wierd things going on in the turns

[ArtD]

Hey Guys, Last weekend I was getting towards the tail end of a 80+ mile ride that I have taken many times. A bit about the route first: its a combination of some very twisty, up and down roads, some fairly long straights, and some very fast sweepers. Great fun Anyway, just at the end, before I was getting to the "cool down" part of things, the bike sort of drifted by itself in the middle of a fast sweeping turn. Extremely unnerving. When I got home I took a look at everything, checked all the suspension bolts, axle nuts, air pressures, nothing seemed amiss. I figured that it was some oil or something on the road, maybe a gust of wind, and basically forgot about it

 

This morning, I went out for the same ride. Same bike as always, same air pressures, same route, etc. As soon as I got to one of the semi fast turns, I felt the same thing. I then proceeded to get this "wander" about, say, one turn in five. Here is what happens: the best way that I can describe this is being hit by a gust of wind. But, there was no wind. The bike, for a split second, goes where it wants to. That might be to veer to the inside, or maybe the outside. It washes out by itself, for that lak of a better expression. Going in a straight line, it will be fine for a while, and then all of a sudden, it wants to move in a different direction. WTF is going on???? The tires have about 3,400 miles on them, and look pretty decent. I did make a rear spring change, but before you go there, it was fine, the spring was a great improvement, I have at least 500 miles on the new spring before it started doing this. Most of it on this exact route. I know this ride very well, and something totally abnormal is happening. My riding and bike knowledge are no-where near good enough to figure out what this is without changing a whole bunch of things. The bike has about 8,000 miles total, and is on its second set of tires. The weather is getting great up here and its time to ride, but not like this! Help!!!!!

[macguzzi]

blow up ypur tyres

[savagehenry]

Have you tried lifting the front end and checking the steering head bearings? Had the same thing on one of my old bikes, and the race was notched. Only started showing up in long sweepers at pretty good speeds, Unnerving

[GuzziMoto]

My wifes V11 did something like that a while back. Turned out to be the bearings in the rear wheel.

[rocker59]

Yep.

 

I'd check steering bearings, then wheel bearings, then the swing arm pivot.

 

 

What cold PSI are you running in your tires? What tires are you running?

[ArtD]

Yep.

 

I'd check steering bearings, then wheel bearings, then the swing arm pivot.

 

 

What cold PSI are you running in your tires? What tires are you running?

 

 

I've got the stock Metzler Sport tec M1's. I have played around the with air pressures, and I have been running 33-34F and 36R I checked the tires right after I got back, and they were spot on 34/36. Those air pressures may or may not be the best, but reguardless, she's always felt good to me, I can't see how that could be the problem. I got the rear wheel off the ground and did not find anything loose. But that was just a casual shake of things. Tomorrow I'm going to take a serious look at the three items you and some other folks have mentioned, and check every bolt on the bike. I have not found anything loose recently, but somthing is going on here, and it can't be that hidden...I don't think so anyway

[Admin Jaap]

Check the steeering damper, could be too tight. Take t off for testing

[stogieBill]

Art,

 

I'm with Rocker on this.

 

You need to check your tire pressures cold, ie before the ride. Having said that, I don't think its your tires. Low tire pressure with give a mushy ride and slight wandering. What you describe is more severe than slight. Wheel bearings, swing arm pivot or steering head bearings is my guess, in that order.

 

Good luck solving your mystery

[Guest ratchethack]

Aye. Wot Rocker and Bill said. Your tire pressures are spot-on (to the pound) by my experience with the M1's (great tire, btw).

 

Good luck. When you figure it out, pls. advise.

[ArtD]

Aye. Wot Rocker and Bill said. Your tire pressures are spot-on (to the pound) by my experience with the M1's (great tire, btw).

 

Good luck. When you figure it out, pls. advise.

 

Ok, I just found it Fast forwarding thru all the assorted checks suggested by you guys..... Decided to take 'er out for a short run on totally different roads to see what (if anything) might happen. And, as I generally do, I checked the tire pressures...and just for the hell of it grabbed my other digital gauge, not the one I normally use. Rear- 30 lbs Yikes. Checked the front,-24 lbs. Already realizing the obvious, I got out one of the old school Milton pen's, yep 30/24. Stuck the wazoo guage on, 36/34. Threw super trick piece of (probably) Chinese crap in trash can. Moral of this little tale, every now and then check your tire gauge against another one!!! As always, thanks for the great input, this is THE best bike crew on the Internet

[rocker59]

Yep. Always a good thing to keep a couple of pressure gauges on hand...

 

Glad it was a simple fix!

[raz]

That reminds me I was planning on putting my torque wrenches against eachother and check how much they differ...

[ArtD]

That reminds me I was planning on putting my torque wrenches against eachother and check how much they differ...

 

Quick story-I have a couple of many year old Snap-on Torque wrenches, a couple of Micrometer type's and several dials. When we moved here from Florida I knew we'd be a long way away from anyone who would calibrate them, so I took them all to the place in Ft Lauderdale that does them for the Aircraft guys. I used them a lot when I was twisting wrenches for a living, they were not "rollaway queens". When I went to pick them up I got a graph with each one showing how much they were off. They were all pretty damm close, I was surprised. Less than 3%.The guy told me that mine were made when they really were the very best you could buy. Thats because they were made by Precision Instruments. He added that, very quietly, Snap-on Torque wrenches have gone to hell over the last 5 (now 8) years. They are now all plastic bearings inside, cheap metal wherever they can get away with it, etc, made in hell knows where. he also mentioned that they are made no better than the other overpriced tool truck wrenches. Here's the punch line: he said that it was not at all uncommon for wrenches just a couple of years old to be off by 20-25%. Thats enough to ruin a Sun afternoon, thats for sure!!! Since this is what he does for a living day in and day out, I was inclined to believe him.