Triumphrat

Gootch · 07-11-2008

My Thruxton is driving me crazy. It feels like it hops with every rotation of the tires -- just hopping/bouncing down the road. It started about a year ago when I had new tires (Metzeler Lasertecs) put on by the local Triumph dealer as they were going out of business. Shortly after, I found a broken rear spoke and a slightly bent one so I ordered the spokes and had my local Honda dealer put them in and true the wheel. The hopping feeling didn't go away. I took my front tire off and into the Honda dealer and had the balance checked -- it was fine. I had been thinking about getting some after market suspension so I bought Racetech shocks and forks and had the nearest Triumph dealer put them on. They talked about how great the bike felt, but the stupid hop was still there. Just today, I had some new Avon Roadrider tires put on by the local Yamaha shop (they semi-supported our unoffical Rat group when we had no dealer). Now the blinking hop is worse than ever -- so bad I can't stand it enough to ride the bike. I don't notice the hop when the bike is leaned over but just riding along at 25-30 or more and there it is. I did check and have others ride the bike and feel it. I'll talk with Yami shop about it but who knows if they can do anything.

I'm pretty much out of ideas (and money). What's left for me to try (other than riding my CBR, which I'll be doing on tomorrow's Triumph ride)?
Thanks,
Tod

SPARKSS · 07-12-2008

Quote:

Originally Posted by Gootch

My Thruxton is driving me crazy. It feels like it hops with every rotation of the tires -- just hopping/bouncing down the road. It started about a year ago when I had new tires (Metzeler Lasertecs) put on by the local Triumph dealer as they were going out of business. Shortly after, I found a broken rear spoke and a slightly bent one so I ordered the spokes and had my local Honda dealer put them in and true the wheel. The hopping feeling didn't go away. I took my front tire off and into the Honda dealer and had the balance checked -- it was fine. I had been thinking about getting some after market suspension so I bought Racetech shocks and forks and had the nearest Triumph dealer put them on. They talked about how great the bike felt, but the stupid hop was still there. Just today, I had some new Avon Roadrider tires put on by the local Yamaha shop (they semi-supported our unoffical Rat group when we had no dealer). Now the blinking hop is worse than ever -- so bad I can't stand it enough to ride the bike. I don't notice the hop when the bike is leaned over but just riding along at 25-30 or more and there it is. I did check and have others ride the bike and feel it. I'll talk with Yami shop about it but who knows if they can do anything.

I'm pretty much out of ideas (and money). What's left for me to try (other than riding my CBR, which I'll be doing on tomorrow's Triumph ride)?
Thanks,
Tod

Hi there Tod. I'll assume that you had both tire/wheels balanced correctly. With all the tires that you've had, the chances of a repeat problem associated wouldn't be very likely so it comes back to what's a common denominator to this problem. Have you picked up each end of the bike and, using a stationary reference point close to each wheel, checked for runout....both radially (from the axle outward towards the tire) and axialy (side to side)? This is where I'd be with your problem......and while you're at it, notice whether there's any scrub & release as each wheel is rotated (brake problem) and whether each wheel is perpendicular to it's axle......this latter check may require removing each wheel, running a true roundbar through the axle cavity extending an equal distance and measuring to the rim at opposite points (should be equal triangles).

Are you using any sort of dynamic balancing scheme on the bike which might be a common area for the problem.......like distributed balls or ????? (there's some different sold schemes out there!).

After the first tires were installed and the problem occurred, I'd suspect (with a fair hop) that the tire bead wasn't seated which will hop like a son-of-a-gun......but with your history, I'd wonder that something may have been damaged at the time those first tires were put on.

.02 worth

Gootch · 07-12-2008

Thanks for the ideas. No dynamic balancing scheme. Have looked at runout (old style, hold screw driver up rim and tire and spin tire to watch result -- had a bike mechanic friend do this too). I'm starting to think something might have been damaged by the first mechanic. I've replaced the rear brake pads since this started -- no brake rub. I'll keep trying things because although I'm discouraged now, I really like riding this bike and want to get back to enjoying it.

Quote:

Originally Posted by SPARKSS

Hi there Tod. I'll assume that you had both tire/wheels balanced correctly. With all the tires that you've had, the chances of a repeat problem associated wouldn't be very likely so it comes back to what's a common denominator to this problem. Have you picked up each end of the bike and, using a stationary reference point close to each wheel, checked for runout....both radially (from the axle outward towards the tire) and axialy (side to side)? This is where I'd be with your problem......and while you're at it, notice whether there's any scrub & release as each wheel is rotated (brake problem) and whether each wheel is perpendicular to it's axle......this latter check may require removing each wheel, running a true roundbar through the axle cavity extending an equal distance and measuring to the rim at opposite points (should be equal triangles).

Are you using any sort of dynamic balancing scheme on the bike which might be a common area for the problem.......like distributed balls or ????? (there's some different sold schemes out there!).

After the first tires were installed and the problem occurred, I'd suspect (with a fair hop) that the tire bead wasn't seated which will hop like a son-of-a-gun......but with your history, I'd wonder that something may have been damaged at the time those first tires were put on.

.02 worth

BriGuy375 · 10-06-2008

Did you ever find a resolution to your hopping problem? I am encountering something similar since changing my tires. My dealership put 3 sets of Bridgestones on before finally upgrading to sport demons at no charge to try to fix it. Never did it on original Metzlers, this all started after the inspected it and put the new tires on. It actually spent almost a month at the dealer while i was out of the country with them trying to fix it. They ended up giving it back to me with a letter basically stating that they tried everything, and they feel that my machine is average. Its not, ive put over 200 miles on these sport demons and its still bouncing.

CAPTDON · 10-06-2008

I had a new Battalax put on the RR. It hopped @ 50 mph as you said. Had all checked & all was OK? Got pissed & took it to the ton & back w/ hard braking to "vent " a # of times- basically just beat the hell out of it! Lo & behold- it is fine now? Why- who the hell knows but its as smooth as a babys ass now! Maybe something needed to seat in or just maybe she's into S&M? Who cares - she's fine now. Did the ft tire & no problems. Maybe I scared her into submission? Good luck!! Maybe she just needs a good whippin??

daleCarlsbad · 10-06-2008

I have heard of & experienced tires being out of round (cheap Cheng Shin OEM) and changing to a different brand solved the problem......which you have tryed.

Would it be possible to swap the front wheel & tire with another bike?
you might gleen some more insight .

billstokes · 10-07-2008

Well, the previous posts have explored all the common causes. How about checking the axles to see if either one is bent?

jimmy bush · 10-07-2008

Check your chain for a tight spot.

McBike · 10-07-2008

Your original post mentioned that you had a broken and bent spoke.
As Bill stated, I would check the axle. Looks like you might have hit something. Pull the axle, clean it up and roll it on a known flat surface.

Mike

FireyPete · 10-13-2008

Hi there, wondering if you sorted out that bouncing problem?
Pete