Tank slapping on the Tracer 900 2015-2017 models.

[David Phipps]

Watching Utube blogs the other day and a guy from the US comment on why the FJ 09 had a speed limiter fitted on them. He reckons it's because the bike goes into a tank slapper at around the 115 mph mark, and he said his did. Does anyone know of problems with the handling at high speeds?

[1moreroad]

That's very possible, although I don't know why Euro FJs wouldn't have the same problem. The front end can get light. It's well documented in this forum. Same reason why you're not supposed to put hard tail and saddle bags on at the same time.

Some of us have the problem and some don't. 

I've had a twitchy front end but it always settles down. Only time it didn't was when a shop (grrr) did not set the forks to the same height in the triple clamps. I got a wobble (not a slapper) at about 100 mph. Easy to fix. I was surprised just how sensitive the bike was. 

[betoney]

45 minutes ago, David Phipps said:

Does anyone know of problems with the handling at high speeds?

While I have never experienced it and have ventured above 110mph many times, there is no shortage of discussion on the topic.

Some attribute it to funky aerodynamics including the bizarre shaped handguards, suspension setup, steering geometry, tire inflation, luggage/weight on the rear of the bike etc.

https://www.tracer900.net/search/?q=front end wobble

[littlebruv]

I changed the handguards to Puig ones and it helped a bit with the high speed wobble as I think the original ones are more like an aileron shape

[chitown]

My '15 FJ-09 experience: "Tank slapper" -- nope. "High speed weave/wobble" - yes but no more. 

Tank slappers IMO are violent affairs and my experiences they came with weight shifted forward. One was catastrophic failure of the front rim at speed. As long as I was on the throttle with weight shifted rearward I could steer so that got me to the shoulder of a freeway. But I had to stop eventually and the last 25 feet had zero control. Somehow didn't drop it. Another was a car pulling out from a mountain turnout suddenly. The other lane was occupied so no escape route. Max braking but car clipped the front tire starting the tank slapper. So violent couldn't input any throttle or steering. Eventually it just flopped over and I didn't roll quite enough and broke a collarbone. 

When completely stock had the beginnings of a weave at high speed a few times. Usually at high speed pulling into turbulent air (semi passes etc). But they were nothing that couldn't be managed by subtle shifting of weight and being mindful of inputs. Since then I've made several changes to the bike and it's not an issue. Endless threads on the topic for your reading pleasure   

  

[coachluciano]

4 hours ago, David Phipps said:

Watching Utube blogs the other day and a guy from the US comment on why the FJ 09 had a speed limiter fitted on them. He reckons it's because the bike goes into a tank slapper at around the 115 mph mark, and he said his did. Does anyone know of problems with the handling at high speeds?

ive ridden at 130+ MPH whenever the opportunity arises - no issues.  Also  - limiter only in the US I believe.  be aware, I do not have anything stock on my handlebars aside from the switches.  So removing the large hand guards and smaller width helps with aerodynamic issues.

[Guest]

I had an XSR900 that started getting wobbly at around 80 but with stock suspension. On my 2017 FJ09 I did K-Tech on both ends and never had a hint of wobble but never got over 110. I got it flashed and had it up to 130 and sure enough I started getting a wobble at 115. That was with a Puig touring screen and no handguards. I suppose Yamaha knows a little bit about what they're doing.

[v1nn1e]

I've cruised at ~120mph-ish (indicated) on several occasions and not noticed any instability/tank slap at all. Mine's a complete stocker and I have the pre-load and rebound damping wound right off front and rear for comfort.

For those that have, what tyres/pressures are you running...?

[keithu]

I've never had anything even remotely like a tank slapper on my 2015 FJ-09, even with stock suspension. If the bike were susceptible to tank slappers I think I would have had one by now. There's a particular corner when I leave work where I'm frequently at WOT while still leaned over. It's not unusual for the front wheel to loft or skip while doing this, which is exactly the sort of thing that can induce a tank slapper. I've had it happen on a ZX-7R, but I've never felt even a hint of it with the FJ. Irresponsible and silly, I know. But also really fun. 

I've experienced high speed weave, but it usually seemed to be induced by wind buffeting off large trucks or vehicles on the highway. I rarely ride faster than 80mph for more than a few seconds.  

[betoney]

8 minutes ago, keithu said:

There's a particular corner when I leave work where I'm frequently at WOT while still leaned over.  Irresponsible and silly, I know. But also really fun.

No further words need be spoken.  😎👍