I'm pickin' up good [bad] vibrations...

[Dakota]

Hey guys, 

 

I know vibrations have been discussed before but I've searched and can't find any suggestions so I thought I'd make a new post in case new info has surfaced.

 

Issue: almost overwhelming vibrations and most RPM's

Mods: 2WheelDynoWorks tune (months ago), stock suspension was tuned (months ago), other bits and bobs I wouldn't imagine could cause this

 

To test if this was motor related, or anything else, while on the freeway yesterday going 80mph, I pulled the clutch to just coast and it was immediately smooth as butter, which leads me to believe it's not a chain/tire/sprocket issue. 

 

Has anyone else had this? I know a few of you may suggest taking it to the dealer, which I can as a last resort, but honestly I don't trust dealers for Shet and would prefer to not have to take my bike to them - especially the one I bought my bike from as a buddy of mine had to take his triumph to them for a warranty issue. He was without it for ~3 weeks and literally nothing was fixed. 

 

Anyways, I appreciate any suggestions you guys have. If there's an answer floating somewhere please link it here and i'm fine to delete this post as I assume it's probably redundant. 

 

Camping tax:

 

 

 

[Dougie]

I’d honestly say the one thing that hits home is tuning by aftermarket boys. No matter who. Sounds like timing. The japs spent a fortune designing the motor. Very rarely is it improved by trying to piss around with it. Like jetting on XTs. Don’t know how many times I tried a little richer here and there. Most mods are usually removed when people get sick of the downsides. 
drivetrain behaviour does  alter under load mind, so don’t rule that out. But my money is on the tune. Hope you sort it soon bud.

like the Bivvy. 

[Dakota]

FYI, i'm at 5200 miles. I thought oil change was every 6k, but it looks like 4k, so once my oil arrives in the next day or two i'll change it. 

[Dakota]

Just now, Dougie said:

I’d honestly say the one thing that hits home is tuning by aftermarket boys. No matter who. Sounds like timing. The japs spent a fortune designing the motor. Very rarely is it improved by trying to piss around with it. Like jetting on XTs. Don’t know how many times I tried a little richer here and there. Most mods are usually removed when people get sick of the downsides. 
drivetrain behaviour does  alter under load mind, so don’t rule that out. But my money is on the tune. Hope you sort it soon bud.

like the Bivvy. 

 Agreed nothing can be ruled out at the moment, but the issue seems to be suddenly worse, seemingly out of nowhere. Only thing I can think is I have taken it off road (moderately) a few time, and one slow speed drop. 

 

I did my tune at 2600 miles, and i'm at 5200 now. I even took it on the track a couple weeks after the tune, and even at 105pmg I don't really recall any significant vibrations.

[Canzvt]

Tires, tires, tires.

 

Change your tires (especially the rear), and re-check. Tires under load (torque) vs unloaded rolling WILL perform differently, especially block type tires. I scrapped the stock Pirelli's after 1000kms, as I hated them on gravel. Put on a full center tread tire if you don't spend a bunch of time off road. If you do, have a look at a v-block type tire with contact patch continuity (meaning no rolling gap as it rolls).

 

I have the 2WDW tune and its fine. Have 3000kms on the tune, 10,000kms on the bike.

[Dakota]

3 minutes ago, Canzvt said:

Tires, tires, tires.

 

Change your tires (especially the rear), and re-check. Tires under load (torque) vs unloaded rolling WILL perform differently, especially block type tires. I scrapped the stock Pirelli's after 1000kms, as I hated them on gravel. Put on a full center tread tire if you don't spend a bunch of time off road. If you do, have a look at a v-block type tire with contact patch continuity (meaning no rolling gap as it rolls).

 

I have the 2WDW tune and its fine. Have 3000kms on the tune, 10,000kms on the bike.

That’s super helpful, I appreciate it. I did think it was tires, but on the freeway I pulled in the clutch at 80mph and it was smooth as butter, vibes only came when the bike was under motor power. I did read something about stock tires using worse rubber than their retail counterparts so either way I’m looking forward to new tires.  

[Dakota]

9 hours ago, Hogan said:

Did it drop on the exhaust side? If so look for interfering/broken exhaust parts. Also just look for anything that could be out of place. Although it's unlikely on a new motorcycle, broken engine mounts can cause such vibrations

 

You've narrowed it down with the clutch test.

Another thing you can do is while holding the clutch in at those speeds and raise the engine back up to the speed it should be. If the vibrations are still there it's the engine. But if they go away then it's probably drive line (chain, sprocket alignment etc) responding to engine torque rather then the speed of rotation. Like a bad universal joint in a drive shaft.

 

I assume the bike idles fine, and it's running on both cylinders. I wouldn't rule out the tune but it seems unlikely if it was a stock ECU flash tune. More likely if it's a power commander or similar rubbish piggy back junk.

 

It did drop on the exhaust side, but i've got crashbars and OEM pannier racks, however i'll definitely go give a more in-depth look, but the damage to the exhaust can best be described as a scrape. 

 

I believe when I pulled the clutch, I did exactly what you're suggesting. I did it more so that there wasn't a harsh acceleration when releasing the clutch, so I tried to match RPM's before engaging the clutch and I definitely felt vibrations all through the motor. The Bike does idle fine (I think, it kinda bounces ~50 rmp). I'm going to do an oil change today, and will do another throttle body sync as well now that I have the proper tools. 

[Canzvt]

So start with the easiest elimination possible, then proceed from there. Does your bike vibrate at 6500-7000rpm (your likely RPM at 80mph) standing still in neutral? If so, take it to the dealer. There is something wrong. Throttle Body synch (or lack thereof) is NOT going to be noticeable at 6500-7000 rpm. That adjustment is usually an idle/off idle/light throttle drive-ability issue.

 

You have 5200 miles on your bike (from above assuming stock tires). You probably need new tires anyway, so I would change them out. Did the problem go away? Does your chain have any kinks/tight spots/etc in it? Change it out. Did the problem go away? While you are changing the tires, have a look at the bearing condition.

 

Likely the chain and bearings are NOT your problem, but worth a check anyway.

[Dakota]

Thanks @Canzvt I'll do the RPM test today. Chain has been well maintained and AFAIK has no hard spots, tires are ~50% worn and on the list to be replaced as well. When they're getting change, i'll make sure all that is looked at. 

[Canzvt]

So, 50% worn on the CA concrete freeways will likely scallop the knobs preferentially one way or another depending upon the front and rear tire due to the aggressive coeff of friction of the concrete roadway. If you look closely at the knobs, your tires WON'T be round anymore, but a series of scalloped notches around the circumference. This is COMMON for knob type tires as they wear, and results in a harmonic vibration directly related to the number of knobs around the circumference and the speed of travel.  The above is why I suggested in my first post to look at tires.

[Dakota]

Yeah, the front tire is wearing unevenly, but the back is relatively "smooth". I thought (hoped) it was my tires, but pulling the clutch on the freeway the bike was like butter, but I know for sure new tires couldn't hurt. 

[Canzvt]

Driving VS rolling will increase the amplitude (so you notice it) of the harmonic. Frequency is a function of speed and # of knobs.

 

There might be a problem with your engine, but my all in bet is your tires are hooped.

 

Good luck!

[Canzvt]

I keep forgetting to mention, that others on the forum have reported out of round wheels, wobbling tires (on the rim) and out of balance wheels. Perhaps one of the above is also contributing.

[Dakota]

Thanks for all your help on this one, i'll report back as things progress

 

[TimeMachine]

I am wondering if its related to an imbalance of power from one cylinder to the other. Does it get worse with more power? If so you might have a leaky header, a valve out of adjustment or damaged, or possibly faulty plug or injector. Also check all your tubes and pipes under the tank. 

Worth checking your plugs for rich/lean condition on one cylinder.

[dirt5track]

I have the same issue, I changed tires, grips, and filled the bars with silicone. Nothing has helped, I did take it to the dealer and they said its normal. It did not start to vibrate until I hit about 4k miles and I ham at 5400 miles now. New tires are tkc70 rocks rear and trailmax mission front all of my services have been done and everything is up to date. Please update if you find a solution. FYI I have the front right caliper rubbing on the rotor and the dealer also said that is normal and not to worry, this dealer is a joke. 

[Hibobb]

8 minutes ago, dirt5track said:

filled the bars with silicone

Do you still have the bar end weights? They were put there to reduce vibration.

 

[Matth]

Thats what i used. The heaviest i could get which were 180g I think and it made it faultless.

tbh it didnt need doing but i put them on knowing the result would be superb 

Edited July 9, 2021 by Matth

[Dakota]

23 hours ago, Hibobb said:

Do you still have the bar end weights? They were put there to reduce vibration.

 

I don't have the stock bar end weights anymore, but I do have the Barkbuster weights, which I think are less. If you know of a way to add more weight, i'm all ears. 

[Hibobb]

6 minutes ago, Dakota said:

 If you know of a way to add more weight, i'm all ears. 

Well... The stock Yamaha hand guards attach to the stock yamaha bar end weights.

Can you attach your hand guards the same way?

Sounds simple, but I don't have the parts in front of me....

 

[Dakota]

Just now, Hibobb said:

Well... The stock Yamaha hand guards attach to the stock yamaha bar end weights.

Can you attach your hand guards the same way?

Sounds simple, but I don't have the parts in front of me....

 

I don't believe so. I think the bolts are different sizes, and the stock bar end weights stick out way more than the BB, which would then pull the brackets closer to the clutch lever / master cylinder. 

[Hibobb]

Take your new B/B off and put the stock setup back on and see if it makes a difference.

If so, then go to plan "B"

[Dakota]

Yeah that's smart, good idea

[dirt5track]

On 7/9/2021 at 11:42 AM, Hibobb said:

Do you still have the bar end weights? They were put there to reduce vibration.

 

Yes, I still have the bar end weights and barkbusters 

[Adventure Jim]

Yes, I have no faith in dealers either, my bike was delivered with the front wheel on backwards - ABS, ODO, and speedo did not work... aside from all the times I have taken bikes to dealers, and they always say, "That's normal"... 

 

 

You should be able to isolate it by revving the engine in neutral with the clutch in. If the vibes are not there, the reciprocating assembly is ok. 

 

Let the clutch out in neutral, and that will add the clutch basket and main shaft into the mix. All my Hondas have a slight pulse from the clutch baskets, I think they do not balance them.

 

Then if you have a rear stand, you can put it in gear, and go through the gears, just make sure your bike cannot come off the stand!

 

If all seems good, I would suspect the above mentioned out of round tires/rims, or the throttle body synch or bad fuel injector, as they would be more obvious as load increases.

 

Hope you get it sorted!