bike wants to buck me off at speed

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kevinha924
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bike wants to buck me off at speed

Post by kevinha924 »

So im new to the dirt bike world and have found something odd with my rear shock when i go over small bumps at speed the rear wheel wants to pop up and buck me off and have been along for the ride on some long nose wheelies which im not really interested in. So im looking to make some adjustments just not really sure where to start? any info is appreciated....thanks..
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Re: bike wants to buck me off at speed

Post by KDXGarage »

I am suspicious the shock is low on oil and / or nitrogen. Can you make it bouncy when riding slowly by weighting the pegs?

I once worked on a 1984 KX125 that had no oil or nitrogen. I could get it to bounce the rear wheel off the ground just by weighting and unweighting the pegs forcefully. I could hear the engine rev up while the wheel would spin free in the air momentarily. REALLY odd.
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Jaguar
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Re: bike wants to buck me off at speed

Post by Jaguar »

the oil going thru the valve is what gives the shock damping and so there's no doubt that the shock is low on oil
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Re: bike wants to buck me off at speed

Post by bob_jones »

It could likely be low on oil, low on nitrogen, and have a failed seal head all at the same time. I just had the same issue with mine. I had to have a rebuild plus I had to have the shaft re-chromed as it was pitted and would have destroyed the new parts if rebuilt without being rechromed.
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doakley
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Re: bike wants to buck me off at speed

Post by doakley »

I'd go for the easy stuff first, unless you are seeing evidence of leaking oil from the shock. Set the sag to suit your weight and make sure all the linkage bearings move freely. Most likely it is a shock in need of service though, I agree.
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Re: bike wants to buck me off at speed

Post by Pinned »

Could also simply be a case of not throttling through the whoops and keeping the front light. Pretty common novice behavior, produces the same result.

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Re: bike wants to buck me off at speed

Post by Jaguar »

No, what he described is not due to rider error.
For all the work and expense of rebuilding the shock (and still just having a middle of the road shock) you might as well just buy a better quality used shock. The Ohlins shock from the GasGas EC200 is the same dimensions as the KDX shock. You might have to put a spacer on the shaft though because I think its travel is a tad more than the KDX shock. YOu can get one for around $115 on EBay. I had one on my KDX and it was a wet dream it worked so good.
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kevinha924
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Re: bike wants to buck me off at speed

Post by kevinha924 »

Thanks for all the replies i see no signs of oil or leaking im sure i need to make some adjustments to the sag, the previous owner was quite a bit heavier than me and if i can't get it dialed in ill definitely look into the gas gas shock..
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Re: bike wants to buck me off at speed

Post by IDRIDR »

kevinha924 wrote:Thanks for all the replies i see no signs of oil or leaking im sure i need to make some adjustments to the sag, the previous owner was quite a bit heavier than me and if i can't get it dialed in ill definitely look into the gas gas shock..
Is it possible the prior owner installed a heavier shock spring?
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