weighmaster
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posted December 29, 2012 10:29 PM
 Edited By: weighmaster on 30 Dec 2012 06:37
lighter tires vs. lighter wheels
I wanted to get some opinions here regarding lighter tires vs. lighter wheels. According to Michelin, every 1 pound less in the tire(s) is equivalent to 3 pounds less in the wheel(s) as far as inertia / unsprung weight. Assuming that is true and about 2.2 pounds (1 kilogram) can be saved in the tire pair going to Michelin Power Pure tire pair from other common street tire pairs such as Bridgestone and a few others, why would people spend a lot of money on lighter wheels when they can just get lighter tires at their next tire change (or like me, swap my existing ZX-14 tires over to some other bike I own)?
So let's take an example... suppose person B and person C have identical stock ZX-14 bikes. B decides to go with lighter wheels and C decides to go with lighter tires. B saves 6.6 pounds in the wheels and C saves 2.2 pounds in the tires. According to Michelins "3 to 1 rule", both should feel about the same performance increase (better braking, better acceleration, better reaction and recovery by the suspension, easier turn in, less gyro effect...).
Between some bikes, the front wheels are a direct swap, making the decision to go with the lighter wheel easier. That is, if someone can save 2 pounds by swapping in a front wheel from some other bike, that is a simple way to lose some unsprung weight. However, rear wheels are not usually that simple to swap, so in that case, it may be better to just have fun and smoke the old rear tire and then go with a lighter new rear tire.
I suppose some enthusiasts can do both (lighter tires and lighter wheels) if they have the funds to do so.
Another good question is how much weight savings in the wheels and tires are needed before it can be felt for typical street riding? For example, if someone wears out their old stock tires on a stock ZX-14 and then has some Power Pures installed, is that enough to feel the difference? What if someone saved a few pounds in the wheels but kept the same tires, can that be easily felt?
In some cases using "heavy" tires, there may be a 2 pound saving just in the rear tire alone. I am not sure what tires are the heaviest but I have a used but still usable Shinko R009 190 50 17 tire here that is 14 pounds and the equivalent size Michelin Power Pure (new) is (according to Michelin) only 12.39 pounds. That is a 1.61 pound savings in just one tire so using the 3:1 "rule", that is almost the same as saving about 5 pounds in the wheel but without all the fuss and expense.
So what I may do on my ZX-14 is swap in a ZX-10 front wheel with a Michelin Power Pure 120/60/17 tire for maximum weight savings but leave the rear wheel stock and just go with a lighter tire. Even the Michelin Power Pure 200 50 17 at a claimed 13.03 pounds (by Michelin) is a pound lighter than the smaller Shinko 190 50 17. I will probably go that route.
  
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eklipse636
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ZX-14
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posted December 30, 2012 03:39 AM
The weight of the tire isn't NEARLY as important as how good the tire performs.
You could have a very light tire, but how good is it if it won't hook or last?
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Best: 60ft 1.351 1/8 5.68 mph 123.98 1/4
8.89 mph 151.32
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weighmaster
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posted December 30, 2012 05:57 AM
Edited By: weighmaster on 30 Dec 2012 13:58
It depends on the application. For someone like me that doesn't lean the bike way over and has 3 bikes so I don't ride any single one a lot, Michelin Power Pure tires seems like a good choice for me with the 120/60/17 front weighing it at 8.05 pounds (claimed by Michelin). That could be close to 2 pounds lighter than a non Michelin brand 120/70/17 tire so suppose it is about 1.67 pounds lighter. Using Michelins 3:1 rule, that is roughly equivalent to 5 pounds saved in the wheel as far as inertia.
I am also going with a bolt on ZX-10R front wheel which is supposedly 2 pounds lighter than the ZX14 stock front wheel (I am talking 2006 model here). Then I just simply have the current ZX-14 front tire transferred over to another bike I have that needs a new (or almost new) front tire. 120/70/17 tires fit so many bikes. The other advantage is that tire will help correct speedo/odo error on my 2005 SV650S which has the speed sensor on the front wheel and currently reads too high with the smaller tire.
My 14 is lowered so by going with a smaller diameter 60 series tire in the front, I'll have the front forks adjusted in the triples to compensate. I probably only need to drop them half an inch or so since the 60 series tire has 12mm less sidewall below the axle. Some people may say that I am changing the steering geometry of the bike by doing that and my reply to that would be so what? What if the previous owner of the bike set it up that way and then sold the bike to me? I would learn how to ride the bike with that setup and not know the difference of that vs. the stock tire setup. I do not race the bike anyway and I prefer to experiment, it is fun.
I've also heard good things about the Power Pure performance such as it warms up quickly and sticks well. Even if it doesn't last as long as other tires, that is not a major concern because of the low miles I ride anyway. 2K miles is about a year of riding for me on any single bike. I would actually prefer the weight reduction and slight performance gain rather than the longevity.
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toledoUPSguy
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posted December 30, 2012 06:33 AM
interesting question. sorry for a slight sidetrack. if the zx10/zx6 wheels bolt right on and are lighter why wouldn't kawasaki have saved some money using the same wheels on multiple models? are they strong enough for the weight and torque of the 14?
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The man on top of the mountain didn't fall there.
2014 ZX14r in nuclear sunset orange and black
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vailes3705
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Gettin Better
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posted December 30, 2012 06:39 AM
I have to agree with eklipse on this one. No matter how light the tire is, it's no good to you if you blow the tire off every time you try to leave hard. I'm not familiar with the Power Pure, is that the same as the Power One?
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2011 ZX14
Best 1/8 mile to date:
5.90 @ 121
1.46 60ft
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weighmaster
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posted December 30, 2012 07:02 AM
Edited By: weighmaster on 30 Dec 2012 15:04
Michelin Power Pure tires use LTT (Light Tire Technology) and are supposedly very popular and a great way to shed unsprung weight without having to do fancy mods such as a rear wheel conversion which usually requires special spacers, sometimes different bearings, possibly different caliper and hanger, possibly different rotor(s)... The tire is guaranteed to fit and work with no headaches and for every 1 pound saved in the tire, that is roughly equivalent to 3 pounds saved in the wheel (according to Michelin) and 4 pounds saved in the rotor(s) (also according to Michelin). The weight in the tire is much farther out away from the axle where it makes more of a difference on inertia.
I remember when I was a kid and went to a science museum, they had 2 wheels on an axle that could be held in my hand. They told me the wheels are the same exact static weight (like if weighed on a scale) but one has more mass out towards the rim and the other has the mass more centralized closer to the hub. There was a BIG difference when I turned the wheels sideways while they were spinning. The one with the mass more towards the outside wanted to yank the wheel significantly harder in that direction than the other wheel.
Once again, some readers here are not following the goals I have set. I do not drag race the bike and my lauches are moderate. I ride 99.99% street. The lighter front wheel and tire should give the bike a nice light feel in the front with easy "flickability", making the bike feel more like a sportbike rather than a sport / touring bike. It is nice when it requires very little input to turn a 500+ pound bike. The bike already steers well with the stock wheels and "regular" tires on so hopefully I can make that even better.
Since I don't do wheelies and/or stoppies and only weigh 170 ready to ride, I should be safe running a ZX-10R front wheel on my 14 because imagine the load on the 10 for someone that DOES do stoppies. I suspect with the lighter wheel and lighter tire, I should save about 3 to 4 pounds total up front. I'll be gearing the bike up so roll on wheelies are not really a concern. I've rolled 1st gear fairly hard and it showed no signs of lifting (my bike is lowered), even with the lower than stock gearing currently (16-41 I think).
I'll be getting the 120/60/17 Power Pure tire soon so I will post the exact weights of the ZX-14 front wheel vs. the ZX-10R front wheel (both 2006 versions) and the weight difference of the tires and also my opinion of how it feels before and after. The front brake rotors are a direct swap so the weights of both wheels can be reported either with or without the rotors because the relative difference in weight between them should be constant (such as 2 pounds). I'll get it exact on my precision scale. After all, I am the weighmaster.
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Shane661
Needs a life
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posted December 30, 2012 07:27 AM
I hope this thread can be of help to your project:
http://www.bikeland.org/board/viewthread.php?FID=27&TID=40269&set_time=
I have weighed most of the major and minor components of the bike. Dyno tests, top speed, 1/4 mile, a lot of data. Good luck with your project. 
Shane
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Lucky14
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posted December 30, 2012 07:33 AM
Edited By: Lucky14 on 30 Dec 2012 15:36
What's next? An OIL THREAD?
Yeah, no one here ever thought about exhausts or lighter wheels/tires.... 
You're a TROLL. You aren't looking for discussion. You just argue with everything suggested by members here who have a LOT MORE knowledge and experience than you will EVER have, even if you live to be 20. 
You even argued with my signature! SERIOUSLY???
"Oh so does that mean if an airplane has trouble with the landing gear flapping in the wind while on final approach, the copilot should climb out there and just put some duct tape on it and that will solve the problem? That makes me feel much better thanks!"
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You only need two tools: WD-40 and Duct Tape.
If it doesn't move and should, use the WD-40.
If it shouldn't move and does, use the duct tape.
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weighmaster
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posted December 30, 2012 08:13 AM
Wrong. Some people join in with the discussion and give good advice and some people like you bash. I encourage open discussion and shared testimonials but remember we don't all do the same thing with our bikes so don't bias your answers with a drag racer mentality if the original poster stated he/she doesn't drag race because it is irrelevant to the application/goal.
Also, how would you know how much knowledge and experience I have? You are just guessing.
An oil thread would be interesting.
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Wheelie
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posted December 30, 2012 08:17 AM
quote:
An oil thread would be interesting.
let us know what oil weighs.
wee
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Shane661
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posted December 30, 2012 08:23 AM
Some people post looking for advice, while others really are just looking for people to agree with them. They are not asking questions at all. They only hear what they want to hear...basically they spend a lot of time telling those who try to help, "no, YOU are wrong".. It's best not to waste too much time with those people, I've found.
Shane
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tuusinii
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posted December 30, 2012 12:33 PM
I really wouldn't go with 60 series front tire in street use application as it makes the suspension very hard because it's much more stiffer in the sides compared to 70 series. Also 70 series has a rounder profile so it will feel more light than 60 series. If Your interested in weight and flickability go with 120/70 front and 180/55 rear - they are the best combo. Or 190/55 rear (not 190/50). Otherwice Michelins are one of the best tires but not cheap...
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INTIMIDA2OR
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posted December 30, 2012 02:10 PM
Lighter tires aren't a bad idea. You wont notice too much of a difference unless you do high speed cornering. Then there is a huge difference. But then again a heavier tire usualy means sport touring or touring so it will be heavier and have stiff sidewalls and if you run a tire of this type on the 14 you wont be doing any high speed cornering anyway.
Michelin pilot powers and 2cts are an excellent choice for making this big bike feel like a much smaller bike in nimbleness.
I agree with not running the 60 series profile too. Dented a front wheel with a driveway that I go through all the time and never had a problem. Untill running the 60. I run the pirelli diablo supercorsas and that is a light tire! Feels every bit like the michelins but a bit quicker in the steering and sticks much harder.
Now lighter wheels now that is something you can feel at any speed ! Well at least I can feel it anyway.
I rode a 14 with carozerrias and that was amazing the difference in both bikes was unreal. It felt like I had powersteering.
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'06 Passion Red ZX-14
*Lee*
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weighmaster
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posted December 30, 2012 04:38 PM
Edited By: weighmaster on 31 Dec 2012 01:05
The Michelin Power Pure 120/60/17 tire weighs (according to the lady I spoke with on the phone when I called the Michelin number), 8.05 pounds. I will be getting one soon so I will check if that weight is correct. I wanted to try going for the maximum possible weight savings within a tight budget and it seemed like a fun idea to try.
The next size up Power Pure front tire is 120/70/17 which (again according to Michelin) is 8.71 pounds. That is a difference of 2/3rds of a pound which using the 1:3 rule is similar to saving 2 pounds in the wheel. So that in combination with a ZX-10R front wheel that is supposedly 2 pounds lighter than the ZX-14 front wheel (both '06 vintage), is like an effective 4 pound saving in the wheel which should be very noticeable. You have to spend some good money to get a front wheel that is 4 pounds lighter than an '06 ZX-14 stocker which is 11.3 pounds (totally bare) so you would need a front wheel 7.3 pounds to "match" my setup if you use a 120/70/17 Michelin Power Pure front tire on your wheel. That formula is only approximate because it of course depends on how the weight in the wheel is distributed.
Also, if the original front tire was more than 8.71 pounds (let's say it was 9.71 pounds), then that would be 1 2/3rds pounds heavier than the Michelin Power Pure 120/60/17 so again using the 1:3 rule, that would be equivalent to 5 pounds saved in the wheel and then add another 2 pounds saved in the actual ZX-10R wheel and that is 7 effective pounds saved. I don't know of any front wheels (even BST) that weigh 11.3 - 7 = 4.3 pounds. That is "feather" light.
If someone knows an aftermarket front wheel that is about 7.3 pounds and can accept a 120/70/17 tire, I'd like to know the price. I am guessing about $1000+ new and $500+ used.
Actually I just checked and Dymag Custom Carbon wheels have a front wheel at 7.3 pounds but that is from a June 2010 article I read. "My" way seems a LOT cheaper though, especially if you need a new front tire anyway. I would think someone with a ZX-10R might want a heavier front wheel to help hold it down. I could have used one on my 10 but instead I used some weights on the front but it still lifted. I guess I needed those static weights, a ZX-14 front wheel, and a heavy front tire and it may have worked. Too late I already sold my 10.
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Quarter Pounder
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posted December 30, 2012 05:15 PM
Your math may not be correct in real world. If all it took was to put on lighter tires, don't ya think everyone would already be doing it instead of lighter wheels?
No tire change is going to be anything like a lightweight wheel swap...ever. The difference a lighter wheel makes is huge. I've done it.
____________
SWB 2008 ZX-14
9.19 @ 151
5.98 @ 123
1.53 60'
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eklipse636
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posted December 30, 2012 05:53 PM
You want to put a heavier wheel on a zx10? Wtf?! You would ruin the handeling of the zx10.
You keep saying its "chaper" to swap tires rather than new wheels. You sound like people never have to get new tires. "Swapping tires" shouldn't be compared to wheels. You are going to get new tires anyway.
____________
Best: 60ft 1.351 1/8 5.68 mph 123.98 1/4
8.89 mph 151.32
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weighmaster
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posted December 30, 2012 06:16 PM
Edited By: weighmaster on 31 Dec 2012 02:17
Do a simple experiment then and you may see I am right. Keeping your back and legs straight, do a few pushups from a horizontal position (like on the floor). Note the effort needed to lift your body a few times in that position. Then rest a bit and try it again, except this time let your knees touch the floor as the point of rotation. You should notice it is much easier to do pushups in this position. Why so much easier? Not because you are not lifting the part of your legs from the kneecap down which is only a small part of your bodyweight, but because your weight is closer to the pivot point with your knees down. So my point is any weight out away from the pivot point (or axis of rotation) makes a BIG difference in effort required to move it about that axis. That is why "regular" pushups are much harder.
Similarly, as weight gets moved away from the wheel axle, it becomes more "critical" as far as effort (power) required to move it and also to slow it down so, (pound for pound), tire weight will ALWAYS make more of a difference than wheel weight because it is ALWAYS farther from the axle.
One thing with purchasing lighter wheels is you do not know where the weight was saved. With a lighter tire, you are guaranteed almost all of the weight is saved out beyond the outer edge of the wheel where it makes the most difference.
I will do more research but it sounds like Michelin's 1:3 ratio that every 1 pound saved in the tire is roughly equal to 3 pounds saved in the wheel seems reasonable.
There is a way to check MoI (Moment of Inertia) to prove this. Perhaps someone really good with Physics can "chime in" and do a few calculations and see if the 1:3 ratio is correct or at least "ballpark". I don't know all the Physics terms but if the "center of mass" for the wheel is roughly at the middle diameter (which it may or may not be) and the "center of mass" of the tire is also at its center diameter (halfway between the inner and outer diameters), then the distance away from the axle of those is more than a 2:1 ratio but not quite 3:1 ratio but I don't think the calculation is anywhere near as simple as that.
If the wheel you are trying to lighten (by replacing it with a lighter wheel) already has a significant percentage of its weight in near the hub, then the lighter wheel probably wont make that much difference but a lighter tire WOULD in that scenario.
That is why MoI is a better "yardstick" of a wheels measure of how it will perform or at least how much energy it will take to get it rolling.
I think it is fun experimenting so on my 2006 ZX-14, I am going with both a lighter front wheel and a lighter front tire and for the rear, probably just a lighter rear tire (for simplicity and cost savings).
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entropy
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posted December 30, 2012 06:38 PM
weird thread...
weird threads generally start to proliferate mid-late december.
right on schedule...
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This moderator uses moderation in moderation
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eklipse636
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posted December 30, 2012 06:46 PM
Like stated above, I understand a lighter tire will make a better difference, but when purchasing tires, performance is a big part of it.
Your talking to us like we do not know that tires weight different amounts. Shane has already done more weighing than a lot of the engineers at Kawasaki.
____________
Best: 60ft 1.351 1/8 5.68 mph 123.98 1/4
8.89 mph 151.32
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INTIMIDA2OR
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posted December 30, 2012 06:56 PM
____________
'06 Passion Red ZX-14
*Lee*
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weighmaster
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posted December 30, 2012 06:59 PM
It is not just about static weight when it comes to wheels and tires. MoI is WAY more important. How many MoIs of wheels and tires has Shane accurately computed, logged, and shared with other people like on this site?
It is a known fact that a lighter wheel is not necessarily a better performing wheel. It depends where the weight is. For example, take a 7 pound front wheel and a 10 pound front wheel. Then add 3 pounds of weights to the 7 pound wheel at the hoop (where they normally add wheel weights). That previously 7 pound wheel that is now 10 pounds will likely have a far worse MoI than the original 10 pound wheel because it is very likely the 7 pound wheel did not lose the 3 pound differential all in the hoop.
Static weight of a wheel is indeterminate as a performance "yardstick". The Moi needs to be known to get a better idea of what to expect. If a wheel manufacturer "hides" the MoI of their wheels then they may not be that great.
I'd like to know if there is any 120/70/17 or 120/60/17 DOT approved street tire lighter than Michelins Power Pures at a claimed 8.71 and 8.05 pounds respectively.
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Quarter Pounder
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posted December 30, 2012 07:25 PM
yer chasing ghosts.
____________
SWB 2008 ZX-14
9.19 @ 151
5.98 @ 123
1.53 60'
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joel787
Zone Head
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posted December 30, 2012 07:33 PM
Edited By: joel787 on 31 Dec 2012 03:34
What type of ridding u trying to do? Guess different wheels/tires would apply different performance to different scenarios....
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http://www.proe-pr.com/cnc.html
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Acat
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posted December 30, 2012 07:37 PM
Weighed a PPPure and a PP @ Cycle Gear. PP was lighter.
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Bently
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posted December 30, 2012 07:52 PM
quote:
yer chasing ghosts.
Ya but with lighter wheels and exhaust those ghost are easy to catch!
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