[BriGuy375]

All-

Im at the point where i want to sell my bike, so if the GURU's could read this, i know its long, i would REALLY appreciate it-

I need your expertise. Please dont be freaked out by the length of my post - This all started this past fall when i took my bike in for an inspection and tire change. I dropped it off, and picked it up with a new set of tires (only had 6000 miles, but the rear was worn and the front had a flat spot) and a fresh inspection sticker. This is where it all starts.

As i left the dealership, i thought the ride felt "rougher" than when i dropped it off, but i attributed it to fresh stiff tires. My bike came with the Lasertech / MEZ2 combo, and it was initially replaced with the Bridgestone Battlaxe combo. After getting the bike on some smooth roads, i realized that something wasnt right. I thought for sure the tire balance was the culprit. The problem i was feeling was an up and down oscillation, or vibration, that would come and go on about a 5 second period at 50 mph. 5 seconds would pass, then the seat would vibrate, then the handgrips, then the mirrors, then it stops. After 5 seconds goes by again, it starts again in the seat.

This problem is COMPLETELY speed dependent and does not change at all with RPM. You can put the bike in neutral, shut it completely off, and roll dowhill at 50 mph and feel it very clearly.

So i take it back to the dealer, and they tell me my rims arent true. They are outside of the factory spec. They true'd my wheels after two different visits to the dealer. This didnt fix it. Then they replaced the tires with another set of Bridgestones. No change. Then the swapped my wheels / tires out with a factory set. This made it better, but it was really hard for me to evaluate because they would only let me drive around the block with the showroom wheels.

Next they switched to Pirelli sport demons, and it is better now than it has been so far, but at typical tire pressures, it is still very evident. If i reduce the pressures to about 32f 33r it gets better, but is still noticable.

The dealership supposedly had triumph ship a new set of wheels to try, but was informed that if they installed the wheels on the bike and sent my wheels back, and no problem was found with my stock wheels, that the dealership would be backcharged 3000 dollars for the new wheels. They wouldnt do anything with these wheels because they didnt want the chance of getting stuck with the bill.

Finally, aggravated, i picked up my bike along with a letter from the dealership stating basically that they feel they are returning to me a bike which has vibrations typical of any bonneville, and to them is perfectly adequate.

My bike rode smooth as glass before i dropped it off, even with the worn tires. Now it does not. I must say, however, through all this i still only paid for 2 tires and an inspection. I get the impression they tried, but just couldnt get it.

NOW, i basically didnt ride for the rest of the season because riding and feeling this vibration pissed me off so much, it wasnt even fun anymore.

Regardless i had some winter mods planned, and moved forward over the winter. I completely disassembled the rear end, checked every bushing, ditched the airbox, and reinstalled everything. I also pulled the front forks to install gaiters, made sure everything was torqued properly, adjustted the steering head bearing, etc. I see no MAJOR runout (radial or axial) in either rim.


Cliff notes:
Bike vibrated up and down at speed. Worst is about 55 mph or so. This vibration starts in the seat, moves to the bars, and finishes in the mirrors. It is a cyclic type vibration, speed dependant, irrevelant of engine, and is about a 5 second repeating cycle.

Bike tracks well and has absolutely no tendency to bar wobble (left to right) at all. With the throttle locked at 55mph, i can completely let go of the bars and the bike tracks straight and true, absolutely NO bar shake side to side at all. Only this up and down hopping feeling.

Things that have been done / checked :
two sets of bridgestones and 1 set of sport demons
wheels trued
wheel bearings inspected
rear end disassembled, inspected, reassembled to proper torque
front end same
steering head bearing adjustment
double check wheel balance.




Im COMPLETELY out of ideas. This wasnt like this before, and it is now, and its killing me.

Its gotten me to the point that i want to trade it on a Concourse 14. I absolutely love this bike though, i love the style, and i used to like how it road.

PLEASE HELP ME!!:??!??!?

I REALLY appreciate your help-

Thanks guys-
Brian

 

[easttex]

I am no Guru, but this sounds like a wheel balance problem.
Maybe take to another shop and have wheels/tires checked on
a different machine.

 

[BriGuy375]

I actually have done that. After the dealership balanced all three sets of tires, after riding the bike i was ABSOLUTELY convinced that the dealerships wheel balancer was out of calibration or something, so while i had the bike apart over the winter i drove the wheels down the road to the local bike shop guy and had him check on his snap on balancer. Dead nuts 0. right on.

 

[BriGuy375]

I understand that ALOT of people on this site run the sport demons successfully, but is there any chance of the bias/bias as opposed to the stock bias/radial could be causing a wierd issue?

 

[easttex]

Hi, I believe there was an older thread on this same problem,
Maybe an answer there. Let us know what the solution is.

 

['08 T100]

I'm no guru or an expert and, in fact have only been riding for about a year.

But allow me an observation. Your bike rode smooth, they touched it, and then it's screwed up.

Unless you are imagining the whole issue, something they did messed up your bike.

One possible scenario is that the initial Bridgestone tires they put on were defective and when you brought it back, they did'nt even consider that, and jumped on saying that your wheels were not true.

They could have screwed up your wheels by messing with them or, even when they did the initial changing of the tires.

One thing that I have noticed is that many times, bike shops/bike dealers, whomever, employ apprentice type mechanics who are paid less than the journeymen, and are delegated to do the menial tasks such as stripping old tires off and putting on the new ones.

Just from my only one year experience with this bike, I get the impression that the spoked wheels these bikes use are not the toughest, sturdiest/stongest wheels around.

Probably it is possible that someone inexperienced could screw them up doing something as simple as replacing the tires.

With all the thought and energy you have put into this, didn't that ever cross your mind?

You say that it is completely speed dependent but, you were not able to really do an accurate test 'cause they only let you drive around the block with the borrowed set of wheels.

Did they ride your bike with your own tires and wheels at the speed that this happens?

At 3k for a new set of wheels, I could see why they would be reluctant to say much of anything except that it feels normal for the type of bike and tire combo.

They have washed their hands of it and you are stuck with something you're not happy with.

Least possible in my mind is, that ALL three types of tires that were tested on your rims are just not compatible with a smooth ride on a Bonneville.

Sorry that I am not able to help you, I'm pretty anal about my stuff and, an issue like yours would bug me too, big time.

Good luck with it,

Mike

As an afterthought, just something to think about, are you absolutely sure that what you are feeling is so bad that it has to be wrong, or could it just be indicative of a different type of tire?

 

[davevv]

Have you considered Dynabeads? They do appear to work as I've read good reports on them in several places. One was an unsolicited testimonial in the blog "40 Years on Two Wheels". Here: http://40on2.blogspot.com/2008_05_01_archive.html

Manufacturer's website here:http://www.innovativebalancing.com/gallery1.htm

If nothing else, it should at least remove any question of balance problems from the equation.

And no, I have no interest in the company. But with all you've done so far, I think it would be my next step.

 

[MES]

...This vibration starts in the seat, moves to the bars, and finishes in the mirrors. It is a cyclic type vibration, speed dependant, irrevelant of engine, and is about a 5 second repeating cycle. .....I also pulled the front forks to install gaiters, made sure everything was torqued properly, adjustted the steering head bearing,

did you go into your forks?

An out of true wheeel, streering head, rear bushing problem would cause side to side motion.
It's not wheels or tires

This sounds suspention related, possably harmonic vibration from the road surface. does it do it on all road surfaces? or at different speeds on different surfaces?

How much do you weigh and are you on stock suspention?
Is it the front or rear that is hoppin?
or
is it hobby horsing? (both front and rear. One up and one down and then the reverse)

 

[johnny black]

Hi what a horrible thing to happen,check your chain ,some bozos replaced your rear tire and pulled it too tight,every chain has a tight spot,even a new one,just my 2 cents worthJ.B.
P.S don't give up on the Bonnie

 

[649cc]

do you know anyone else with a bonnie who let you swap wheels over and see if that fixes it and makes the problem on the other bike?

 

[Aussie_T100]

It would appear that all of the obvious things have been checked except for the axles possibly? Maybe a bent axle could be causing the problem???

The problem didn't exist before the original change of tyres so logic would suggest that the problem was caused at that time, that is, during the removal and refitting of the wheels or during the removal and refitting of the tyres so one needs to look at problems that may have ocurred during that process.

Are the beads seated properly on both tyres? With the bike on the centre stand or on a jack can you see any eccentricity in the tyres themselves when you spin the wheels?

If the wheels were handled a bit roughly during the removal & refitting of the first set of tyres that may have been the cause of the rims being out of true. It's interesting that you've only been charged for 2 tyres and the inspection which suggests to me that the dealer accepts responsibility for the wheels being out of true because he didn't charge you for the repair of same.

Can you set the wheels up in V blocks and rig a dial gauge up to test the rims and/or tyres for trueness? Short of changing out the complete wheel assemblies, one at a time, for known good units that's about all I can come up with.

 

[davidc]

did you go into your forks?

An out of true wheeel, streering head, rear bushing problem would cause side to side motion.
It's not wheels or tires

This sounds suspention related, possably harmonic vibration from the road surface. does it do it on all road surfaces? or at different speeds on different surfaces?

How much do you weigh and are you on stock suspention?
Is it the front or rear that is hoppin?
or
is it hobby horsing? (both front and rear. One up and one down and then the reverse)

That's what I was thinking - if you believe the accuracy of all the tire checking and wheel truing. I'd do a real close examination of all the fork components. Who knows what happened while it was in the shop with the wheels off. The forks can get out of line a bit because the manual points out the should be properly aligned. And fork springs have broken, fork oil levels can be off.
Hope you figure it out, man. Selling the bike is extreme, not to mention how would you sell it if it hops like a rabbit.
Confidence, my man! The bike was good before; therefore, it can be good again!

 

[CHRIS211083]

I Know!!!!!!!!!!!!!

HI ALL, I KNOW WHAT YOU PROBLEM IS!!!!
hi, im a triumph machanic. i had this problem with my own bikeand others firstly these bikes dont like bridgestones. had a pair and i rebalenced the wheels 3 times.....no change???? if you switch back to the metzlers the bike came with from factory then it will be fixed. i know they arnt as sticky but when the me's warm up they are fine. secondly, measure your wheel alighnment from the swing arm pivot and dont rely on your adjusters!!!!! and finaly i found running 33f/38r was not right as im 6'5 and 19 stone. if your heavy go to 34f/40r this helps. i would also recomend you squeeze your spokes and make sure there tight. i have not tryed avons or any others so if any one finds some that work well on a thruxton then let me know. cheers chris.

 

[jdd5300]

This might be really dumb, but have the tubes been replaced at any point? I'm only asking because the behavior of the bike sounds an awful lot like what happens when you replace a bicycle tube incorrectly. Seat bounces, bars wiggle, feel like you're on square wheels after a while. Since the tires have been changed so many times it's not likely that there is a twist in the tube, but could be a funky spot that is bulging once inflated?

I know it's a little out there, but thought I'd chime in anyway.

Finally, if these vibrations are "normal" (which they aren't) ask the dealership to mount a set of demo wheels from another floor bike temporarily so you can take a spin with those.

Don't give up on your Bonnie. Any kind of buzz you get from these bikes is sort of fun and expected, yours sound downright annoying.

 

[Dale_K]

Just a guess... loosen up the chain a bunch and check it out really closely. Move all the links by hand and see if any feel tight or bound up. Also check the runout on the wheels both vertically and side-to-side by spinning them while the bike's in the air. Maybe pull the calipers so you can let them spin free and set some kind of stable marking thing, like a bent wire up against the tire so you can tell whether they are true. I also like the idea of the other poster who said to check the axles for straightness.

 

[BriGuy375]

Like i said, the bridgestones have now been replaced with pirelli sport demons.

I dont see any major runout issues, axially or radially, in the rims.

Chris said to switch back to the Metzlers, is it OK to mix a bias with a radial tire? I mean, they came that way from the factory, but i always thought not mixing was rule number 1?

The chain and spocket are original, they have 6000 miles on them. I dont see any wierd sprocket wear, and the chain seems okay. I havent however inspected each individual link.

I sort of ruled out the chain because the bouncy doents change with the application of throttle. It would seem to me that a chain problem wouldnt be overpowering rolling in neutral.

Im at the point where i think im going to order another set of tires just to see if it fixes it. Unless there is someone local who would be willing to trade one wheel at a time with me for a quick ride around. Im at my wits end here, and dont want to spend 300.00 or more if i dont have to-

Also, if i buy another set of tires, should i buy another set of sport demons hoping that they are better than the first set, or just order a set of metzlers lasertec front MEZ2 rear? Also, a few sites say the MEZ2 is discontinued?????

Thanks for all the advice so far guys, hopefully we will figure this out. Im reluctant to take it back to the dealer because of their attitude the last time, plus the last time they had the bike, they had it for over 3-4 weeks !!!

Thanks again
Brian

 

[BriGuy375]

By the way, i am kind of a heavy guy. Im about 6'7 and a little over 320. I dont see why the suspension would work fine before, and see fixed now though.

I have never been inside the forks, and dont have any fluid leaks or anything. I suppose i can check to make sure the fluid is the same level in both pretty easily.

 

[BriGuy375]

So there is a slight hump in the tread of the rear sport demon thats on it now. Ive had some people tell me that an up and down hump in the tread is normal, and a side to side wiggle is bad, then ive had people tell me that no irregularity is normal.

Im grasping at straws here, still thinking it HAS to be the tires somehow because thats all that was changed, i ordered another rear sport demon from motorcycle superstore and will switch it out myself and see if my probllem goes away. If not, ill take offers on the bike !

Its the strongest running stock engine Kissell motorsports dyno operator had seen-

B

 

[BriGuy375]

Okay, so based on what ive heard here, i have pretty much narrowed it down to wheels, tires or chain. I have ordered a replacement set of sport demons, if they dont fix it, ill have a spare set, and a chain. Like i said, i looked at the chain, and i didnt think it was that bad, but im really grasping at straws here-

Aside from inspecting the front suspension for oil levels and stuff, is there a way to tell if the rear suspension is boinked? It was okay driving it in for the inspection, and isnt okay now. I dont know how they could make suspension fail, but is there a way to test the rear shocks?

Thanks
Brian

 

[Aussie_T100]

Okay, so based on what ive heard here, i have pretty much narrowed it down to wheels, tires or chain.

So you've ruled out the possibility of a bent axle then have you?

I notice that you posted in another thread about this over 5 months ago where another forum member was having a very similar problem, have you tried any of the suggested remedies posted in that thread?

The post where the guy said that he let his tyres right down then pumped them up to 50psi before dropping them back down to normal pressures again sounds interesting - maybe that would be worth a try.

Here's the thread:-

http://www.triumphrat.net/twins-technical-talk/89767-f-n-hopping-down-the-road.html