New rear tires for 300 Magnum

[leeinark]

Hey folks: Found out that Innova makes a rear tire larger than what we currently have on the 300 Magnum. The stock tire is a 190/50-12. The Innova tire is a 215/50-12. Circumference is almost 3" more and width is 1.5" more. The speedometer reading comes off of the front tire so there should be no change in your MPH reading but your rear tires will be turning slower. I imagine the top speed will increase but the low end pull will most surely suffer some. I was initally contemplating change to a 13" rear wheel but this tire will solve me having to do that.

[rapidjim]

Here is the tire calculations

Specs 190 50 12 215 50 12
Side Wall 3.6 in 4.2 in
Radius 9.6 in 10.2 in
Diameter 19.35 in 20.5 in
Circum. 61.2 in 64.3 in
Speed at 60 60 mph 63.1mph

I don't think that low end would suffer much at all seeing that the speed difference at 60 is only 3.1 mph. That tire should work fine.

Jim

[edfr]

Yep it will be just fine, just watch the width of the tire it may rub on the Fender holders if they are close. Here is a Speed Tire Calculator to find out your new Gain or Loss of Speed when changing tire and or rim size at certain speeds.
Lefty
www.csgnetwork.com/tireinfo4calc.html

[leeinark]

Thx Jim/Lefty: I initially had been looking at a 255/50-12 tire but it is 10 inches wide. I think I could still use it but I am going to have to measure for a different rim with deeper inside offset.

[edfr]

Leeinark,
If there is at Least 1/2" space on the inside of your tire before it touchs something it will fit.
Lefty

[triker]

Checker and I are looking for better tires, too. Thanks

[leeinark]

Yeah there are no worries on the 215 size but the 255 is going to require a wider rim with more inside offset to fit.

[edfr]

Leeinark,
The 255s are HUGE, go and see Wildmans Thread SUPER TRIKE and actually see the difference of the 255 compared to what it came with as well as a 205. If the rim width is over 8" they will fit nicely on the rim. The only problem you may have is the Inside Part of the Tire Rubbing against something Like maybe the Fender holders. Also they may rub under the Fender and or hit the fender holders holding the fender on. So also check how much space you currently have between the tire and the underside of the fender and holders.
Lefty

I found the Thread to show the difference 255 make:
Scroll down and that will give you and idea of how big they are.

scootdawg.proboards.com/index.cgi?board=threewheelers&action=display&thread=29108&page=16

[rapidjim]

Seems because of the limited space we deal with on the Magnums, our tire options are not abundant. My local tire guy can't find anything close to what some are looking for.

I did find this link, maybe it will help.

www.golfcarttrader.com/tire_pics_/12_Low_Profile.htm

Jim/Owner
Rapid Repair

[leeinark]

Thx Jim but those are all 35 series not 50 series so I would not gain any overall circumference. It appears for now the best way for me to go is the Innova 215/50-12 over the stock Kenda 190/50-12.

[rapidjim]

Lee, give them a call they have others not listed.

Jim

[edfr]

Here are some taller ones- 255/50-12 will be like 4 inchs taller 2 on top and 2 on the bottom: So make sure you either can raise your Fenders as well as the inside that it will not hit anything. For the inside you will need to have aboutt 1" clearance. The top inside the fender you already have some room but check if the extra 2" will hit the fenders underside and or the Holders.

at 50 mph the difference is almost 6mph.
Lefty
www.nivelparts.com/pages/product.aspx?sku=40279&c=021003001&n=

[leeinark]

Lefty I did do the measuring. It is my opinion that I will need an additional 1" inside offset. I'll yank the rim completely off one of these days and get the exact diminsions needed. I've seen somewhere a 8 or 8.5 inch Cragar SS type wheel that is 4 lug 12 rim with offset. I'll have to find it again though. To cold to do much of this stuff right now so it hasn't been high on my to do list. Thx all.