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14" Wheels

Posted: Sat Feb 29, 2020 7:32 pm
by Adoepner
Hello all,

I have successfully fitted 14" x 5.5" steel wheels to my 2012. It required a bit of work … but it works! I did this to open up a large market of used wheels/tires from other compact cars since replacing the stock-size tires are expensive. It is easy to find used tires around here in decent shape for really cheap.

To fit the rims, the following needed to happen:

1) A bracket on the front strut needed to be ground down to clear inside of the rim.
2) The inner lip of the rim at the tire bead needed to be cut back to the minimum required to hold the tire to clear the front strut.
3) 12mm spacers were fitted for strut clearance, but I will have them milled down to the actual minimum thickness required once this project is done. They could easily lose 2-3mm with the 175 width tires I have tried, possibly more with 165 width tires.
4) Longer studs were fitted.

Restrictions:
The front rims must use stick on wheel weights on the inside. Thin weights must be used, otherwise they can be sheared off by the strut bracket (the same one that was ground down, clearances are tight).

Learning points:
1) The centering boss on the rear hubs is 54.1mm.
2) The centering boss on the front hubs is 56.1mm. Others have indicated that there is a pressed-in collar on the front hubs that you can remove. I would call this collar a boss extension. Even when removed, there is still a 56.1mm centering boss on the front hubs that is just shy of 9mm tall. I used hub-centric spacers, so this required a trip to the machine shop to have my spacers opened up a touch.

Pics to follow once I get the car back from the shop. I will be trying a few tire size combinations and will report on what keeps the car happy.

Andrew

Re: 14" Wheels

Posted: Sun Mar 01, 2020 1:39 pm
by Don
It will be interesting to see what tires sizes you end up going with , front and rear, so that ASC and regenerative braking aren't adversely affected. Hint . . . . you don't need tires the same exact circumference as the OEM sizes, but you do have to carefully maintain the difference between the front and rear circumference in order to not mess up your ASC and regenerative braking - If you vary very far from the OEM ratio, you'll be buying some tires you can't end up using

You can buy spacers of most any thickness quite cheaply on eBay - Probably cheaper than milling down the ones you already have unless you have access to a free lathe or milling machine

FWIW, I have 175/55R15's on the front of one of my cars, without using any spacer - It does require a 5" wide wheel though and clearances are pretty tight

The downside to playing around with alternative tires is that you probably will not end up using true LRR tires and if that's the case, the car is going to have a noticeably shorter range when you're done . . . . but, you can make it handle TONS better than it does on the stock Dunlops

Don

Re: 14" Wheels

Posted: Mon Mar 02, 2020 7:39 pm
by Adoepner
I have 175/65R14 tires on the front currently with the stock rear (175/60R15). I got the 175/65R14s for free, so no harm in experimenting. I was out with the car today in town and it was happy. I haven't taken it on the highway yet. No ASC/ABS or regen issues today at up to 80 km/h (50 mph).

This combination is a -2.4% change from the stock front/rear ratio. I used minus because the size difference between front and rear is decreased.

My long term plan is to run 165/65R14 tires on the front and 185/65R14 tires on the rear. This combination is a +0.7% difference from stock. I hope to find LRR tires in these sizes, but also plan on running snow tires in the winter. My range will definitely suffer and I am ok with it.

Don: I read a post about you using 165/60R15 fronts with 175/65R15 rears. That combination is a +1.1% difference from stock.

So far so good!

Re: 14" Wheels

Posted: Tue Mar 03, 2020 10:09 am
by Don
I currently have 185/60R15's on the rear and 175/55R15's on the front and that Front to Rear ratio keeps the car's computer happy . . . . everything works. The tires are Continental 'Eco' Contacts, but I'm not sure what they mean exactly by 'Eco' because they for sure are nothing like true LRR tires . . . . and the range decrease proves it. The big change for me has been the need to disable ASC before I get to a set of curves near the house, where I never needed to before . . . . but, that's because they are marked as 35 mph curves and I'm now going around them both at 45 mph or more, which I never did on the stock tires because I could feel the front end washing out on me, especially when roads were damp. Now it goes around them at 50 if I want to (wife doesn't care for that) and it handles like it's on rails - Never thought I'd be saying THAT about any iMiEV!

Don

Re: 14" Wheels

Posted: Tue Mar 03, 2020 1:46 pm
by JoeS
... and be sure to experiment with tire pressures, recognizing that 'stock' is 36psi (248kPa). It's my subjective belief that higher pressures are conducive to better i-MiEV handling and range improvement, at the expense of some teeth falling out :roll:

Re: 14" Wheels

Posted: Tue Mar 03, 2020 1:49 pm
by Don
I've been running 45 psi in my Continentals ever since I put them on the car - Doesn't help the range any, so far as I can tell

Don

Re: 14" Wheels

Posted: Tue Mar 24, 2020 6:29 pm
by Adoepner
As promised, here are some photos and a bit more of a write-up.

My goal here was to move from 15" rims to 14" rims to open up more options for tires. I have successfully mounted 5.5x14 ET45 rims on the front and rear. This required me to use wheel spacers and install longer studs. I went with 12mm hub centric spacers to start to ensure clearance and plan to thin them down with my dad's lathe later this summer. With 175/65R14s up front on 5.5x14 ET45 rims, the spacers as thin as 8mm can be used. Clearance on the rear is not an issue. Rear spacers were used to match the track width of the front with the stock rear rims and tires for now.

Shopping list:
1) Wheel spacers: https://www.amazon.ca/dp/B01CLYZEJE/ref=pe_3034960_233709270_TE_item
2) Studs: https://www.ebay.ca/itm/173864574613
3) Hub-centric rings: https://www.amazon.ca/dp/B06XKKNT4T/ref=pe_3034960_236394800_TE_3p_dp_1

The front struts had to be clearanced. There was interference between the lower mounting bracket and the inside of the rim. There is not a lot of room for wheel weights on the inside of the wheel. I've had to use the thinnest stick-ons available with the 5.5 wide rims.

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To mount the above spacers on the front, the centre bore of the spacers needed to be opened up to 56.1mm to a depth of 9mm.

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The inside lip of the rim also had to be ground down to clear the strut. I used an angle grinder while a friend spun the rim.

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With the spacers, the stock studs are not long enough to have adequate thread engagement of the lug nuts. Only half of the nut thread was caught by the stud thread. I had to install longer studs. Installing longer studs in the front is a breeze. The old studs can be pressed out with a tie-rod end separator https://www.princessauto.com/en/detail/universal-tie-rod-end-separator/A-p8355828e. The thin shield behind the disk needed to be bent a little to allow the new studs to be inserted.

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On the rear, there is only enough clearance between the back of the hub and the drum brake plate to maneuver a stock-length stud. I had two options: 1) remove the hub (a pain in the a$$), or drill a clearance hole in the drum brake plate. I elected to do the latter. A 3/4" hole is all that is required. I elected to go to a 7/8" so I could seal the hole with a 1/2" knockout plug (https://www.homedepot.com/p/Halex-1-2-in-Knock-Out-Seals-4-Pack-26071/100191724) and polyurethane caulking. I started the hole with long regular twist drill bits, drilling through the large hole in the hub, and finished with a step drill on an extension. I would have preferred to use a rubber grommet-style plug over the metal knockout plug, but the brake plate was too thick to accommodate grommet plugs from the set I had on hand. They were made for thin sheet metal, which this plate is not.

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I'm happy with the results, except that I feel that the wheels stick out a bit too much. The tread of the tires is just barely inside the fender flare. Thinning the spacers by 5mm to 8mm should help.

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After I did all of the above, I got my hands on a set of Mitsubishi Mirage 165/65R14 tires on stock Mirage 4.5x14 ET46 rims. With the front struts clearanced, this rim/tire combination bolted up with no issues, no spacers required. I wish I had just started with these! Oh well ... Here are some photos of this combination. Note that regular wheel weights can be used on the inside with no issues.

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165/65R14s seem to be used by only the Mirage in North America ... so another "rare" tire, but not as rare at the stock Miev fronts.

I hope this info is helpful to someone else. I now have 4 stock steel rims (with worn-out rubber), TPMS sensors, and hubcaps for sale. If you are interested, PM me.

Andrew

(edit: I used Dropbox for the photos. It didn't seem to work. Any ideas for alternatives?)
(edit: Dropbox links fixed.)

Re: 14" Wheels

Posted: Wed Mar 25, 2020 9:02 am
by Don
Adoepner wrote:My goal here was to move from 15" rims to 14" rims to open up more options for tires.

As a former owner (20 years) of a first generation NA Miata, I can tell you with much certainty that there are not nearly as many 14" tires to choose from as there used to be - The number of cars that came with 14" tires is down by about 95%. Huge numbers of Miata owners over the years have changed to 15 or 16 inch wheels just so they can find quality tires

I completely understand your desire to find other tires for your iMiEV because tires to fit it are so limited and so expensive, but going to 14" wheels seems like a big step backwards . . . . at least to me - I would be looking at 15 or even 16" sizes instead

The problem is, of course, with the front end geometry of our cars. They designed the front struts for a 4 1/2" wheel and there isn't any easy way to go much wider without using spacers to fit a wider wheel, which isn't an ideal solution because spacers increase the track width and thereby the scrub radius which causes the tires to scrub when the wheels are turned and that increases tire wear and decreases range . . . . and it makes the tire stick out from the fenders

My 'solution' is only a little bit better - I took a stock 15" by 5.5 inch BMW Mini wheel and cut two of them apart on a lathe, removing 1/2" from the center of the wheel and then welded them back together again. This gave me a 5 inch wide wheel which barely clears the front struts, and without the need for spacers or longer studs - No modifications to the car at all were necessary. This allowed me to use a 175 series 15 inch tire on the front - The tire also just barely clears the front strut. But . . . . the overall track width of the front is still increased just a bit, but not to the extent that it is using a spacer - The tires are still well within the fender, but I still hurt the scrub radius just a little

My aim was to increase the handling by reducing understeer and that part worked out just fine - It's not like driving an iMiEV at all . . . . and I have two of them, the other one with a fresh new set of stock Dunlops on it, which I drive every week or so . . . . and I can tell you the difference is pretty dramatic

It's such a shame the front struts and wheel hubs are so vastly different from anything else on the road, or the best solution would be . . . . a set of struts off some other car which would allow 5.5 inch wheels to fit without increasing the track width - I'd run out tomorrow and do both cars if there was even a 'semi-correct' way to do that

Don

Re: 14" Wheels

Posted: Wed Mar 25, 2020 11:45 am
by Adoepner
Hi Don,

I don't disagree that the automotive world seems to be moving away from 14" wheels in favour of 15" and larger. I, however, have had no issues sourcing used tires in good condition in 14" sizes. In the stock 15" sizes it was a fruitless search. I picked up a set of nearly-new mounted 165/65R14s for $100 CAD, and a set of nearly-new mounted 185/65/R14s for $80 CAD. At today's exchange rates that is $130 for two complete sets to ready-to-go tires for my Miev. Not bad. The 175/65R14s I am currently running on the front were free (and on rims)! That is the upside of 14s!

Now that I've discovered that 14" Mirage rims are a good fit for the front (after clearancing the strut and without spacers), I'll be moving to 165/65R14s on the front when my current rubber is worn out (at the end of the summer) and ditching the spacers. The work and expense of the spacers and longer studs was in vain, but life is a learning experience, no?

Andrew

Re: 14" Wheels

Posted: Wed Mar 25, 2020 3:55 pm
by Don
I haven't put a used tire on any car in at least 40 years - I hope you're reading the date codes on them and not using anything old, no matter how good they look. My motto, drilled into my kids and grandkids heads is "Quality tires are cheaper than fenders" so don't scrimp at all where the rubber meets the road! (When you leave the road due to a poor tire, you usually end up bending fenders . . . . if you're lucky and it stays right side up, that's all you do)

It's impossible to tell if a tire has been overheated from running it low on air without dismounting it from the rim and very carefully inspecting the inside of the carcass - Even then, if you don't know what you're looking for, you could be riding on a ticking time bomb because a heat damaged tire can come apart at any time. It's just not a risk I'm willing to take, so if used tires are something you're looking into, be very careful

Don