Front end wobble at highway speeds near large vehicles

[PhotoAl]

Took a 250 mile ride today - it's rough being retired :-) 180 miles of interstate.  Paid particular attention and it defiantly does not have any wobble or instability.  I have never felt the need to rush by a truck due to instability.  What I do notice is it is very quick to turn and is not super directional i.e. it will wander a bit if I don't pay attention but I can put it exactly where I want it and keep it there without problems.  IMO that is related to it ability to quickly turn, it surprises me at how light and nimble it is.  Never had instability with OEM tires but didn't wait for them to wear out - took them off and gave them away.  Running a Michelin Pilot Power 5 front with a 32 to 33 PSI pressure.  Rear is 38 to 40 PSI and a Michelin Road 5.  However I don't think tires cause or cure instability but can help or aggravate a problem.  I'm at 7mm drop on the front forks.  IMO there is something in the build tolerances or adjustments of the front end that causes this issue.  Seems like there are bikes that have it and others that don't which is perplexing.

Hope some of this info helps those who are having the issue.  

[l3ry4n3]

@Ride365 did you ever get this figured out, I am experiencing the same on my 2019 tracer 900 GT

[PeterL]

Interesting thread.

I note my 2019 GT is much more susceptable to crosswinds/turbulence than things like my C14 or RT are. A good part of that is just good old mass, but the Tracer is also set up for a quicker steering response than a true touring bike is generally. It's uncomfortable but not unsafe per se.

If your chassis is well sorted, you could consider a shorter windscreen. That can make a huge difference. A top box is also something that catches wind with astonishing efficiency.

I'd like to understand how the handguards affected some contributors. I've not noted them to be that much a factor compared to all the other stylish but not especially aerodynamic features of the Tracer.

[PhotoAl]

Just back from a 5,000 mile trip.  Rode thru some winds as well as rain.  Some roads had speed limits of 80mph and flow of traffic was faster.  I have a MRA touring windscreen, triples dropped 7mm, 37 liter Yamaha top case plus 58 liter duffle on rear seat in addition to side cases.  Kept the top case mostly empty (well that was the plan) but did get running shoes, rain jacket and a few bottled drinks. Had no trouble with wobble or weave at speeds - lets just say 80 plus one or two.  As mentioned above bike turns in very quickly and is quite responsive to pressure on the bar.  Rode with just left hand on the bar some using cruse control to rest right hand, on a couple of empty stretches could even take both hands off the bars and bike tracked true and could be steered by shifting weight.  Ran 38PSI in front (Michelin Pilot Power 5) and 42 in rear (Road 5).  It seems like the top case has not affected stability or sensitivity to cross winds.  I dont track gas mileage that carefully but seems like it get a little better mileage with the top case.  I'm thinking maybe it smooths the air flow off the back a bit.

[OZVFR]

On 7/2/2021 at 11:33 AM, PhotoAl said:

Just back from a 5,000 mile trip.  Rode thru some winds as well as rain.  Some roads had speed limits of 80mph and flow of traffic was faster.  I have a MRA touring windscreen, triples dropped 7mm, 37 liter Yamaha top case plus 58 liter duffle on rear seat in addition to side cases.  Kept the top case mostly empty (well that was the plan) but did get running shoes, rain jacket and a few bottled drinks. Had no trouble with wobble or weave at speeds - lets just say 80 plus one or two.  As mentioned above bike turns in very quickly and is quite responsive to pressure on the bar.  Rode with just left hand on the bar some using cruse control to rest right hand, on a couple of empty stretches could even take both hands off the bars and bike tracked true and could be steered by shifting weight.  Ran 38PSI in front (Michelin Pilot Power 5) and 42 in rear (Road 5).  It seems like the top case has not affected stability or sensitivity to cross winds.  I dont track gas mileage that carefully but seems like it get a little better mileage with the top case.  I'm thinking maybe it smooths the air flow off the back a bit.

You ran 38PSI on the front and it felt fine?

To me the Tracer lacks front end feel at 32PSI let alone 38PSI. 

I’ve also raised the forks  10mm to try and place a bit more weight on the front wheel. 

Edited July 3, 2021 by OZVFR

[roadrash83]

19 hours ago, PeterL said:

Interesting thread.

I note my 2019 GT is much more susceptable to crosswinds/turbulence than things like my C14 or RT are. A good part of that is just good old mass, but the Tracer is also set up for a quicker steering response than a true touring bike is generally. It's uncomfortable but not unsafe per se.

If your chassis is well sorted, you could consider a shorter windscreen. That can make a huge difference. A top box is also something that catches wind with astonishing efficiency.

I'd like to understand how the handguards affected some contributors. I've not noted them to be that much a factor compared to all the other stylish but not especially aerodynamic features of the Tracer.

   I had some buffeting on my 2019 GT, with a medium size top case on the back, around big trucks. I put the Givi hand guard extensions on to help keep my hands warmer in the winter. One of the side effects was that they really helped with the buffeting and the light front end feeling at speed. 

[PeterL]

 

7 hours ago, OZVFR said:

FFS, you ran 38PSI on the front and it felt fine?

The Tracer seriously lacks front end feel at 32PSI let alone at 38PSI.

Is it pressure or tire selection affecting your feedback? (not a criticism, just a question)

I have Michelin Road 5's on mine currently. Solo I run 34f/38r, and with a pillion I go to 38f/42r. The manual recommends 33f/36r solo or 36f/42r 2-up for my 2019. I just made adjustments based on what I felt while riding (I am ~235# in gear), and I do monitor my tire wear closely. I'll be spooning on some Pirelli Angel ST's in a few more miles and will probably have to baseline things all over again.

[duckie]

FWIW........Do not forget how temp effects tire pressures.

If you set a pressure say at 38 psi in a shade or garage, when you get in sunlight and get moving, you will be over 40 psi in no time.......and then add high ambient heat. 

I set my temps in my garage always 1-2 psi lower or not depending on outside temps, than what I want cause heat will cause them to increase  

Sunlight is the poor mans race tire warmers.....

BTW.......getting buffeted by wind is just part of motorcycling.

[betoney]

1 hour ago, duckie said:

FWIW........Do not forget how temp effects tire pressures.

If you set a pressure say at 38 psi in a shade or garage, when you get in sunlight and get moving, you will be over 40 psi in no time.......and then add high ambient heat. 

I set my temps in my garage always 1-2 psi lower or not depending on outside temps, than what I want cause heat will cause them to increase  

Sunlight is the poor mans race tire warmers.....

BTW.......getting buffeted by wind is just part of motorcycling.

Very true.  I just returned from a road trip in Oregon, California and Nevada where ambient temps got up to 108F (or higher) at times.  I had set my cold tire pressure to 36F/38R and in the heat of the day my TPMS was showing 42F/46R.

[j-bone]

I also believe this is attributed to the handguards. I don't necessarily feel a wobble as much as a single skew of the handlebars because if a blast of wind on a handguard. 

I could see it manifesting as wobbles if someone was holding the bars for dear life, I haven't felt that sensation, only a single little blip in the bars that is immediately self-corrected. 

[duckie]

Well, go outside and look at your front end. You got a fender and two big metal discs that provide alot of surface area for wind to hit and dont forget about wind hitting you arms also. 

Look at the side of the motorcycle. That tank and engine also provide a large surface area for wind. 

If ya want really fantastic wind protection..drive.

[cy685]

I have about 1k miles on my 2020 GT and I have encountered the feeling of front end instability/wind pushing the bike around above 65-70 MPH, on days with no wind and no trucks or other large vehicles anywhere near me.  I'll try some of the suggestions here to see if they help.  I have a Puig touring windscreen and stock handguards currently. 

[thewrenchbender]

13 hours ago, j-bone said:

I also believe this is attributed to the handguards. I don't necessarily feel a wobble as much as a single skew of the handlebars because if a blast of wind on a handguard. 

I could see it manifesting as wobbles if someone was holding the bars for dear life, I haven't felt that sensation, only a single little blip in the bars that is immediately self-corrected. 

If you don’t have it-you don’t have it. And if you do (and did riding it home from the dealership) then you do something about it.

It’s still there with the stabilizer but only get the extreme edges of the periodic oscillation…and only then over 100…goes away if I climb up on the tank, just like it did without the stab. 

[PhotoAl]

On 7/2/2021 at 9:23 AM, OZVFR said:

You ran 38PSI on the front and it felt fine?

To me the Tracer lacks front end feel at 32PSI let alone 38PSI. 

I’ve also raised the forks  10mm to try and place a bit more weight on the front wheel. 

Yes, it is 38psi cold and felt fine to me.  Running a sticky front tire - Power 5 not a Road 5.  I did a lot of faster secondary roads and interstates on the first and last 1,100 miles and a lot of straight fast secondary roads on the rest of the trip.  However hit a lot of fun mountain roads along the way and the front felt good.  It wasn't perfect but was descent and would like a more planted feeling but only one time did I feel like it was slipping.  Held it's line well and was stable.  Only 2 days did I run the bike unloaded and cornered hard all the time I was on mountain roads.  Fast enough to have a lot of fun but always keeping a margin for the lapses in judgment or unexpected road change or cow or deer in the road.  

[jamespz03]

On 7/3/2021 at 8:56 AM, cy685 said:

I have about 1k miles on my 2020 GT and I have encountered the feeling of front end instability/wind pushing the bike around above 65-70 MPH, on days with no wind and no trucks or other large vehicles anywhere near me.  I'll try some of the suggestions here to see if they help.  I have a Puig touring windscreen and stock handguards currently. 

Same here but it's just freeways and just some of the time now. I ensured my stock dunlops were 36/42 per manual and removed the handguards and the stock screen. Both have helped but there is still a touch here and there. I also had the suspension tuned locally and that helped too. 

I'm hoping new tires will help as well but wind will be wind and you can't help that.