The article focuses on the track, but it could make a difference on the street as well.
Riding Skills Series: Tire Management - Sport Rider Magazine
Riding Skills Series: Tire Management - Sport Rider Magazine
SportRider Riding Tips: Tire Management
- Thread starter ksanbon
- Start date
Oddly enough, tire pressure has been on my mind lately. I had set my tires to the recommended pressure on the side of the tire. Then I thought differently and set the pressure according to the manual. Since I've done that, my back tire has started to flatten in the middle, but some chattering I was feeling on the front end has calmed down.
Marthy sets his tire pressure when they're hot. I can't see that. Seems like all the recommended pressures, be they by manual or on the tire, would take into account the fact that pressure is checked when the tire is cold.
When I was running twisties yesterday, the flat of my rear tire became evident. I've never felt the rear of this bike start to slide, but I felt it many times on that ride. "Disconcerting" would be a serious understatement.
It was around 90 degrees F, ambient. My tires were definitely warmed up. I don't mind changing the pressure before I make those twisty runs, but they're an hour and half away.
Meanwhile, I commute and ride pretty boring, straight roads with the occasional tight turn. That flat spot again. So. What's the answer? Run the higher pressure recommended on the tire, and avoid the flat spot? Run the lower pressures recommended in the Owner's Manual? Check while hot or check while cold?
Marthy sets his tire pressure when they're hot. I can't see that. Seems like all the recommended pressures, be they by manual or on the tire, would take into account the fact that pressure is checked when the tire is cold.
When I was running twisties yesterday, the flat of my rear tire became evident. I've never felt the rear of this bike start to slide, but I felt it many times on that ride. "Disconcerting" would be a serious understatement.
It was around 90 degrees F, ambient. My tires were definitely warmed up. I don't mind changing the pressure before I make those twisty runs, but they're an hour and half away.
Meanwhile, I commute and ride pretty boring, straight roads with the occasional tight turn. That flat spot again. So. What's the answer? Run the higher pressure recommended on the tire, and avoid the flat spot? Run the lower pressures recommended in the Owner's Manual? Check while hot or check while cold?
So. What's the answer? Run the higher pressure recommended on the tire, and avoid the flat spot? Run the lower pressures recommended in the Owner's Manual? Check while hot or check while cold?
I'm pretty sure that the higher pressure was responsible for the premature wear in the middle of your tire tread. The ideal pressure for you will depend on the combined weight of the bike, you, plus anything you're carrying.
I weigh 145 and usually don't carry more than a 10 pound backpack. I love corners, but I'm not super-aggressive. I keep my Pilot Road 2's at the lower 33 psi front / 36 psi rear for max tread life.
i would say the correct answer varies rider to rider. some like their tires with a softer ride while others harder. it's whatever feels better to you
will say when i was riding on tracks, everyone said start out at 30/30 and go from there, doing some laps then checking to see how much they rise. usually end up around 31-32 front and 32-34 rear. skip the 42 rear unless you are carrying a passenger, heck i wouldn't go any further than 36/38
will say when i was riding on tracks, everyone said start out at 30/30 and go from there, doing some laps then checking to see how much they rise. usually end up around 31-32 front and 32-34 rear. skip the 42 rear unless you are carrying a passenger, heck i wouldn't go any further than 36/38
I'm trying to get a handle on the best pressure for the tires as well. My service tech says 36/42 (cold) even riding 1-up. I'm about 180lbs, but that still seems high, and I'm developing that rear tire flattened center, after about 5500 miles. You'd think that would be a low pressure issue, but apparently not. (Stock Dunlop RoadSmarts. I'm very happy with them otherwise).Oddly enough, tire pressure has been on my mind lately. I had set my tires to the recommended pressure on the side of the tire. Then I thought differently and set the pressure according to the manual. Since I've done that, my back tire has started to flatten in the middle, but some chattering I was feeling on the front end has calmed down.
Marthy sets his tire pressure when they're hot. I can't see that. Seems like all the recommended pressures, be they by manual or on the tire, would take into account the fact that pressure is checked when the tire is cold.
When I was running twisties yesterday, the flat of my rear tire became evident. I've never felt the rear of this bike start to slide, but I felt it many times on that ride. "Disconcerting" would be a serious understatement.
It was around 90 degrees F, ambient. My tires were definitely warmed up. I don't mind changing the pressure before I make those twisty runs, but they're an hour and half away.
Meanwhile, I commute and ride pretty boring, straight roads with the occasional tight turn. That flat spot again. So. What's the answer? Run the higher pressure recommended on the tire, and avoid the flat spot? Run the lower pressures recommended in the Owner's Manual? Check while hot or check while cold?
Sport Rider recommends changing out the tire when that happens, since I'm rarely on long straight roads, and that flattened center can be an issue on curves. So, I'm looking for thoughts on this. I do NOT want to sacrifice grip, so I'll change it out sooner than later.
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Chevyfazer
New Member
Your rear pressure seems really high and I'd say that is a big part of why the center is going flat. I normally run 35/35 but when my rear tire starts to show signs of flattening out I drop the rear 5-6lbs and it makes the tire last a lot longer without flattening the center or sacrificing grip.
On motorcycles we all know that long straights eat the center of the tire but on all tires the center wearing faster than the rest is also a symptom of high pressure while the outside wearing faster is a symptom of low pressure. So if you can drop the rear pressure enough that it won't dramatically change the handling it will help with the overall wear of the tire and allow you to get more miles out of the tire.
On motorcycles we all know that long straights eat the center of the tire but on all tires the center wearing faster than the rest is also a symptom of high pressure while the outside wearing faster is a symptom of low pressure. So if you can drop the rear pressure enough that it won't dramatically change the handling it will help with the overall wear of the tire and allow you to get more miles out of the tire.
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Yeah, I also thought the pressures, as per the tech, were high. I normally put them up there when I ride 2-up, but, before the recommendation from the service tech, I'd keep them at 35/38, which I've gone back to (it's an approximate interpolation of the UM's guidelines). I also stepped the suspension up to "5," months ago... seems to be a good combination.
Question is, now that the rear is showing some (not gargantuan, but noticeable) signs of center flattening, how long before it should be changed out... I think waiting for the wear indicators to show would be too long in this case... So, I've already started looking for a new rear... however, might not have it mounted prior to the start of the new riding season (mid-late Feb., here in Atlanta, although I'll ride year 'round, it's less frequent in the winter).
Question is, now that the rear is showing some (not gargantuan, but noticeable) signs of center flattening, how long before it should be changed out... I think waiting for the wear indicators to show would be too long in this case... So, I've already started looking for a new rear... however, might not have it mounted prior to the start of the new riding season (mid-late Feb., here in Atlanta, although I'll ride year 'round, it's less frequent in the winter).
Chevyfazer
New Member
It really depends on how much you ride, how hard, and other things. If you drop the pressure down about another 5psi you should be able to get at least 1000 more miles out of it or more before it gets too flat in the center
I'm checking my pressure cold just like about everyone else. What I did mention once is for track day, as we do in racing, what really matter the most is hot temps psi. This is most accurate and more consistent. If you have a heavier driver, more abrasive pavement, stiffer spring or damping, hot or cold day... all those parameter will influence your cold temps. By example if you check your tire cold in your garage or in the middle of a parking lot in a hot summer day, your pressure might be 4-5 psi different? Not sure how it can change the handling of a bike but on cars, 1/2 psi make a good difference. Might not be an accurate number 1psi can be 25 lb/in of spring rate. So it's like changing springs. There's a lot of psi tuning during a race usually since some cars have telemetry these days... if you know where you start in psi and know where you end up... you can adjust the handling of the car by changing cold psi.Oddly enough, tire pressure has been on my mind lately. I had set my tires to the recommended pressure on the side of the tire. Then I thought differently and set the pressure according to the manual. Since I've done that, my back tire has started to flatten in the middle, but some chattering I was feeling on the front end has calmed down.
Marthy sets his tire pressure when they're hot. I can't see that. Seems like all the recommended pressures, be they by manual or on the tire, would take into account the fact that pressure is checked when the tire is cold.
When I was running twisties yesterday, the flat of my rear tire became evident. I've never felt the rear of this bike start to slide, but I felt it many times on that ride. "Disconcerting" would be a serious understatement.
It was around 90 degrees F, ambient. My tires were definitely warmed up. I don't mind changing the pressure before I make those twisty runs, but they're an hour and half away.
Meanwhile, I commute and ride pretty boring, straight roads with the occasional tight turn. That flat spot again. So. What's the answer? Run the higher pressure recommended on the tire, and avoid the flat spot? Run the lower pressures recommended in the Owner's Manual? Check while hot or check while cold?
Note the date on my post you quoted. Ever since then I've run the Manual recommended pressure, measured when cold. I made the change some while ago now, and can give you a review, such as it is.I'm trying to get a handle on the best pressure for the tires as well. My service tech says 36/42 (cold) even riding 1-up. I'm about 180lbs, but that still seems high, and I'm developing that rear tire flattened center, after about 5500 miles. You'd think that would be a low pressure issue, but apparently not. (Stock Dunlop RoadSmarts. I'm very happy with them otherwise).
Sport Rider recommends changing out the tire when that happens, since I'm rarely on long straight roads, and that flattened center can be an issue on curves. So, I'm looking for thoughts on this. I do NOT want to sacrifice grip, so I'll change it out sooner than later.
Sent from my Nexus 7 using Tapatalk 2
Handling on the bike improved, mostly. The older, higher pressure I was running was definitely nice in the twisties. The bike rolled over easier and quicker, and I like that. It was also a little more skittish under most circumstances, and I liked that, too.
However it killed my tires. When I dropped them to the manual recommended pressure, measured cold, the bike still handled well, if not quite as nimbly. The extreme tire wear I was seeing dropped off, though. The large flat spot on my rear tire actually started rounding back out.
I've got new tires now, and I run them at the spec the manual says. The grip is good for everything I do, and the wear seems to be acceptable. Personally, unless you're running track, I'd go with what the manual says.
I am still running OEM pressures of 36/42 on the gixxer, and yes I suffer early center wear (starts at around 1000 miles). But, I have tried lower rear pressures and didn't like the squirm / vague feeling, at 42psi the handling is razor sharp. I suppose I would eventually adapt to the less sharp feeling of say a 36 rear, and may revisit that at some point, particularly with cooler weather coming. My thinking is also that during high summer heat on a lower psi rear, the tire may get over-heated and prematurely bake out - my understanding is that lower pressures allow more flex in the tire which is a big source of heat, so the higher pressure tire should run cooler.
The article speaks directly to my use of throttle, no doubt that conservative smooth throttle into and out of corners makes tires last longer and in particular staves off center wear. However, center wear is inevitable on HS tires with long straights in your rides; I would say conservative throttle could delay onset of center wear by perhaps a few hundred miles on HS, but that's about it (yes, I have actually tried).
However, I ride to blow off steam and get exhilaration from the power of these awesome machines, and yes hammering the throttle enhances that feeling on straights and exits, and it is more expensive to ride this way, it just depends on whether it is worth it to you. I mean if super smooth throttle doubled the life of my tires, then yeah, I may chill a bit, but it seems more like 20% tops between all out aggressive and super conservative (street). And, I do understand that 'aggressive' is not necessarily faster than 'smooth', but I am in this for recreation, not lap times. I just ride for fun, and I do ride super smooth sometimes, but when I am feeling aggressive, I do that as well.
The article speaks directly to my use of throttle, no doubt that conservative smooth throttle into and out of corners makes tires last longer and in particular staves off center wear. However, center wear is inevitable on HS tires with long straights in your rides; I would say conservative throttle could delay onset of center wear by perhaps a few hundred miles on HS, but that's about it (yes, I have actually tried).
However, I ride to blow off steam and get exhilaration from the power of these awesome machines, and yes hammering the throttle enhances that feeling on straights and exits, and it is more expensive to ride this way, it just depends on whether it is worth it to you. I mean if super smooth throttle doubled the life of my tires, then yeah, I may chill a bit, but it seems more like 20% tops between all out aggressive and super conservative (street). And, I do understand that 'aggressive' is not necessarily faster than 'smooth', but I am in this for recreation, not lap times. I just ride for fun, and I do ride super smooth sometimes, but when I am feeling aggressive, I do that as well.
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I've always used the tire pressure recommended for the actual tire and check when the tire is cold.
80% of my riding is commuting and i currently have almost 6,500 miles on the Battlax tires i have on the bike and they look good, got 11,000 out of the first set, but only had around 7,000 miles on the Roadsmarts i tried, when the center of the rear tire was worn out and the front tire was cupping badly.
80% of my riding is commuting and i currently have almost 6,500 miles on the Battlax tires i have on the bike and they look good, got 11,000 out of the first set, but only had around 7,000 miles on the Roadsmarts i tried, when the center of the rear tire was worn out and the front tire was cupping badly.
Deathdiesel
New Member
Umm wow...new info to me. Well I have noticed a flat spot on my tires, and im only at around 2500 miles on the tires. I keep my psi around 32ish, however I unfortunately live in a pretty flat area so a lot of my travel is on highway, would that be why?
Yeah, all that straight-line driving makes the flat spot. It kind of makes sense. The sides don't get used as much as the center, so the center wears faster.Umm wow...new info to me. Well I have noticed a flat spot on my tires, and im only at around 2500 miles on the tires. I keep my psi around 32ish, however I unfortunately live in a pretty flat area so a lot of my travel is on highway, would that be why?
Many modern tires have a harder compound in the center, to try to help combat that. My cheap-ass, but pretty good so far, Shinko's are NOT dual compound. I'm keeping a close watch on the center-wear.
In my experience, running too high a pressure made the center of the tire wear faster, though I liked the way the bike handled.
I was amazed what a difference just two or three pounds PSI made. I try to keep it within manual specs for my loaded weight now. Working good so far.
Chuckwick357
New Member
When it comes to psi I usually end up calling the tire manufacturer (they have a whole division devoted to answering this type of question) and I tell them my make, model, my weight and riding / driving style. I found my bike tires where too low and my car tires where way too high. I run sport tires on my ZX so rarely get more then 5-6k out of a set of tires.