[Goo Tae Uck]

Hi Guys.

I'm a Korean riding F20 120d.

want to change my wheels but here in korea there are not many wheels available to 1er
hope I can get useful information about F20


I have one question.


In Korea's F20 forum, people said installation just a spring to lower the car not together with shock will bring the bad balance to the car.

I wonder how foreign users of F20 think about this.

thx

[ovekvam]

Originally Posted by Goo Tae Uck

In Korea's F20 forum, people said installation just a spring to lower the car not together with shock will bring the bad balance to the car.

I wonder how foreign users of F20 think about this.

It is quite common to replace only the springs, and many people
seem to be happy with that. I do however agree with the Korean
forum members that replacing springs and dampers together is a
lot better. I would not swap only the springs.

[Goo Tae Uck]

Originally Posted by ovekvam

It is quite common to replace only the springs, and many people
seem to be happy with that. I do however agree with the Korean
forum members that replacing springs and dampers together is a
lot better. I would not swap only the springs.

Thanks for your opinion.

Do you also agree on the idea that changing only spring will unbalance the car?

[bmw-performance]

Originally Posted by Goo Tae Uck

Thanks for your opinion.

Do you also agree on the idea that changing only spring will unbalance the car?

I do agree with them. A stock Bimmer is beautifully balanced with or without M-sport suspension. Replacing the springs might look great but they definitely not going to improve balance of your Bimmer. If you do it, do it with a combination of springs and dampers.

[AusF20/F48]

Changing the wheels 17" to larger 19" diameter will normally also change the profile.
Larger wheels should have a lower profile tyre than the ones you replace to stay within the same overall wheel/tyre rolling diameter (that is what the suspension is set up for and the speedo).
You will be surprised how 19" wheels with lower profile tyres will change the stance of the car and its handling characteristics. I would change the wheels first before going to all the trouble of changing the suspension. Once you have the new wheels and have done a few Ks then decide if you need to change the suspension
You may have to go online and buy them over the net from Japan or get a set from one the other 1er owners from the forum

[ovekvam]

Originally Posted by Goo Tae Uck

Thanks for your opinion.

Do you also agree on the idea that changing only spring will unbalance the car?

The problem is that shorter springs are stiffer than the stock ones, and then the dampers will be too soft. It ends up with a suspension that oscillates too much. This can cause wheel bouncing and bottoming out. When the suspension hits the rubber limiters, it stiffens up significantly, and this upsets the balance of the car. The oscillation will also reduce grip and comfort.

[Goo Tae Uck]

Originally Posted by bmw-performance

I do agree with them. A stock Bimmer is beautifully balanced with or without M-sport suspension. Replacing the springs might look great but they definitely not going to improve balance of your Bimmer. If you do it, do it with a combination of springs and dampers.

Thanks.

Is there any damper that shows great combination with H&R or Eibach Pro-Kit springs?


As there aren't many users for F20 here in Korea, hard to find the good combination for our car.

[Goo Tae Uck]

Originally Posted by AusF20

Changing the wheels 17" to larger 19" diameter will normally also change the profile.
Larger wheels should have a lower profile tyre than the ones you replace to stay within the same overall wheel/tyre rolling diameter (that is what the suspension is set up for and the speedo).
You will be surprised how 19" wheels with lower profile tyres will change the stance of the car and its handling characteristics. I would change the wheels first before going to all the trouble of changing the suspension. Once you have the new wheels and have done a few Ks then decide if you need to change the suspension
You may have to go online and buy them over the net from Japan or get a set from one the other 1er owners from the forum

really? I'm worried about the performance that would become bad when I change mine to 19" wheels.

If I set 19" to my F20, which size of tires do you recommend?

[AusF20/F48]

Originally Posted by Goo Tae Uck

really? I'm worried about the performance that would become bad when I change mine to 19" wheels.

If I set 19" to my F20, which size of tires do you recommend?

There are a lot of the owners with their 1er on this forum who have put 18 & 19" on their 1ers
I am happy with the 18" wheels on my 125i M Sport.
I think that most 17" use a 205/50R17 whereas a 19" can have 30 or 35
Have a look though the thread 'Please post pics of your F20' to see some of the 1ers fitted with larger wheels.
I am sure that some of the others reading this post who are in your region can also help you

[No one]

Originally Posted by Goo Tae Uck

I'm a Korean riding F20 120d.

I noticed your profile signature says you drive F20 118d. So seems the Korean BMW site: 120d looks available in M Sport Package only, which is lacked by the car in your pictures.

So what do you really ride once you've mentioned? (No offence, I don't mind dreaming. I just mind cheating and improper application, if any. )

Originally Posted by AusF20

I think that most 17" use a 205/50R17

In regard to BMW originals, just the opposite: it's only the 380 Y-Spoke 17" (I like their look a lot, wanted them at least for the winter) pictured in the starting message that wear 205/50. All the rest are 225/45 (front ones, if applicable).

Originally Posted by AusF20

Attached Images

Amazing, but the 2" rim diameter difference is so hard to spot!

Originally Posted by Goo Tae Uck

If I set 19" to my F20, which size of tires do you recommend?

I would recommend noticing the BMW recommended (just don't say it's obvious for I know already ). Looks like 225/35 front (or around) and 245/30 rear (for 7 1/2J front/around and 8J rear rims!).

[Goo Tae Uck]

Originally Posted by No one

I noticed your profile signature says you drive F20 118d. So seems the Korean BMW site: 120d looks available in M Sport Package only, which is lacked by the car in your pictures.

So what do you really ride once you've mentioned? (No offence, I don't mind dreaming. I just mind cheating and improper application, if any. )



In regard to BMW originals, just the opposite: it's only the 380 Y-Spoke 17" (I like their look a lot, wanted them at least for the winter) pictured in the starting message that wear 205/50. All the rest are 225/45 (front ones, if applicable).



Amazing, but the 2" rim diameter difference is so hard to spot!



I would recommend noticing the BMW recommended (just don't say it's obvious for I know already ). Looks like 225/35 front (or around) and 245/30 rear (for 7 1/2J front/around and 8J rear rims!).

I just attach the 120d emblem to the 118d sports. it's ok. i don't mind your saying like that.

what do your prefer 19" or 18" ?

most korean users put just 18" to their 1er hatch.

[No one]

Originally Posted by Goo Tae Uck

what do your prefer 19" or 18" ?

most korean users put just 18" to their 1er hatch.

The larger the rims the firmer the drive (as has been noted already). Yet, the more they are vulnerable to poor road quality and theft.

I guess I'd choose the sportier 19", although I don't appreciate huge rims looks. Yet, the ride might appear too firm then: the road quality should be really good.

[Goo Tae Uck]

Originally Posted by No one

The larger the rims the firmer the drive (as has been noted already). Yet, the more they are vulnerable to poor road quality and theft.

I guess I'd choose the sportier 19", although I don't appreciate huge rims looks. Yet, the ride might appear too firm then: the road quality should be really good.

Thanks for your answer.

could you please tell me where i can see all of the specs for the original BMW wheels?

[ovekvam]

Originally Posted by No one

I guess I'd choose the sportier 19", although I don't appreciate huge rims looks. Yet, the ride might appear too firm then: the road quality should be really good.

When people have several sets of wheels, they will usually prefer smaller wheels than 19" for track days or autoX. Smaller and lighter wheels generally perform better. Large wheels are mostly for looks, and room for huge brakes.

[AusF20/F48]

Originally Posted by Goo Tae Uck

Thanks for your answer.

could you please tell me where i can see all of the specs for the original BMW wheels?

I like both the 18" M and M Sport wheels

Depending on the number of spokes the 19" can look a bit of a wagon wheel on a 1er with standard brake calipers

Anything in a 5 spoke (single or double spoke) should look good

[No one]

Originally Posted by Goo Tae Uck

could you please tell me where i can see all of the specs for the original BMW wheels?

I gave the link to the official BMW wheel configurator already: the link was labelled "the BMW recommended". Here it is again, labelled itself plain text: http://www.bmw.com/com/en/owners/acc...els/index.html, which is "http://www.bmw.com/com/en/owners/accessories/bmw_complete_wheels/index.html" (no quotes) to show complete for copy/paste.

Just click the link, click the "Start wheel configurator" (the blue button or the link below the introduction text) and proceed to fill in your vehicle information. When through, notice it's the winter sets presented by default: you need to choose "Summer" on the left I guess. Click the rim to choose (the style/name are shown above), use the view buttons on the right to turn the car/zoom and the "Product details" button to review the complete info (with tyres and "Part number" for reference to order at your dealer) on the rim selected.

[No one]

Originally Posted by ovekvam

When people have several sets of wheels, they will usually prefer smaller wheels than 19" for track days or autoX. Smaller and lighter wheels generally perform better. Large wheels are mostly for looks, and room for huge brakes.

And smaller engines, too (for lightness and ease of power handling on ice/snow)? I know it's common to choose smaller rims for winter, I just guess you mean summer conditions as well.

Nice to know as my rims (both sets) are 17", large enough to house my M Sport brakes, safe(?) from the "show off" point, cheaper and their looks is just all right for me: I don't appreciate "too much" of anything. 18" could be still better but impractical on poor roads anyway. Thank you!

[ovekvam]

Originally Posted by No one

And smaller engines, too (for lightness and ease of power handling on ice/snow)? I know it's common to choose smaller rims for winter, I just guess you mean summer conditions as well.

Yes, some of us even prefer smaller engines, but that is not so common. My E30 318iS could usually beat an E30 325i on twisty tracks due to the lighter front end. That is why BMW chose a four cylinder engine for the E30 M3.

Originally Posted by No one

Nice to know as my rims (both sets) are 17", large enough to house my M Sport brakes, safe(?) from the "show off" point, cheaper and their looks is just all right for me: I don't appreciate "too much" of anything. 18" could be still better but impractical on poor roads anyway. Thank you!

Some people prefer the quicker steering response from the lower sidewalls on the tyres that fit larger wheels. Apart from that, there are pretty much no performance benefits. Even formula one cars run on very small wheels.

[No one]

Originally Posted by ovekvam

Some people prefer the quicker steering response from the lower sidewalls on the tyres that fit larger wheels. Apart from that, there are pretty much no performance benefits.

Really? I thought you meant this again:

Originally Posted by ovekvam

It is mostly about feeling what the car is doing through the seat. What you want to feel with your butt, is the grip from the tyres. The higher you sit, the more movement you will feel from the car moving around on the suspention, mostly leaning from side ot side.

This is very noticeable if you are in a bus. If it rides over a small bump with one wheel, or leans over in a corner, you can feel a lot of sideways movement starting and stopping. Lots of G-forces that you are not really interested in. What you want to feel, is in the ground level, at the tyre contact patches.

this time in regard to tyre profile - the higher it is (especially the soft wall non-runflat ) the more it's responsive to the G-forces, adding to the suspension softness, isn't it? I thought you had meant at some point the rim weight played above the tyre stiffness, but now you seem to suggest tyre stiffness is almost negligible.

Originally Posted by ovekvam

Even formula one cars run on very small wheels.

Formula One is a different world, I suppose: lot's of regulations and different technologies - rock-hard suspension(?), aerodynamics extremely involved, quite different tyres, etc. It could be as different as the looks, I guess.

[ovekvam]

Originally Posted by No one

this time in regard to tyre profile - the higher it is (especially the soft wall non-runflat ) the more it's responsive to the G-forces, adding to the suspension softness, isn't it? I thought you had meant at some point the rim weight played above the tyre stiffness, but now you seem to suggest tyre stiffness is almost negligible.

Actually I prefer to have quite a bit of compliance in the tyres. They mainly soak up small bumps and irregularities in the road surface. If the sidewall is stiff, the wheel will have to do a lot more vertical movement. Combine this with a heavy wheel, and you will get a lot of variations in grip. Sometimes a heavy low profile wheel will actually skip and bounce. You can also feel it inside the car as decreased comfort.

The tyre deformations of the high profile tyres do however also soak up some of your steering inputs, causing slightly slower steering response. This is mostly noticeable when driving very fast in strong wind, where you can feel the car move around a bit more.