View Full Version : Tankslapper - number 2!
It happened AGAIN! 2nd tankslapper in 3 and a bit months of SV ownership, same stretch of road aswell as my 1st!
My friend was following on a KTM lc40, went over the same bumps and his bike handled it fine although he said it was very bumpy. But my SV went all over the shop.
Kept the throttle as constant as I could and fought the handlebars straight again - phew! Im not very happy about this, 2 tankslappers in 3 months. In my biking experience, a harsh tankslapper is about the scariest thing Ive encountered and im sure i shouldnt be experiencing them this frequently!
I posted a thread on how to recover a tankslapper not long ago, we came to the conclusion of doing a wheelie and letting go of the handlebars but now Ive had a 2nd chance to relish the experience my advise is hold on, scream loudly and say the hail mary.
I dont need this kind of thing.
454697819
13-02-05, 04:49 PM
out of interest, has your bike been in a prang at all in its life?
weegaz22
13-02-05, 05:19 PM
is it a naked sv you ride?
Are the headstock bearings adjusted correctly?
Do you ride like a nobber?
northwind
13-02-05, 07:21 PM
Are you now or have you ever been a member of a terrorist organisation?
Sorry, I meant to ask if you've made any adjustments or modifications to the geometry or components... Tankslappers while cruising most often originate from bad rear suspension, strangly enough, so first thing I'd do is check your rear suspension settings.
Carsick
13-02-05, 07:24 PM
Do you ride like a nobber?
Don't hold back, Jabba!
...and tyre pressures.
What tyres are you on? Some bikes can be very sensitive to front tyres (i.e. the make and therefore stiffness) especially, though I'm not aware the SV is particularly fussy.
Carsick
13-02-05, 07:59 PM
I find the K4 a bit prone to shaking it's head if you coincide a blast on the throttle with some bumps.
I stupidly did it at about 80mph when I was going over some cat's eyes. I got away with it and made the overtake, but it's easily done if you forget yourself.
wheelnut
13-02-05, 08:31 PM
Im not aware of ever having one never mind two :shock:
Have you faffed about with your rear preload? if so put it back to where it was
Is a tank slapper what us schoolkids use to call a speed wobble? We were quite proud of them in 1970 :P
Carsick
13-02-05, 08:34 PM
An actual tank slapper is a headshake where it goes all the way to the stops and bounces off of those.
Otherwise it's just unpleasant.
ronlarimer
13-02-05, 08:43 PM
...and fought the handlebars straight again...
Relax a bit and don't hold the handle bars so tight.
My SV is completely standard, never fiddled with any preload settings - nothing. Tyre pressures are fine on Dunlop sportmax (I think its sportmax) tyres.
Was overtaking at about 60 - 65 mph, hit some pretty harsh and close together bumps and the handlebars snatched left, did the same as last time progressively snatching more violently left to right. Really is not a nice feeling, control is completely taken out of your hands. The last thing you want to do at that speed is turn the handlebars especially full lock!
As ive said I havent played with anything on the bike at all, its a completely standard full faired 04 SV but something must be wrong with it.
And thanks Jabba for your comment. :roll:
northwind
14-02-05, 12:56 AM
No wonder you're having problems if you've never dialled in your suspension... Suspension setup should be different for everyone. Especially with such budget items on the bike... The SV's rear doesn't need a excuse to tie itself in knots...
How heavy are you, out of curiosity? Because I'm about the right weight for SV stock settings at 10 stone...
My SV is completely standard, never fiddled with any preload settings - nothing. Tyre pressures are fine on Dunlop sportmax (I think its sportmax) tyres.
Was overtaking at about 60 - 65 mph, hit some pretty harsh and close together bumps and the handlebars snatched left, did the same as last time progressively snatching more violently left to right. Really is not a nice feeling, control is completely taken out of your hands. The last thing you want to do at that speed is turn the handlebars especially full lock!
As ive said I havent played with anything on the bike at all, its a completely standard full faired 04 SV but something must be wrong with it.
And thanks Jabba for your comment. :roll:
So is it naked or not?
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Mr Toad
14-02-05, 09:31 AM
. . . its a completely standard full faired 04 SV but something must be wrong with it.
So is it naked or not?
.
I guess that would be a not :D
I weigh just under 11 stone and it has aftermarket fairing
Okay smart @rse :lol: .
It's certainly far less common (it seems) for the S to have slappers than the naked. With the right tweakiing it can all but be eliminated though a steering damper would certainly be an improvement IMHO but the cost of that is just stupid.
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Balky001
14-02-05, 01:23 PM
I only had the one tank slapper on my SVS, right after it was serviced. It was rough but fairly decent tarmac and the front had lifted slightly on an overtake around 50mph. Yours experience might be a little different but if you were going over bumps your mates off-roader will have longer suspension travel and his front wheel may not have lifted even if your did, so it might be a run of the mill slapper (if there's such a thing) Otherwise headstock, fork brace, wheels and brakes should be checked (as no geometory has been messed with) 11 stone is pretty bang on the right weight for standard suspension settings. Fitting Steering damper might be a bit extreme but would give piece of mind.
northwind
14-02-05, 04:05 PM
I weigh just under 11 stone and it has aftermarket fairing
Hmm, i'd asumed you'd be heavier from your problems. But I'd still recommend that you check out recommended sag settings (don't have alink for the really good website, but I'm sure somone does) and see how that helps.
Steering damper would fix it, but it's treating the symptoms not the cause... Better to go to the source.
I wouldn't completely rule out the possibility that you've just been very unlucky, to be fair, and that you won't get anoht er wobble for 100000 miles. But I understand that that's not something you'd want to count on of course.
Steering damper would fix it, but it's treating the symptoms not the cause... Better to go to the source.
Whilst that's true, to change the source would mean a new frame, new forks, new suspension... :lol: Now why someone can't make a fifty quid steering damper I really don't know.
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Dicky Ticker
14-02-05, 04:41 PM
I just like the idea of "Run of the mill SLAPPERS" :D
Can I have two please? :lol: :lol:
Gforceuk
14-02-05, 05:03 PM
Do you ride like a nobber?
lmao... thats what i was going to ask..
northwind
14-02-05, 05:32 PM
Whilst that's true, to change the source would mean a new frame, new forks, new suspension... :lol: Now why someone can't make a fifty quid steering damper I really don't know..
Me neither... though nobody'd fit a £50 steering damper, they wouldn't trust it :) I might have a cheap one going soon but you'll need to build your own brackets I think...
Shouldn't take a whole-frame swap, i know the naked's fundamentally rubbish ( :lol: ) but steady-speed slappers almost always originate from the rear... Sorting out the rear shock should make a massive step towards fixing slapper problems. Mine were entirely caused by the fact that I knew f-all about setting up suspension and I'd made a hideous dogs breakfast of it when i fitted the new shock :roll:
Just fit clip-ons, er, and a faired model's front end, and you've sorted all the naked's problems :)[/i]
Just fit clip-ons, er, and a faired model's front end, and you've sorted all the naked's problems :)
Strangely, not quite what I had in mind. :lol:
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Dicky Ticker
14-02-05, 08:22 PM
N.W. You never cease to amaze me If there is a simple answer
you definately can find the complicated one As a matter of interest how much money have you spent doing mods and trick bits on your bike? :o :roll: :o :roll: :o :roll: :o :roll: and i'm not being nasty I am serious because you always seem to be changing something
p.s. I was going to ask you to list them but maybe not :lol:
Have you tried heavier weight bar ends???? This can sometimes fix the problem. It has for me in the past. I used to own a CBR 6 that ALWAYS wanted to shake its head at me. I slapped some heavy weight bar ends on it and hey presto, tank slappers stopped completly.
Could be that your holding the bars too tight.
I wouldn't reccomend a Steering damper unless you have sharpened up the geometry a lot, as otherwise it just simply masks an easily sortable problem.
I find the SV does slap sometimes acellerating hard on bumpy roads, but its mainly just a mild oscillation for me, and it doesn't bother me that much. Just the bikes way of saying "were getting a move on are we?".
Only mild speed slap I had was when acellerating out of a roundabout with a big fat lad on the back lol. I'm sure the SV isn't designed for 32 stone lol!
Dan
northwind
15-02-05, 12:54 AM
N.W. You never cease to amaze me If there is a simple answer you definately can find the complicated one
As a matter of interest how much money have you spent doing mods and trick bits on your bike? :o :roll: :o :roll: :o :roll: :o :roll: and i'm not being nasty I am serious because you always seem to be changing something p.s. I was going to ask you to list them but maybe not :lol:
:) I used to list them in the sig but it was too small :) I'd say... Probably... Not counting genuine maintenance stuff like tyres, and damaged parts... probably about £1200. I could've afforded a brand new K3 but I know what a mod addict I am so I deliberately bought a cheaper bike and budgeted for mods... Still been cheaper than a new one, and it's a far, far bettre bike, only slowed down by its barely competent rider :roll: I am not going to tell you what the new project is, until I know I can make it work ;)
Quite a lot of that is reclaimable to be fair... If I broke the bike for trick bits today I could probably get much what I paid for the shock, system and spare wheels , which were the big expenses, since i got good deals used on them all.
But no fair! I've suggested setting up the suspension properly, which is free, and now I'm suggesting the suspension fix because it'll be far cheaper than most dampers...
For an injected bike, pick up a GSXR K shock, and swap (as far as I understand it, not sure exactly which shock you want for an injected). Slightly harder to fit than the damper of course, but I don't think you can argue with the economics- spend maybe £50, maybe £100 if you need to have it fitted by a pro, vs £120 I think the cheapest dampers are? Plus of course you have the benefit of a better shock, whereas with a damper you still have the same bedspring on the rear.
Still, I'm surprised that he's so close to the "proper" weight, that threw me... But untul he checks out the settings there's basically no point in looking any further.
The chances of doing a wheelie are slim to none, it was just an idea from a biker I know and I was like :shock: erm yeah, thats a good idea.
Ive had alot of comments that it could be the way I ride, both of them have been on a straight piece of road and acclerating not particularly hard on an overtake but over bumps. I dont see what I could of done to cause a tankslapper by my own means???? Ive ridden my SV much harder in the past I know that much!
And im not exaggerating, these were'nt small speed wobbles they were lock to lock blaze of arms and legs tankslappers - speed wobbles I can handle.
The second one I was overtaking, it wasnt even progressive like the 1st the handlebars just snapped full lock to the left, I nearly went into the side of the car I was overtaking! Im not claiming it to be a show of skill but Im amazed I kept the bike upright on both occassions. I so thought I was going to crash it.
I think the 2nd slapper has actually damaged the bike even more because now it wants to follows imperfections in the road ive noticed, it seems to drift to the left or right when I just want to go in a straight line.
I could really feel the 2nd one jarring the whole bike and im sure its caused more damage. Im not riding it now, its going into the dealers. 3 months old it is! Not impressed.
Well my SV has gone back to the dealers, they dont know whats wrong with it so its going back to Suzuki for testing apparantly. They said they have never heard of this kind of handling problem on a new SV!
So there you go, im on the bus for a while. Im not sure if I even want the thing back now to be honest.
northwind
15-02-05, 03:47 PM
Not good...
Dicky Ticker
15-02-05, 04:11 PM
All tank slappers are gyroscopic and the problem is finding what is causing it Tyre pressures,wheel imbalance, suspension set up, warped disc,road surface,geometric set up the list is endless The other problem is that if somebody else sets the bike up for their weight/profile and riding style it may or may not conform to your own personal requirement
Have a good hard think and try to come up with a reason for the wheel to start wobbling You have mentioned the road surface and I've had a couple of "MINOR" wobbles due to this and when I changed my tyres I had the back snaking but uping a notch on the rear suspension cured that
Double check your tyre pressures with a GOOD tyre guage
Good luck in your quest
Professor
15-02-05, 05:54 PM
Reading this thread is making me even more paranoid. The last bit of
my commute is along a very bumpy and neglected forest road. Hadn't
had a tankslapper yet but am living now in constant anticipation. :shock:
Big Bad Al
15-02-05, 07:38 PM
Reading this thread is making me even more paranoid. The last bit of
my commute is along a very bumpy and neglected forest road. Hadn't
had a tankslapper yet but am living now in constant anticipation. :shock:
me too. Never had one and hope I never do. However I can't stop worrying about them. I'd love to understand exactly what causes them and how common they are.
You're only likely to suffer from one if you really cane your bike over a poor and uneven surface.
Newish tyres, sorted front suspension (i.e. correctly set up springs. oil and preload spacers) and tightened headrace bearings should ensure you never experience a slapper.
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fizzwheel
15-02-05, 08:33 PM
I've had a couple and both times caused by canning it on a poor road surface not a nice experience.....
Professor
15-02-05, 08:38 PM
You're only likely to suffer from one if you really cane your bike over a poor and uneven surface.
Newish tyres, sorted front suspension (i.e. correctly set up springs. oil and preload spacers) and tightened headrace bearings should ensure you never experience a slapper.
.
I keep it under 30 on the bumpy road in question. Probably not fast
enough to cause a tankslapper.
Also, on this stretch of road I operate the throttle and brake very gently
+ hardly steer at all. As far as I understand now tankslappers are caused
by more energetic riding.
fizzwheel
15-02-05, 08:41 PM
Prof, spot on energetc riding on a bumpy road has been the cause of both mine, both were not pleasant experiences
Once your actually into your tankslapper, its like the front wheel cant straighten itself because the power from the rear is burying the front sideways into the tarmac.
ive thought about this alot, you hit a nasty bump at speed which knocks the front wheel slightly sideways as the wheel comes back into full contact with the road its not straight, this alters the speed of the front wheel to be slower than the rear so there is more momentum at the back of the bike and this causes the power from the rear wheel to start burying the front sideways into the tarmac and depending on the speed I guess determines how violently the handlebars snatch.
Now Ive thought about this I would have to conclude that the rear brake must help to level out this effect?
Both of mine have been on overtakes, although I wasnt really gunning it past but accelerating moderately fast. going over hatched white lines. Im now really paranoid about them!
Big Bad Al
15-02-05, 09:32 PM
Do track bikes / off road bikes suffer a great deal from this - I assume by the nature of the sport they are being ridden very enthusiastically on a very bumpy surface:?:
My friend was behind me when my 2nd one happened on a KTM LC40, he did say that the road was really very bumpy but his bike handled the bumps ok. We were doing the same speed, went over exactly the same patch of road but the KTM absorbed it ok
Carsick
15-02-05, 09:55 PM
an LC40 is a completely different type of bike, nuff said.
Balky001
16-02-05, 08:56 AM
rear brake doesn't help as front forks as well as the rear shock will slightly depress when used, which makes the slapper worse - and any raking force will add further pressure to the front wheel which is already bucking. You were right in the first place just to try and keep it steady and see through it. Some you won't be able to save.
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