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Scott, I am asking you, since you have experienced it, I've been thinking about a steering damper. I know you went thru a tank slapper, but was wondering your opinon, ALL bikes can be prone to them, small(620) or larger? Can they happen at ALL speeds( slow or fast)?
I get a very very very slight shimmy( very minimal back and forth motion) in my front end when hitting a bump at 50-70( or more), It's hardly noticable, but I notice it.
If you are sitting on the bike stopped and not running , and wiggle the bars ever so slightly , you can sort of simulate this movement, am I being paranoid or should I be concerned???
 

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Deb,

What you're describing is "head shake." A bike's gonna shake. The question is whether the shake damps out naturally or is amplified into a tankslapper.

Nobody can guarantee you that the shake you've experienced won't, under some circumstance, become a 'slapper. But, on the other hand, the fact that you've felt shake doesn't mean a 'slapper is inevitable.

Regarding the size of the bike; it has some bearing. The more torque, the more the bike will unweight the front end. Lightening of the front under acceleration is one of the contributing factore in 'slappers. I would say that a 620 is less likely to have tank slapping problems than a 900. but I wouldn't say it's immune.
 

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Don~

I am thinking of dropping my front suspension more on my bike, I have been told that will quicken the steering... I have a damper, just wondering about the changes with the suspension.
 

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Deb, I'll jump in ahead of Scott with something related to your concern:

I recently posted about swapping to adjustable forks and having to lower the forks 13.5 mm in the clamps to get the adjusters to clear the handlebars. This effective raised the front ride height about 12 mm vertically.

I liked what it did for handling in the first 40 mile test ride. Saturday, I got to wring it out on the track for 4 sessions until I broke the throttle cable. I really like the overall effect that raising the front ride height had. The bike is more stable and less "nervous". I used to have a barely perceptible waggle in the front when driving out of some very high speed corners. And the bike used to turn in almost too quickly. Now it behaves much better and feels way more stable. It still flicks from full left to full right in some very tight chicanes with no more effort and just as quickly as before.

If the wobble you get makes you nervous, you may want to experiment with lowering the forks in the clamps 5 or 10 mm to raise the front a little. Can't guarantee the results, but I was pleasantly surprised with my outcome.
 

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Deb,

Dropping the front will make the bike noticably quicker. I raised the rear on mine; same effect but with an improvement in ground clearance instead of the reduction you will experience.

I've been thinking about Mark's comments and would welcome the ability to experiment with my front ride height. But with my above-tripple clip-ons, I can't raise the front as he did.

Yet an important difference to note is that with my clip-ons, I have less of a rear weight bias than Mark has with his stock bars. That should reduce the tendency to 'slap.

I have to say that I like razor sharp handling and I'm willing to suffer side effects (short of crashing ;D)

Um... where am I going with this?

Oh yeah, since you have the damper, I don't think you need worry. Try the quicker steering and see if you like it!
 
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Deb.....some of this can be suspension and geometry related.
I would assume you have got your sag set...also tires can contribute to head shake..what kind of tires are you running?..I had constant headshake over bumps and a few wild oscillations with Dunlop 208zr's...and had that confirmed by several tire guys, that that was a fairly common occurance. They went away when I switched tires. monsters have a fair amount of trail and self correct normally farily well....I would never say not to get a damper but to be sure one has explored the suspension first so as not to mask any problems, because a tank slapper can occur with a damper also.
If the problem is suspension related it should not be covered up by a damper. Head shake is fairly common but one should try to ascertain
if it is normal or something is wrong.....improper damping of forks, etc..
Every bike and rider will be different enough to warrent a singular investigation into headshake to ascertain why. If you ask should you be concerned, I would say yes in the sense that you might want to figure out what is going on. Also is this something that just started happening?
If yes have you changed anything?
Is there a good suspension person where you are? How many miles on your forks? on your shock? How many miles on your steering head bearings and swing arm pivots? Stuff like that is worth consideration I believe.
Ally have you considered raising the rear or is it too high a seat then?
You can get some height with the hoop through the heim joints, without losing the ground clearance......
 

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Retro~

It is in the standard stock position currently. I figured with dropping the front the back would have to be adjusted higher, not an issue I am 5'5. If I made the rear higher, would it still give me the quick steering effect I am seeking?
 
G

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It should help to turn in quicker yes...and less concern draggin hard bits...you will have to see if it turns in quick enough for you without droppng the front also....suspension can also play a role, for example my SBK forks have too much comp damping and the springs are too heavy and now my bike tends to go wide.....so I need to fix that, but when things were well, just raising the rear and dropping the forks a little the bike was very quick to turn...not everyone likes that of course, but I do.
 
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Mark1305 I have a question, do you know what kind of springs or internals you are running in your forks...?
I am curious if raising the front changed the front height from say the bars to the ground, from your previous forks?
cuz a general rule for what you expressed as waggle coming out of
a turn is associated with the rear, and a light front end....I wonder if the forks are quite different enough to ascertain that the height change is the reason or the different forks just work better, and/or the actual height from the bars to the ground may not be 12mm?
Monsters are normally farily light in the front already, and many have suspected this is one reason they may be prone to headshake, since they do have purty good trail.
Having said all that of course racers depending on the track also raise and lower their front end. I'm just very interested in learning more about suspension. Thanks. Sorry for hijacking the thread.
 

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I've been curious if it's more common for the larger/heavier Monster riders to have headshake issues... ???

On the 'light front end' topic, I've wondered about that too. I noticed that my S4 got a tiny bit more nervous when I fitted the tall CycleCat bars, and attributed that to a little less weight on the front wheel. I can't raise the forks in the triples without the fender/tire crunching my radiator at full bump. I'm really not looking for quicker turn-in, and I don't have a lack of cornering clearance, so raising the back with pushrod adjustment doesn't seem like a good path for more front-end weight. I posted quite a while ago asking if anyone knew of a longer Duc swingarm that was a bolt in (or nearly so), but IIRC, got no answers.
 

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I bought the engine/frame from Scott and upon disassembly, I thought that the engine mount bolts were not as tight as they should be. Not loose, mind you, but not tight either. Just another data point with probably no real meaning.
 

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That explains the pic you posted of a Monster engine & frame with acid damage...I didn't think that was Pongo.

Seeing as the swingarm is attached to the engine, and the front end is attached to the frame, if the joint between them is not so tight, that could have contributed. Then again, the tankslapper and subsequent pounding on the pavement puts big-time loads on that stuff too, and could have stretched things a bit.

We do need to keep an eye on those bolts, just the same.
 
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I always thought that Scott had just had his forks redone also, and he had mentioned he had been through there many times before with no incidence and this was the first time through with the reworked forks? Maybe I am not remembering correctly, but I do remember thinking about it when he posted his accident. I don't remember it ever coming up
as a causal connect. I should prolly re-read the thread.
 

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Discussion Starter · #14 ·
6500 miles on my bike, stock tires, stock forks... but FBF did lower the suspension in the back for me when I bought the bike.
I first noticed this slight shake after the 6000 mile service. But it is so slight that I really wasn't concerned, and I don't think that I noticed it all the time, I can't say that it has gotten worse or more frequent, but since this is the first I rode her for 4 weeks, I have " re-noticed" the shake.And mind, it is ever so slight, my husband probably wouldn't even notice if he took the bike out.
 

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In answer to Retro - Unfortunately I had to swap the SS forks on before I could open them and check the internals, change the oil, etc. From close inspection of the outside bits, it appears that they are probably undisturbed stockers (from a 96 SS).

I did/do take careful measurements of everything to help sort out suspension tuning. The SS forks are the same dimensions as the non-adjustables, except for the added height above the tube of adjusters compared to a plain top bolt. I wanted to test the SS forks as close to the same setup as the stock forks as possible to attack one variable at the time.

The stock handle bars prevented me from backing the preloads out to the minimum settings which closely approximated the softer springs in the stock forks as judged by pushing one of each down in compression at the same time. So with the preloads set at the "factory" setting to clear the handlebars, I wound up with two variables right off the bat: (1) The forks lowered in the clamps 13.5mm; (2) sag with rider reduced (sorry don't have the numbers handy at this desk) due to spring preload. And I could feel the difference between the SS fork set this way and the OEM fork when I pushed them down against the floor simultaneously.

Damping adjusters I set at the "factory" settings as per Haynes just to have a starting point.

And, yes it really raised the height of the bike. I now put a .5" thick aluminum pad under the sidestand to reduce the lean angle of the bike to something close to normal. I can't say with certainty about increased clearance at extreme lean angles, because I was still getting dialed in on the track Saturday when the bike broke, but I didn't ground out the sides of my boots like I did last time out - But that could be because (a) the bike has more clearance; (b) I have been practicing better foot positioning; or (c) I wasn't cranking it over as far because I hadn't reached my comfort zone with that track surface. Or all of the above.

Of course, since I like this set up so far, it means when I decide to go for clip ons, I'll HAVE to spring for Cycle Cats so I can mount them below the triple clamp and preserve my high front set up ;D
 

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Deb,

Do you think that perhaps you've been riding the bike harder now that you have some miles under your belt?

Aggressive acceleration, particularly out of corners and out of bumpy corners, tends to reveal head shaking tendencies that may otherwise go unnoticed. It's unweighting the front, and possibly the geometry change induced by extending the forks.
 

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Retro, IFAIK, Scott had just gotten his forks redone.
 

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This thread has gone a long way before I had a chance to notice it. For those interested in reading the earlier threads, here are the links:

http://www.ducatimonster.org/cgi-bin/yabb/YaBB.cgi?board=forum1;action=display;num=1065383117
http://www.ducatimonster.org/cgi-bin/yabb/YaBB.cgi?board=SFBMHA;action=display;num=1065312800
http://www.ducatimonster.org/cgi-bin/yabb/YaBB.cgi?board=SFBMHA;action=display;num=1067356780

I remember reading about "wobble" and "weave", where one is slow oscillations (less than three per second) and the other is higher speed oscillations. The slow ones are actually made worse by a steering damper, and I've experienced that personally on a Monster. It's just annoying, nothing to panic about.

When my bike went into a tank slapper, it didn't slowly creep up on it like the one in the famous video from the Isle of Man (go to google, search for "Isle of Man tank slapper" if you're not familiar with it). The bars were already going full lock within 10-20 feet of going over the cattle guard. A steering damper prevents the bars from moving so quickly, so you're much more likely to be able to get it under control. I had about one second to "enjoy the ride" and realize that I was going down. There was nothing I could do to recover because it all happened too quickly. With a damper, I'm quite sure I would have been able to recover after a few oscillations.

And by the way, I had experienced front end oscillations on the Monster dozens of times from hitting bumps in curves, landing wheelies a little crooked, or going over bumps when accelerating hard. They had never bothered me before and I don't think I ever gave them a second thought. It was always easy to get things straightened back out.

As for the newly revalved forks, I don't think they deserve any of the blame. Before they were reworked, the bike was truly frightening to ride on that very same road. It was after riding it on Mines/Del Puerto Canyon that I went home and took the forks right off of the bike. Braking into corners that were anything less than perfectly smooth caused the front end to bounce and ride like a jackhammer. I was afraid to even use the front brake.

After the forks were revised, the bike was more planted in corners than it had ever been in its entire 19,600 miles. I could brake in bumpy corners without concern. The bike was just handling way better.

At the time of the accident, I had ridden about 90 miles that day. I was a mile from our lunch stop and was probably thinking about lunch rather than something so trivial as crossing a cattle guard. I had already crossed more than a dozen cattle guards that day, including that very one in the other direction, and I considred it to be no big deal.

I still don't know what really happened, but I'm guessing that I wasn't in a correct riding position, maybe had one hand more firmly ahold of the bar than the other, and probably didn't have the bike firmly locked in place with my legs. Since the road was almost straight, but had a very slight curve to it, I probably was applying more pressure with my right hand to countersteer the bike in the direction of the slight curve. If I went over a bump capable of bouncing the front tire an inch in the air while exerting light pressure the right bar and no pressure at all on the left, that would be enough to turn the front wheel a bit before it came down. That's my best guess as to the cause.

As for me breaking my left hand and dislocating my thumb, my right glove was scraped and torn and close to letting the road get through to my skin, but the ONLY injury to my right hand was one fingernail that went dark. Nothing hurt at all on the right hand. The left glove, however, has no scratches at all and still looks the same as before the crash. That sort of tells me that impact with the road probably did not cause either injury. My best guess here is that the handlebar was swinging back and forth with such force that it pulled my thumb bone out of both sockets, then on the next pass hit the back of my hand hard enough to fracture a bone. By the way, the dislocated thumb has been about 10 times worse than the broken bone. The bone was completely fixed in four weeks. The thumb is about 90% fixed after four months.


I don't know exactly how steering dampers work. For forks, you want them to privide a lot of damping when things are moving slowly and less damping when things move quickly. With fixed orifices for the oil to go through you'll get just the opposite, where there is little damping at slow speeds, and they're almost solid at high speeds. I would expect that the best thing for a steering damper is to have just one orifice so that slow movements have no resistance but fast movements can't happen because the oil can't move through the holes fast enough. Such behavior would clearly prevent the bars from swinging back and forth as quickly as they did on the Monster.
 

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I had more to say, but couldn't post it all in one message because the board software thought it was too long. ::)

So now I'm riding an ST2, which has a bit more stable steering geometry than the Monster, since the front end is not so steep and there is more trail. It does not have a steering damper and I haven't seen anybody on the Yahoo ST2 list claiming that one is needed. It's clearly more stable than the Monster on rough turns, but it doesn't steer as quickly either. I'm going to give it a year or two and experience Sport Touring for a while before I get another Monster, or buy a new Multistrada.

I'm hoping somewhere in my ramblings is some useful information.
 
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