Front end "bouncing"

[SpencerChedid]

I've been noticing that the front end is kind of bouncing at both low and high speeds (anything from 30km/h to 110km/h). The bouncing rate changes accordingly, so at high speeds the bouncing frequency is higher and feels more like a constant vibration as though the bike was a thumper.
Things to consider:
- I did play with compression/rebound adjustments but currently it's dialed back to the factory settings and the boucing is still present;
- I did adjust the rear sag to my likings, so preload/compression/rebound has been changed but not much;

- Tire pressure (front/rear): currently at 30psi/35psi;

Apart from the bouncing feeling, I'm hearing a noise coming from the rear end that I can only describe as a chug, and the chug frequency changes according to the speed, just like the bouncing. I guess it's coming from the tire but also sounds like a bad bearing. The more I lean towards the rear end of the bike the more I hear it chugging.
I tried hooking a GoPro close to the rear wheel but the chug was not audible through the footage, so unfortunately I can't provide a sample.

Anyone had this experience before? 

[mpatch]

Lose a wheel weight? 

[norei]

Couldn't it be radial runout in the front tire? Pirelli had a problem there. Did you have this from the beginning or did it occur later?

[SpencerChedid]

22 minutes ago, mpatch said:

Lose a wheel weight? 

I gotta check but I don't think so.

 

17 minutes ago, norei said:

Couldn't it be radial runout in the front tire? Pirelli had a problem there. Did you have this from the beginning or did it occur later?

I heard about Pirelli issues on this tire, may be the case. I can't really tell if I had this from day 1, but probably yes, just less noticeable. Maybe I'm noticing it now because I've been playing with suspension adjustments therefore I tend to be more focused on how the front end reacts to the changes.

[winddown]

The factory suspension is ok,  but after I upgraded it to quality aftermarket it was like a completely different bike.  I didn't do so much for ride quality but because some guys I trusted who rode these bikes hard said that they were a lot safer on the gravel roads with the upgrade.   They actually said I had a good chance of dropping the bike under certain road conditions if I didn't upgrade the springs.  Washboard sections was one if memory serves me correctly?

[Black99S]

Chain too tight?  
You adjusted suspension sag to your liking. No idea what you mean. Rider sag is normally ⅓ of full suspension travel. 
Tightest chain will be when rear axle, swingarm pivot and countershaft  are on same plane. 
if your chain is tight and you backed off preload then what you describe makes sense. 
Tight chains destroy sprockets, chains and countershaft bearings 

[AZJW]

@SpencerChedidOut of round tire, balance issue or rim runout issue is what I'd focus on first. Good luck, let us know what you figure out.

[Redneckj]

The bouncing your feeling is called "stiction".  Maybe the oil seals are dry?  

[SpencerChedid]

19 hours ago, Black99S said:

Chain too tight?  
You adjusted suspension sag to your liking. No idea what you mean. Rider sag is normally ⅓ of full suspension travel. 
Tightest chain will be when rear axle, swingarm pivot and countershaft  are on same plane. 
if your chain is tight and you backed off preload then what you describe makes sense. 
Tight chains destroy sprockets, chains and countershaft bearings 

Chain slack looks fairly loose and it's roughly 47mm, which falls within the factory recommendation (43 to 48mm).
The rider and static sag has been adjusted to what it should be (30% and 10% respectively) not to my likings. It was just bad wording there, sorry about that
 

17 hours ago, Redneckj said:

The bouncing your feeling is called "stiction".  Maybe the oil seals are dry?  

That's new to me. Thanks for bringing that up.
I've done some research on stiction and found this Dave Moss' videos:

I was able to rock the susp back and forth and it's not sticking at all, though I'm gonna have to do it properly over the weekend to make sure.

[SpencerChedid]

Yesterday I re-checked all fork and suspension settings bringing them all back to factory and looks like I felt less bouncing. 
So probably I've got + or - 1 click off from one of the forks.

[winddown]

On 8/31/2022 at 7:49 AM, SpencerChedid said:

Yesterday I re-checked all fork and suspension settings bringing them all back to factory and looks like I felt less bouncing. 
So probably I've got + or - 1 click off from one of the forks.

 

You never mentioned your weight Spen, I believe the springs suit a 70kg rider, so if you're a way heavier like me, 100kg, it will be difficult to find a setup that suits varying road conditions.  Did you discover what the "chug" noise was?  Noises on bikes drive me crazy, even the little idler roller under the chain drives me mad.  I want to push some grease into it, and probably will lol.

[DT675]

Id be looking at the tires for out of round and the wheel itself (spoke lacing) for out of round.  My front "wheel" was laced out of round giving me what you describe.  The tire was also bad so it was tough to find.

 

On a side note- Ive felt like my front tire "rides on top" of (kind of a busy feeling)  the ground rather than the forks moving in and out with the bumps keeping the bike flat like the rear does.  Just for experiment i removed all rebound from the front (full soft/ slow) and sure enough the front end feels much less busy.  Im then going to add in a little rebound at a time as i find it needed (It will now be a bit wollowy)  until i get the best balance between the two.  At the end of the day, this is all because the suspension is budget and kinda crap and cannot be properly adjusted with the OEM internal valving.  Their will come a time I'll need to pony up and get some new stuff.  My $10k bike is already a $14k bike, why not make it a $18k bike...

 

 

[prowlnS10]

With regards to the front wheel not tracking road surfaces or pogoing...potential causes could be excess stiction/binding (see blog post), bent forks, too much compression adjustment, forks set at different heights in the triple clamp, internal fork issue (seals, oil level, damage), over inflated or damaged tire.  As for the rear noise..possible causes could be over tightened chain, damaged chain, the chain rollers (oem are very noisy), bearings, misaligned rear tire, rear chain guide (optional accessory).  The rear spring at 70 Nm is under sprung for riders/loads > 65-70 kg or 143-154 lb according to Rally Raid..having correct sag for your weight & riding puts the shock higher in its stroke improving response + can load the front end more.  I would suggest to start with the basics & ensure proper fork operation & adjustment (the T7 front fender & misaligned floating right fork can cause stiction)...& do the same for the rear wheel alignment & chain adjustment.  If you don't have a service manual you can download it from this forum.

 

Tenere 700: Correct Fork Alignment - Floating Right Fork Needs to be Set Correctly on Axle to Obtain Equal Gap for Brake Caliper & Rotor - Service Manual Front Wheel & Tightening Torques - 'Everything Tenere' & Dave Moss Videos: Align Fork Legs Properly After Mounting The Wheel

---

Yamaha Tenere 700, Yamaha Super Tenere 1200 ES, Ride Reviews

 

[chris94]

I chased this issue for about 15,000 km .. Turns out that during production the rim has been grinded too much after welding, which ultimately resulted in mounting issues with most tires I tried. I could very clearly see the tire dipping down in the rim at this section when spinning the front tire.

Had the rim replaced under warranty by Yamaha. The new rim was also heavily grinded, but I've had far less issues after this. I often have to give it 60-70 psi to seat the bead.

Bouncing on a smooth surface is probably a tire runout or balance issue, especially if it changes correlating to speed.

[SpencerChedid]

Thanks for all the inputs guys.
There are lots of information here and I'll read evething carefully. All in all, after I reset all the susp/fook setting to the factory I feel the bouncing less pronounced. It's still there but it doesn't bother me that much.

FYI
- My T7 is a 2022 with 2500km in it, so brand new;
- I'm more on the heavy side weighting around 98kg;

I've read about the rear spring not being suitable for heavy riders even before I buy the bike, I'm seriously consideting getting the Rally Raid 90Nm or the 95Nm one.

[TexasT700]

Related story. I had a Tiger 900 Rally Pro that started front end bounce on smooth looking asphalt. Dealer could not notice it. I spent at least 2000.00 trying to find issue. Sent front forks to Race tech for gold valves and rebuild. Had couple shops balance front and back, check for runout. Nothing changed the bounce much. Finally gave up, sold bike. T7 is perfection on same roads that Tiger could not deal with. At the time, I accepted the Tacoma Narrows bridge theory that some bounce issues are due to so many variables, can't be fixed, basically bad engineering.

I still wonder if that Tiger bounce coulda been solved. So, I watch with great interest any threads like this one about front bounce.

There has to be a cause in there, becuz on T7 it is mostly not an issue....

[TexasT700]

Yes, tried 2 new different sets of tires, still bounced.

Tourance Next and

Dunlop Mission

Edited September 9, 2022 by TexasT700
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