Front Wheel Oscillation-Part 3: The Resolution (merged) - Motorcycle-Journal Forums

nicocorea · 04-24-2008, 09:13 PM

Hi folks. I bought my 2008 M50 about a month ago in Albuquerque NM. I have 1500 miles on the bike and for the most part, I think it's a wonderful machine. But there is a troubling issue with it...

At between 40-55 MPH, the front seems to gently hop up and down as if the wheel were slightly egg-shaped, or it had a flat spot on the tire. At higher speeds, it smooths out. I first mentioned it to the dealer when I brought it in for the 600 mile service. One of the techs took the bike for a ride and said he couldn't detect anything abnormal. So I rode another few hundred miles thinking "it's just me." But as I racked up the miles, getting more and more familiar with the bike and with riding on a wider variety of roads, there was no more fooling myself: the front end absolutely moves up and down at the same rate as the front wheel is spinning.

So I returned to the dealer and asked them to balance the front wheel. They put wheel on the balancing machine and reported that the wheel was balanced, but that the tech noticed a "flat spot" on the tire. They agreed to replace the front tire free of charge. I was happy as a clam! I wasn't imagining things after all! They replaced the original IRC with a Dunlop--but it was free, so I didn't argue. But when I rode off the dealer's lot and got up to speed, alas, the hopping was still there--in fact, it was more pronounced! So it wasn't the tire after all, I thought, it must be the wheel itself.

I decided I needed an unbiased, independent opinion. So I took a recommendation from a fellow rider at work and took the bike to a motorcycle wheel specialist that he recommended. They came back to me with the following report: they verified that the front end is indeed "hopping", the wheel is perfect, but the tire is out-of-round.

What is the chance that I get two bad tires in a row? So I took the bike back to the dealer and explained that the tire replacement made the problem a bit worse, that I had another shop take a look at it and they verified the hopping, and that the other shop's conclusion was that the new tire was bad.

The manager himself took the bike for a ride and--surprise--said there's nothing at all wrong with the bike. I argued with him for a while, but to no avail. Finally I told him I wanted to buy a new tire. He had none in stock, but I ordered a Metzeler ME880 because I've heard good things about them. It should be here early next week.

If the new tire doesn't solve this problem, I'll have no idea what to do next!

Anyone out there have any ideas?