Rear tire wear = Front end wobble/shimmy on the Forza 300?
Posted: Sat Dec 03, 2016 5:57 pm
I'm just going to tell this story in case anyone else has had a similar thing happen. I'm wondering if this is known lore or whether I still have a second issue that I need to find.
I've been riding the Forza for 18 months now, but only have about 4650 miles (7500 km) on the odo. Despite my Iron Butt days, I'm clearly just a commuter now, which is exactly why I downsized to the NSS300. Back in September, when I had ~3700-3800 miles on it, I started to notice a front-end wobble (or shimmy) at around 25 mph (40 kph). Since the road on which I live is marked at 25 mph, and since my 5 mile (8 km) commute to work involves streets flagged for 25 (40), 30 (50), 35 (55) and 40 (65) mph (kph) and lots of turns/corners, I have often found myself this semester having to apply a bit of pressure to the handlebars in order to fight the wobble when making a turn, since they normally happen at around 25mph/40kph. As the semester has gone on, the wobble started happening down as low as 15 mph / 25 kph.
Also during the semester, I noticed that the center of my rear tire (stock Dunlop) was going bald. So I knew that I was going to have to swap it out. I read the experiences with various tires of people here on the forum, and settled on trying the Michelin City Grip in a 150/70-13 size, but had to find the right time to get the thing changed. (Finding time to do things / get things done is not easy on a teacher's schedule here in The States.)
The front end wobble on the Wing was a design problem that was ameliorated (but never entirely eradicated) by replacing the upper & lower steering stem ball bearings with tapered bearings. But the wobble on the Forza was getting worse as time went on. In my head, I was running through a whole list of things I was going to have to try over Christmas break to get rid of it.
But then, just a couple of days ago, I had my thoroughly worn-out rear tire changed (stock Dunlop at 4613 miles / 7427 km). And now the wobble is gone. The handlebars stay straight & steady at all speeds from 0-75 (0-120), even when I lock the throttle and take my hands off of them.
So, there it is.
Has anyone else had this experience? Does your front end develop a wobble as your rear tire wears out? Is this a weird design artifact native to the Forza that I can use to tell me when a rear tire is dying? Is it something particular to the way a rear Dunlop for this bike dies? Or should I be looking for some other factor on my particular bike that ought to be corrected?
Curious,
Michael
I've been riding the Forza for 18 months now, but only have about 4650 miles (7500 km) on the odo. Despite my Iron Butt days, I'm clearly just a commuter now, which is exactly why I downsized to the NSS300. Back in September, when I had ~3700-3800 miles on it, I started to notice a front-end wobble (or shimmy) at around 25 mph (40 kph). Since the road on which I live is marked at 25 mph, and since my 5 mile (8 km) commute to work involves streets flagged for 25 (40), 30 (50), 35 (55) and 40 (65) mph (kph) and lots of turns/corners, I have often found myself this semester having to apply a bit of pressure to the handlebars in order to fight the wobble when making a turn, since they normally happen at around 25mph/40kph. As the semester has gone on, the wobble started happening down as low as 15 mph / 25 kph.
Also during the semester, I noticed that the center of my rear tire (stock Dunlop) was going bald. So I knew that I was going to have to swap it out. I read the experiences with various tires of people here on the forum, and settled on trying the Michelin City Grip in a 150/70-13 size, but had to find the right time to get the thing changed. (Finding time to do things / get things done is not easy on a teacher's schedule here in The States.)
The front end wobble on the Wing was a design problem that was ameliorated (but never entirely eradicated) by replacing the upper & lower steering stem ball bearings with tapered bearings. But the wobble on the Forza was getting worse as time went on. In my head, I was running through a whole list of things I was going to have to try over Christmas break to get rid of it.
But then, just a couple of days ago, I had my thoroughly worn-out rear tire changed (stock Dunlop at 4613 miles / 7427 km). And now the wobble is gone. The handlebars stay straight & steady at all speeds from 0-75 (0-120), even when I lock the throttle and take my hands off of them.
So, there it is.
Has anyone else had this experience? Does your front end develop a wobble as your rear tire wears out? Is this a weird design artifact native to the Forza that I can use to tell me when a rear tire is dying? Is it something particular to the way a rear Dunlop for this bike dies? Or should I be looking for some other factor on my particular bike that ought to be corrected?
Curious,
Michael