SuzukiSavage.com - Tank Slap and Headshake

Suzuki_Sam

Ex Member

Tank Slap and Headshake
06/27/05 at 20:13:26

Okay, WD brought these up and I, like Karen, had never heard of it. My husband installed a shield on my bike and I have not ridden with it yet. (I think it needs to be lowered a bit, it feels kind of like some of my vision is now obstructed.) I would prefer not to learn about tank slap the hard way, Wink

so aside from WD's "what to do if this happens..." how do I do all I can to prevent it in the first place? Is there a minimum speed that this happens?

Back to top

IP Logged

Gitarzan Serious Thumper 2004 No Login Offline ! Posts: 827 Columbus, Oh, Earth, Solar Sys Gender:	Re: Tank Slap and Headshake Reply #1 - 06/27/05 at 20:54:14 You'll usu. get some warning. At very high speed you may notice that the forks are wanting to wobble back and forth. That's a good sign to slow down a little. Keep forging ahead and they might really start slapping. Common sense will cover it (for most people).
Back to top	2001 Cherry Red and Ivory Yamaha VStar 1100 IP Logged

sluggo Serious Thumper ModSquad Offline big singles lead, twins follow the pack Posts: 4744 moses lake washington Gender:	Re: Tank Slap and Headshake Reply #2 - 06/27/05 at 21:04:19 Gitarzan wrote on 12/31/69 at 16:00:06: At very high speed that's usually where the trouble begins.
Back to top	SINGLES RULE, HARLEYS DROOL IP Logged

WD

Serious Thumper
2005 No Login

Offline

Professional
"scooter
trash".

Posts: 5207
Rosemark TN
Gender: male

Re: Tank Slap and Headshake
Reply #3 - 06/27/05 at 22:35:09

I've pushed my Savage to the ragged edge (and beyond). The oscillation starts at roughly 100 mph, and by 105, you are through it. Trust me, you'll never see that out of a stocker. I know of 3 WORLDWIDE that can "safely" and consistently top 100 mph, and NONE are stock.

Keep it at legal speeds and you shouldn't have problems. HOWEVER, that being said, keep an eye on the maintenance... The most common cause of a light cruiser tank slapping after too high a speed for the tires is the wheel bearings. They are sacrificial items. As the grease dries out, the bike will develop a slight front end wobble, maybe even some "pogo sticking". Change the bearings in the wheel and check the steering stem bearings, replacing if/when necessary.

Watch the tires. IRC tires will dry rot and cup long before the tread is worn off.

Keep the shield square to the front end.

Keep the swingarm and axle nuts tight. they DO back off courtesy of the single cylinder thumping. Ditto the engine nuts.

IF your bike gets seriously goofy on you, pull over. Odds are you've popped a tube. It happens, and is why higher end bikes have tubeless tires (much safer in a flat tire situation).

File it in the back of your mind. No point dwelling on it. 95% of riders won't have a true tank slapper happen to them. I'm in the 5%. It wasn't fun. Interesting, yes, painful, definitely, costly, umm, yes. Cost me a restored 1963 FL cop bike.
-WD

Back to top

On 2 wheels since 7/87

Black and Chrome 2003 1950s style custom

IP Logged

Savage_Rob Serious Thumper Alliance Member Offline Mechanically Inclined Amateur Posts: 6972 Texas (Dallas area) Gender:	Re: Tank Slap and Headshake Reply #4 - 06/28/05 at 05:19:31 A fork brace (Superbrace is the brand I bought) is great for helping to stabilize the front end of the Savage too. I can't recommend it enough.
Back to top	1998\|MAC muffler\|ceramic coated header\|K&N air filter\|Amal Mk2 carb\|Odyssey battery\|iridium plug\|NC windshield\|Dunlop 491s\|Superbrace\|EBC brake rotor\|12.5" Progressive shocks\|Kuryakyn ISO grips IP Logged

Ed L. Serious Thumper Alliance Member Offline "We All go a Little Crazy Sometimes" Norman Bates Posts: 2808 Sunny Florida Gender:	Re: Tank Slap and Headshake Reply #5 - 06/28/05 at 06:54:27 Ditto on the fork brace, after installing the Superbrace on my '02 the wobble that occured after hitting bumps when riding over 65mph went away. Can't recomend it enough for tighter handling. Just my .02 cents worth. Ride Safe, Ed L.
Back to top	Silver '02, clubman handle bars, Cobra headlight, Sportster muffler, K+N stock air filter, 152.5 main, Superbrace, oil cooler, 1/2 inch aluminium plate forward controls, spark advance, goes like stink IP Logged

WD

Serious Thumper
2005 No Login

Offline

Professional
"scooter
trash".

Posts: 5207
Rosemark TN
Gender: male

Re: Tank Slap and Headshake
Reply #6 - 06/28/05 at 07:51:12

Come to think of it, another easy way to keep the bike behaving is to run a stiffer fork oil. SAE30HD works well in most standard 'glide front ends. "Fork oil" is for cartridge forks, the Savage has 1950s HD knock-offs.

Sluggo brought up previously (and of course I completely spaced) making sure your spokes are tight. Loose spokes will definitely pull a wheel out of true. Yet another reason that heavier machines use cast wheels. Having the wheels balanced occasionally is a good idea as well. But, even changing the tire at 7.5 years on the bike didn't require any weights or spoke adjustment for my 98 model.

I'd add a fork brace, but, my forks completely bottom out at every stop. Angry

Either I ride it too agressively, or, I've completely destroyed the springs. Whichever, I'll try some SAE40 or 50 and see if it helps.

Well, I'm off to work. To find a BUNCH of parts. Like: fork seals, exhaust gasket (head to pipe), brake pads, brake shoes, wheel bearings, swingarm bearings (or bushings, not sure which the Savage uses), head set bearings, grips, 12 inch over stock throttle/clutch cables, air filter, sparkplug, one piece riser cap... sheesh...might be cheaper to just get another Savage. Undecided

Like I said, I'm rough on my bike...
-WD

And it's still the only one that takes the beating and comes back for more. 8)

Back to top

On 2 wheels since 7/87

Black and Chrome 2003 1950s style custom

IP Logged

vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: Tank Slap and Headshake Reply #7 - 06/28/05 at 08:23:46 WD wrote on 12/31/69 at 16:00:06: And it's still the only one that takes the beating and comes back for more. 8) Hahaha. It is true! This buke loves abuse!
Back to top	IP Logged

Suzuki_Sam Ex Member	Re: Tank Slap and Headshake Reply #8 - 06/28/05 at 08:36:31 Thanks, guys. I'm going to look into the fork brace. As I understand it, as long as my bike's in proper shape and I'm not doing the Evil Knieval thing, this is something I don't need to obsess about. I appreciate your help!
Back to top	IP Logged

Hammy211

Ex Member

Re: Tank Slap and Headshake
Reply #9 - 06/28/05 at 09:21:33

Savage_Rob wrote on 12/31/69 at 16:00:06:

A fork brace (Superbrace is the brand I bought) is great for helping to stabilize the front end of the Savage too. I can't recommend it enough.

Which one did you get? I only saw braces for Suzuki Bandits. I get some wobble going around high speed corners. Do you think this would help with that?

Back to top

IP Logged

Reelthing Serious Thumper Alliance Member Offline Fish or ride that is the question Posts: 5397 Houston,Tx Gender:	Re: Tank Slap and Headshake Reply #10 - 06/28/05 at 09:50:49 I agree on the Superbrace - when I first put it on the '95 I was more impressed with it's looks than function - but after >4k miles with it the couple of times I've taken it off just fooling around - it goes back on fairly quick - I'll add one to the '02 shortly.
Back to top	IP Logged

Reelthing

Serious Thumper
Alliance Member

Offline

Fish or ride that is
the question

Posts: 5397
Houston,Tx
Gender: male

Re: Tank Slap and Headshake
Reply #11 - 06/28/05 at 10:02:33

Hammy211 wrote on 12/31/69 at 16:00:06:

Which one did you get? I only saw braces for Suzuki Bandits. I get some wobble going around high speed corners. Do you think this would help with that?

It's there on the website - number 3335 I think - and don't waste you time on the fork shields - junk -

I believe it does, as well as proper tire pressure - and as Sluggo pointed out - the spokes need to be tuned every now and again

Back to top

IP Logged

Savage_Rob

Serious Thumper
Alliance Member

Offline

Mechanically
Inclined Amateur

Posts: 6972
Texas (Dallas area)
Gender: male

Re: Tank Slap and Headshake
Reply #12 - 06/28/05 at 10:55:34

Reelthing wrote on 12/31/69 at 16:00:06:

It's there on the website - number 3335 I think - and don't waste you time on the fork shields - junk -

I believe it does, as well as proper tire pressure - and as Sluggo pointed out - the spokes need to be tuned every now and again

Yes, it is listed and it is 3335. The item Reelthing is saying not to bother with is the stainless fork protector #6004 (below). I don't have those but hadn't really given them any thought. And I notice the difference in a lot of places, uneven surfaces are some of the most noticeable: rain grooves, gravel, minor holes and bumps, etc.

Back to top

IP Logged

SavageDude

Serious Thumper
Alliance Member

Offline

Posts: 561
OC_California
Gender: male

Re: Tank Slap and Headshake
Reply #13 - 06/28/05 at 11:31:52

Quote:

some of the most noticeable: rain grooves, gravel, minor holes and bumps, etc.

Just my 0.02 Grin

I worked on airplane for 16 years now and notice that everytime the plane landed; the crewchief wipe down the Main Landing Gear strut(same as our front fork's principle)with a spray of oil and a rag. These MLG struts have been in service for the last 35 years and I haven't rebuild too many of them.

So maybe we can do the same for our forks and extend their life with minimal effort Wink

SavageDude

Back to top

2005 S40, debadged, Tkat FB, saddle bags, sissy bar, HD Sporter muff, Fly screen, white spacer mod, 150 main jet.....and sssslowly upgrading

IP Logged

Savage_Rob

Serious Thumper
Alliance Member

Offline

Mechanically
Inclined Amateur

Posts: 6972
Texas (Dallas area)
Gender: male

Re: Tank Slap and Headshake
Reply #14 - 06/28/05 at 12:14:54

SavageDude wrote on 12/31/69 at 16:00:06:

Just my 0.02 Grin

I worked on airplane for 16 years now and notice that everytime the plane landed; the crewchief wipe down the Main Landing Gear strut(same as our front fork's principle)with a spray of oil and a rag. These MLG struts have been in service for the last 35 years and I haven't rebuild too many of them.

So maybe we can do the same for our forks and extend their life with minimal effort Wink

SavageDude

The simulation from the Superbrace site shows the bowing of the forks that the brace is intended to reduce/alleviate. I can personally attest to the fact that it works. I also wipe down the struts regularly. While I'm relatively sure it's a good maintenance practice, I'm equally sure it made no noticeable difference in the wobble inherent in this bike's front end.

Back to top

IP Logged