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How Do You " Read " Tire Wear?


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640 miles at Road America

 

I consulted the magic 8 ball and this is what it said. lol

 

On warmers? Because it looks like it. Why do I think that? Because of the cupping on the forward sides of the tread are sheared off. Common with q2's and I see it in my own q3's. I feel a rebound adjustment in your future.

 

Not on warmers. 32 psi front 30 psi rear fresh off the trailer. Tire temps coming into the pits is a little deceptive but they typically were in the 135-143 range by the time I got stopped and could check, so I suspect running they were atleast 5 degrees more? But I did hustle to check when I checked. front tire was always less by about 3-6 degrees than the rear and air pressures would climb to 36f/35r fresh off the track checking as quickly as possible too. These are Q3's

 

I had softened the rebound dampening by 2 clicks, 18 out of the 33 available on a Penske 8987. Because I was thinking the same thing, but it seemed to get worse so went back two clicks the other way to 14 out and it didn't feel as good so ended back at the 16 and just rode it. The shock has about 1000 miles of track use on it now.

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  • 3 weeks later...

Will (the mechanic) inspects the tires on every school bike every day, he certainly has plenty of experience in that area! The coaches see a lot of different tires on various bikes during tech inspection for students who bring their own bikes - but they are typically in new or nearly-new condition as the school policy requires.

 

One good place to see all kinds of different tire wear is at the club races! Racers work the tires hard and they are on a budget so many guys will run the tires as long as they can - plus changes in suspension, tire compounds, track surface, or unusual weather (typically on the cold side) can result in some surprising and unexpected wear. Anyone who has ruined or nearly ruined an expensive set of race tires in one or two sessions through cold-tearing know it can be an expensive mistake!

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I'm curious. What kind of suspension is that bike running?

 

Stock suspension, forks were serviced and new seals maybe 2 years ago, the shock I'm pretty sure has never been serviced 28,880 miles on the Odometer

 

 

What about the front tire? Please post those pics also.

 

The light was bad where I was parked so I couldn't get a good photo of the front tire, but I'll post some when I get it unloaded from the van and back in the garage

 

 

Those look great. Very clean wear patterns. Looks like the track had a lot of Lefts vs Rights if I'm looking at the tire correctly. :)

 

Its a fairly balanced track, depending on what you count as a corner its pretty much 8 rights and 8 lefts, but you do spend more time at full lean on the left side of the tire

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Are these the Woodcraft front axle sliders?

 

Yes indeed they are. I went with the entire range of Woodcraft protection for the bike. Axle, Swingarm, Frame, Case guards and Rearsets.

 

Great stuff. Reasonably priced and they support their products long term with the ability to buy individual bits and pieces that might get damaged in a crash rather than replacing the whole unit.

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  • 4 weeks later...

Alright, I'll take a shot at this but I am not very knowledgeable in this area, so take it with a grain of salt. Looks to me like a dual compound tire with a harder compound in the center stripe, and a relatively soft (maybe too soft) compound everywhere else. Looks like the rider is putting down a lot of horsepower with the bike at a shallow lean angle - he/she probably has a good pick-up and uses it a lot, or else rides with more of a point-and shoot style that gets hard on the gas once the bike is pointed down track, instead of rolling on gradually while the bike is still leaned over a lot. This tire has a very pointy profile anyway but the wear has made that worse, and in this photo it does look like the right side has worn down significantly more than the left, indicating either a lot of right handers or an unequal tire compound for left versus right side - those do exist but I doubt that is the case here.

 

Again, I'm hardly an expert but from what I see, I would take a look at whether that tire is too soft for the track surface or weather conditions, and take a look at rider style to see if the tire could be made to last longer - maybe see if he/she could change the throttle control to get on the gas earlier and more gently in the turn and carry more speed through the corner rather than standing it up and driving hard on the exits, if the track has corners that are conducive to that and conditions allow. OR the rider could try a rounder-profile tire, it may allow him/her to ride with a more varying lean angle - the shape of this tire could be making the bike want to 'set' at a particular angle. It probably gives a TON of grip at that particular angle, though, and some riders like that feel. At that point it could become a trade-off between desired grip/feel versus how long you want a tire to last.

 

The wear pattern of the rubber itself looks OK to me (it is wearing a lot but it doesn't seem to be tearing, melting, or cupping) except for that strip right next to the center that looks extra-worn but I think that could be just the change in compound that makes it look odd there.

 

There is a only one thing I can say for sure about the conditions where this tire was used... there are a lot of little white rocks on the ground. :)

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Good stuff so far. You guys have guessed that this track has a lot of right hand turns. I'll give some more information. The Asphalt temp was 140 degrees and that tire was ridden "all day" for two days.

 

Here's my tire on the same track ridden for a small handful of sessions at a MUCH slower pace. Gotta love the little white rocks though. :)

 

IMG_0570.JPG

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Hey Buddy,

 

Looks like your rebound is off whack - A little too fast, and the tire is kinda skipping along the surface of the track.

 

Going out on a limb here, but there may be an issue with compression/preload/spring as well.Mostly compression.

 

Do you have high and low speed adjustment?

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I'll chime in about Roberts bike. It's a 2014 S1000RR that is set up for his weight and adjusted for him.

Now that his pace and riding style are improving he may soon need to revisit his suspension settings. Maybe a quick trip back to the shop (in the trailer) before the street wears off all the hard work and fun from last weekend.

As for the Pro's tire, it's his home track and he holds the track record there.

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Hey Buddy,

 

Looks like your rebound is off whack - A little too fast, and the tire is kinda skipping along the surface of the track.

 

Going out on a limb here, but there may be an issue with compression/preload/spring as well.Mostly compression.

 

Do you have high and low speed adjustment?

 

I also see this when the rider downshifts with a bit too much speed and/or the rev match is off. Just throwing it out there. :)

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I'll chime in about Roberts bike. It's a 2014 S1000RR that is set up for his weight and adjusted for him.

Now that his pace and riding style are improving he may soon need to revisit his suspension settings. Maybe a quick trip back to the shop (in the trailer) before the street wears off all the hard work and fun from last weekend.

 

 

Hey That's an awesome idea Jeff!

 

The other "problem" is I'm running completely stock suspension and I have yet to start tinkering with tire pressures. The Asphalt got to 140 degrees both days and I set the pressure in the morning and never revisited it. As the day progressed I could "feel" a lot of unhappy behavior in the back especially over the bumpy bits. I'm going to start reading up on the whole hot/cold tire pressure adjustment stuff soon. There's too many schools of thought in regard to that and it gets confusing FAST.

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