6 February 2010 – Tire Thoughts (Ken S.)
A recent post to the BB about tires started the gears turning in my head: “Why do tires do the things they do?” Further, I suspected that this could be another Daily Desmo exploration; perhaps one that has been answered a thousand times, but needs to be asked anew.
Fear not, there will not follow deep thoughts about silica compounds and Kevlar woven, of mold release agents and other such wizardry which is beyond my reach – nay, let me be honest – beyond my threshold of caring.
I just want to know why front and rear tires wear differently enough to warrant a swap of one and not both?
Is it only my secret shame that I equally wear both the front and rear tires on my Ducatis?
Perhaps I’m doing “it” wrong? Not since years ago and far away has a thought plagued me such as this – not really, but give me a little dramatic license here.
Looking at motorcycle dynamics, and perhaps influenced by my own “push the front” riding style, you would think that a front time would – by design – undergo the same amount of wear, or perhaps more, than the rear tire in a given amount of miles. Consider the sportbike design: the transition of weight from front to rear during acceleration, especially when coming out of corners. That rear tire is like Hercules himself performing great feats of strength as it literally sacrifices its skin in the catapult-like launch of machine and muscle (we’ll make some assumptions here – you know who you are) against for evil forces of inertia, gravity, wind resistance, and friction. But wait! Like the Titan Atlas, on whom all of the Firmament was rested on his shoulders, we have this poor front tire who seems to do all the heavy lifting in the motorcycle world: breaking, steering, an unequal amount of the vehicle’s weight given its smaller size… Hey, who keeps picking on the little guy and expecting that he’ll run twice as far as his big brother, the rear tire?
No, this is not #1 choice for rubber reincarnation: The Rear and Front tires seem to share a Doctor Evil and Mini-Me relationship while not being equal in stature or roles – “You complete me!”
If I had to choose a rubber product to be reincarnated as, I’m thinking a front motorcycle tire would be at the bottom of the list (I’ll keep what’s at the top of the list to myself).
So, why do I routinely hear of people burning through their rear tire and then having enough tread left on the front for a double-date?
A few possibilities:
The front tire is tougher than me, always has been, and always will be. Well, that’s a given. Drag me behind a car for about a block and I’ve had enough, but we’re talking about something else here entirely. I can understand a Harley running through a couple of rear tires given the weight distribution and general handling characteristics, but in a sport bike it seems that tire manufactures would build in some “planned obsolescence” to ensure that you were either close to the limit or right at the wear markers on your front tire when the rear gave up. Examine, for example, the new “multi-band” long-wearing tires that have hard(er) rubber, or at least what passes for it these days, sandwiched between two nice soft bands of “please let me make it through this curve” that will wear away more quickly. As seen below, they’ve even made the rear tire harder in the center band than the front tire – almost like they’re daring you to try getting two rear tires out of this front…
The newest of the new in tire technology might be able to give you longer overall tire wear, improved grip, and equal mileage out of both tires.
Maybe it’s the way we have our bikes set up? Who hasn’t bought a motorcycle and thought to themselves: “You know what this thing needs? A lot more weight on my wrists and an even more extreme neck angle!” Perhaps we’re fighting the natural process by taking our sport-bread stallions and putting a 300-pound jockey in the saddle… What was that I read the other day? Oh yea, you’ll love this: “Motorcycle dynamics optimized for a 150-pound rider.” Huh? Is that in a Speedo? I don’t know about the rest of you, but I’m 5-feet 8-inches with a 46-inch chest (no jokes about implants) and in a full race-replica Alpinestars GP suit with boots, gloves, helmet, and a spine protector I think I’m just a taste over that 150 (at taste can equal anywhere between 5 and 100 pounds – just go with me on this one). So, we get that nice comfy seat, change the pegs, raise the bars, and maybe the sacrifice for the improved ergonomics is an increase in rear tire wear (with the subsequent offset for the front tire). What if we follow that rabbit a bit further and start talking about weight distribution during acceleration out of a curve when the rear tire is already loaded up more than designed (for that 150-pound rider), partly because of the increase in rear preload, partly because we’ve shifted our weight back to be more comfortable, and even more so because we have to really put the spurs to it because the bike is moving a brick instead of a feather?
If this is the rear tire, and it looks like all of it is getting a workout, I wonder what the front looks like…?
Maybe we’re just taking chances? Well, the logic here is that since I’m riding a “murder-cycle” anyway I might as well get every penny out of those tires as I can; after all, and this is just between us, those tire manufacturers only put those wear bars on the tires because the Depart of Transportation makes them. Just look at the tires those race guys use: they don’t have any treat on them at all! These tires here are just finally getting “cut in” like they should be in the first place. I’ll hold off until I start seeing belts, then I’ll spoon some fresh ones on (and you know that those new tires are deadly for about the first hundred miles or so, just look it up!). You think I’m joking here, do a search. Better yet, get on eBay and look at your 748s, 916s, 996s, and 998s that are for sale. I’ll bet a sandwich that you’ll find at least a few that fit this pretty well: ten years old, original tires (oh, and original belts and hoses too), and less than 3,000 miles. Only ridden to and from Starbucks on Sundays – recently inspected by Such-and-Such Expert Motorcycle Guys as absolutely perfect to pick up here at my house and ride cross-country to your home! “I’ll even pick you up at the local airport…”
Mileage or burnout? It doesn’t really matter – this tire is dangerous!
Maybe it just works. All the huffing and puffing aside, there are folks who fit a certain set of tires, ride for a certain number of miles, swap out the back and get a full two-tires out of their front. I’m not bitter, just curious.
In case you can’t read the script: 15,782 miles out of this rear tire (although I would hope that an Avon Venom R isn’t exactly what you’d fit on your 1198R with its 827-pound load rating). This thing has to be as hard as woodpecker lips…
Well, I think I’ve satisfied my own desire to write about this subject. I hope I’ve stirred up some curiosity in those of you who take time to read this. Whatever your tire tales might be, keep them warm and fresh – with that I expect you’ll outlive us all.
A recent post to the BB about tires started the gears turning in my head: “Why do tires do the things they do?” Further, I suspected that this could be another Daily Desmo exploration; perhaps one that has been answered a thousand times, but needs to be asked anew.
Fear not, there will not follow deep thoughts about silica compounds and Kevlar woven, of mold release agents and other such wizardry which is beyond my reach – nay, let me be honest – beyond my threshold of caring.
I just want to know why front and rear tires wear differently enough to warrant a swap of one and not both?
Is it only my secret shame that I equally wear both the front and rear tires on my Ducatis?
Perhaps I’m doing “it” wrong? Not since years ago and far away has a thought plagued me such as this – not really, but give me a little dramatic license here.
Looking at motorcycle dynamics, and perhaps influenced by my own “push the front” riding style, you would think that a front time would – by design – undergo the same amount of wear, or perhaps more, than the rear tire in a given amount of miles. Consider the sportbike design: the transition of weight from front to rear during acceleration, especially when coming out of corners. That rear tire is like Hercules himself performing great feats of strength as it literally sacrifices its skin in the catapult-like launch of machine and muscle (we’ll make some assumptions here – you know who you are) against for evil forces of inertia, gravity, wind resistance, and friction. But wait! Like the Titan Atlas, on whom all of the Firmament was rested on his shoulders, we have this poor front tire who seems to do all the heavy lifting in the motorcycle world: breaking, steering, an unequal amount of the vehicle’s weight given its smaller size… Hey, who keeps picking on the little guy and expecting that he’ll run twice as far as his big brother, the rear tire?
No, this is not #1 choice for rubber reincarnation: The Rear and Front tires seem to share a Doctor Evil and Mini-Me relationship while not being equal in stature or roles – “You complete me!”
If I had to choose a rubber product to be reincarnated as, I’m thinking a front motorcycle tire would be at the bottom of the list (I’ll keep what’s at the top of the list to myself).
So, why do I routinely hear of people burning through their rear tire and then having enough tread left on the front for a double-date?
A few possibilities:
The front tire is tougher than me, always has been, and always will be. Well, that’s a given. Drag me behind a car for about a block and I’ve had enough, but we’re talking about something else here entirely. I can understand a Harley running through a couple of rear tires given the weight distribution and general handling characteristics, but in a sport bike it seems that tire manufactures would build in some “planned obsolescence” to ensure that you were either close to the limit or right at the wear markers on your front tire when the rear gave up. Examine, for example, the new “multi-band” long-wearing tires that have hard(er) rubber, or at least what passes for it these days, sandwiched between two nice soft bands of “please let me make it through this curve” that will wear away more quickly. As seen below, they’ve even made the rear tire harder in the center band than the front tire – almost like they’re daring you to try getting two rear tires out of this front…
The newest of the new in tire technology might be able to give you longer overall tire wear, improved grip, and equal mileage out of both tires.
Maybe it’s the way we have our bikes set up? Who hasn’t bought a motorcycle and thought to themselves: “You know what this thing needs? A lot more weight on my wrists and an even more extreme neck angle!” Perhaps we’re fighting the natural process by taking our sport-bread stallions and putting a 300-pound jockey in the saddle… What was that I read the other day? Oh yea, you’ll love this: “Motorcycle dynamics optimized for a 150-pound rider.” Huh? Is that in a Speedo? I don’t know about the rest of you, but I’m 5-feet 8-inches with a 46-inch chest (no jokes about implants) and in a full race-replica Alpinestars GP suit with boots, gloves, helmet, and a spine protector I think I’m just a taste over that 150 (at taste can equal anywhere between 5 and 100 pounds – just go with me on this one). So, we get that nice comfy seat, change the pegs, raise the bars, and maybe the sacrifice for the improved ergonomics is an increase in rear tire wear (with the subsequent offset for the front tire). What if we follow that rabbit a bit further and start talking about weight distribution during acceleration out of a curve when the rear tire is already loaded up more than designed (for that 150-pound rider), partly because of the increase in rear preload, partly because we’ve shifted our weight back to be more comfortable, and even more so because we have to really put the spurs to it because the bike is moving a brick instead of a feather?
If this is the rear tire, and it looks like all of it is getting a workout, I wonder what the front looks like…?
Maybe we’re just taking chances? Well, the logic here is that since I’m riding a “murder-cycle” anyway I might as well get every penny out of those tires as I can; after all, and this is just between us, those tire manufacturers only put those wear bars on the tires because the Depart of Transportation makes them. Just look at the tires those race guys use: they don’t have any treat on them at all! These tires here are just finally getting “cut in” like they should be in the first place. I’ll hold off until I start seeing belts, then I’ll spoon some fresh ones on (and you know that those new tires are deadly for about the first hundred miles or so, just look it up!). You think I’m joking here, do a search. Better yet, get on eBay and look at your 748s, 916s, 996s, and 998s that are for sale. I’ll bet a sandwich that you’ll find at least a few that fit this pretty well: ten years old, original tires (oh, and original belts and hoses too), and less than 3,000 miles. Only ridden to and from Starbucks on Sundays – recently inspected by Such-and-Such Expert Motorcycle Guys as absolutely perfect to pick up here at my house and ride cross-country to your home! “I’ll even pick you up at the local airport…”
Mileage or burnout? It doesn’t really matter – this tire is dangerous!
Maybe it just works. All the huffing and puffing aside, there are folks who fit a certain set of tires, ride for a certain number of miles, swap out the back and get a full two-tires out of their front. I’m not bitter, just curious.
In case you can’t read the script: 15,782 miles out of this rear tire (although I would hope that an Avon Venom R isn’t exactly what you’d fit on your 1198R with its 827-pound load rating). This thing has to be as hard as woodpecker lips…
Well, I think I’ve satisfied my own desire to write about this subject. I hope I’ve stirred up some curiosity in those of you who take time to read this. Whatever your tire tales might be, keep them warm and fresh – with that I expect you’ll outlive us all.







