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Bmw i3 spare tire and dealing with nail puncture

Posted: Fri Dec 25, 2020 8:11 am
by labtebo
link to tire comparison https://photos.app.goo.gl/7VQpGpAzPZtWG29T7
link to new spare tire https://photos.app.goo.gl/P7JiygZaxr8ioASE7
I just bought a spare tire for my i3 (ecopia tire/aftermarket wheel). I tried to buy a used wheel/rim at ebay but they cost more than the brand new rim.

looking at an i3 tire/wheel on the car seems the tire looks small. But the i3 tire is a fairly decent size tire. See photo of a civic full size spare tire and my newly purchase i3 spare tire.

i always upgrade my donut spare tires to full size tires like this civic spare. So i am fairly confident that i3 tire could easily be fixed for nail punctures using dynaplugs which i have been using for the past 10 years on punctures on all my car tires - wherein before i have to visit a tire shop to plug nail punctures.

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Fri Dec 25, 2020 8:51 am
by MKH
In the last 20 years, all my tire punctures have been from nails or screws, five or six all total (all on previous ICE vehicles - none on my i3) , and all were slow leaks that adding air would keep the tire driveable for the day. And with the TPMS system, always lots of warning as soon as a tire starts losing a little air. Twice I found a tire 'very low' after being parked all night, added air, then drove to work and back before stopping at Discount Tire for a free patch. Never had a catastrophic flat that would have needed a spare tire swap since TPMS - what destroyed tires was driving on them when you didn't know they were low/losing air/already almost flat - that no longer is an issue with TPMS. Invested in a small tank air compressor for the garage for quick tire inflation when needed instead.

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Fri Dec 25, 2020 9:34 am
by labtebo
i agree. most of nail/ screw punctures would last me a week before the tmps sensor alarm kicks in. i just had one nail puncture too near the side wall that needs tire replacement.

i just prefer to have a spare tire - maybe a bit of old habit where i came from - here in the US, i was amazed when i get my first US car with a donut spare tire. Back in my home country, we even have double spare tires - going into rural areas over dirt and muddy roads

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Fri Dec 25, 2020 8:15 pm
by eNate
I picked up my spare from a So Cal junkyard via car-part.com, which is a nationwide auto salvage aggregator a little like Craigslist. I was pleased to find a grade B 428 wheel, tire with great tread left, and TPMS, for about $150. That was easily $100 below the cheapest wheel-only options I could find on eBay.

I also found a used but nice condition BMW screw jack which has the jack point adapter built in.

But even more handy is the tire puncture repair kit and nail puller which I carry with me and have used on a couple of occasions.

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sat Dec 26, 2020 7:24 am
by labtebo
thanks. good info for car-part.com;
i'll check this out when i need parts for my old hondas including the i3

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sat Dec 26, 2020 10:26 am
by MKH
I also found a used but nice condition BMW screw jack which has the jack point adapter built in.
Yeah, at one time BMW sold a very nice jack kit that included the screw/scissors jack made for the BMW jack points, lug wrench, lug torque wrench, mechanics gloves, folding wheel chock, white tire grease pencil, and heavy canvas carry case. Fits nicely in the Frunk. Part# 71102182448, but almost impossible to find now.
bmw jack kit.jpg
bmw jack kit.jpg (30.83 KiB) Viewed 2090 times

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sun Dec 27, 2020 6:27 am
by MKH
Actually, just found that there IS a space-saver spare wheel/tire available for the i3.
K.O.M. Wheels in Italy makes lightweight aluminum alloy space-saver spares for modern spare-less cars, and they have one that fits the i3.
Sells as a complete kit with a jack, or just the wheel and tire. The jack kit is nothing special and not designed for the BMW lift points specifically, so would need a jackpad of some sort.

Sold in the UK by Tyreman.

Sold in the USA by Modernspare - $300 for the wheel and tire (not including the jack) is not too terrible:

https://modernspare.com/product/2013-20 ... t-options/
sparei3.jpg
sparei3.jpg (25.07 KiB) Viewed 2046 times

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sun Dec 27, 2020 11:18 am
by eNate
When I hear "space saver". I think of the expandable spare that was tucked under the floor of my Audi wagon.

https://youtu.be/GjFnCOI7NUQ

Since there's no place to store a tire of any size inside the i3, it just makes sense to have a full size, no compromise replacement sitting in the garage, especially for as cheap as they can be had.

I wonder how that 135mm tire and 4" wheel handle on the i3? I bet that's skinny enough fit under the trunk floor of my wife's car!

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sun Dec 27, 2020 11:38 am
by alohart
If this space-saver tire's outside diameter is significantly different from that of a standard tire, I wonder how traction control would react.

Re: Bmw i3 spare tire and dealing with nail puncture

Posted: Sun Dec 27, 2020 12:09 pm
by MKH
If this space-saver tire's outside diameter is significantly different from that of a standard tire, I wonder how traction control would react.
The manufacturer, K.O.M. Wheels, says that they try to keep the rolling radius difference to below 2.25% to 3% of the OEM wheels. They show how they calculate this using a standard tire size 225/45r17 with diameter of 24.97.

Tire size 225/45R17.

First, multiply section width by profile

Section width (225) x profile (45) = 10’125

Secondly, divide (10’125) by 2540 and multiply by 2 = 7’972

Thirdly, add the rim diameter (17”) 7’972 + 17 = 24.97”

Full sum below:

OE tire size = 225/45R17

1, 225x45/2540x2+17 = 24.97 (“)

Space saver tire size = 145/70R17

1, 125X80/2540X2+17 = 24.87 (“)

Which is a 0.10” or 0.04% difference

Maybe 'space-saver' in this case is a bit of a misnomer - more a light-weight temporary spare