Odd tire wear (FR)

[genespleen]

Hi everyone,

I fitted a new front tire this morning and thought I'd run a question to you about the old tire, for I've never seen a wear-pattern like this before. The left side of the tire (left=side w/o a brake rotor) is worn away significantly more than the right. I've only had the bike since late Sept. and have put at most 1000 miles on it. The pattern was evident when I first brought the bike home. Are there any obvious causes for such a pattern? (Say hello to Henry the Fly.)

best wishes,
David

 

[the Ferret]

road crown

 

[dduelin]

Left turns in the USA are larger in radius compared to right turns and the bike is leaned left for a longer period of time. This is a normal wear pattern in countries where we drive on the right side of the road. It’s reversed in countries where they drive on the left side.

Road crown is 3% or less and cannot account for tire wear seen from tread centerline to tread edge.

 

[Rydinon]

Ignore Dave and Ferret, they have no manners. Hi, Henry! Hope you have a nice day.

 

[genespleen]

Ignore Dave and Ferret, they have no manners. Hi, Henry! Hope you have a nice day.

Thanks. I get that about left-side wear, but I've been riding an '85 CB650SC over the same roads for 14 years, and have never seen anything like this kind of uneven wear. Admittedly, the previous owner will have put by far the most miles on the tires, and he lives in another part of the state.

 

[Rydinon]

Thanks. I get that about left-side wear, but I've been riding an '85 CB650SC over the same roads for 14 years, and have never seen anything like this kind of uneven wear. Admittedly, the previous owner will have put by far the most miles on the tires, and he lives in another part of the state.

A number of riders have pictured the same tire wear on the STOwner's website. It is not only your bike exhibiting this wear. Uneven tire wear, especially cupping or feathering can be caused by, or exacerbated by specific tires, air pressure, and a suspension that is not up to snuff. Riding habits also influence tire wear.

You might try phoning your tire brand's customer service and describe to them the tire wear and ask what causes it. On occasion, you can get a knowledgeable person on the other end of the line who might give you useful information*. If the person tells you to hold a second (while he/she looks in their computer for an answer) hang up and call back.

*In my limited experience, this is not rare, but most of the cust service folks are useless. I had a question about mc tires and I called a bunch of the major mfrs - maybe half a dozen of them. I got one very knowledgeable guy, most of the others were varying degrees of useless. I define useless as not giving me an intelligent answer that speaks directly to my question (even if someone else refutes it). I forget what my question was, but I think it might have been about using tubes in tubless radials on a spoked wheel.

 

[Alias]

Found this on another site.

Google Image Result for http://ridermagazine.com/wp-content/uploads/2018/04/Crowned-Roads.jpg

 

[670cc]

Found this on another site.

Google Image Result for http://ridermagazine.com/wp-content/uploads/2018/04/Crowned-Roads.jpg

The illustration in that article shows some really significant road crowning and about 45 degree angle tire wear. We have nothing of that sort where I ride. I like dduelin‘s cornering radius explanations better.

 

[CamaroEric]

I don't really believe the road crown stuff, faster sweeping left turns I do. I have had this on at least one of my bikes, it was extremely evident on dual compound tires. I think they were Metzelers. I hate Metzelers.

 

[TNHoosier]

Poor rear wheel alignment can make this problem worse. Have you checked the rear wheel alignment? Did you buy the bike new or used? If used do you know if it was ever wrecked?

 

[Alias]

The illustration in that article shows some really significant road crowning and about 45 degree angle tire wear. We have nothing of that sort where I ride. I like dduelin‘s cornering radius explanations better.

View attachment 54156

Don't you think the illustration could be exaggerated for effect?

 

[tripNines]

If it were "road crown" wouldn't the rear tire show at least some of the same wear pattern?

 

[Rydinon]

If it were "road crown" wouldn't the rear tire show at least some of the same wear pattern?

If all things were created equal, yes, we would expect so. However, the forces seen by the tires are different which is why manufacturers tell us not to put a front tire on the rear and v. v. Front tires do most of the braking, and rear tires most of the accelerating - the plies are wound on the drum differently when they are being made, and different compounds are used to maximize life under these loads.

I think a better person to answer your question would be a tire manufacturer's rep in the racing department. Since road races are a closed course run in one direction, they must wear out one side of the tires faster than the other, and it would be instructive to know if front and rear show the same wear patterns. Remember, however, that race tires are a tad different than street tires.

 

[genespleen]

Bought used (it's a 2020 and I wrote that I bought it last year). Previous owner had seemed meticulous about upkeep. I'm happy enough with the road-crown + left-turn radius explanation. Just had never seen the pattern before in 20 years with my '86 Nighthawk 650 (bias-plied tires). It may be that the PO had a completely different riding environment.

 

[dduelin]

If all things were created equal, yes, we would expect so. However, the forces seen by the tires are different which is why manufacturers tell us not to put a front tire on the rear and v. v. Front tires do most of the braking, and rear tires most of the accelerating - the plies are wound on the drum differently when they are being made, and different compounds are used to maximize life under these loads.

I think a better person to answer your question would be a tire manufacturer's rep in the racing department. Since road races are a closed course run in one direction, they must wear out one side of the tires faster than the other, and it would be instructive to know if front and rear show the same wear patterns. Remember, however, that race tires are a tad different than street tires.

Nonsensical. Racing bikes take the racing line around the turns. Generally outside - inside - outside. Road bikes on public highways describe different lines around the same turn depending on direction of travel.