unstable at high speeds

[alonzo]

Originally Posted by dieselhead

one more quick note, the rear axle adjustment slots are way off on my 07 gy5. When I first set the wheel up out of the crate, I figured I would just match the open slot hole behind the axle to both sides. Then I eye balled the tires in line and ended up with nearly 1/4" difference in the slot holes after readjustment! Calibration is non existent on these adjusters.

yep, I think a better gauge is to look at the filth and grease on your sproket, if it has a nice even clean spot where the chain pulls from you are straight, if it has a slant to the scum line, you need to adjust.

[katoranger]

I use a tape measure to measure from the swingarm bolt the to rear axle.

Do it on both sides.

Allen

[GY_Racing]

I had brought mine on the highway real quick and it was the same thing. At about 65ish it would start to be unstable. I was afraid to take it on the highway again. It felt like the crosswinds were pushing the bike around but I never get that on regular motorcycles so im confused at what it is. It could be the tires, weight of the bike, height of the bike, who knows? But its defiantly there for me too and I haven't taken it near a highway since. It almost feels like the frame is flexing?

Id love to find out how many people take their bikes on the highway, the real highway on a regular basis and if they have the same problem at high speed. It does feel like a crosswind but it was not windy that day. I think a big truck could knock the bike over if it flew by just right 8O

i get pushed around by the wind but honestly just figured it was the fact that I am a big non aerodynamically designed dude riding a relatively light bike. My advice would be, if you don't feel safe on the highway or expressway or whatever, take the hog trails wherever you need to go.

Learned that expression while I was living in Atlanta, Ga. My co-worker and good friend (now gone but not forgotten) used to say that (hog trails) when we took the back roads instead of getting out on 285. Stuck with me.

[John_Allen]

Originally Posted by alonzo

opps, after checking the tire pressure it was really low, "15 psi" after putting it back to 32 psi it actually behaves like a motorcycle. DUH! no more comments needed this bike handles like a 279 pound bike should.

Thanks to everyone.

I read this and noticed the same thing so I went to the garage and checked my tire pressure. I was shocked, it barely even showed up. I went from about to 12 psi to exactly 32 in both tires. I was planning on taking the truck to work tomorrow, but want to ride to see how it feels. Ill report back tomorrow night.

[katoranger]

You can't look at the tires and tell that they are low. You need to check them.

Allen

[maf119l]

Originally Posted by katoranger

You can't look at the tires and tell that they are low. You need to check them.

Allen

one trucking company i worked for made everyone buy a tire gauge from them when you started.(They would buy it back if you quit)then they told you when it comes to checking tires,"don't bump 'em,pump 'em".Even with truck tires requiring 105 lbs just a couple of pounds short would cause problems

[ambassador]

I was thinking about getting some clam shell type axle adjusters like the ones on my old XR and just slobbering some pins in place, what do you guys think??

[driller]

The clamshells aren't a bad idea, I thought about it myself

I ran a string line along both sides of the tires to true up the rear because of the unsteadiness at highway speed (07 GY-5) and it still does it. I have about decided it is the tires, I want the Duro's 8)

[dieselhead]

The stock rear tire is nearly the worst tread pattern you could put on the road. If a tight trials tread tire dosen't fix the squirley-ness my next move would be to slide the fork tubes up some and a slightly shorter rear shock. Dropping the high center of gravity a inch or 2 may make a noticable difference.

[katoranger]

The stock tires are not the best at higher speeds either.

You will like the duros I think. The tighter spacing and large blocks are more stable.

I just check both my tires again today and had to add some air.

Allen

[monkeyboy]

I had my tires almost maxed and felt like they wandered more than after I backed 10 or so pounds out of them. This adjustment was made on the fly on a gravelly fireroad though. The softer tires tracked much straighter in the loose stuff anyway.

[IronFist]

A tire that is out of round, or "square tire" can give a bump at certain RPM's. Sometimes it feels like a speed wobble. Faster or slower and you won't feel it.

[pimptron]

i get vibration at about 80 km up to 110 km which is my max speed.

I think it's because my tire pressure is too low or because my tires are not balanced I don't know if balancing matters that much?

my tire pressure was about 25 pounds

I moved it up to 30 to see if there's going to be a difference don't know yet.

[FastDoc]

Originally Posted by Q

One of the most common causes of an unstable feel is notched steering bearings. Easy to check by putting something under the engine to hold the front wheel off the ground, then turning the handlebars slowly back and forth to see if it turns smoothly.

Another thing to check is the swing arm bolt and bushings. Grab hold of the back of the rear wheel and try moving it from side to side while holding the main frame. It shouldn't move.

Q

Copy that. On both that I assembled the steering head bearings were overtorqued. Check yours as that could cause poor steering feel and damage the bearings. Knowing Chinese manufacturing techniques, they are probably no stronger than cheese.