Antaris
Posts: 24
Joined: Thu Jan 17, 2013 9:00 pm

How to fix under steer

Sun Jan 20, 2013 10:36 pm

Any ideas for fixing the under steer?

Llecentaur
Posts: 240
Joined: Thu Dec 27, 2012 7:56 am

Re: How to fix under steer

Sun Jan 20, 2013 11:11 pm

Not enirely sure but hunch would be wider front wheels, maybe spacers, a tad less pressure at the back.

Lets see other feedbacks.

Antaris
Posts: 24
Joined: Thu Jan 17, 2013 9:00 pm

Re: How to fix under steer

Mon Jan 21, 2013 10:50 pm

I got to thinking last night, a set of rear wheels and tires put on the front end would be worth trying.

Llecentaur
Posts: 240
Joined: Thu Dec 27, 2012 7:56 am

Re: How to fix under steer

Tue Jan 22, 2013 3:27 am

Here are the dimensions, indeed the front and back wheels are different

Front: 145/65 R15 72S Front Wheels: 4.00x15 ET35
Back: 175/55 R15 77S Rear Wheels: 5.00X15 ET35

I guess the narrower the better for economy, yet at the back they must have put larger ones for the sake of transmitting the power to the ground and avoiding to often small skids.

Don
Site Moderator
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Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: How to fix under steer

Tue Jan 22, 2013 9:36 am

There's a removable metal sleeve on the front hubs which won't allow the rear wheels to bolt on the front. If you remove that sleeve so you can bolt the rear wheels on the front, the track width gets way wider - I've done it . . . . The wheels and tires stick outside the fenders

The design of the front wheels (their offset) is very unusual. It will require a wider wheel with a very large offset to get the rubber back inside the fenders. I'm not aware of any other cars which use wheels with this unusual offset . . . . but I'm still looking

Getting new rubber under the car to make it handle properly is the one thing I'd really like to get done . . . . even if it means I have to custom build a set of wheels for the front

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

Antaris
Posts: 24
Joined: Thu Jan 17, 2013 9:00 pm

Re: How to fix under steer

Tue Jan 22, 2013 8:09 pm

Don
If you cut the front inner wheel out and welded a rear outer wheel in place do you think that would work? I have not had a chance to pull wheels and measure but I will when I get a spare hour.
Daryl

Don
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Location: Biloxi MS

Re: How to fix under steer

Wed Jan 23, 2013 3:52 pm

I'm not sure what you can do with the steel wheels from the ES - I've never had a close look at those
I do think that getting a wide enough wheel to fit a suitable tire is going to require some cutting and re-welding though - It's not going to be an easy fit

I wish they had designed the front end of the car to use the same wheels as the back. I suspect what happened is we just got stuck with the same design they used on the original gas engine i-car, which was a much more rear weight biased car than the electric version - Our battery pack and the lighter drivetrain give us a pretty much 50/50 weight bias . . . . much more neutral than the original car and keeping the tail heavy ICE suspension under our car is why we get the understeer. I'm 95% sure the car would handle much better if it had all 4 wheels/tires the same size. It's never going to be a sportscar of course, but with the very low CG, it should handle lots better than it does, IMO

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

Llecentaur
Posts: 240
Joined: Thu Dec 27, 2012 7:56 am

Re: How to fix under steer

Thu Jan 24, 2013 12:09 am

Just an alternative idea to fix the front vs back balance...

Why not use front wheels in the back with spacers.

The spacers would bring the wheels back out to look normal. Of course, back tires would be very narrow but the same as back, then that shoukd balance the car ?

Don
Site Moderator
Posts: 2845
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: How to fix under steer

Thu Jan 24, 2013 6:38 pm

True - That *should* balance things, but only by making the rear of the car perform just as poorly as the front currently does. Two of the 145/65R15 tires on a 2600 pound car is already two too many, IMO - I'd hate to drive the car with four of them :shock:

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

alohart
Posts: 377
Joined: Wed Apr 25, 2012 10:15 am
Location: Honolulu, HI, and Uppsala, Sweden

Re: How to fix under steer

Thu Jan 24, 2013 11:56 pm

If a LRR 165/60R15 tire exists, would it be a possible 4-wheel compromise? Would it work on the 4" front wheels with respect to the narrow wheel width and tire clearance?
Aloha,
Art
Honolulu: 2014 BMW i3 BEV (formerly 2012 i-MiEV SE)
Uppsala, Sweden: 2000 Honda Insight

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