DaNuGuy

Ever since I put these Cooper tires on (Discoverer St 285/75), I've had a hop between 40 and 45 mph. It's not a shimmey and the steering wheel doesn't shake, it's more of a hop that you feel in the whole truck. I bought a 5th tire, same as others, and mounted it on the spare rim and swapped it out with the others, one at a time hoping to find the bad tire. Well, it doesn't seem to be one bad tire. The hop changes but doesn't go away completely.

Anyone have any similar experiences? Solutions? I've heard that it is a "Cooper" thing.

Thanks.

j-fox

I've got the same tire/size and they are fine. Have then checked.
Or, jack the truck up and spin the tires. Using jack stands of course.

tenbrooks

sounds like they are out of round, were they discounted? A friend of mine put some discoveries on his custom van and they bounced. I told him to go with michelins & he wouldn't have that problem.

Barry Smith

The tires are not on the rim right. There is a dot on the tire that lines up with the valve stem most of the time that works. On my Revos they had to break them own and turn them on the wheel 3 times ending up 3/4 of the way around from the dot. When they mount them and put them on the balancer watch the up and down of the tire if there is movement have them break them down and spin the tire on the rim.

Shovelhead

I've been running Coopers since last December.
I went with the SRM II series.

Had them spin balanced.
No Hop.

ARAcummins

I always run coopers and have never had a problem
Heath

DaNuGuy

I did not see a dot when I mounted them. Then again, I wasn't really looking either. They were first line tires, not discounted. I have them all replaced under warranty. I had Goodyear AT/S on before and they rode very well. I like the ST for its agressive yet quiet ride. I just need to get rid of this darn hop.

Thanks all.

Rain Man

Cooper doesn't have the market on tire hop. I went to Goodyear tires and they have a tire hop issue. The dealer went thru 15 different tires to get 6 good ones. There is still one that has the hop at 40mph. It will be the last Goodyear that I will run. Back to Michlen.

Barry Smith

You've got to watch the guys mounting the tires. After I heard one say "that'll be alright on the back" I said whoa! And watched every tire. You can see the bounce in the tire in the machine. If it does, break it own spin it 1/4 of a turn air it back up. No tire has the market on bouncing. I've had 2 sets of Coopers, 2 sets on Michelin's, and these Bridgestone Revo's and they all had a little bounce.

P.S. I didn't figure the break down and spin thing until the Revo's if I had I coul have saved alot of numb buttoms!

ade's ram

Mine were fitted just before i brought my truck , i've done about 10,000 miles on them, everything seems to be oK, except one of the rear tires had a duff valve, and i had it changed, when the guy got the tyre off, the wheel had a large build up of rust on the inside and i mean a large build up, he had to chip it off with a small pick hammer, it took him about 1/2 hour to remove the worst, perhaps thats your problem

DaNuGuy

I think I've narrowed it down to the right front tire. Of course it was the last one I needed to switch out. I called my Cooper rep and he said he'll write up the credit.

Thanks for all the input.

Rhino

I have had the Cooper tire hop on more than one set of Coopers. I won't be buying another set.

CoastalDav

I don't have Coopers, I have Michelins. I had the hop in the rear at 40mph when I first put them on. I've sence found out that the rear shocks were bad believe it or not, on the rear, with all them springs back there.

Just thought I'd throw that in.


Dave

DaNuGuy

Yes, this is more what I was looking for. Examples of other things that might be causing the hop. I have 83k the truck and original shocks(I think). It just seemed a conincidence that the hop started when I put the Coopers on. We'll see what hoppens(pun intended ) with the replacement of the rf tire.

Happy Thanksgiving All. Remember to give thanks to the Lord Jesus Christ for the bountiful year. Without Him, nothing is possible.

DaNuGuy

Well, I dismounted that rf tire this am and what did I find? A completely separated cord running laterally across the tread. It was not visable from the outside but plain as day from the inside.

Thanks for all the replies.