved. I couldn’t guess if it was just bumped or removed and reinstalled.

 

Thanks Mikey

[Tool Man]

What’s the likelihood either shock was partially removed to take the engine out?

 

Yes..rear could have been manipulated or handled...front no.

 

I wouldn't worry about your shock being commandeered. I did have an instance once of a prototype wheel and brake conversion I did that was pirated from a customers (Italian) bike we can discuss the next time your up this way having lunch at the Yodler

 

Do as was discussed and let me know if any improvements. If you get in a bind and feel like coming up to the Toolshack before you leave, we can get it dialed in.

[Laney]

So I checked everything according to the directions that came with the shock.

 

The results are in, but I don't quite know what they mean...

 

Static sag Front is 44 mm, Ohlins recommends 15 - 30 mm

 

Staic sag Rear is 30mm, Ohlins recommends 10 - 20 mm

 

Ride height front is 44 mm, Ohlins recommends 35 - 50

 

Ride height rear is 47.6, Ohlins recommends 25 - 40

 

These shocks have the standard off the shelf spring, which is intended for a much heavier person than I am, so I don't know why I squash it down so much.

 

If I completely max the preload on the rear shock I can get the rear static sag to about 16 mm

 

I didn't change anything on the front.

 

I know numbers now, but am not sure what I should do about them.

[EffBee]

Some additional thoughts. Is it possible that the Nitrogen has leaked out of the shocks? Or what about leaking past the air/oil separator, turning the shocks into emulsion shocks? If your hydraulic fluid was not designed to run as an emulsion mixture, you could be getting internal frothing which would create a great deal of additional pressure, leading to resistance against the shock shaft entering the body and displacing volume. This might be a big contributing factor to the harshness you now feel.

 

Call Stig. See if he thinks he can check the either shock for proper nitrogen pressure without removing it from the bike. If that's the problem on one shock, it is likely the problem on both.

[Tool Man]

Laney,

Thanks for the history lesson about your shocks installation scenario. Those numbers are on the soft side and I'm wondering what your damping setings are. However, since Stig is familiar with the original install and the rear has been R&R'd I agree with Fernando (again)on this. Call Stig and get it into him for a preasure test and if required a complete rebuild. Unless specified otherwise, the standard spring is intended for a 175# rider. Unless you've eaten an awfull lot of donuts since we last met, they're definately the wrong spring set for you.

 

Let us know what Stig diagnosis is.

[Laney]

Call Stig and get it into him for a preasure test and if required a complete rebuild. Unless specified otherwise, the standard spring is intended for a 175# rider. Unless you've eaten an awfull lot of donuts since we last met, they're definately the wrong spring set for you.

 

I have the standard springs, and while I agree they’re the wrong spring set for my weight, when I bought them from PPS Stig said they’d be better than softer springs. Even in the best of times they were a bit harsh, but the harshness was tolerable and they worked well

 

The thing is -- I’ve lived with that spring set just fine for over a year – so I don’t know that changing springs should necessarily be a requirement???

 

The soonest Irv Seaver’s could schedule removing the shocks would be late next week – which is when I would have been leaving for Torrey. What would you (or anyone else that wants to jump in) suggest I do to try to make what I have right now work at least a little better (if that’s possible). This bike will not be going to Torrey the way it is right now.

[SteveB]

Is it possible that nothing has actually changed except your perceptions? While Buddy has been in the shop you have been riding the VFR and gotten accustomed to the ride but now that you get back on the KRS it just doesn’t feel right compared to the Viffer. I held on to the Harley for over a year after getting the RT but every time I got on the Harley I wondered how I ever did a SS100 on it!

 

Have you tried the KRS with the bags fully loaded for a trip? Did that feel any better?

[Laney]

Is it possible that nothing has actually changed except your perceptions? While Buddy has been in the shop you have been riding the VFR and gotten accustomed to the ride but now that you get back on the KRS it just doesn’t feel right compared to the Viffer.

 

Oh, don't I wish!

 

That's what I originally thought during the first few weeks. It seemed harsher, but I just figured I wasn't remembering accurately. But last Sunday, when I took a much longer rode over lots of different roads, rather than just the commuting and short runs I'd done since I got the bike back, as the miles went on I got more and more convinced Buddy wasn't riding in the same way.

 

I would really much rather it be my imaginitive comparison, but the way I hurt Monday morning was one more reminder that it just wasn't the same ride.

 

I seem to feel the harsh feedback from the front, not the rear, but it seems as if the rear shock has the most potential for problems. In the initial install, he rear shock on Buddy had to be “convinced” to fit on the bike, and the dealership didn’t understand why it was such an odd fit. Later on, when I’d seen a few other current KRSs and some GTs with an Ohlins shock on the rear, I realized I’d been sold the wrong year shock – the one I have on my ’02 is for an ’01 or older RS. My rear shock probably was removed and reinstalled during the recent repairs, and maybe a hose that was marginally pinched is now pinched to where it has a negative effect on performance.

 

It’s all just guessing. I know so little about the magical mysteries of suspension.

 

I’m getting a new front tire Friday to eliminate that as a possible contributor. It’s not to the wear bars yet, but if I get to take this bike to Torrey, it would probably be a necessity. I’ve also reduced both rebound and compression damping to about a third over their minimum settings. I’ll probably run the tire pressure in the front lower than usual.

 

Over the weekend, I’ll see if that makes any difference.

 

Have you tried the KRS with the bags fully loaded for a trip? Did that feel any better?

 

I'll throw all the luggage on and see how that goes -- that's a good suggestion. If nothing changes, I guess I park it and decide what’s next.

[Laney]

Last night I got a new front tire at a local place, Cycle City. I asked the mechanic to take an extra good look at the shock, forks, and anything else he could think of while he was changing the front tire. I described what kind of change I'd experienced, and he knelt down, looked at and felt the front tire, and said he thought the wear on the tire might be the major cause of the rough ride. Since he has lots more time in the M/C world than most, I figured there was every reason to hope he was right.

 

I'd also been thinking about SteveB's comment -

 

Have you tried the KRS with the bags fully loaded for a trip? Did that feel any better?

 

Avon tires on an RS with a topcase create a weird kind of thing that makes the bike feel light and dancey. (So maybe dancey isn't a real word, but it fits). It was a little unnerving initially, but after 4 sets of Avons, I'm pretty used to it, and don't really think much of it, even though I always ride with a topcase and the effect is always present.

 

I've had Avons on the RS since the Ohlins were put on, and have almost never ridden without a topcase. Sidecases make for more work when lanesplitting, topcases don't. Steve's comment about luggage made me wonder if the tire wear plus lack of topcase could add up to some of the effect on the front end harshness? Maybe it was always a bit harsh since the Ohlins were installed, but fresher tires and a topcase introduced a lightness that kept me from feeling the full impact?

 

I don't know for certain, but when I took the bike out this morning to check the new tire on the same stretch of freeway that was brutal last Sunday, I added the topcase.

 

One or the other, or the combination, or intervention from the MC angels, or all the messing around I did with the rear shock, or all of the above -- seems to have resulted in a noticeable improvement. I ran over Botts dots, pot holes, and went along a straight stretch of concrete freeway with the cruise on and my hands lightly resting on the bars to see what kind of feedback I was getting, and the harshness is definitely diminished. I don't grip the bars very much, and riding the VFR has made me develop an even lighter hand on the bars, so I'm really certain I haven't contributed to the problem by gripping too tightly.

 

I'm still kind of out of whack on the settings for the rear shock. I'm hoping just following the directions in the Ohlins manual will get me more into the place that's right. I think I'd be better off with a lighter spring on the front in the long run, but it's not something I need to worry about just now. If I take the same route I took last Sunday and don't come home wincing and whining about how my shoulders hurt, I'm comfortable things are OK as they are, even if I can't adjust the rear to the right place.

[russell_bynum]

 

 

[Laney]

Just give me a week with it. I'm sure it's all that "riding like a girl" stuff you do that's causing the problem.

 

I just went back to re-read Fernando's post to get the info on adjustments to see where to go from here.

 

I think this didn't sink in the first time I read it.

 

You'd better be running for cover!!!