1970 Bonneville Vibration

[teganbarr]

I know these old Bonnie's have a tendency to vibrate like none other, but should it effect me as much to not take it on a longer distance ride? (as in on the highway for greater than 30 minutes haha) I used to ride it out of the city, probably 15 minutes of highway riding at 110km to work and back once or twice a week, but i'm starting to be more hesitant as of late, having lost one license plate already and a stress fracture on a tail light causing it to break off the bracket. Not to mention having a close call with one nut on the back tire going loose, but luckily I noticed before taking off or something serious could've happened. So as a result, I have been strictly riding it around town under highway speeds preventing any further damage. Should I just be getting in the habit of doing pre ride checks and just make sure everything is secured? then no need to worry? Because I really want to take it out for longer distance rides, I probably haven't rode it on the highway for more than 20 minutes at a time in fear of something serious happening.

Thanks
Tegan

 

[devo]

Is the vibration rev related or speed related
If it is rev related,then it is an imbalance in the motor,however if it is speed related it will be one or both of the wheels and should be an easy fix.
Its not a HD,so if it is ratteling parts of the bike, then their is something seriously amiss.

 

[Rocky]

I agree with what devo said, it shouldn't be that bad. You should be able to cruise for hours and not have things fracture or fall off.

 

[Village Idiot]

A quick check of the engine mounting bolts and the head stays will eliminate the possibility of that being the problem. The old ones did vibrate rather "nicely", as you know. Whenever my new T100 seems to be vibrating a bit too much, I just take the '70 Tiger for a ride...............................and then the T100 seems so much smoother!!

Words of wisdom from the "village idiot": Jim

 

[The Seeker]

The engine seems like it's running well? I mean....no missing, popping, rough running? Does it accelerate smoothly?

If everything seems OK in that department, then it has to be the engine mounts (front, rear, and stays at top of cylinder heads), or something suspension or wheel balance related.

However...a badly vibrating rear fender sounds like it's engine vibration. They DO indeed vibrate and cracked license plates, etc are a classic spot for it to show itself.....but not to such a degree as you seem to have.

-- Posted with TapaTalk

 

[gumpt1oo]

As you say, all Bonnies vibrate, It is the nature of the beast!
It sounds to me like engine vibration. My T140 vibrates worse than normal when the carbs go out of sync.
I would start by checking that both carbs open in sync with one another, and check all tappets are correct, and that the timing is spot on.
I regularly use my T140 for 150 mile day rides and last year I did 320 miles in a day and nothing fell off!
You never know 1/2 a day in the shed and you could be feeling 'good vibrations'!

 

[teganbarr]

Is the vibration rev related or speed related
If it is rev related,then it is an imbalance in the motor,however if it is speed related it will be one or both of the wheels and should be an easy fix.
Its not a HD,so if it is ratteling parts of the bike, then their is something seriously amiss.

I think it is rev related, but thank you for you input! I'll have to check things out again, then take it for a ride.

 

[teganbarr]

As you say, all Bonnies vibrate, It is the nature of the beast!
It sounds to me like engine vibration. My T140 vibrates worse than normal when the carbs go out of sync.
I would start by checking that both carbs open in sync with one another, and check all tappets are correct, and that the timing is spot on.
I regularly use my T140 for 150 mile day rides and last year I did 320 miles in a day and nothing fell off!
You never know 1/2 a day in the shed and you could be feeling 'good vibrations'!

Right on thank you, i'll check it out.

 

[teganbarr]

The engine seems like it's running well? I mean....no missing, popping, rough running? Does it accelerate smoothly?

If everything seems OK in that department, then it has to be the engine mounts (front, rear, and stays at top of cylinder heads), or something suspension or wheel balance related.

However...a badly vibrating rear fender sounds like it's engine vibration. They DO indeed vibrate and cracked license plates, etc are a classic spot for it to show itself.....but not to such a degree as you seem to have.

-- Posted with TapaTalk

Yeah it is running alright I thought to a certain extent. Definitely not rough, and acceleration is smooth throughout. I just wanted to be sure nothing wasn't seriously out of sync. Like I said it is common for vibration, but at highway speed it is quite a bit, my butt goes numb fast haha and with the tail section it had me wondering this most likely isn't common to have that much, even on our terrible roads.

 

[teganbarr]

A quick check of the engine mounting bolts and the head stays will eliminate the possibility of that being the problem. The old ones did vibrate rather "nicely", as you know. Whenever my new T100 seems to be vibrating a bit too much, I just take the '70 Tiger for a ride...............................and then the T100 seems so much smoother!!

Words of wisdom from the "village idiot": Jim

Yeah I think that will be my first assessment, hopefully its nothing major and that will be the ticket. Thank you for your input.

 

[CarlS]

These old Triumphs vibrate. Checking fasteners and tightening them is routine maintenance.

 

[Village Idiot]

Yeah, Carl: Too bad we can't do the same for our aging joints!! Oops..........................................we'd want to loosen them, wouldn't we..............................

 

[CarlS]

Indeed we would!

 

[Rocky]

Locknuts and blue Loctite keep mine together.

 

[CarlS]

I used Locktite, too; but I still check them - probably the long years of habit.