When I got my toaster I had the stock 15's on their for about a week; upgraded to 17's with a 45 series tire loved it. But after time stoppping was a pain due to the heavy weight of the rim 22 pounds to be exact. Sold those and know have another set of 17's and they are 17 pounds each I love the feel of the rims but I'm hating them now.

I really wanna get 15" lightweight rims for two reasons. I might get better acceleration but thats not the main reason. After my two inch drop I really didn't like the feeling of it but it looked so sweet I kept it.

If you go to tirerack.com and there are two rims that I am debating on Motegi Tracklite 2.0 the ones that are black with a chrome lip(yeah I know black rim with chrome lip is kinda played out a tad) and the SSR that are 8.8 lbs

Can I throw either one of these on my car with my stock tires with no problem and a 2 inch drop. Anyone that has lightweight rims that are really light please chime in; btw the rims that I am riding on right now need a home; any takers

 

what are the specs on both wheels? you should be okay. but id get a shorter tire.

 

Well I went from 24lb 17's with 215/45 tires to 15lb 15's with 195/50 tires that were 5lbs lighter as well. so that was about 14lbs saved per corner. There is a huge difference in acceleration and deceleration. any reduction in unsprung weight is dynamically equivalent of 4-5 times that of sprung weight, so it feels like the car is 200-300lbs lighter.
The challenge of course is finding light 15's that don't look dinky on the xB...

 

One important factor to keep in mind is that smaller diameter wheels are eaiser to stop because your brakes are basically getting better 'leverage' on the ground. Similarly, this is also one of the biggest benefits of big brake kits, where the brake pads are spaced further from the center of the wheel because it takes less effort to stop the wheels. The same is true in an opposite sort of way when dealing with oversized wheels. Even given the same moment of inertia, 17" wheels will naturally be harder to stop than 15" wheels.

 

hehe another reason why i souldn't get some rims!!! sweetness!!!

 

I recently put on a new set of 15" wheels/tires. I imagine the entire thing weighs are 28lbs so I'm not saving that much per corner but the right w/ OEM sized tires is worth it!

Our OEM goodyears sucked compared to many other tires out there.

 

I remember a saying from my bicycling days.

"an ounce off the wheels is like a pound off the frame"

 

I have a set of 15" Work Equips that are very light and I have a set of 17" Speedy Lite 5s which are heavier. I just put my 17s back on for winter and now I miss the acceleration that I got with my 15s.

 

Yeah, I can't believe so many hang on to them. If you're buying new wheels, buy new tires! The Yokohama AVID TRZ I got were cheap and a big improvement. They were about 2 lbs heavier per tire than the Goodyear though, so they pretty much just offset the weight savings from the alloys. I stayed away from the super lightweight alloy wheels because I wasn't sure how they'd stand up to potholes and whatnot.

 

I also just put the Avid's on and for the quiet ride and smoothness - they do what I want. I didn't do anything recently to go faster but for my comfort.

I used to never want to drive the xB, now I drive it everywhere.

 

Sorry, your logic is flawed. What affects braking is over all outside diameter of the tire. Not wheel size. The brakes can't tell the difference between 15 and 17 inch wheels except for the weight difference.

BTW, I don't understand why everyone hates the OEM Goodyears. Mine corner great and handle the snow like crazy. Guess I'll see a difference after I change them out. :?

 

I beg to differ, at the same weight you still extending the leverage against the brakes. You are in effect using a longer lever thus giving more of a mechanical advantage. HMO

 

I give up

 

Have you ever spun around in a chair? Extend your legs and you will slow down. Bring them in close and you will speed up, even though your weight has not changed.

So how does this compare? Let's try to simplify this:

OK when you start spinning and do not keep spinning yourself, you have a given rotational inertia, or momentum. Stick those legs out and you go slower. Your center of mass is not as close to what you are spinning around and that momentum you had (while still there and unchanged) is met with a larger resistance to keep you spinning since your center of mass is further away from what you are spinning around.

OK now say you have a 15" wheel and a 17" wheel that weight the same. We should all realize that aluminum or steel (wheel) weigh more than rubber (well, rubber and a nominal amount of steel in a tire.) If you get that heavier material closer to the center of rotation then it will be easier to get spinning and stop spinning.

I hope that makes sense.

 

Motegi tracklite 2.0

6-spoke design
1-piece forged construction
Push-in center cap with exposed lug bolts
Machined lip
Finish Shown: Black w/Mach Lip
Size Selected: 15x7
Price: $232 (each)
Recommended Tire Size: 185/60-15
Wheel Offset: +35mm
** Lightweight: 10.4 lbs.

SSR Type C
Size Selected: 15x6
Price: $299 (each)
Recommended Tire Size: 185/60-15
Wheel Offset: 38mm
** Lightweight: 8.8 lbs. **

 

Check the weight of your desired tires. You may find you are putting 20 pound tires on ten pound wheels, and the tire's weight is mostly carried in the tread/belt area, which is waaay out on the end of that moment arm.

Lighter is better as far as unsprung weight that the suspension has to deal with, but our suspensions are not race suspensions and don't really take a whole lot of notice. They are too damped and slow moving to notice.

Ben is right about the longer moment arm having more effect, but most of the time the tire's tread is the biggest effect on that...

Tom

P.S. IIRC, the OEM Goodyear POS tires are 18 pounds, and my aftermarket skins are 21 with most of the difference being in tread weight...

 

sorry max but yu must have failed physics or i did, cause what you said is ok, i skipped most of it but, the farther away the weight is the easier it is to spin, not the other way around, its basic physics that the more distance traveled, the less force must be used,

 

I'd say you failed physics.

 

 

Maybe I was using "wheel" too liberally, but you're right, I was referring to the overall diameter. But in general, the overall diameter of the wheel/tire will increase with the size of the wheel. True, there are a few wheel/tire combos that would allow for a larger wheel with a smaller overall diameter, but then you're just looking to a technicality to contradict what I'm saying.

To put it another way, say you have a short stick (~1ft) and a long stick (~3 ft). Taking the short stick first, if you hold one end in your hand and rest the other end on the edge of a table (so the stick is parallel to the ground) and you try to press down on the table, you will be able to exert much more force with the short stick than with the long one. Now imagine those sticks are spokes on a wheel and you'll see what I'm saying.

The reason I say big brake kits work in a similar but opposite sort of way is this: Imagine your friend is now holding your stick (not that stick, pervert! ) and your fingers are on the edge of the table. Would you rather your friend press on your fingers with the 1ft stick or the 3 ft stick? It takes less work to stop the longer stick because now the advantage is on your side. It all depends on which side you're looking at it from.

You all are totally right about the weight issue as well, so don't start jumping all over me about weight being more important. It is. I'm simply presenting yet another reason why larger wheels make it harder to stop/start.