[tcl]

Normal tire wear? about 12000 miles on this rear tire pilot road. Before removing, I noticed 1/4th of the tire seemed more worn a smidgen more then the rest by 1-1.5 mm. That is, there was this small section that the treads were gone completely but the rest still had at least some tread. I suspect this is pretty normal as in every picture I've seen of tires down to the cords, they were not popping out all the way around.

Am I going to die?
Front wheel, right side dust seal looks a little worn or something. The axle has a corresponding black mark on it (no photo). Is this just a normal wear item I should replace or is it indicative of a problem?

left side:

 

[tlc4diving]

I've had a tire "cup" before. That's when I knew it was time to upgrade the rear suspension.

That flat in the middle tire wear happens sometimes when you cross Oklahoma, Texas and New Mexico.

 

[tcl]

I've had a tire "cup" before. That's when I knew it was time to upgrade the rear suspension.

That flat in the middle tire wear happens sometimes when you cross Oklahoma, Texas and New Mexico.

LOL!
I completely misspoke, or at least should have been more specific. I wasn't talking about the flat spot. I mean that 90 degrees of the tire (eg, 45 minutes, eg 1/4th the circumference) has a smidgen more wear in my flat spot then the rest of the tire.

I've had a tire cup too, and that's when I upgraded my suspension too.

In retrospect, I'm pretty happy I didn't put brand new tires on before I left (as planned), though was seriously worried the whole time about not making it on the already aging pilot roads. I filled the rear to 45 psi for some extra margin and I think two solid days of rain gave me some cushion too.

 

[tlc4diving]

I was wondering. You'd have to be a complete noob not to know the cause of cupping.

 

[locoblanco]

for 12000 miles it's not so bad. many tires don't make it that far. the dust seal looks pretty grungy, clean it up and look for wear, probably ok but cheap and easy to change if it looks worn.

 

[tcl]

I was wondering. You'd have to be a complete noob not to know the cause of cupping.

Why are we talking about cupping? I don't see cupping. do you see cupping?

 

[tlc4diving]

Just by looking at the center portion of the tire, the tread bars seem to look to be different depth. It may just be the picture but look at the top of the tire and just follow the center portion around to the bottom. It looks like the tread bars are deeper at the top than at the bottom.

But it may just be the angle of the picture that makes the tire look that way.

 

[TeeRiver]

Normal tire wear? I noticed 1/4th of the tire seemed more worn a smidgen more then the rest by 1-1.5 mm.

Aside from being manufactured a little 'thin' in that spot, what else might cause that uneven wear?

This is a kinda long post so please just skip it if it starts to make your head hurt! smiley

One idea: The worn part of the tire is thinner and causes the wheel to be *ever so slightly* out of round. You have some rubber at the long radius, and some rubber at the short radius of the wheel. The long radius section of tire would repeatedly get more wear. Probably not the right answer since this would put extra wear on the *thick* rubber (long radius), evening out the wear, instead of concentrate it.

Another idea: If you chain is very worn, then it has a tight(shorter) section and a loose(longer) section. When the longer section of chain comes around, it moves the rear wheel a *greater* distance and thus puts a heavier load on the rubber at that point. Why?, because for a single revolution of the countershaft sprocket, say 15 teeth, the 15 long links move the back wheel a little more that the 15 short links!

So, if the worn section of chain were somehow in sync with the worn patch of the tire, that might explain it. This is true, only if the number of links in the chain is an *exact* multiple to the number of teeth on the rear sprocket, like 135 chain links to a 45 tooth sprocket, 3:1. Not so for the SV650. Any off multiple would end up distributing the wear.

Any other ideas?smiley


By the way, I think the second part does explain why worn chains always end up having tight/loose sections.

 

[SVstryker]

i think teeriver is on the right track, i almost want to say your chain adjusters aren't lined up-----and i don't mean by the tick marks. if the axle isn't lined up properly, you'll have not only premature sprocket & chain wear, but uneven wear of your tires. just my .02

 

[Marc]

How about out of balance?

 

[Firestick]

Has this been crashed? Looks like a mis-alignment problem.
First clean your bike, then get it to a GMD Computrack if there's one near you. They'll measue the alignment of the frame, frt end, swingarm, frt and rear wheels realtive to each other and tell you what's out of shape and how to correct it.

 

[tcl]

Has this been crashed? Looks like a mis-alignment problem.
First clean your bike, then get it to a GMD Computrack if there's one near you. They'll measue the alignment of the frame, frt end, swingarm, frt and rear wheels realtive to each other and tell you what's out of shape and how to correct it.

Heh, funny you should mention cleaning, I just got caught up (toothbrush treatment) on it last week. Much more shiny now. I'm very diligent about oil/coolant/ filters/ cables/ chain/ pivots, etc. but living in NYC, washing was more of a PITA then it was worth. I'd spray the lower bits down with wd40 or wax occasionally to try to stave off corrosion so that didn't help with the aesthetics either.

This concern all for the little bit (1%) of wear difference on the rear tire? If I put 100 more or 100 less miles on the tire, I would never have noticed. I was mostly just curious.

I think I poorly described my observation. I'm saying that over 12,000 miles, a portion of the tire rear wore ever-so-slightly more then the rest of it. Every time I've seen cords showing on other people's tires, It wasn't uniform around the tire so I wasn't too concerned. I suppose It could be slightly mis-aligned or something- I think I aligned by string when I first put the tire on but have just counted turns of the chain adjusters since.

The sprocket looks great for 20,000 miles. I jumped the gun a couple years ago and put on a new chain (paranoia before a long trip) well before the last was dead so the sprockets really haven't worn (not hooked at all). I have new ones waiting that I suppose I could throw on sooner then later- I was planning on letting this chain go for another 5+ k then replacing them together.

guesses: a) normal / roundness b)balance c)sprocket d)alignemnt e)the tire was still going at 12000 miles, what more do you want?

 

[TeeRiver]

guesses: a) normal / roundness b)balance c)sprocket d)alignemnt e)the tire was still going at 12000 miles, what more do you want?

I would agree, most likely typical out of roundness, or balance. Not sure how alignment, even if off a alot could cause it. I would think bad alignment would wear one side of the tire, as opposed to one section.

 

[locoblanco]

i still say that tire's not bad for 12000 miles. as was noted, even on tires with cords showing, you don't usually see cords all around, just in some spots. at the first sign of cords, do you say "what's wrong with this bike?" or do you say "this tire is way beyond worn out, get it outta here."
put on a new tire and evaluate it after about 1000 miles. if it has obvious uneven wear, then start checking for other problems.

 

[TeeRiver]

i still say that tire's not bad for 12000 miles. as was noted, even on tires with cords showing, you don't usually see cords all around, just in some spots. at the first sign of cords, do you say "what's wrong with this bike?" or do you say "this tire is way beyond worn out, get it outta here."
put on a new tire and evaluate it after about 1000 miles. if it has obvious uneven wear, then start checking for other problems.

I agree. I don't think the reason for the uneven wear is of much practical concern, because as you say 12kmi is pretty good. For me, and perhaps tcl who brought it up, I get curious and want an explanation when I see something like that. Mostly it makes for a fun puzzle to try to solve.

If the tire was not manufactured that way to begin with, there must be some mechanism that causes it. All the answers posted seem plausible, but none give me that 'ah haaaa, that's it!' feeling.

 

[Marc]

I think when tires are made, they come out of the mold nice and round but the depth of the tread is not absolutely perfect all the way around.

 

[TeeRiver]

I think when tires are made, they come out of the mold nice and round but the depth of the tread is not absolutely perfect all the way around.

I never thought of that. That might be a harder parameter to control during manufacture. Perfectly round is easy since the tire mold can be made precise. The tire core relative to the nice round outside like you say might be cause. I like that explanation best so far.