Motorcycle Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter #1
Hiya;

I bought new tires for my 2004 VTX 1300 C.

Metzeler tire that is the correct size for the bike: 110/90-19m

I believe my old front tire is a bit skinnier.

Rear tire is also size designed for bike and is a new Metzeler.

I doubt I have more than 100 miles on the tire. I measured pressure on front tire after 10 minutes of riding and it was 25 lbs.

What is strange is when I ride the bike at various speeds with just me on it (with Mustang seat), it rides fine.

When I tie my back pack to the rear of the seat, and it weighs about 10 lbs with stuff in it, there is a noticeable wobble of the handlebar. Not serious, but enough to make me notice it. I take the back pack off and ride again, and it feels ok again. Maybe a verrrry slight notice of something, but hardly anything.

Thoughts?
 

·
Registered
Joined
·
15 Posts
Discussion Starter #2
Hmm... found this interesting video:

But frik if this forum won't let me post it cause I'm too new. Waah.

Google motorcycle tire wobble and you will see that video right away. It infers that it was a bad tire. Hmmm.. Except that guy is getting wobble without the back pack on the seat.
 

·
Premium Member
Joined
·
5,643 Posts
Try running the tire at 35psi, instead of 25; that is really low for that size bike. My old CB450 (~475lbs), with a similarly sized tire, says 26 in front, but I won't use less than 33 with modern tires.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #4
Try running the tire at 35psi, instead of 25; that is really low for that size bike. My old CB450 (~475lbs), with a similarly sized tire, says 26 in front, but I won't use less than 33 with modern tires.
Thanks for the suggestion. I'm also taking it to the shop that installed the tires tomorrow morning.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #5
Hmmm.... just read a thread at another forum where it sounded like the concurrence was 38 to 40 lbs both tires. Radical. I'll try to boost it up to 33 and see if it stops the wobbling.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #6
Another thread with Metzeler's is almost unanimous.... 40/40. Can't wait til tomorrow to experiment.
 

·
Ace Tuner
Joined
·
2,935 Posts
Considering the tyres are new, cupping in the front tyre is not the cause.
25 PSI does sound a little low for the air pressure. More air could stop the shake.

Worn or loose steering neck bearings can do some odd things like you describe.
If you can get the front wheel of the ground check for smoothness when turning the bar from side to side.
Also check for a spot that feels like a "notch" when the bar is pointed straight forward.

Of course the tyre being out of balance could cause a wobble but you would expect it to happen with or without a load on the rear seat.
I had a defective Avon tire that did that one time but it was consistent no matter what type of load was on the bike.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #8
Considering the tyres are new, cupping in the front tyre is not the cause.
25 PSI does sound a little low for the air pressure. More air could stop the shake.

Worn or loose steering neck bearings can do some odd things like you describe.
If you can get the front wheel of the ground check for smoothness when turning the bar from side to side.
Also check for a spot that feels like a "notch" when the bar is pointed straight forward.

Of course the tire being out of balance could cause a wobble but you would expect it to happen with or without a load on the rear seat.
I had a defective Avon tire that did that one time but it was consistent no matter what type of load was on the bike.
Thanks. Good comments. Well when I had prior Dunlop tires on the bike for 6 years I never had any wobble no matter what. Even with a bag tied to the back. The mechanic at the time (now out of business) put a slightly skinnier tire on the front for some reason. So I'm doubtful that it's bearings.

I spent quite awhile trying to find the correct tire pressure years ago, and I had it jotted down on a piece of paper that I've misplaced. Oh well. I think it was lower pressure than 30 in the front. Well, these Metz tires are pretty different, so I guess I need to put the past behind me.
 

·
American Legion Rider
Joined
·
23,605 Posts
Yeah, 25 pounds is way too low for that bike. I know it makes the ride better but 38 pounds in the front and 40 in the rear is what I ran in my VTX.
 

·
Premium Member
Joined
·
5,643 Posts
There is usually a tag on the bike with the recommended pressures. On my VS800 and CB450, it is on the swingarm, but on my Valk, it is on the tag with the VIN. Of course, those values are a bit soft, even for the original tires; you're usually better off with more pressure than what is on the tag.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #11
Wobble fixed! 38/40 set. Found my piece of paper that said 36/38 F 38/40 R. LOL. I think I just got lazy after I had the tires changed and it sat a couple of months and didn't check it.
 

·
Retired twice: Navy and as a govt contractor
Joined
·
14,359 Posts
Glad it was an easy fix
 

·
Troublemaker
Joined
·
2,517 Posts
Also, running the pressure that low could be bad if there are potholes in your area, it is not enough pressure to keep the rim from contacting the earth resulting in a bent or broken rim.

Myself, I take whatever max cold pressure on the tire and drop it a couple pounds, it will be harder on the stem bearings and ride, but those are cheap compared to tire cupping.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #14
Also, running the pressure that low could be bad if there are potholes in your area, it is not enough pressure to keep the rim from contacting the earth resulting in a bent or broken rim.

Myself, I take whatever max cold pressure on the tire and drop it a couple pounds, it will be harder on the stem bearings and ride, but those are cheap compared to tire cupping.
Thanks. I've been lucky so far to avoid potholes for the life of the bike. We don't have as many in TX as up north.

My Dunlop tires seemed to stay well inflated and lasted a long time, but most are ringing the bell for Metz tires these days. So far they seem pretty good.
 

·
Ace Tuner
Joined
·
2,935 Posts
Here's something I put on the repair order every time I install a new tire:

Check tire air pressure in 3~4 days, then weekly.


Newly mounted tires will loose air faster than tires that have been in service for a while.
You might want to check the wheel air valve for cracks (at it's base) if you're loosing more than a pound or two per week.
Motorcycle tires loose air quicker than cars/trucks do. If you check em weekly, you'll get a handle on what to expect.
I've installed and used all the major brands, they all seem to loose air at about the same rate, less over time.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #16
Here's something I put on the repair order every time I install a new tire:

Check tire air pressure in 3~4 days, then weekly.


Newly mounted tires will loose air faster than tires that have been in service for a while.
You might want to check the wheel air valve for cracks (at it's base) if you're loosing more than a pound or two per week.
Motorcycle tires loose air quicker than cars/trucks do. If you check em weekly, you'll get a handle on what to expect.
I've installed and used all the major brands, they all seem to loose air at about the same rate, less over time.
Good tip. Thanks. I will certainly keep a closer eye on it now.
 

·
Premium Member
Joined
·
5,643 Posts
Motorcycle tires lose air pressure quicker than cars or trucks, because of the smaller volume; actual air volume loss rate is similar. Just being anal.:p
 

·
Ace Tuner
Joined
·
2,935 Posts
Motorcycle tires lose air pressure quicker than cars or trucks, because of the smaller volume; actual air volume loss rate is similar. Just being anal.:p
Dang it! Left a word out.
Thanks for the correction. :biggrin:
 

·
Registered
Joined
·
15 Posts
Discussion Starter #19
Road the bike today. Definitely all wobble gone with proper tire pressure. It definitely gives me a firm ride now. If I hit a bit of a bump, it's pretty solid. But in general, it feels good. I had a heavier backpack load of about 20 lbs today and no effect.
 
1 - 19 of 19 Posts
Top