strange vibration in left leg...gt380

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Ramjam
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strange vibration in left leg...gt380

Post by Ramjam »

dear team
i'm a bit concerned about something. Mainly on deceleration, i feel this weird 'vibration' or grinding from the left footrest. is it the chain? . Before i did the rebuild, it wasn't there so it's something that i have done. please help if you can.
best
MJ
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Alan H
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Re: strange vibration in left leg...gt380

Post by Alan H »

Chain too tight?
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Ramjam
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Re: strange vibration in left leg...gt380

Post by Ramjam »

i noticed, in fact, the faint vibration also on acceleration. it might be yes, but i always do my chains to about 1 inch of movement. Is that too tight then for this bike?
thanks
MJ
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Alan H
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Re: strange vibration in left leg...gt380

Post by Alan H »

An inch each way is too much, an inch up and down is about as much slack as you need.
The true test is to try and pull the chain away from the sprocket - if you can, it's knackered.
Check both sprockets condition as well - no hooking, teeth should look the same on both sides of each tooth.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Ramjam
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Re: strange vibration in left leg...gt380

Post by Ramjam »

what about oiling it? i heard two accounts: one says 80/90 gearbox oil and another says wd40.
which is it? As for sure i know that regular 20/50 just flies off and hits all of the rear section and is a mess/
MJ
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Alan H
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Re: strange vibration in left leg...gt380

Post by Alan H »

Any 'normal' oil will fling. You need specific chain lube.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
pearljam724
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Re: strange vibration in left leg...gt380

Post by pearljam724 »

+1. How old is your chain ? If there is hidden rust or heavy grime in and round the pins. The chain will have binds or kinks in 1 or more location that you may not be aware of by looking at it installed. This causes bad drive train noise and excessive chain and sprocket wear. You can test that by removing it and seeing if it bends easily through out the length of the chain. Being clean, lubricated and properly adjusted is critical to a chain. It's proper maintenance to perform that. At least every 600 miles or every couple months depending how much you ride. Especially, non o-ring. If the chain is old. Clean it very well with a lubricant and soak it in a bucket of oil for a few days. Moving it around time to time. Lubing a chain with oil works. But, it's ancient messy technology. Buy yourself a can of Dupont Teflon. It doesn't sling the slightest, penetrates pins and plates. Then dries to a lube within minutes. Unlike, other lubes that are pasty the moment you apply it and don't penetrate.
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Ramjam
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Re: strange vibration in left leg...gt380

Post by Ramjam »

Brilliant advice! thanks a lot !!

MJ
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tz375
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Re: strange vibration in left leg...gt380

Post by tz375 »

On non-O ring chains we used to clean them and then boil up a can of chain lube which was like wax with moly in it. Then it had to be removed from the stove top (tricky) and the chain hung up to cool. It was the only way to get the lube in to the pins and rollers.

WD40 is used by some O ring chain users to wash off dirt. It doesn't lube the chain.

Too much slack allows the chain to rub slightly on acceleration and when decelerating the slack is all in the top run so it rubs on the frame and other places.
pearljam724
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Re: strange vibration in left leg...gt380

Post by pearljam724 »

Another thing to consider in replacing a chain. I have bought brand new cheaper o ring and non o ring chains. That no matter how much you clean, lube and maintain them they will begin to rust very quickly. That's due to a poor galvanization that is on those chains. Or no plating at all. The more expensive chains are either anodized or galvanized well enough that they won't rust very easily. The anodized gold plated chains always hold up for very long periods without rust setting in. I once had a stock one on a sportbike last over 20 k miles and it looked the same the day I bought the bike new once I finally decided to replace it. But, I also cleaned and lubed the heck or it. The cheaper chains are guaranteed to rust, the day after a ride in rain. If you don't immediately clean and lube them.
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Suzukidave
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Re: strange vibration in left leg...gt380

Post by Suzukidave »

A vibration through the pegs can also be traced to in correctly mounted pipes . The rear mounts are often bolted up solid to the frame when really the pipes are suppose to float on the rubber mounts inside the rear hangers . Its a easy test .. look at the rear mounts and if they are tight agnist the frame they are mounted wrong but easy to fix . Slip some washers on the through bolt to space the pipe hangers off the frame but also small enough round so they also dont touch the frame .
the older i get the faster i was
Ramjam
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Re: strange vibration in left leg...gt380

Post by Ramjam »

thanks Suzukidave!
great advice about the pipes needing rubber washers !
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Suzukidave
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Re: strange vibration in left leg...gt380

Post by Suzukidave »

Its not that they require rubber washers but just plain metal washers , there should be rubber mounts already inside the rear frame mounts . You just have to add metal washers to the bolt that goes through the mount to space the pipe hangers away from the frame .. but .. the washers also have to be small enough round so they also dont touch the frame . I am sure a short spacer would also work well and would only need to be maybe 4mm long .
the older i get the faster i was
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ConnerVT
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Re: strange vibration in left leg...gt380

Post by ConnerVT »

Yes, and once you get it sorted out, both of your legs will vibrate equally. :lol:
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Suzukidave
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Re: strange vibration in left leg...gt380

Post by Suzukidave »

A bit tougher to get the vibs out of the 500's huh :roll: but it can be done modding the cases for GT750 rubber mounts :up:
the older i get the faster i was
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