Triumphrat

Moochy

This was on my '06 ABS Sprint, dry conditions, at a very low speed . . . a good outcome, but it scared the bejeezus outta me.

It happened making a left turn at an intersection with 4 lanes either way so the turning arc was moderate. My lean angle also was minimal. There was construction in the area that put down a bit of dust on the road, but the road conditions were good.

About a 1/4 of the way into the turn I had a bit of pressure on the front brake and the handlebars started bucking like crazy. I let go of the brake and started getting back to vertical as quickly as possible (muscle memory from the MSF course may have kicked in here). The violent motion didn't stop until the bike was headed straight and was fully upright. This all lasted maybe a few seconds, but it seemed longer. And to add to the fun a lady to my right decided to head left right across my bow!?!

Needless to say my confidence was a bit rattled, but nothing else happened that was out of the ordinary for the balance of the ride. Upon checking the tire pressure everything was normal. The bike has 2200 miles on it with OE tires, and there's been no suspension mods.

I suspect the slight front brake and the bit of dust on the road were the main culprits. Mind you the speed was only about 10 to 15 miles per hour and the turn was moderate, but the shaking was so hard that my arms tingled for 20 minutes or more afterwards.

This is one of those things you wouldn't want to wish on anyone. If I hadn't had a gorilla grip on the bars I surely would have high-sided.

Anyone have ideas as to why that kind of violent occilation occurs? Would a bit of rear brake keep it from happening again?

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Tbirdnz

You really shouldn't be on the front-brake into a turn, it dips the forks and affects the steering, I think this was your biggest problem, you probably had more speed on and more front-brake on than you realised. My 2 cents.

Glad you saved it and thanks for sharing this.


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Catenaccio

Scary experience. MSF course paid for itself.

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skiTTles

+1 scrub off all your speed before you turn in. Accelerate through the corner, don't brake through it!

joelk

hey guys, not to hijack but this seems like the right place. i've only been riding for about a month ... never heard of tank slapping til today. saw plenty of scary youtube videos of it. did some googling to try to find the proper approach to deal with it after it happens.

some say push forward on both handles (not down) to act as a human damper. others say just hold the handle bar loosely and ride it out. is there a consensus on the correct way to deal with this? i get the impression the worst thing to do is to brake and hold the handlebars as firmly as possible.?

i assume it happens to everyone at some point? how common a problem is it with triumphs ... say a thruxton for example :-)

skiTTles

DON’T grip the bars tightly DO slow down gradually. I had been told in the past to accelerate through it, but I’ve been convinced otherwise these days.

I’ve never had one on the street and I ride around 25k miles a year on the public byways and highways.

A tankslapper is enhanced tremendously on a bike with a narrow rake, read: a sportbike. The reason behind the desire for a narrow rake is it allows the bike to turn in quickly, so you can see where such a nature would aid in the creation of a tankslapper. This is why race bikes, and rece reps, will have a steering damper affixed but you won’t ever see one on a Harley. I would think a Thruxton would not be subject to an unnatural amount of tankslappers (though if you want a Triumph as a first bike I would suggest a Bonneville as the upright riding position would allow for you to concentrate on riding first before racing. You can later on easily mod a bonnie to be a café racer $0.02).

DaveB

Moochy had a bad experience (& I'm very glad that he overcame it OK) & I also think that the combination of front brake & a dusty road surface got the bike out of sorts. I've had plenty of tankslappers in my time but all on bikes manufactured in the early Eighties & I've never had one at anything under 65 mph.

To answer your very important question joelk, high speed tankslappers are incredibly violent. The handlebars oscillate from stop to stop at incredible speed. You have absolutely no way of dampening or slowing the movement by applying, or not applying, force. The world's strongest man wouldn't be able to do this!

If you can even retain your grip on the bars (and you have to) you've done well. The only thing that will allow you to ride it out is a change of speed & the quicker the better. Once I had to emergency brake at the same time as contending with a fullblown tankslapper at 80 mph. It worked. As the speed was shed the oscillations stopped. It was one wild ride . The other times I've always been able to accelerate which soon overcame the problem.

All my tankslappers were caused by travelling over roadwork sections (some marked & others not) too fast & not paying enough attention to the rough pavement & joins. I'm very lucky I never crashed as a result of those tankslappers.

I've done nearly 12,000 miles on the Sprint & it doesn't even shake its head (steering head), let alone give any indication that it will ever tankslap .

I hope this helps.

DaveB.

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joelk

thanks very much guys for the replies!

be350ka

joelk,

If you haven't already, pick up the book "A Twist of the Wrist II". It is geared toward racing techniques, but the techniques and theory all work where ever you ride.

Kieth Code would say that in an event like this you grip the bars lightly (probably VERY tough to do when they are doing everything in their power to make sure you don't do this) and allow the natural stability of the bike to pull it through.

The other suggestions about not braking in the turn and using a steady roll on of throttle through the turn seems to be spot on.

be350ka

.....OH, and Moochy,

Good job and I'm glad everything worked its way out for you.: