Speed wobble vs Weight Poll

[rebar]

I'm curious what "wacked people from the Widwest" look like. Anyone? Nobody?

Look at my profile pic.:biglaugh:

You took a 25 year old tire up to that speed. No offense, but I do believe that is a fine line between crazy and stupidity.

Agreed. remember.. Im from the midwest..:rofl_200:

 

[RaWarrior]

When I had my '82 GS450 I spun the original tires up to the bikes top speed....about 85mph....going down a hill! Back when I was young(er) and stupid(er), or knew any better.

Even a hint of dry rot on a tire makes me nervous now, though my tires rarely hang around for more than the better part of a season.

 

[Shuriken]

Wasn't expecting this many responses... Thanks guys.

Nobody: it's obvious I have some mechanical things to correct on the bike. I've already replaced the front forks and will soon be able to move on to the other things (bearings) on my list. No I won't get a Harley. Many of them have the same problems, so I hear.

At the time of this post, 7 people reported more stability with more suspension load. I'm in that group of posters and I'd like to find out why.

 

[dannymax]

Shuriken....don't be overly discouraged if you can't eliminate your wobble....trying to get a handle on the it is like trying to grab a handful of smoke.

You may be able to eliminate it, you may only reduce it or everything you do may have little to no affect at all.

I realize you are talking about a speed wobble but I went to battle with a decel wobble on my '06 with 11K on the clock. I replaced: swingarm bearings, front wheel bearings, steering head bearings...installed delrin motor mounts and a new ME33 Metzler Laser Tec front tire.

Only the Metz tire made any difference at all, but still left a tiny wobble. I torqued the head bearings down a touch over factory spec and the wobble disappeared.....until yesterday when I noticed a tiny one beginning again.

I have no idea if the de-cel and hi speed wobbles are related, if it's a characteristic of some v max's and not others (some guys with brand new max's have reported a wobble of one kind or the other) or what the deal is.

Although there is no record of it I strongly suspect Yamaha battled this issue for the better part of 20 - 25 years with no sucess. I experienced the speed wobble several times back when I had my '85.....the thought of it gives me the shivers these days as it can turn into a non-recoverable tank slapper in the blink of an eye.

Be careful with this guys.....you don't want to hit the blacktop at the speeds where 'the wobble' lives!!

 

[Rand-5107]

There are 3-4 venders selling fork braces on E-bay. Also most V-max venders web sites carry some kind of brace. As Rodney King said can't we all just get along. Lol

 

[Redbone]

I have had hints of a wobble but I think it was mostly due to lower than proper air pressures. I have had more worries with frame flex, mostly at higher speeds with bumps/ undulating roads that really upsets the stability. I've added progressive lowering springs (2"), fork brace, ricor intiminators, progressive hd 440's, delrin motor mounts, adjusted/ greased swingarm and steering bearings, new tires (shinko tourmasters) but still have some of the frame flexing issues.
Maybe a braced swing arm and radials (MM will love to hear this I imagine:bang head will help this mid 80's designed bike handle better. I'm happy enough with the way Redbone handles as I don't have the twisties to ride on a normal basis.

 

[COP RUNNER]

Timmy, you live in a world much different from the rest of us!!!:rofl_200::rofl_200::rofl_200::biglaugh::rofl_200::rofl_200::rofl_200:

YES DANNY , WELCOME TO " MY REALITY " IT'S NOT EASY BEING ME ! .. :rofl_200::biglaugh::rofl_200:

 

[Rand-5107]

I agree with the effect of tire pressure on handling. My bike has the feel of a hinge under the seat in high speed sweepers. I believe that's frame flex or swing arm flex or a combination of both. Haven't gone to solid motor mounts. I'm afraid of vibration. How are the delrin in that regard? Biggest improvements so far were new steering bearings, Ohlin rear shocks, and race tech springs for my weight.

 

[COP RUNNER]

The First Time I Experience The " WOBBLE " I'm Going To Buy A " HAYABUSA " , That Will Cure My " WOBBLE " For Sure , But I'll Keep My " MAX " Just To Ride Through Small Towns & Scare Everybody + I'll Still Be Welcome On This Forum !

 

[rebar]

When the wobble starts.. pull back hard and go faster.

 

[dannymax]

YES DANNY , WELCOME TO " MY REALITY " IT'S NOT EASY BEING ME ! .. :rofl_200::biglaugh::rofl_200:

Hate to say this buddy but, sometimes it's not easy being around you either!!!

Like in front of your bike as it's rocketing up the driveway about 60 miles an hour!!

Oh yeah.......SIDEWAYS!!! :surprise::surprise::surprise: :rofl_200:

 

[dannymax]

I agree with the effect of tire pressure on handling. My bike has the feel of a hinge under the seat in high speed sweepers. I believe that's frame flex or swing arm flex or a combination of both. Haven't gone to solid motor mounts. I'm afraid of vibration. How are the delrin in that regard? Biggest improvements so far were new steering bearings, Ohlin rear shocks, and race tech springs for my weight.

Yup, that's frame flex! You won't mistake the wobble for anything else if it shows up!

A lot of guys do complain about excessive vibration but when I went to delrin mounts there realy wasn't that much difference. Maybe a little more buzz in the mirrors over 70 or so, but that's about it.

And who doesn't want a little more buzz....eh?? :coolgleamA:h yeah::coolgleamA:

 

[COP RUNNER]

Hate to say this buddy but, sometimes it's not easy being around you either!!!

Like in front of your bike as it's rocketing up the driveway about 60 miles an hour!!

Oh yeah.......SIDEWAYS!!! :surprise::surprise::surprise: :rofl_200:

" LOL " " LOL " , WELL , IS IT NOT EASY BEING AROUND ME OR IN FRONT OF ME ? .. OR BOTH ? .. :confused2: .. :rofl_200::biglaugh::rofl_200:

 

[dannymax]

" LOL " " LOL " , WELL , IS IT NOT EASY BEING AROUND ME OR IN FRONT OF ME ? .. OR BOTH ? .. :confused2: .. :rofl_200::biglaugh::rofl_200:

All three!!! :rofl_200::rofl_200::rofl_200::ummm:

 

[gamorg02]

the $200~ shindy (daytona) steering dampers will help out a lot. yea its sorta like a bandaid but it still helps.

 

[Hulign]

Haven't gone much over 100 with the new wheel(COO) but with the the divvy wheel on it I have buried the speedo(17 inch wheel up front so who knows what the speed was).

Mine doesn't seem to wobble but seems to go tight... gyroscopic effect maybe? just hard to explain.

Tons of changes thru the years and has always seemed the same up top. I wouldn't say its sportbike smooth but it hasn't tried to kick me off yet.

This is with hand machined forks (to clear the wheel), racetech springs and gold valves,fork brace, radials... but I never had any problems with the stock stuff either.

Further testing of COO rear wheel and Shinko tires will happen after rear brake bracket arrives and 4pot caliper is back in place.

As for Nobody.... he likes getting people wound up... ignore him or give him his way, your choice.

BTW I was speed stupid and fast crazy before I moved to the midwest.

unk:

 

[gamorg02]

lets keep this topic on topic... i removed some posts b/c they didn't contribute at all. keep it civil guys.

 

[DanQuin]

Been rather interesting reading, from the standpoint that sportbike guys view almost any instance of shake as a need for a damper, and you folks are looking for the cause. Kudos! :clapping:

In my limited experience, most shake issues come from:

• Improper inflation of tires
• Steering head bearings
• Uneven tire wear
• Improper suspension

There are a few other causes and this is not intended to be an all inclusive list. Just places to check out and the order of things I check on my Vmax (I actually check the same things on sport/race bikes in this order).

The first three are pretty simple to check, and there is some awesome how to information on this Forum for specifics on steering head bearings. So lets talk about suspension.

The Vmax forks from 85-92 had .404 kg/mm springs, and 93-07 got .382 kg/mm springs. At my weight of 230 the bike would need a 1.0 kg/mm springs. Using this example the front end of the bike is undersprung in the 60% range. This will decrease trail and have the rake a bit steeper. Simply changing to a more suitable spring rate will help out greatly. The Vmax had air adjustable "preload" for what it's worth, but it's not the greatest of adjustments. You'd need an accurate gauge and since it's dynamic the chore of damping (which is handled by damping rods) becomes more challenging.

In my opinion the fact that adding weight to the rear of the machine and having it increase stability supports the trail and rake discussion above. By having more weight in the rear we change the steering head angle slightly restoring some trail and providing more relaxed rake.

In any event, after checking the tires, steering head bearings and basic suspension function/setup, I would recommend putting a more suitable spring in, and while you are in there consider a valve emulator/Ricor valves or other suitable damping solution.

 

[Mod Monkey]

Been rather interesting reading, from the standpoint that sportbike guys view almost any instance of shake as a need for a damper, and you folks are looking for the cause. Kudos! :clapping:

In my limited experience, most shake issues come from:

• Improper inflation of tires
• Steering head bearings
• Uneven tire wear
• Improper suspension

There are a few other causes and this is not intended to be an all inclusive list. Just places to check out and the order of things I check on my Vmax (I actually check the same things on sport/race bikes in this order).

The first three are pretty simple to check, and there is some awesome how to information on this Forum for specifics on steering head bearings. So lets talk about suspension.

The Vmax forks from 85-92 had .404 kg/mm springs, and 93-07 got .382 kg/mm springs. At my weight of 230 the bike would need a 1.0 kg/mm springs. Using this example the front end of the bike is undersprung in the 60% range. This will decrease trail and have the rake a bit steeper. Simply changing to a more suitable spring rate will help out greatly. The Vmax had air adjustable "preload" for what it's worth, but it's not the greatest of adjustments. You'd need an accurate gauge and since it's dynamic the chore of damping (which is handled by damping rods) becomes more challenging.

In my opinion the fact that adding weight to the rear of the machine and having it increase stability supports the trail and rake discussion above. By having more weight in the rear we change the steering head angle slightly restoring some trail and providing more relaxed rake.

In any event, after checking the tires, steering head bearings and basic suspension function/setup, I would recommend putting a more suitable spring in, and while you are in there consider a valve emulator/Ricor valves or other suitable damping solution.

Well said!!! Of course there is also the option of upgrading the front end to a USD one as well........ Would make your Mod Monkey happy:eusa_dance:

 

[DanQuin]

Well said!!! Of course there is also the option of upgrading the front end to a USD one as well........ Would make your Mod Monkey happy:eusa_dance:

Oh yes, there is that, and it would help open up the world of 17 inch wheels and tires. But I'm a retro person. I wanted a Vmax since 1985, and I like the legacy of a bike that has remained the same. :worthy: