Reminds me of my Yamaha R6 and hitting the grooved pavement when they a resurfacing the highway... YIKES! That's a little pucker factor!

 

I didn't ignore your post but the same tire and wheel wiggles on one car but not another. This does not point to the tire in my opinion.

 

I equate it to a car that has its suspension dialed in... You want to feel the road.

 

Saying it again....bushings.....the extra wiggle from even sligtly worn ones eill make tramlining worse....the tread pattern on the tire is important, as is wheelbase....
And shocking news, dealers are not suspension experts...they are parts swappers, and are usually fresh techs just out of school.....then .dealers send them to mini school, and they learn just mini, and then the most common items to fix on new cars...stuff they do all day and make $$ for the dealer on....the more obsure stuff gets learned when they move on to a more general automotive shopthat does many makes/models, generaly older cars that need different stuff fixed beyond typical newer car stuff.

 

The Clubman wheelbase is 3.2" longer than the hatchback and 9.4" longer overall. A longer wheelbase simply won't wiggle as much as a shorter one. Various tires/treads will produce differing amounts of wiggle. I've had numerous brands of tires on my '05 R53 and my wif
e's '07 R56 and they will both wiggle depending on the tire and tread. When the tread gets worn it gets more noticable.

 

 

Thanks for the input. How can I get the Dealer to replace the bushings under warranty? Any ideas?

 

I have a 2007 MCS, and I drive I96 and M14 quite a bit, and mine does the same thing. I also have a 330i and Z4M and neither one of them do it, but I have driven other cars in the past (can't remember which ones) that do the same thing. I notice it most where the concrete has those longitudinal groves cut into it, it almost feels like it's wandering side to side from groove to groove, sort of hunting for a stable path to track in.

I have 3 sets of tires for my MCS, 17" Conti DW (summer daily) 16" star-specs (track), and 16" Blizzaks (winter) and they all do it to some degree.

I'm a chassis development engineer, and I haven't studied this exact phenomenon in detail, but it has to do with the tire's compliance characteristics combined with the car's steering geometry and dynamic alignment (The car's alignment changes when you're driving because of compliance in the rubber bushings, tire, and strut/control arms). It's the interaction between all the parts of the system that is causing it, and nobody outside of an OEM is going to have the equipment or know-how to properly analyze it. Things you can do:

Get an alignment to the center of the factory specs. Not just "within factory spec," but dead nuts center. Factory specs have a huge range to allow for fast throughput on the assembly line. You'll want a dealer or a GOOD alignment shop to do this.

Experiment with tire pressure

Check your bearings, ball joints, and tie rods.

Worn bushings might make the issue worse, but unless you're having other symptoms of worn bushings, this probably isn't the issue. FWIW, I bought my car with 20K miles, and I've had the issue consistently since new. Even with close to 50K miles, I don't see any issues with my bushings.

Stiffer control arm bushings would theoretically reduce the steering compliance and help the issue, but they WILL increase NVH. Anyone who tells you otherwise doesn't know what they're talking about. Personally, I wouldn't make that trade-off on my Mini.

Long story short, there's nothing wrong with you car, and the dealer won't/can't fix it.

 

Thanks for the detailed explanation. I actually drive the I96 M14 combo every day to go to work. I find it is worse going towards Detroit than towards Plymouth. More so in the Express lanes of I96.

I was just concerned because our Clubman does not do it at all and then I got the Cooper and "holy crap" this thing moves all over the place. But if it can't be fixed because it is "normal", I will have to live with it.

Thanks again for all the posts!

 

I have an '09 as well. It's likely neither your tires nor wheels. I was annoyed with the same thing.

At WMW's suggestion in my slow but steady efforts to reduce/eliminate understeer, Way suggested I upgrade the lower control arm bushings with higher quality poly bushings. Since you have to disconnect the FSB to swap out the bushings, he also recommended replacing the FSB bushings with poly bushings too. As soon as I did upgrade the side benefit was a significant reduction in the lateral travel you describe. Might want to give Way a holler. You do have to realign afterward, though. WARNING: if you do go with poly bushings, I discovered the bushings take more lube than normally used for OEM... If you don't some vibration might occur which will travel right down the chassie to the rear of the car where you will wind up hearing annoying "thumping" while coming out of 1st gear from a stop.. Good luck

Jahan - I'm confused.. This isn't theoretical. Doesn't increasing the ratio of body/bushing stiffness improve damping? Therefore, does it not follow upgrading the bushings IMPROVE NVH? I may be totally misunderstanding, but I thought this is a key concept for auto manufacturers. What's the tradeoff?

 

Softer bushings aren't as precise from a handling standpoint, but they do transmit less NVH from the road surface to the cabin. To improve NVH, you have to damp and dissipate the energy, not transmit it.

- Mark

 

Cary Cooper . . .

You are exactly right in that the body local stiffness to bushing stiffness ratio IS a key concept in reducing NVH. However, it’s not a “more is better” type of thing, it’s an optimization problem. Not having enough damping is a bad thing, but too much damping increases transmissibility of impacts, road noise, tire vibration. And super-stiff bushings in one place just means that compliances in other areas become more prevalent, and the overall balance of the system goes out of whack. OEM bushings are typically very close to being optimized for NVH already, and when the engineers tune for that type of thing, they are working in increments of +/-5% in durometer. Or they are working to optimize the shape of the bushing and housing to get the characteristic they want. The tuning window they are working in is relatively small, and pretty much any aftermarket product is well outside that window. Even “OEM replacements” such as the Meyle HD bushings that are so popular for 3-series cars add a noticeable amount of NVH.

Also, it’s a fact that most people are poor vehicle evaluators. Preconceived notions, personal bias, poor evaluation technique, and differences in individual’s sensitivity all contribute to that fact. But keep in mind that evaluating the effect of, say, a bushing change is NOT subject to personal opinion. If someone says they didn’t FEEL a difference in ride quality when they installed X or Y bushing, you could run a test that proves that, regardless of what that individual felt, there IS, in fact, a difference. Maybe that person wasn’t paying attention, or just doesn’t know what to look for.

Also, not saying poly bushings suck, weather the trade off is worth it is up to the individual owner.

 

Thanks, Jahan.
Going back to Roca68's original question, and your explanation above, all I can say in the poly upgrades I made there was a noticeable difference. All of my upgrades I did one by one to feel the difference each made. The engine mount poly bushing upgrade resulted in less engine roll and more precise shifts (that one was HUGE). Once the RSB went in that was of course a massive improvement (which comes with poly bushings I believe). Next came the shock upgrade and definitely was further improvement However, it really exposed the front feeling "sloppy" being now put out of balance as you say and felt like the front end and balance overall wasn't as neutral as as I thought it would be. Road handling feedback in the front feel lacking and sloppy side-to-side - particularly in situations like ROCA68 experienced. Understeer still there. The last upgrade I did was the lower control arm and FSB bushings - another improvement in feedback for me and helping me in my goal to decrease understeer and make it more neutral. It also wiped out the tendency to want to ricochet from side-to-side in road ruts and now feels more planted. It feels now like I'm pretty much there with an upgrade in tires. I think you're right, though in that it comes down to personal preference - mine is handling and reduction in understeer. I'm not going to blow smoke up the underside, you're not going to slap them in and hear angels trumpeting in glory, but I felt an improvement, and it helped me reduce that tracking problem. Thanks, too Jahan, great info.