New PR4 GT rear, now wiggly feeling

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kleake

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Ran PR3's previously, installed a new PR4 a few months ago, had the forks rebuilt due to a leak. No issues through all of that, but I put on a new PR4 GT and now the rear feels loose and wiggly. I got my first ever real wiggle like you see on those super high speed races when a bike comes out of a corner hard. I was going about 50 on an entrance ramp with a slight right hander. Not pushing the tires at all, but it caught my attention. It feels like I'm running over tar snakes when I turn out of parking lots, but there isn't any tar snakes. It seems to do it worse turning right, but it does it both ways. At about 45-50mph, in 3rd, back off and get back on the throttle abruptly and it feels like the rear is pushing to the right, the back off and it settles back in. It does the consistently, but just started with the new PR4GT tire. I double checked my axle nut and other components and didn't find anything. I never felt this before and I've been through 3 sets of tires on it. It's squirmy enough that it really has me concerned, and it doesn't feel like it's just a new tire breaking in. Any ideas?

 
Sometimes a tire is out of spec and not caught by inspection. If you have handling issues that were not there previously, and the only change is the tire, the tire is the most likely culprit. A front end wobble and loose feeling rear tire is not the handling you want.

Most riders like this tire, but I seem to recall at least one other that had a defect and resulted in vibration and handling like you describe. What pressure is the tire at?

 
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I'm running it at 42, and it definitely feels like it's coming from the rear and not the front. The previous tire issue you may be remembering may be mine as well. I seem to have issues with new tires. So far I've had a bad front PR3 and a PR4, both after replacement they were spot on again. Now I may have a bad rear, but the feel doesn't seem like it's a tire. It feels more like when I abruptly gas it, that the swingarm is moving or something. In a curve it just feels slippery, even if I am barely leaning. It can even be parking lot speeds it feels weird, but it's not consistent. Braking feels fine, and strait riding is fine unless I blip the throttle. The tire balanced with 2oz of weight and there isn't any bounce or vibration at all, just really squirmy feeling.

 
More than 1 bad tire from Michelin? I would consider the source, (dealer) where you purchase your tires from? I'm guessing the 4's are so new in production they wouldn't be "old stock"? If it's just your bad luck I wouldn't consider flying anywhere for the next little while!

 
At the angles that I tested, yes, it is worn in, but probably not all the way. The edges I'm still working on, and the first day it was solid, but now I'm going easy on it. Just put it on last weekend and I'm up to about 250 miles on it so far. I could understand it feeling a little squirmy as I get out to the edges, but the squirmy coming out of a parking lot with only a slight lean and very light throttle, as well as the abrupt throttle issue doesn't seem like it would be the mold oil. hmmmmmm,,,,,, what if a bead was slipping? How likely would that be?

jmgrif: Yea, the two bad front tires were from Cycle Gear, and I had bad experiences with them both times. I only used them trying to save myself the time of doing it. The rear I am dealing with now came from Rocky Mountain ATV and I installed it myself. I've done plenty before so unless I goofed somewhere, I feel pretty confident about the installation.

 
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With 250 miles it is broken in. I would start looking at other things rather than the tire. Missing washer, Loose bolts something out of order. I would put it on the center stand and check for wobble for one. If your careful you can do this while running also. You might want someone else around at the time just in case. If it was the tire I would think you would feel it getting gradually worse as the speed picks up.

Just sayin,

Dave

 
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I have a set of PR4 GTs on my ST1300 and I HATE them. HATE!!! is not really strong enough to describe my feelings toward these tires.

The rear PR4 GT always feels "wiggly" and it follows road irregularities worse than any tire I ran back in the '80s. It is worn out at 8400 miles. As they wore they created a rhythmic vibration/harmonic that is worse than irritating. I will say that even though it feels wiggly it does actually stick.

I put this issue down to the narrow rear rim on my ST and the very round tire profile that results. I just ordered a new PR3 to replace it since I will have to ride the ST until my new FJR arrives.

 
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Though you said you checked the axle and other components, I going to ask about the axle pinch bolt anyway. It screws into the end of the right hand swing arm.

 
Dave: I'm with ya, and that is why I'm posting. The first couple of days it seemed ok, but then I noticed a slight wiggle, then yesterday if gave me the bigger wiggle in the curve. I would say I might have been leaned over half way and only about 50-60% throttle when it did it. It wasn't enough that I backed off, but it was enough that I didn't add any more, then went to testing and feeling on the way home. At one point I even pulled over to look at it and make sure something wasn't working it's way loose. When I got home, I put it on the center stand and checked all bolts and tried to wiggle the swing arm and forks and everything seemed solid. I don't feel it over bumps or dips, but throttle or while turning I do.

Redfish Hunter: This really concerns me to hear that, because I absolutely loved my PR3's. I felt I could push them to "my" limits and I always felt like they were solid. I never even felt them slip or drift at all, so to feel the PR4 squirm like this when I'm not even pushing it, really has me concerned. And yes, I noticed it follows the road irregularities more as well. The PR4 on the front seems to be ok while I was running the PR3 on the rear, but I am seeing some funny wear on it with less than 2k miles.

 
Old Guy: Yep, checked the pinch bolt and the 4 bolts that hold the rear assembly to the swing arm since I also lubed the splines while I had the wheel off. Those 4 were my first thoughts when I felt the first wiggle.

 
Since you did all that then the tire must be the culprit. I would be ordering a set of PR2's ASAP. I hope they never stop selling the PR2 tire. It has always been a great tire for me.

Toss that PR4,

Dave

 
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Pretty much everthing I would ask or point out has already been asked except what is the road condition? Wet or dry?Never felt the love for PR3's, especially on wet roads.

 
I am going to triple check my work and put it on the lift to make sure there isn't something else, but if it's still feeling squirmy around the 500 mile mark, I will be taking it off. I liked the PR2's and the PR3's, both felt really good, but I did have a bad (out of round) front PR3.

Gregory: Roads were dry in all rides. Rain won't stop me from riding, but if I know it's going to rain then I drive due to the idiots I commute around. Someone sneeze on the road and there will be 3 wrecks on my way to work. I can't say that the 2 or 3 felt much different to each other wet or dry, but as mentioned, they both rarely see the wet.

 
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My PR4's played the same game on me, checked the pressures from the shop that mounted them for me and found they were super low...

Bumped up the pressure proper like, fine for over another 1k miles....

PR2's for many years and many miles, PR4s are just as good IMO... I'd say you got some bum tires

 
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I've got 10,000 miles on PR3s on my one FJR and have thoroughly enjoyed these tires, except the added whine from the front caused by the extra siping. I have a new set of PR4s on my other and did notice the squirmy tendency but I've only got about 600 miles on them. It seemed worse when they were brand new and has settled down since. Good heads up to keep an eye on them. My buddy just put on PR4s too and I'll let him know to monitor their performance.

 
I've got about 4k miles on my PR4GT's and so far have not noted any issues with them. I'm running a 190/55 on the back.

I had them on new for NAFO and then left on the following Tuesday for a trip to the twisty's in Arkansas for 2,400 miles and they performed great. Very little wear so far. I'll have to keep an eye on things as they wear to see if they start to wiggle.

I wonder with some of the issues folks are having, if there were some bad lots sent out. I've heard a lot of good reports on the PR4's also.

Hmmmm.........

 
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