When does a tank slapper become a head slapper?

[biggjohn]

I was out riding last weekend and a guy on a bike with a pair of ape hangers went by in the other direction. Now of course he was not wearing a helmet which seemed to be doubly dangerous. If he ever got into a tank slapping situation, it could end up being a head slapper. Sometimes when I am riding, I wonder about things like this.

John

 

[Fencer]

When does a tank slapper become a head slapper?

When you realized you coulda had a V-8

 

[FJRski]

If you have time to think about things like this, you are not going fast enough.

 

[biggjohn]

If you have time to think about things like this, you are not going fast enough.

You could be right, but then I am still breaking in my FJR.

John

 

[OrangevaleFJR]

If you have time to think about things like this, you are not going fast enough.

In some cases, it just doesn't matter how fast you are going. Thinking still sneaks in.

I'd be surprised if a bike with bars that wide could not be muscled out of the gyration.

 

[FJRski]

Agreed. I sometimes start thinking about the same things. That's when I realize I am not going fast enough.

I think a head slapper is what happens to the guy with the ape-hangers after he leaves the bar.

 

[fatrat]

went down on x- mas morning,1968, when yamaha 350 went into a tank-slapper. asked on another forum [bonevilleamerica.com] what causes this,,,, got vague answers. so Big John,, it concerns me too. what about it guys,,, how likely is the chance of this happening with todays "modern" bikes???? I STILL REMEMBER!!!!!!!!!!! running about 70 m.p.h. when i went over, was 24 then,,, can't take another now, any thoughts?????

 

[FJRski]

Was it a RT 350? I learned to ride on DT 360.

Tank slapper happens when front end gets light and takes a different line than the rear. Can't really explain it well. Could happen under a variety of conditions.

Don't think the geometry on the FJR is highly susceptible, that's why you don't see damper kits on it. (If you are asking about other sport bikes, each one has its own characteristics.) I experienced a high speed wobble for the first time 2 weeks ago, on the slab in a corner. I was heavily loaded with luggage and had mixed brands of similar tires. I don't think it was the tires. It could have turned ugly, but the FJR is very stable and predictable. Just weighed the pegs and backed off a bit.

In this case, I was going too fast and needed to slow down and think about things.

 

[Ed_Grant]

I've had a bit of high speed weave on my FJR,, fully loaded with a Tanji Aux tank and large Motofizz bag on the aux tank. Guess it was about 130 mph after I had passed a group of bikes. Backed off the throttle and everything settled down.

I have had one tank-slapper. It was in 2003 on a '02 V-Strom. Nov 30th, 2003 to be exact. I ended up bailing off the bike at about 65 mph. The bike did a tumbling routine that tore off most everything plastic, bent the rear subframe, crushed the front subframe, cracked the main frame and dented the gas tank and bent the radiator. I ended up with much bruising but no cracked or broken bones.

The bike had all the Suzuki hard bags mounted but empty. The wind was blowing very strongly straight into me with gusts to 50 mph. Best I can figure is after I passed a pickup truck the combined effects of the headwind, my speed and luggage made the front end very light. When I counter-steered to move back into the right lane the front tire was mostly off the ground and then all hell broke loose. Maybe a steering damper would have helped. I might have been able to stop the oscillations be going WFO on the throttle but at the time chopping the throttle seemed like the thing to do. Just made it worse.

I bought another '02 V-Strom last April and this one has a Scotts steering damper installed just in case.

 

[Ari Rankum]

how likely is the chance of this happening with todays "modern" bikes???? I STILL REMEMBER!!!!!!!!!!! running about 70 m.p.h. when i went over, was 24 then,,, can't take another now, any thoughts?????

It's got much less to do with the bike or the age of the bike, and lots more to do with whether or not the rider has ridiculous, oversized frog legs.