Tank Slapper

**Death 'N' Taxes** · 15th April 2004, 13:15

The only one I have had was on an old 1986 GSXR750. Sitting at the lights on Grafton Road turning right to go up the Stanley St on ramp heading south (prior to the big roadworks).

Next to me on the inside of the turn was a guy on a 250 who thought he could give me a go. So I accelerated hard into the turn, back end got a bit loose. I did want you're not supposed to do and shut the throttle, tyre got grip and bike tried to flip me. Held on, only to go through a nasty tank slapper with my legs flapping about hitting the sides of the bike. Once the bike slowed it was fine. But after looking like a complete prat I nailed it up to the m'way, went around the left hander and found a wall of traffic - slammed on the front brakes but nothing happened. Pumped as hard as I could and got them to work finally.

Ended up speaking to a mechanic who said that those bikes were prone to throw the pistons in the callipers out from the disk during a tank slapper and you have to pump them to regain contact with the disk.

One shit scary experience.

**Bleck K6** · 19th April 2004, 20:25

Originally Posted by DEATH_INC.

Had a good one on my mates TL1000s out hunua,just pulling past my mate doing about 240kph and she just went mental,no real reason.Kept her nailed (good old MX learning

) and it just got worse and worse,the whole bike was leaping from side to side (the rear was trying to come around

)my mate who owned it was following and said he could see daylight under both wheels.....got to the point I knew it wasn't gonna come out of it and started looking for somewhere to crash it(I still had a bit of directional control.....)and decided to try to slow down a bit before I hit the ground

,and buttoned off(amazing how fast yer brain works in these situations isn't it?)......and it stopped

Didn't ride it far after that

When I gave it back to my mate(after a quick change of daks)He told me 'yeh it does that,I just button off and it stops'(though he'd never had it happen that fast....)

I was in front of DEATH.INC when this happened.
All I noticed was the headlight in my mirror waving all over the place, Then he went past me I was doin about 240kph & he started slowing down,He pulled over & switched back not long after that.

**Big Dog** · 20th April 2004, 16:22

Originally Posted by Jim2

Here's a nice intellectual study on roading induced slappers.

http://www.ee.ic.ac.uk/CAP/Reports/2001/roadforcing.pdf

Well after reading the whole thing ... finally, it has become apparrent that outsisde of the description of the program used to simulate the experience outside of the physical perameters of the original design the only thing a rider can do is weigh 20kg more, or lean over the tank. Unless i have lost the ability to read techy data the intention was to desribe how to use autosim and how it will benifit designers, which parameters are user defined etc.
Endless references to data not supplied left me feeling

.
If anyone else found a more salient point be my guest.

ps the 20kg thing might be why in 160,000kms I have only experienced one tank slapper, as in theory I am 2.2 riders. (based on Industry standard of assuming that average rider weight is 68kgs)

**Deano** · 20th April 2004, 16:48

Originally Posted by TILLER

I was in front of DEATH.INC when this happened.
All I noticed was the headlight in my mirror waving all over the place, Then he went past me I was doin about 240kph & he started slowing down,He pulled over & switched back not long after that.

Used to get quite a few on the two stroker, kept the throttle hard on and hung on to the bars a bit tighter, all good - had a couple on the SP-1 but not too bad.

Never ridden a TL but I would have been swapping bikes back after that experience.....or if I owned it I would fit a steering damper or have the thing checked out.....best thing to do though would be to buy a HONDA

**MacD** · 20th April 2004, 23:02

Originally Posted by Jim2

Here's a nice intellectual study on roading induced slappers.
http://www.ee.ic.ac.uk/CAP/Reports/2001/roadforcing.pdf

Interesting read!

The other point that may be of use to people is that increasing your front suspension damping (ie: fork damping) reduces the "weave mode resonance" at higher speeds - in other words, tank slappers.

That, and as Big Dog pointed out, gaining 20-30kg would help too!

**Bleck K6** · 20th April 2004, 23:07

Originally Posted by Deano

Used to get quite a few on the two stroker, kept the throttle hard on and hung on to the bars a bit tighter, all good - had a couple on the SP-1 but not too bad.

Never ridden a TL but I would have been swapping bikes back after that experience.....or if I owned it I would fit a steering damper

I have had a couple on the TLR but it just rides through them.

His was a 99TLS all TL's had steering dampers from factory after the problems they had in 97.

As for buying a honda? they just don't do it for me.

cheers

**FROSTY:Me** · 22nd April 2004, 01:04

I saw a guy today on a little stroker get a nasty looking slapper after the rail crossin in new lynn. I think that guy fair shat his daks -arms and legs flying in all directions--then it seemed to settle down and he rode off--slowly

**2_SL0** · 16th October 2004, 23:19

I found tanks slappers occur on both my KDX and KX dirtbikes. Best advice was open up the throttle. (as someone else pointed out, MX style "When in doubt, GAS IT" I prob dont recommend that for the road.

**TwoSeven** · 17th October 2004, 18:34

I get a wicked head shake on my 250 just about every day, but its deliberate.

I have a right hand corner that I nail in first and exit full throttle in 2nd. As the bike comes upright I let go of the bars and sit up. Then grab the bars ready to nail a sharp left half throttle in 2nd.

When I let go of the bars the weight drops back on the front that shakes something wicked. Is fun and I always forget to not let go of the bars for that corner. Sorts itself out if I get back on the gas again. Probably the only corner I know of where a steering damper would help.

**Lou Girardin** · 18th October 2004, 19:16

Originally Posted by Tiggerz

As the bike comes upright I let go of the bars and sit up. Then grab the bars ready to nail a sharp left half throttle in 2nd.

Let go of the bars?

RIP

**pipeman** · 18th October 2004, 20:08

Yep not a nice feeling, fear shit me self. I had just past two of my mates fear giving it on my RGV250 on long left and just come over a small crest lifting the front when keeped on giving it gas to get out of it. nealy broke my rists off though. also on my old CB750 could never work that one out because they DONT have a very steep rake i think the problem was in the rare some where if that makes seen.

**aff-man** · 19th October 2004, 06:39

full lock tank slapper at 180km/h front wheel locking up. Managed to hold it together somehow but fully fucked the front wheel bearings

**Fryin Finn** · 19th October 2004, 08:24

You get tank slappers in soft sand on heavy trail bikes. The bikes bang side to side eventually ploughing the front end and spitting you over the handle bars. You get up saying "oh dear that was unpleasant" and repeat the proceedure until you learn to ride flat out in sand and ignore the wobbles until you have to stop.

**2_SL0** · 19th October 2004, 08:29

Originally Posted by Fryin Finn

You get tank slappers in soft sand on heavy trail bikes. The bikes bang side to side eventually ploughing the front end and spitting you over the handle bars. You get up saying "oh dear that was unpleasant" and repeat the proceedure until you learn to ride flat out in sand and ignore the wobbles until you have to stop.

YEP, you learn quickly from that problem, it helps develop the no FEAR atitude for sand riding.