# Light Wheels?



## bblocher (Jul 30, 2008)

I haven't gotten to the stage where I'm ready to replace my wheels yet, but it's coming so I've thought about it a little bit. Any aluminum rim will be much lighter than a steel rim. You may already have a light weight wheel on the vehicle. Hard to say how much weight you could save without weighing one of your rims and then heading down to a tire shop with your scale for comparisions 

It would also seem the smoother the rim design the less rotational wind drag it would have. Not sure this accounts for much compared to body design, wheel wells, etc. though.


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## sailfish11 (Sep 15, 2007)

I've heard that rotational weight is somehow 'heavier' than simple weight. Maybe some engineer-types could confirm that?

I'm limited to shopping over the internet, so directly comparing weights isn't an option for me right now. If anyone knows of a good wheel site that lists the weight of its wheels, that would be appreciated.


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## TX_Dj (Jul 25, 2008)

Well, I'm no engineer... but yes... The heavier and/or larger diameter of a rotational items, the more energy it takes to accelerate it.

I.E. the barstool example. If you sit on a barstool with your arms and legs outstretched, it takes far more energy for your friend to spin you up to a certain RPM than it does if you pull your arms and legs in to your body. The same is true if the diameter is the same, but the weight is increased.

Bigger or heavier wheel/tire combos require far more force to accelerate than smaller or lighter wheel/tire combos.

When I first bought my Tacoma, I didn't like the tires it came with. They had no wet traction to speak of, and lots of sidewall flex. I had some heavy-duty 10-ply all-terrain tires left over from my previous truck, which I had mounted in place of the stock tires. Immediately I felt the effects of the added unsprung weight, in addition to the extra rotational mass.

I drove with those tires another 20,000 miles before I finally wore the rest of the tread off of them, and then replaced them with a lighter tire that had better characteristics than the stock tires. I noticed immediately the reduced unsprung weight, and the reduced rotational mass. The truck felt peppy and spritely, unlike any of the previous 20,000 miles. The reduced unsprung weight made the ride incredibly more comfortable.

I would recommend using the absolute lightest and most aerodynamic wheels you can find on an EV. Every bit of weight and drag that you can save will have a direct impact on your range and performance.


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## Evan (Feb 20, 2008)

Just to add a funny story, I used to own a '97 Ford Escort one of the lower HP cars made for the American market. I got it used from some very nice Canadians. The funny thing is that it came with magnesium alloy wheels. It saved gas but those wheels cost, I one of them was ultimately almost done in by a Cambridge pothole.


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## sailfish11 (Sep 15, 2007)

Dj, thanks for using an example I can relate to, barstools! I shouldn't joke about that, right now I'm in Kuwait -- no alcohol. 

That makes sense -- even from a non-engineer.

Is aluminum the best choice then, or are there lighter alloys?


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## Coley (Jul 26, 2007)

I have some light weight aluminum wheels, that I ran on my V8 Vega (now there was a fun car - 350 w/4 speed).

The only problem is that when I could really use the weight savings, as in winter, the aluminum wheels corrode so badly, from the damn salt they put on the roads.

I ran some magnesium wheels for a while, but they would even corrode in the summer.

If you don't live in the rust belt, they would probably help....


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## Guest (Sep 23, 2008)

Yup, those big ugly 22" Chrome Rims are costing their owners a bundle at the pump. Very high rotational weight. Rim size is a component in design. Don't disregard that fact. Stock stamped rims are actually pretty light. Keeping the proper size they are not any worse than installing some larger rims that will increase the rotational weight. So it kinda negates the fact that some aluminum rims are lighter in weight. Not all aluminum rims are lighter than the stock stamped steel rims. Stock is perfect for my application. Looks good too. Better than most aftermarket rims. Again for my application.

Pete : )


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## EV'er wannabe (Aug 1, 2008)

sailfish11 said:


> Dj, thanks for using an example I can relate to, barstools! I shouldn't joke about that, right now I'm in Kuwait -- no alcohol.
> 
> That makes sense -- even from a non-engineer.
> 
> Is aluminum the best choice then, or are there lighter alloys?


Magnesium.
The real Mag wheel.
Jerry


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## sailfish11 (Sep 15, 2007)

Hmm... corrosion would be a problem. My EV will be a daily driver and I live in upstate NY -- you may have heard, we get a lot of snow up here (and a LOT of salt).

Does anyone know of a website selling wheels that publishes their weight?


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## TX_Dj (Jul 25, 2008)

Another rotational weight item that many fail to consider is the size of a brake disk rotor.

In the sport compact world, there's a trend to put the largest wheels that fit with the largest brake rotors that fit. It can be argued that a larger weight and/or diameter wheel will require more stopping power, but increasing the diameter of the brake rotor has the same effect.

I've actually seen dyno results of a before/after of this kind of setup, going from stock sized wheels and brakes to gigantic aftermarket of both, and apparent power where the rubber meets the road is definitely impacted by the "performance upgrades"


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## Evan (Feb 20, 2008)

TX_Dj - You have a point there. The auto industry should have more seriously investigated ceramic disk breaks 20 years ago.


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## ice (Sep 8, 2008)

Agree with TX_Dj... And you're right Evan...


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## kixGas (May 2, 2008)

I don't know if they are the lighest wheel out there but Sportmax makes some fairly light wheels- especially for the money.
http://www.xxrwheels.com/sportmax_003.shtml


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## Zer0 (May 9, 2008)

As a general rule, a forged wheel is going to be lighter than a cast wheel, but also more $$$.

If you are looking for a place that publishes weights, I would recommend 
www.edgeracing.com. They publish weights for *some* of their wheels and also *some* of their tires (they carry multiple brands of both). I believe that they weigh new products themselves, because it appears the listed weights of the wheels vary by size and even offset. I and friends have dealt with them before, there were some hiccups with my order due to the size I wanted not being in stock at their warehouse, but I got my wheels/tires fairly quick considering and was more or less satisfied with the service.


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## Guest (Sep 24, 2008)

They did. : )



Evan said:


> TX_Dj - You have a point there. The auto industry should have more seriously investigated ceramic disk breaks 20 years ago.


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## ISellMiataParts (Sep 24, 2008)

sailfish11 said:


> Any thoughts on a set of good looking, lightweight wheels for my EV? I've looked around a bit and wheel dealers don't seem to publish the weight of their wheels. Any suggestions?


Do you have a weight in mind? Most racing publications will advertise weights of wheels with the ads since thats something club racers are concerned with. Shouldn't be hard to find a 15x7 wheel under 10-12 lbs? Kazeras, rotas, etc.

the honda Civic VX and HX came with a set of hollow spokes that are pretty snazzy and super light weight, so did some of the Miatas. They're 14" rims though.


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## ISellMiataParts (Sep 24, 2008)

sailfish11 said:


> I've heard that rotational weight is somehow 'heavier' than simple weight. Maybe some engineer-types could confirm that?


The other thing to consider is that "unspring" weight like rotor discs and wheels/tires is also more expensive as well.

In racing we cross drill rotors to both reduce weight as well as make the cooling of the pad more efficient. you can also have a brake rotor turned down to its smallest usable size to reduce on weight but you lose usable life with that approach. In racing we dont care, in saving the environment you probably do 

I have heard some discussion of a "polar moment" being more expensive in some applications too, like between these two wheels, the Team Dynamic Race 1.2 and 2.0 models:

http://www.306gti6.com/forum/attachments/4501_prorace2black.jpg

http://www.teamdynamicsracing.com/images/procomp1white.jpg

what is the truth in that?


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## john818 (Aug 1, 2008)

One of the bigger wheel and tire companies in the US is The Tire Rack. (http://www.tirerack.com/) I've ordered from them a couple of times and had good experiences. I just popped into their site and saw weights listed on their wheels. You can search for what will fit your actual make, model, and year. They have a wide selection, but of course, they don't carry all brands.


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## bblocher (Jul 30, 2008)

You guys know if light weight rims are then lighter than the tires? So like are you better off going with a 17" rim (for example) and a lower profile tire or a 15" rim with a higher profile tire. So basically you have the same circumference but one or the other is bound to give you less rotational mass. Wonder which way that would be and what some of the draw backs may be.


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## ISellMiataParts (Sep 24, 2008)

bblocher said:


> You guys know if light weight rims are then lighter than the tires? So like are you better off going with a 17" rim (for example) and a lower profile tire or a 15" rim with a higher profile tire. So basically you have the same circumference but one or the other is bound to give you less rotational mass. Wonder which way that would be and what some of the draw backs may be.


rubber has got to be heavier than alloy, there is simply a lot more material in a tire (thicker walls + two walls vs only one on the wheel) than the metal wheel. There is a lot of cost to going with two thin of tire, however, as the sponginess of a rubber tire adds to the damping force of your suspension, in essence it becomes a part of the suspension. 17" wheels with thin rubber == crappy ride quality.


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## sailfish11 (Sep 15, 2007)

Wow -- great discussion and good links! Thanks much!!!!


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## sailfish11 (Sep 15, 2007)

I REALLY like that www.tirerack.com website! It's great to be able to view the wheels on your car!


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## dtbaker (Jan 5, 2008)

sailfish11 said:


> Any thoughts on a set of good looking, lightweight wheels for my EV? I've looked around a bit and wheel dealers don't seem to publish the weight of their wheels. Any suggestions?


some of the online places like http://www.tirerack.com/ do publish weights. What is interesting is some of the 'economy' AL wheels are 4 or 5 pound lighter per wheel than other Al, and probably 10 or more lighter than steel.

...and yes, rim weight plays a fairly significant part in energy required to accelerate. There are lots of equations, but the essentials are that spinning weight has a dual effect. You have to move it around, AND spin up to speed.


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## sailfish11 (Sep 15, 2007)

Although the tirerack is a great site, I'd like to find some other sites that publish weights. Does anyone know of any other sites with published weights? You'd think there would be more!


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## sunworksco (Sep 8, 2008)

For the strongest,lightest wheels, look at the Black Mamba at
www.blacksonetek.com
This is what I am using on my 600lb. EV Trike.
I custom machine the hubs to fit the uprights.


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## sailfish11 (Sep 15, 2007)

Sunworksco, could you check the link -- I can't get it to work!


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## sunworksco (Sep 8, 2008)

A thousand apologies! I was very tired when I wrote that.Enjoy.
http://www.blackstonetek.com/


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## Gary Sconce (Oct 4, 2008)

Thin and small is good. Notice that ICE econoboxes have tiny wheels that are moderately thin. Thin tires do not necessarily have worse traction for normal driving, as Pascal's principle, or Force/Area=pressure, shows that there is a maximum best pressure applied to the street for the weight of the vehicle/(4 x wheel area). I would even consider adding a set of Moon aluminum flat hubcaps for your wheels to maximize wheel aerodynamics. 

Also, in a related topic, putting an aerodynamic lightweight pan over the entire underside of the EV would cut out a large amount of drag... but I am sure that has been previously talked about on this site.


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## order99 (Sep 8, 2008)

Try 

http://ecomodder.com/

About 60% of the techniques they mention (driving techniques, bodymods etc) would be applicable to EVs...they have an EV Sub-forum too BTW.


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## martymcfly (Sep 10, 2008)

Mini-stock racers have always been concerned with rotating weight, but are limited to steel wheels. The last set that I ordered were 13x7 Falcon racing wheels. They weighed in at a little under 13 lbs. each. The problem is that they are not street legal.


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## TX_Dj (Jul 25, 2008)

Why are they not street legal? Just missing a DOT stamp, or what?


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## martymcfly (Sep 10, 2008)

It just says on the box that they are not for street use. There are several racing wheel manufacturers. Bart wheels, Aero wheels Pete Paulsen wheels, etc. I suspect they are not DOT approved.


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## sailfish11 (Sep 15, 2007)

My challenge is to balance efficiency with cosmetics. My EV is a '65 Mustang, and I've allowed myself a pretty high budget for the conversion/restoration.

So although I want to get wheels/tires that are efficient, I'm also somewhat constrained by my choice to keep the Mustang's retro look (not necessarily stock, but in line with the 60's style).

American racing makes some nice wheels actually designed for Mustangs. I may end up going that route.


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## Ioku (Sep 27, 2007)

ISellMiataParts said:


> rubber has got to be heavier than alloy, there is simply a lot more material in a tire (thicker walls + two walls vs only one on the wheel) than the metal wheel. There is a lot of cost to going with two thin of tire, however, as the sponginess of a rubber tire adds to the damping force of your suspension, in essence it becomes a part of the suspension. 17" wheels with thin rubber == crappy ride quality.


You may get a crappy ride but thinner walled tires usually have less tire deflection so less energy wasted and better efficiency.


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## sailfish11 (Sep 15, 2007)

Ioku said:


> You may get a crappy ride but thinner walled tires usually have less tire deflection so less energy wasted and better efficiency.


Perhaps, but I still need to balance efficiency with good looks, so here's what I'm thinking:

American Racing Vintage Torque Thrust D, 15" wheels
Michelein X Radial P205/65R15 tires


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## DavidDymaxion (Dec 1, 2008)

http://www.tirerack.com lists a bunch of wheels and wheel weights.

http://www.mooneyesusa.com/Store/index.php these are the choice of land speed racers for reducing aerodynamic drag.

Don't assume an alloy wheel is always lighter than a steel wheel -- sometimes the stock steel wheel will be lighter.

The land speed guys use space saver wheels. They weld the whole seam for strength (they are generally just welded together in spots). These are narrow, which helps aerodynamics, and cheap.


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## john818 (Aug 1, 2008)

DavidDymaxion said:


> Don't assume an alloy wheel is always lighter than a steel wheel -- sometimes the stock steel wheel will be lighter.


Same goes for stock alloy wheels. Some stock 14" x 6" Miata wheels were under 11 lbs! These obviously aren't your bolt pattern, but with a little effort, maybe you can find some light stock wheels that have the right bolt pattern and offset.


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## sailfish11 (Sep 15, 2007)

hmm.... time to expose my ignorance on all things 'wheel'. How universal are wheels? You mention bolt pattern and offset; one of the problems I'm going to have is that my donor doesn't have stock spindles. The car is a '65 Mustang, but the previous owner said the rear axle was off a Ford Versailles.

Is there a way to tell what bolt pattern and offset I need? Do I have to measure something or look something up?


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## john818 (Aug 1, 2008)

They're not very universal.

Basically, bolt pattern refers the the number of bolts and their spacing. Most cars have 4 or 5 bolts per wheel and spacing will vary quite a bit. Offset refers to where the wheel rim is in relation to the bolt holes, either toward the center of the car or away. This affects clearance at the fender or suspension. Here's a link to the Wikipedia page on wheel sizing. It should answer most of your questions.
http://en.wikipedia.org/wiki/Wheel_sizing

According to Discounted Wheel Warehouse, classic Mustangs have a 4 x 4.5 (4 x 114.3 metric) or 5 x 4.5 bolt pattern, and the offset is what they call low or medium. I don't know for sure, but I would guess the the V8s had 5 bolts and the Inline 6s had 4 bolts.
http://www.discountedwheelwarehouse.com/Ford___Vehicle_Bolt_Pattern_Reference.cfm

You probably have stock hubs on the front, and even if someone swapped the rear axle, they might not have had to change the hubs. Most likely, the bolt patterns match. I suppose you could swap wheels front to rear to check if they fit the same. If it's a different bolt pattern it won't fit. Or maybe you could make a pencil rubbing.

By the way, I Googled Versailles, and there was a Ford Versailles sold in France in the 50's and one sold in Brazil in the 90's, but there was a Lincoln Versailles sold in the U.S. in the late 70's. It was basically a rebadged Ford Granada.


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## shoup (Feb 10, 2009)

Team Dynamics has some lightweight wheels that look great. Here is a link to a distributor in the US:

http://www.teamilluminata.com/Shop/TeamDynamics/TeamDynamics.htm

Kosei, SSR, Volk, Rays, Gram Lights are a few other wheel manufacturers that offer lightweight racing wheels. Be ready to dish out $$$ for light forged aluminum wheels.

Tire weight is also very important and Tire Rack publishes the weights.


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## sunworksco (Sep 8, 2008)

shoup said:


> Team Dynamics has some lightweight wheels that look great. Here is a link to a distributor in the US:
> 
> http://www.teamilluminata.com/Shop/TeamDynamics/TeamDynamics.htm
> 
> ...


The nice thing about reverses trikes is that you can use lightweight motorcycle wheels weighing as little as 5.5lbs. yet stronger than steel wheels. http://www.blackstonetek.com/


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## vonterk (Apr 2, 2009)

sailfish11 said:


> I've heard that rotational weight is somehow 'heavier' than simple weight. Maybe some engineer-types could confirm that?
> 
> I'm limited to shopping over the internet, so directly comparing weights isn't an option for me right now. If anyone knows of a good wheel site that lists the weight of its wheels, that would be appreciated.



Not sure if anyone answered this already, but I used to work in the wheel industry and rotational weight is 4x the weight of the wheel+tire. So for a 15lb wheel/tire combo your looking at 60lbs of rotational weight (which if you can get a 15lb combo like that for a street car I would be surprised. Expect around 20+lbs for most tire+wheel combos). The same holds true for rotors and any other rotating mass on the car.


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## dtbaker (Jan 5, 2008)

'rotational weight' refers to the inertial mass, affecting energy required to start and stop. wheel mass has little to no effect at steady state; aerodynamics would be far more important at steady speeds over 25 or 35 maybe. Since most 'acceleration events' from a stop last under 20 seconds, the amount wheel weight will affect overall efficiency is not that big unless you typically are driving short city blocks.

Looking at inertia, you'll find that the closer to center, the less it matters. So, smaller dia tires are lighter and have WAY lower inertial mass.


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## Duncan (Dec 8, 2008)

Possible danger here using motorbike wheels, bikes lean into corners so the stresses are all in line with the rim,
A non leaning machine puts side loads on the wheel
A Bike wheel may be able to cope with a big heavy fast bike but fail on a lighter trike


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## dtbaker (Jan 5, 2008)

Duncan said:


> Possible danger here using motorbike wheels, bikes lean into corners so the stresses are all in line with the rim,
> A non leaning machine puts side loads on the wheel
> A Bike wheel may be able to cope with a big heavy fast bike but fail on a lighter trike


Absolutely true.... also the reason why dragsters and such can use super light front wheels... no side loads.


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## sunworksco (Sep 8, 2008)

Each BST carbon fiber bike wheel can handle 750lbs. load.
Reverse-trike car figure 3 wheels x 750lbs. = 2250lbs. total load.My trike will weigh between 600-700lbs.A third of the total wheel load.
BST is also made to handle side loads.There engineering tests are on their website.
I have spoken with the factory engineer and they have already sold some BST Black Mambas for electric cars.I'm also using these for my Porsche 550 Spyder EV.The Spyder will only weigh 1200lbs.Anyone out there who needs help setting up a Spyder with front and rear control-arm suspension can get back with me.I use this design for the VintageSpyders.com frame.Both of my designs have inboard coil-over shocks and rear has inboard brakes.


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## john818 (Aug 1, 2008)

Duncan said:


> Possible danger here using motorbike wheels, bikes lean into corners so the stresses are all in line with the rim,
> A non leaning machine puts side loads on the wheel
> A Bike wheel may be able to cope with a big heavy fast bike but fail on a lighter trike


I haven't heard of wheel problems on reverse trikes, but I have heard of one or two swingarm problems. Bending under heavy load. Of course, I've heard of many with no problems, too, so I assume it depends on each application .


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## IamIan (Mar 29, 2009)

I didn't see it listed yet so I figured I would throw this out there too.

The Aptera as far as I know is using the same wheel and tire as the Gen-I Insight did ... and the OEM Bridgestone Potenza RE92 165/65R14 is a very LRR tire.

The Gen-I Insight Wheel and Tire specs:
the combination comes in @ ~22 pounds.

*Stock Wheel*
Mfg: Asahi Tec Corporation
Size: 14 x 5.5 J
Bolt Pattern: 4-100mm
Lug Size: 12 x 1.5mm
Offset: +45H
Weight: 11 lbs
Finish: Aluminum
Style: 12 slot

*Stock Tire*
Mfg: Bridgestone
Model: Potenza RE92
Size: 165/65 R14
Compound: 78S
Treadwear: 260
Traction: A
Temp: B
Weight: 11.5
Pressure: 44psi
RPM: 926

The following tire sizes are currently available to fit the stock wheel from major tire chains.

165/65 R14
175/65 R14 
185/60 R14 
195/55 R14

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there are materials that could be used to make the tire / wheel system lighter ... but the cost goes up rather quickly ... as it has been said depending on construction method ... Magnesium can be better than Aluminum ... Titanium can be better than Magnesium ... and structural Carbon fiber can be better than Titanium... but cost keeps going up and up... and it keeps getting harder and harder to make it ... with fewer and fewer people interested ... and fewer and fewer people able to to it ... until above magnesium you pretty much have to have it custom designed , engineered , and fabricated from raw materials.

------------------

but like others have already posted... there are other considerations as well... brakes ... weight ... driving conditions ... etc...

--------------------

Oh I bumped into this...

dry carbon wheel project ... is a 100% carbon fiber wheel weighing ~6 pounds.


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## sunworksco (Sep 8, 2008)

john818 said:


> I haven't heard of wheel problems on reverse trikes, but I have heard of one or two swingarm problems. Bending under heavy load. Of course, I've heard of many with no problems, too, so I assume it depends on each application .


 I'm using BMW F800ST motorcycle single-sided swing-arm for my reverse-trike EV.Here is an image :


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## john818 (Aug 1, 2008)

sunworksco said:


> I'm using BMW F800ST motorcycle single-sided swing-arm for my reverse-trike EV.Here is an image :


Wow! That looks sleek! Are you using a bike tire or car tire? The left side of that swingarm looks shaped for a bike tire. Will a car tire clear it okay?

I'll probably fab my own to fit my application. I'm sure it'll be ugly, but I hope it works right!


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## sunworksco (Sep 8, 2008)

john818 said:


> Wow! That looks sleek! Are you using a bike tire or car tire? The left side of that swingarm looks shaped for a bike tire. Will a car tire clear it okay?
> 
> I'll probably fab my own to fit my application. I'm sure it'll be ugly, but I hope it works right!


Smart question! You will go far with your EV build.Not kidding.
Since I am machining a Ducati 1098/BMW style axle/hub,this will alow me to create more width on the axle.This will give the suspension 3 Ducati style axle/hubs for the BST carbon fiber wheels.The tires will be dry season 205/40/17.
The EV will be front-wheel drive with limited-slip differential and single motor driven by Kevlar belt/pulley(7-1 gear ratio).
Here are some images of the axles.


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## Xtremek (Jun 13, 2009)

A bit about the bolt pattern. Probably the reason the previous owner swapped out the stock rear axle for the Versailles, is that the Versailles has the same bolt pattern and offset as the Mustang and it came with disc brakes. It's a common swap for Ford and Chrysler owners who want to get discs in the rear. And the implication of the last sentence is right, that older Ford's and Chrysler's share the same bolt pattern. If you want to go really light, go mag. Run the steels during the winter and mags in the summer. That way you can snow tires in the winter and keep the mags pretty. That's what I do. If you've got a lot of potholes in NY like we do here in Michigan, I wouldn't mind running a 50 series but stay away from the "rubber bands". You're not going to drive a '65 in the winter are you?


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## COS (Dec 23, 2008)

Here's my 2cents...
http://cgi.ebay.com/ebaymotors/15-I...bs-racing_W0QQitemZ200353162717QQcmdZViewItem

Claimed to be 10.6lbs. Been looking at this for a while. Can't buy till I have my EV conversion.
________
SexxyMolly


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