06 KTM640 Vibration!!! Any Help?

[unicycle]

g'day all...
just been riding my new girl and have found that it's pretty viby.
anyone else had this problem? it's not so bad under 60km/h but sitting at 70km and up it almost blurs my vission sometimes and it's a shit feeling on the old ass.
I've herd you can get the ktm gell insert replacement seats would that help?
Also filling the bars with silicon and bar weights?
How can i stop some of the vibration?! :? bars and seat! :x
OR is there something wrong with the bike and it shouldn't be this viby?
Any help is always appreciated cheers

[albonator316]

it getting worse at higher speed suggests it maybe the wheel, have they been balanced? does it look like one of the wheel balance weights have fallen off?

[SMC690]

Hey Uni,

They (625/640's) just vibrate a heap. Bar weights or silicone wont help as the bars are already mounted in rubber widgets to the triples to remove some of the vibes. There are also the rubber blocks on your footpegs which the SMC doesn't have but they don't help much either.
The 'comfort' seat will stop your arse from splitting on a long ride but I don't think that will help the vibrations but I stand to be corrected. I rode a 640 with a comfort seat and it was basically the same.
If it's extra mega super vibey then the counter balance might be out by a tooth or two but I doubt it very much.
Paul (Supa4) had a 640 and mentioned he had trouble reading street signs sometimes so it's the same shizzle.
I'm used to my 625, you should get used to it after a while.

Thick winter gloves help a bit with the bars but suck arse in summer.

[albonator316]

geez, didn't realise they vibed that bad

[unicycle]

it getting worse at higher speed suggests it maybe the wheel, have they been balanced? does it look like one of the wheel balance weights have fallen off?

yeah actually it does! the front wheel has two black marks that i thought might have been old weights? :? it doesn't really feel like it's outer balance but i'll take them both off and get them balanced and see what that does... cheers

[SMC690]

Nick has a good point too, one of the tyres could be seriously out of balance, especially if it's the front which would just make it worse than they already are.

[unicycle]

g'day SMC625

cheers heaps for the info i spose as you say ill just get used to it :lol:
i'll the leave the bars alone and mybe try the seat coz it's a good thing anyway... i too have trouble at some revs/speeds with street signs :lol: all part of the fun i spose. i'll just have to keep myself amused with more 3rd gear whoolie's! 8)

[albonator316]

if the front wheel is off balance then whoolie's will help a lot ;)

[Daws]

As Juz said, At first, my 640 used to vibrate so bad I couldn't read street signs - I found it lessened off after 10,000km but it was still noticeably vibey.

<---- My 640, my first Motard... Good times!

It is possible to check if the wheel is out of balance by loosening your grip on the bars at the affected speed and seeing if it wobbles - Best not try letting go completely at first in-case it sends you into a death wobble! Or take it to a tyre man, they will probably check it for free.

[SMC690]

You could also self check it by putting it up on a stand so the front wheel is off the ground (milk crate) and loosing off all the lower fork bolts and give the wheel a light spin, if it keeps returning to the same lower point every time then it's out of balance, gaffa tape 2 dollar coins to the point opposite the bottom point (180 deg) until it no longer settles in the same spot each spin. :)

[albonator316]

there must be a less technical way juz :lol: :lol2:

[SMC690]

No mate, that's the bush mechanics way and I'm not talking about gynecologists either.

[gaz]

hi unicycle Ive got 620 duke I took the bar weights out and didnt notice much difference. Ive owned a couple of lc4s over the years and found that they vibrate a lot if the exhaust is loose check the support rubbers.

[unicycle]

:o wow thanx boys you really no what your talking about!!! :shock: i took the wheel off first for safety sake then that seemed ok so i took it for a belt and took my hands off at 90k and it was fine so yeah musn't be that i'll check the exhaust now make sure it has all the right rubbers. it's done 11k now so i spose it wont get any better. cheers again for all the support! :)

[SMC690]

Mines done 15k and it's nice and loose now for an LC4 as should yours be. I don't notice the vibes anymore, I never really did to be honest but I have been riding 600cc+ tard singles for 6 years now so I guess I am pretty immune to it.

If you ride it hard enough you won't even think of the vibrations, you will be too busy scanning the road for mobile chicanes and setting up for blitzing the next corner, you are a bloke, you can't multitask anyway. ;)

[Ozmoto]

I have warned you guys about these pumpkins.....

Do something sensible & buy an Aprilia :lol: ;)

[SMC690]

And start saving immediately for your next $2k 'service'. Yeah, right! :P

[playwme]

My 640 vibes a lot as well. KTM do a super rubber mounted bar clamp kit but its about $400 so I've never tried it.

Best fix I found was buy a 690. Smooth as silk in comparison.