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Discussion Starter #1
Hi all,

I am puting together a '70 Triumph T120R chopper with stock frame with 4" over hardtail. Before I finalize things, I would like to get some ideas on how to reduce engine vibration. A friend of mine has a '69 Triumph and the cafe racer handlebars & forward controls vibrate like crazy from mid to upper RPM. It feels like the bike will self destruct...

I will be using forward controls and 12" ape hanger handlebars.

Has anyone done anything that made a difference?

Here is a list of things that I know already:

- Use all the top engine steadies.
- Use handlebar weights and/or the snake. (Which is better?)
- Use spacers for the bottom engine mount to take away any gaps between frame & engine.
- Use good rubber handlebar grips.

Thanks.
 

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If you're using the stock triple trees, make sure that the rubber mounts for the handlebar clamps are in good condition. Also, if you're rebuilding the engine, have it professionally balanced by someone who knows what they're doing. But....it's a vertical twin, and they do vibrate.

Hope this helps a bit: Jim
 

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I'll second Jim's advice. I've heard that having the engine balanced goes a long way toward reducing vibration...and I've witnessed it on a 650 BSA, there was a noteable reduction in vibration. Good luck.
-heavy
 

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Want a vibration free Bonneville? Buy a new one.
The old ones vibrate, it's part of the heart and soul of a classic Triumph. When the front wheel really gets to rockin', ain't it cool?
Mad`
 

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I agree with Mad. We have thinner aluminum license plates in Missouri and I have had a couple fracture at the corners where they are bolted on from the vibration. When you have both cylinders moving up and down at the same time there is not much to counter the mass. With a hard tail too, it sounds like you'll not only have some numb hands but also be pissin' blood from the nice kidney road massage.
 

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I should say..............

How dare you all........you's ourta be ashamed of yerselves!!!!

Triumph twins don't vibrate, they pulsate with life!!!

It is their heartbeat!!!

Seriously, if you get the motor balanced, the vibration can be altered to suit your riding style. A good machinist can move the vibration up or down the rev range.
So that at say 4000 rpm the bike smooths right out and the vibrations don't come back till say 6000 rpm.

But you'll never get rid of it completely unless you stall or run out of gas!!

[ This message was edited by: tridentt150v on 2005-12-16 17:40 ]
 

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There's vibration & vibration. Firstly there's the vibration we all know & love on our bikes. Then, back in the days of yore, there was the vibration on Little Tony's '78 T140!! I was pillion &, I kid you not, had to get him to pull over after less than two miles, because I could no longer hold onto the grabrail, or indeed anything else, both hands having gone completely dead. Now that's vibration. Aided in that particular case by badly out of synch carbs I believe.
Regards
Cuppa
 
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Discussion Starter #12
Thanks guys!

I will work on moving the vibration at a different RPMs so that my hands do not go numb when cruising.

Has anyone installed a 20 or 21 tooth front sprocket with a 46 tooth rear? I am not interested in take-off speed & this is a single rider bike.
 
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